TXNIP mediates NLRP3 inflammasome activation in cardiac microvascular endothelial cells as a novel mechanism in myocardial ischemia/reperfusion injury

Alda-1 Ameliorates Oxidative Stress-Induced Cardiomyocyte Damage by Inhibiting the Mitochondrial ROS/TXNIP/NLRP3 Pathway

Alda-1 functions as an agonist of aldehyde dehydrogenase (ALDH2) within the mitochondria, contributing to the preservation of mitochondrial structure and function. This study aimed to determine whether Alda-1 inhibited the accumulation of mitochondrial reactive oxygen species (mtROS) and improved cardiomyocyte damage under oxidative stress. Cardiomyocytes derived from human induced pluripotent embryonic stem cells (iPSC-CMs) and human AC16 cardiomyocytes were chosen for the experiments. Oxidative stress was induced in both cardiomyocyte types using hydrogen peroxide (H2O2), a commonly employed agent. The mtROS accumulation and mitochondrial functional status were assessed by measuring the ROS content, mitochondrial membrane potential, and mitochondrial respiratory chain function. Co-IP experiments were used to analyze whether mtROS promoted protein interactions between TXNIP and NLRP3 and induced NLRP3 inflammasome activation. The results showed that Alda-1 mitigated damage to mitochondrial structure and function under oxidative stress, concurrently reducing the accumulation of mtROS. Co-IP experiments revealed that elevated mtROS levels attenuated the protein interaction between TXNIP and TRX while intensifying the interaction between TXNIP and NLRP3. Consequently, this triggers activation of the NLRP3 inflammasome, leading to cardiomyocyte damage. In contrast, TXNIP knockdown inhibited H2O2-induced myocardial injury and enhanced the therapeutic effects of Alda-1. Collectively, the results show that, in an H2O2 environment, Alda-1 increased the production of ALDH2 activity in cardiomyocytes, hindered the production of mtROS, disrupted the interaction between TXNIP and NLRP3, and alleviated myocardial damage during oxidative stress.

Endothelial KLF11 is a novel protector against diabetic atherosclerosis

BACKGROUND

Atherosclerotic cardiovascular diseases remain the leading cause of mortality in diabetic patients, with endothelial cell (EC) dysfunction serving as the initiating step of atherosclerosis, which is exacerbated in diabetes. Krüppel-like factor 11 (KLF11), known for its missense mutations leading to the development of diabetes in humans, has also been identified as a novel protector of vascular homeostasis. However, its role in diabetic atherosclerosis remains unexplored.

METHODS

Diabetic atherosclerosis was induced in both EC-specific KLF11 transgenic and knockout mice in the Ldlr-/- background by feeding a diabetogenic diet with cholesterol (DDC). Single-cell RNA sequencing (scRNA-seq) was utilized to profile EC dysfunction in diabetic atherosclerosis. Additionally, gain- and loss-of-function experiments were conducted to investigate the role of KLF11 in hyperglycemia-induced endothelial cell dysfunction.

RESULTS

We found that endothelial KLF11 deficiency significantly accelerates atherogenesis under diabetic conditions, whereas KLF11 overexpression remarkably inhibits it. scRNA-seq profiling demonstrates that loss of KLF11 increases endothelial-to-mesenchymal transition (EndMT) during atherogenesis under diabetic conditions. Utilizing gain- and loss-of-function approaches, our in vitro study reveals that KLF11 significantly inhibits EC inflammatory activation and TXNIP-induced EC oxidative stress, as well as Notch1/Snail-mediated EndMT under high glucose exposure.

CONCLUSION

Our study demonstrates that endothelial KLF11 is an endogenous protective factor against diabetic atherosclerosis. These findings indicate that manipulating KLF11 could be a promising approach for developing novel therapies for diabetes-related cardiovascular complications.

IL-1 blockade in cardiovascular disease: an appraisal of the evidence across different inflammatory paradigms

Pre-clinical and clinical studies suggest a role for inflammation in the pathophysiology of cardiovascular (CV) diseases. The NLRP3 (NACHT, leucine-rich repeat, and pyrin domain-containing protein 3) inflammasome is activated during tissue injury and releases interleukin-1β (IL-1β). We describe three paradigms in which the NLRP3 inflammasome and IL-1β contribute to CV diseases. During acute myocardial infarction (AMI), necrotic cell debris, including IL-1α, induce NLRP3 inflammasome activation and further damage the myocardium contributing to heart failure (HF) (acute injury paradigm). In chronic HF, IL-1β is induced by persistent myocardial overload and injury, neurohumoral activation and systemic comorbidities favoring infiltration and activation of immune cells into the myocardium, microvascular inflammation, and a pro-fibrotic response (chronic inflammation paradigm). In recurrent pericarditis, an autoinflammatory response triggered by cell injury and maintained by the NLRP3 inflammasome/IL-1β axis is present (autoinflammatory disease paradigm). Anakinra, recombinant IL-1 receptor antagonist, inhibits the acute inflammatory response in patients with ST elevation myocardial infarction (STEMI) and acute HF. Canakinumab, IL-1β antibody, blunts systemic inflammation and prevents complications of atherosclerosis in stable patients with prior AMI. In chronic HF, anakinra reduces systemic inflammation and improves cardiorespiratory fitness. In recurrent pericarditis, anakinra and rilonacept, a soluble IL-1 receptor chimeric fusion protein blocking IL-1α and IL-1β, treat and prevent acute flares. In conclusion, the NLRP3 inflammasome and IL-1 contribute to the pathophysiology of CV diseases, and IL-1 blockade is beneficial with different roles in the acute injury, chronic inflammation and autoinflammatory disease paradigms. Further research is needed to guide the optimal use of IL-1 blockers in clinical practice.

Macrophage-derived PDGF-BB modulates glycolytic enzymes expression and pyroptosis in nucleus pulposus cells via PDGFR-β/TXNIP pathway

OBJECTIVE

Intervertebral Disc Degeneration (IVDD) is one of the leading causes of low back pain, significantly impacting both individuals and society. This study aimed to investigate the significance of macrophage infiltration and the role of macrophage-secreted platelet-derived growth factor-BB (PDGF-BB) in IVDD progression.

METHODS

To confirm the protective function of macrophage-derived PDGF-BB on nucleus pulposus cells (NPCs), we employed Lysm-Cre transgenic mice to genetically ablate PDGF-B within the myeloid cells. Immunohistochemistry was utilized to detect the expression of glycolytic enzymes and pyroptosis-related proteins during the process of IVDD. Western blot, RT-PCR, ELISA and immunofluorescence were used to detect the protective effect of recombinant PDGF-BB on NPCs.

RESULTS

Macrophage-derived PDGF-BB deficiency resulted in the loss of NPCs and the increased ossification of cartilage endplates during lumbar disc degeneration. Also, PDGF-BB deficiency triggered the inhibition of glycolytic enzymes' expression and the activation of pathways related to pyroptosis in the nucleus pulposus. Mechanistically, our results suggest that PDGF-BB predominantly conveys its protective influence on NPCs through the PDGF receptor- beta (PDGFR-β)/ thioredoxin-interacting protein pathway.

CONCLUSIONS

The absence of PDGF-BB originating from macrophages expedites the advancement of IVDD, whereas the application of PDGF-BB treatment holds the potential for retarding intervertebral disc degeneration in the human body.

Proliferative mechanism of benign prostatic hyperplasia by NLRP3 inflammasome through the complement pathway

OBJECTIVES

The expressions of complement component C5a and NLRP3 inflammasome and the antiproliferative effect of resveratrol in benign prostatic hyperplasia (BPH) model rat were analyzed to clarify the BPH proliferative mechanism.

METHODS

This study used the pathological stromal-dominant BPH model rat by urogenital sinus implantation (UGS). Expression of C5a, NLRP3, Caspase-1, IL-1β, and IL-18 using rat BPH tissues at 2, 3, and 8 weeks (n = 6, respectively) after UGS implantation were analyzed by qRT-PCR, western blotting analysis, and immunohistochemical (IHC) analysis. Serum IL-1β levels in BPH model and sham rats were measured by enzyme-linked immunosorbent assay. Furthermore, resveratrol, as the NLRP3 pathway inhibitor, was administered to BPH model rat to assess the antiproliferative effect on the BPH proliferative process. The proliferative effect on prostate was evaluated by Ki-67 protein expression.

RESULTS

The expression levels of C5a, NLRP3, Caspase-1, IL-1β, and IL-18 in qRT-PCR, western blotting, and IHC were significantly upregulated in BPH tissues compared to control prostate tissues and showed increases with time (all p < 0.05). Serum IL-1β levels in BPH model rats had significantly increased compared to sham rats. On IHC, deposition of C5a, NLRP3, Caspase-1, IL-1β, and IL-18 was abundant in stromal areas of BPH. The administration of resveratrol significantly decreased prostate weight and expressions of NLRP3, IL-1β, IL-18, and Ki-67 (all p < 0.05).

CONCLUSIONS

NLRP3 inflammasome activation by complement C5a produces IL-1β and IL-18 through Caspase-1 during the BPH proliferative process. NLRP3 inflammasome have the possibilities to be a therapeutic target for BPH proliferation by inhibiting the NLRP3 inflammasome pathway.

Novel NLRP3 inhibitor INF195: Low doses provide effective protection against myocardial ischemia/reperfusion injury

BACKGROUND

Several factors contribute to ischemia/reperfusion injury (IRI), including activation of the NLRP3 inflammasome and its byproducts, such as interleukin-1β (IL-1β) and caspase-1. However, NLRP3 may paradoxically exhibit cardioprotective properties. This study aimed to assess the protective effects of the novel NLRP3 inhibitor, INF195, both in vitro and ex vivo.

METHODS

To investigate the relationship between NLRP3 and myocardial IRI, we synthetized a series of novel NLRP3 inhibitors, and investigated their putative binding mode via docking studies. Through in vitro studies we identified INF195 as optimal for NLRP3 inhibition. We measured infarct-size in isolated mouse hearts subjected to 30-min global ischemia/one-hour reperfusion in the presence of three different doses of INF195 (5, 10, or 20-μM). We analyzed caspase-1 and IL-1β concentration in cardiac tissue homogenates by ELISA. Statistical significance was determined using one-way ANOVA followed by Tukey's test.

RESULTS AND CONCLUSION

INF195 reduces NLRP3-induced pyroptosis in human macrophages. Heart pre-treatment with 5 and 10-μM INF195 significantly reduces both infarct size and IL-1β levels. Data suggest that intracardiac NLRP3 activation contributes to IRI and that low doses of INF195 exert cardioprotective effects by reducing infarct size. However, at 20-μM, INF195 efficacy declines, leading to a lack of cardioprotection. Research is required to determine if high doses of INF195 have off-target effects or dual roles, potentially eliminating both harmful and cardioprotective functions of NLRP3. Our findings highlight the potential of a new chemical scaffold, amenable to further optimization, to provide NLRP3 inhibition and cardioprotection in the ischemia/reperfusion setting.

Inhibitors of NLRP3 Inflammasome Formation: A Cardioprotective Role for the Gasotransmitters Carbon Monoxide, Nitric Oxide, and Hydrogen Sulphide in Acute Myocardial Infarction

Myocardial ischaemia reperfusion injury (IRI) occurring from acute coronary artery disease or cardiac surgical interventions such as bypass surgery can result in myocardial dysfunction, presenting as, myocardial "stunning", arrhythmias, infarction, and adverse cardiac remodelling, and may lead to both a systemic and a localised inflammatory response. This localised cardiac inflammatory response is regulated through the nucleotide-binding oligomerisation domain (NACHT), leucine-rich repeat (LRR)-containing protein family pyrin domain (PYD)-3 (NLRP3) inflammasome, a multimeric structure whose components are present within both cardiomyocytes and in cardiac fibroblasts. The NLRP3 inflammasome is activated via numerous danger signals produced by IRI and is central to the resultant innate immune response. Inhibition of this inherent inflammatory response has been shown to protect the myocardium and stop the occurrence of the systemic inflammatory response syndrome following the re-establishment of cardiac circulation. Therapies to prevent NLRP3 inflammasome formation in the clinic are currently lacking, and therefore, new pharmacotherapies are required. This review will highlight the role of the NLRP3 inflammasome within the myocardium during IRI and will examine the therapeutic value of inflammasome inhibition with particular attention to carbon monoxide, nitric oxide, and hydrogen sulphide as potential pharmacological inhibitors of NLRP3 inflammasome activation.

Research advances in the therapy of metabolic syndrome

Metabolic syndrome refers to the pathological state of metabolic disorder of protein, fat, carbohydrate, and other substances in the human body. It is a syndrome composed of a group of complex metabolic disorders, whose pathogenesis includes multiple genetic and acquired entities falling under the category of insulin resistance and chronic low-grade inflammationand. It is a risk factor for increased prevalence and mortality from diabetes and cardiovascular disease. Cardiovascular diseases are the predominant cause of morbidity and mortality globally, thus it is imperative to investigate the impact of metabolic syndrome on alleviating this substantial disease burden. Despite the increasing number of scientists dedicating themselves to researching metabolic syndrome in recent decades, numerous aspects of this condition remain incompletely understood, leaving many questions unanswered. In this review, we present an epidemiological analysis of MetS, explore both traditional and novel pathogenesis, examine the pathophysiological repercussions of metabolic syndrome, summarize research advances, and elucidate the mechanisms underlying corresponding treatment approaches.

A novel anti-inflammatory strategy for myocardial ischemia-reperfusion in rats with cinnamamide derivative compound 7

Reperfusion after myocardial ischemia would aggravate myocardial structural and functional damage, known as myocardial ischemia-reperfusion (MI/R) injury. Cinnamamide derivatives have been reported to exert cardioprotective effects, and we have previously reported that compound 7 played a role in cardioprotection against MI/R via anti-inflammatory effect. However, exact mechanism underlying such beneficial action of compound 7 is still unclear. The protective effect of compound 7 was determined in H9c2 cells under H2O2 stimulation with or without nigerin (NLRP3 activator). Electrocardiogram, echocardiography, myocardial infarction size, histopathology and serum biochemical assay were performed in MI/R rats. Metabolomics in vivo and mRNA or protein levels of NLRP3, ASC, cleaved caspase-1 and its downstream IL-18 and IL-1β were detected both in vitro and in vivo. Compound 7 significantly ameliorate H2O2-induced cardiomyocyte damage, which was supported by in vivo data determined by improved left ventricular systolic function and histopathological changes, reduced myocardial infarction area and cellular apoptosis in heart tissue. Cardiac differential metabolites demonstrated that compound 7 indeed altered the cardiac reprogramming of inflammation-related metabolites, which was evidenced by down-regulated cardiac inflammation by compound 7. Additionally, compound 7 alleviated myocardial injury by inhibiting the NLRP3 pathway rather than other members of the inflammasome both in vitro and in vivo, which was further evidenced by CETSA assay. Whereas, nigerin blocked the inhibitory activity of compound 7 against NLRP3. Cinnamamide derivative compound 7 ameliorated MI/R injury by inhibiting inflammation via NLRP3.

Targeting NLRP3 Inflammasomes: A Trojan Horse Strategy for Intervention in Neurological Disorders

Recently, a growing focus has been on identifying critical mechanisms in neurological diseases that trigger a cascade of events, making it easier to target them effectively. One such mechanism is the inflammasome, an essential component of the immune response system that plays a crucial role in disease progression. The NLRP3 (nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain containing 3) inflammasome is a subcellular multiprotein complex that is widely expressed in the central nervous system (CNS) and can be activated by a variety of external and internal stimuli. When activated, the NLRP3 inflammasome triggers the production of proinflammatory cytokines interleukin-1β (IL-1β) and interleukin-18 (IL-18) and facilitates rapid cell death by assembling the inflammasome. These cytokines initiate inflammatory responses through various downstream signaling pathways, leading to damage to neurons. Therefore, the NLRP3 inflammasome is considered a significant contributor to the development of neuroinflammation. To counter the damage caused by NLRP3 inflammasome activation, researchers have investigated various interventions such as small molecules, antibodies, and cellular and gene therapy to regulate inflammasome activity. For instance, recent studies indicate that substances like micro-RNAs (e.g., miR-29c and mR-190) and drugs such as melatonin can reduce neuronal damage and suppress neuroinflammation through NLRP3. Furthermore, the transplantation of bone marrow mesenchymal stem cells resulted in a significant reduction in the levels of pyroptosis-related proteins NLRP3, caspase-1, IL-1β, and IL-18. However, it would benefit future research to have an in-depth review of the pharmacological and biological interventions targeting inflammasome activity. Therefore, our review of current evidence demonstrates that targeting NLRP3 inflammasomes could be a pivotal approach for intervention in neurological disorders.

Role of inflammasomes in endothelial dysfunction

The vascular endothelium dynamically responds to environmental cues and plays a pivotal role in maintaining vascular homeostasis by regulating vasomotor tone, blood cell trafficking, permeability and immune responses. However, endothelial dysfunction results in various pathological conditions. Inflammasomes are large intracellular multimeric complexes activated by pathogens or cellular damage. Inflammasomes in vascular endothelial cells (ECs) initiate innate immune responses, which have emerged as significant mediators in endothelial dysfunction, contributing to the pathophysiology of an array of diseases. This review summarizes the mechanisms and ramifications of inflammasomes in ECs and related vascular diseases such as atherosclerosis, abdominal aortic aneurysm, stroke, and lung and kidney diseases. We also discuss potential drugs targeting EC inflammasomes and their applications in treating vascular diseases.

The Role of Bacterial Extracellular Membrane Nanovesicles in Atherosclerosis: Unraveling a Potential Trigger

PURPOSE OF REVIEW

In this review, we explore the intriguing and evolving connections between bacterial extracellular membrane nanovesicles (BEMNs) and atherosclerosis development, highlighting the evidence on molecular mechanisms by which BEMNs can promote the athero-inflammatory process that is central to the progression of atherosclerosis.

RECENT FINDINGS

Atherosclerosis is a chronic inflammatory disease primarily driven by metabolic and lifestyle factors; however, some studies have suggested that bacterial infections may contribute to the development of both atherogenesis and inflammation in atherosclerotic lesions. In particular, the participation of BEMNs in atherosclerosis pathogenesis has attracted special attention. We provide some general insights into how the immune system responds to potential threats such as BEMNs during the development of atherosclerosis. A comprehensive understanding of contribution of BEMNs to atherosclerosis pathogenesis may lead to the development of targeted interventions for the prevention and treatment of the disease.

TXNIP knockdown ameliorates hepatic ischemia/reperfusion injury by inhibiting apoptosis and improving mitochondrial dysfunction via HIF-1α

This study aims to investigate whether thioredoxin-interacting protein (TXNIP) regulates cell viability, cell apoptosis and mitochondrial damage in OGD/R-induced hepatocytes and to explore its underlying mechanism. AML12 cells were cultured under oxygen-glucose deprivation/reperfusion (OGD/R) conditions. TXNIP mRNA was detected using qRT-PCR, and the TXNIP protein was analyzed using western blotting. TXNIP-targeted short hairpin RNA (sh-TXNIP) lentivirus was used to infect the AML12 cells. CCK8 and TUNEL assays were applied to detect cell viability and apoptosis, respectively. DCFH-DA probe was used to determine reactive oxygen species (ROS) release level, and JC-1 probe was used to evaluate mitochondrial membrane potential (MMP). The localization of TXNIP and HIF-1α was observed using immunofluorescence. Our results showed that TXNIP markedly increased in AML12 cells treated with OGD/R. TXNIP knockdown increased cell viability and reduced cell apoptosis under OGD/R treatment. Moreover, MMP significantly increased and ROS release decreased in cells after TXNIP knockdown under OGD/R treatment. Additionally, TXNIP knockdown markedly increased the expression of HIF-1α. HIF-1α exhibited nuclear translocation following OGD/R induction, and TXNIP knockdown further promoted it. Compared with the OGD/R + sh-TXNIP group, HIF-1α agonist ML228 inhibited cell apoptosis and ROS release, and increased MMP. However, HIF-1α inhibitor PX478 had the opposite effect. In summary, TXNIP deletion ameliorated AML12 cell injury caused by OGD/R via promoting HIF-1α expression and nuclear translocation, manifested by inhibiting cell apoptosis and alleviating mitochondrial dysfunction.

Pyroptosis in myocardial ischemia/reperfusion and its therapeutic implications

Ischemic heart disease, a prevalent cardiovascular disease with global significance, is associated with substantial morbidity. Timely and successful reperfusion is crucial for reducing infarct size and enhancing clinical outcomes. However, reperfusion may induce additional myocardium injury, manifesting as myocardial ischemia/reperfusion (MI/R) injury. Pyroptosis is a regulated cell death pathway, the signaling pathway of which is activated during MI/R injury. In this process, the inflammasomes are triggered, initiating the cleavage of gasdermin proteins and pro-interleukins, which results in the formation of membrane pores and the maturation and secretion of inflammatory cytokines. Numerous preclinical evidence underscores the pivotal role of pyroptosis in MI/R injury. Inhibiting pyroptosis is cardioprotective against MI/R injury. Although certain agents exhibiting promise in preclinical studies for attenuating MI/R injury through inhibiting pyroptosis have been identified, the suitability of these compounds for clinical trials remains untested. This review comprehensively summarizes the recent developments in this field, with a specific emphasis on the impact of pyroptosis on MI/R injury. Deciphering these findings not only sheds light on new disease mechanisms but also paves the way for innovative treatments. And then the exploration of the latest advances in compounds that inhibit pyroptosis in MI/R is discussed, which aims to provide insights into potential therapeutic strategies and identify avenues for future research in the pursuit of effective clinical interventions.

The cGAS-STING pathway in cardiovascular diseases: from basic research to clinical perspectives

The cyclic guanosine monophosphate (GMP)-adenosine monophosphate (AMP) synthase-stimulator of interferon genes (cGAS-STING) signaling pathway, an important component of the innate immune system, is involved in the development of several diseases. Ectopic DNA-induced inflammatory responses are involved in several pathological processes. Repeated damage to tissues and metabolic organelles releases a large number of damage-associated molecular patterns (mitochondrial DNA, nuclear DNA, and exogenous DNA). The DNA fragments released into the cytoplasm are sensed by the sensor cGAS to initiate immune responses through the bridging protein STING. Many recent studies have revealed a regulatory role of the cGAS-STING signaling pathway in cardiovascular diseases (CVDs) such as myocardial infarction, heart failure, atherosclerosis, and aortic dissection/aneurysm. Furthermore, increasing evidence suggests that inhibiting the cGAS-STING signaling pathway can significantly inhibit myocardial hypertrophy and inflammatory cell infiltration. Therefore, this review is intended to identify risk factors for activating the cGAS-STING pathway to reduce risks and to simultaneously further elucidate the biological function of this pathway in the cardiovascular field, as well as its potential as a therapeutic target.

The role of the NLRP3 inflammasome and pyroptosis in cardiovascular diseases

An intense, stereotyped inflammatory response occurs in response to ischaemic and non-ischaemic injury to the myocardium. The NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome is a finely regulated macromolecular protein complex that senses the injury and triggers and amplifies the inflammatory response by activation of caspase 1; cleavage of pro-inflammatory cytokines, such as pro-IL-1β and pro-IL-18, to their mature forms; and induction of inflammatory cell death (pyroptosis). Inhibitors of the NLRP3 inflammasome and blockers of IL-1β and IL-18 activity have been shown to reduce injury to the myocardium and pericardium, favour resolution of the inflammation and preserve cardiac function. In this Review, we discuss the components of the NLRP3 inflammasome and how it is formed and activated in various ischaemic and non-ischaemic cardiac pathologies (acute myocardial infarction, cardiac dysfunction and remodelling, atherothrombosis, myocarditis and pericarditis, cardiotoxicity and cardiac sarcoidosis). We also summarize current preclinical and clinical evidence from studies of agents that target the NLRP3 inflammasome and related cytokines.

Shexiang Tongxin dropping pills protect against ischemic stroke-induced cerebral microvascular dysfunction via suppressing TXNIP/NLRP3 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Patients with ischemic stroke (IS) often continue to exhibit cerebral microcirculatory dysfunction even after receiving thrombolytic therapy. Enhancing the function of cerebral microvascular endothelia represents a pivotal advancement in the therapeutic strategy for ischemic microcirculatory disturbances. A traditional Chinese medicinal formulation named Shexiang Tongxin Dropping Pills (STDP), has been clinically employed to ameliorate microcirculatory abnormalities. Existing literature attests to the beneficial role of STDP on endothelial cells (ECs). Nevertheless, specific impacts and underlying mechanisms of STDP in rectifying IS-induced cerebral microvascular dysfunction warrant further exploration.

AIM OF THE STUDY

This investigation seeks to delineate the effects of STDP on cerebral microvascular endothelial damage induced by ischemic stroke and to elucidate the underlying mechanism involved.

MATERIALS AND METHODS

Middle cerebral artery occlusion and reperfusion (MCAO/R) technique was employed to established ischemic stroke model in mice. The therapeutic efficacy of STDP on cerebral microvascular function was assessed through laser speckle contrast imaging, behavioral assays, and histological evaluations. Biochemical markers in the brain tissue, including GSH, SOD, MDA, and ROS, were quantified using specific assay kits. In vitro study, oxygen-glucose deprivation and reperfusion (OGD/R) was performed in bEnd.3 cells. The cytoprotective potential of STDP was then evaluated by measuring cell viability, LDH activity, endothelial permeability, and oxidative stress parameters. Important targets in critical pathway were verified by immunoblotting and immunofluorescence both in mice brain slices and bEnd.3 cells.

RESULTS

STDP decrease brain infarct size, repaired microvascular cerebral blood flow and attenuated neurological deficiency in MCAO/R mice. Moreover, STDP abolished MCAO/R-induced oxidative stress which was reflected by rescuing GSH content, restoration of SOD activity and T-AOC, reduction of MDA and ROS. Ex vivo, STDP increased cerebral microvascular endothelial cells viability, abolished oxidative stress and decreased their permeability after ODG/R. Mechanistically, STDP significantly suppressed endothelial ROS-TXNIP mediated the activation of NLRP3 inflammasome in vivo and in vitro.

CONCLUSION

STDP improves ischemic stroke-induced cerebral microcirculatory deficits by regulating cerebral microvascular endothelial ROS/TXNIP/NLRP3 signaling pathway.

Colchicine ameliorates short-term abdominal aortic aneurysms by inhibiting the expression of NLRP3 inflammasome components in mice

BACKGROUND

Abdominal aortic aneurysms (AAA) are often associated with chronic inflammation and pose a significant risk to affected individuals. Colchicine, known for its anti-inflammatory properties, has shown promise in managing cardiovascular diseases. However, its specific role in the development of AAA remains poorly understood.

METHODS AND RESULTS

In this study, we employed a short-term AAA model induced by angiotensin II (Ang II, 1000 ng/kg/min) and calcium chloride (CaCl2, 0.5 mol/l) in male ApoE-/- and C57BL/6 mice (8-12 weeks old) to investigate the effects of colchicine on AAA progression. Colchicine (0.4 mg/kg) was administered orally once daily, starting on the same day as AAA induction. After a 4-week duration, we observed a significant reduction in AAA diameter, degradation of elastic fibers, and expression of components related to the Nucleotide-binding oligomerization domain-like receptor family protein 3 (NLRP3) inflammasome in the vessel wall of colchicine-treated mice compared to the saline group. Mechanistically, colchicine (5 μm/l, for 24h) inhibited the expression of NLRP3 inflammasome components through the P38-ERK/MicroRNA145-toll-like receptor 4 (TLR4) pathway in RAW264.7 cells.

CONCLUSIONS

Our study demonstrates the effectiveness of colchicine in suppressing NLRP3 inflammasome components, thereby delaying AAA progression in the Ang II and CaCl2-induced short-term model. These findings suggest the potential of colchicine as a pharmacological treatment option for AAA.

Exosomal OIP5-AS1 attenuates cerebral ischemia-reperfusion injury by negatively regulating TXNIP protein stability and inhibiting neuronal pyroptosis

BACKGROUND

Cerebral ischemia-reperfusion injury (CIRI) can cause neuronal apoptosis and lead to irreversible brain injury. Numerous lncRNAs have been reported to play important roles in CIRI, but it is unclear whether these lncRNAs can function through exosomes.

METHODS

In this study, we utilized the middle cerebral artery occlusion/reperfusion (MCAO/R) animal model and the oxygen-glucose deprivation/ reoxygenation (OGD/R) cell model. RNA sequencing was performed to screen for differentially expressed lncRNAs in M2 microglia-derived exosomes (M2-Exos). RNA pull-down, RNA immunoprecipitation, co-immunoprecipitation and ubiquitination assays were used to explore the molecular mechanism of OIP5-AS1 in alleviating CIRI.

RESULTS

M2-Exos could alleviate nerve injury and pyroptosis after CIRI in vitro and in vivo. OIP5-AS1 was found to be significantly up-regulated in M2-Exos and down-regulated in OGD/R neurons, MCAO/R mice and ischemic stroke patients. In MCAO/R mice, OIP5-AS1 could reduce cerebral infarct size, cerebral edema and mNSS scores, and inhibit the expression levels of pyroptosis-related proteins in brain tissue. TXNIP was confirmed to be a reliable binding protein of OIP5-AS1. OIP5-AS1 overexpression significantly attenuated MCAO/R-induced upregulation of TXNIP at the protein level, but not at the mRNA level. OIP5-AS1 promoted the TXNIP degradation process and increased the ubiquitination of TXNIP. ITCH could bind to TXNIP. ITCH overexpression or knockdown did not alter the mRNA level of TXNIP, but negatively regulated TXNIP expression at the protein level. ITCH accelerated the degradation and ubiquitination of TXNIP, which could be attenuated by OIP5-AS1 knockdown. OIP5-AS1 could improve neuronal damage and inhibit neuronal pyroptosis through TXNIP.

CONCLUSIONS

M2-Exo-derived OIP5-AS1 can induce TXNIP ubiquitination and degradation by recruiting ITCH, negatively regulate TXNIP protein stability, inhibit neuronal pyroptosis, and attenuate CIRI.

Fumaria indica (Hausskn.) Pugsley Hydromethanolic Extract: Bioactive Compounds Identification, Hypotensive Mechanism, and Cardioprotective Potential Exploration

Fumaria indica (Hausskn.) Pugsley (FIP), a member of the Papaveraceae family, has a documented history of use in traditional medicine to treat cardiovascular ailments, particularly hypertension, and has shown substantial therapeutic efficacy among native cultures worldwide. However, the identification of bioactive compounds and the mechanism of hypotensive effect with the cardioprotective potential investigations are yet to be determined. The study aimed to identify bioactive compounds, explore the hypotensive mechanism and cardioprotective potential, and assess the safety of Fumaria indica (Hausskn.) Pugsley hydromethanolic extract (Fip.Cr). LC ESI-MS/MS analysis was performed to identify the bioactive compounds. In vitro experiments were conducted on isolated rat aorta and atria, and an in vivo invasive BP measurement model was used. Acute and subacute toxicities were assessed for 14 and 28 days, respectively. Isoproterenol (ISO) was used to develop the rats' myocardial infarction damage model. The mRNA levels of NLRP3 inflammasome and the abundance level of Firmicutes and Lactobacillus were measured by qRT-PCR. The hypotensive effect of FIP bioactive compounds was also investigated using in silico methods. Fip. Cr LC ESI-MS/MS analysis discovered 33 bioactive compounds, including alkaloids and flavonoids. In isolated rat aorta, Fip.Cr reversed contractions induced by K+ (80 mM), demonstrating a calcium entry-blocking function, and had a vasorelaxant impact on phenylephrine (PE) (1 μM)-induced contractions unaffected by L-NAME, ruling out endothelial NO participation. Fip.Cr caused negative chronotropic and inotropic effects in isolated rat atria unaffected by atropine pretreatment, eliminating cardiac muscarinic receptor involvement. Safety evaluation showed no major adverse effects. In vivo, invasive BP measurement demonstrated a hypotensive effect comparable to verapamil. Fip.Cr protected the rats from ISO-induced MI interventions significantly in biometrical and cardiac serum biochemical indicators and histological examinations by reducing inflammation via inhibiting NLRP3 inflammasome and elevating Firmicutes and Lactobacillus levels. The network pharmacology study revealed that the FIP hypotensive mechanism might involve MMP9, JAK2, HMOX1, NOS2, NOS3, TEK, SERPINE1, CCL2, and VEGFA. The molecular docking study revealed that FIP bioactive compounds docked better with CAC1C_ HUMAN than verapamil. These findings demonstrated that Fip.Cr's hypotensive mechanism may include calcium channel blocker activity. Fip.Cr ameliorated ISO-induced myocardial infarction in rats by attenuating inflammation, which might be via inhibiting NLRP3 inflammasome and may prove beneficial for treating MI.

High-Density Lipoproteins at the Interface between the NLRP3 Inflammasome and Myocardial Infarction

Despite significant therapeutic advancements, morbidity and mortality following myocardial infarction (MI) remain unacceptably high. This clinical challenge is primarily attributed to two significant factors: delayed reperfusion and the myocardial injury resulting from coronary reperfusion. Following reperfusion, there is a rapid intracellular pH shift, disruption of ionic balance, heightened oxidative stress, increased activity of proteolytic enzymes, initiation of inflammatory responses, and activation of several cell death pathways, encompassing apoptosis, necroptosis, and pyroptosis. The inflammatory cell death or pyroptosis encompasses the activation of the intracellular multiprotein complex known as the NLRP3 inflammasome. High-density lipoproteins (HDL) are endogenous particles whose components can either promote or mitigate the activation of the NLRP3 inflammasome. In this comprehensive review, we explore the role of inflammasome activation in the context of MI and provide a detailed analysis of how HDL can modulate this process.

Inhibition of NOX2 or NLRP3 inflammasome prevents cardiac remote ischemic preconditioning

Introduction: Short episodes of ischemia-reperfusion (IR) in the heart (classical ischemic preconditioning, IPC) or in a limb (remote ischemic preconditioning, RIPC) before a prolonged ischemic episode, reduce the size of the infarct. It is unknown whether IPC and RIPC share common mechanisms of protection. Animals KO for NOX2, a superoxide-producing enzyme, or KO for NLRP3, a protein component of inflammasome, are not protected by IPC. The aim of this study was to investigate if NOX2 or NLRP3 inflammasome are involved in the protection induced by RIPC. Methods: We preconditioned rats using 4 × 5 min periods of IR in the limb with or without a NOX2 inhibitor (apocynin) or an NLRP3 inhibitor (Bay117082). In isolated hearts, we measured the infarct size after 30 min of ischemia and 60 min of reperfusion. In hearts from preconditioned rats we measured the activity of NOX2; the mRNA of Nrf2, gamma-glutamylcysteine ligase, glutathione dehydrogenase, thioredoxin reductase and sulfiredoxin by RT-qPCR; the content of glutathione; the activation of the NLRP3 inflammasome and the content of IL-1β and IL-10 in cardiac tissue. In exosomes isolated from plasma, we quantified NOX2 activity. Results: The infarct size after IR decreased from 40% in controls to 9% of the heart volume after RIPC. This protective effect was lost in the presence of both inhibitors. RIPC increased NOX2 activity in the heart and exosomes, as indicated by the increased association of p47phox to the membrane and by the increased oxidation rate of NADPH. RIPC also increased the mRNA of Nrf2 and antioxidant enzymes. Also, RIPC increased the content of glutathione and the GSH/GSSG ratio. The inflammasome proteins NLRP3, procaspase-1, and caspase-1 were all increased in the hearts of RIPC rats. At the end of RIPC protocol, IL-1β increased in plasma but decreased in cardiac tissue. At the same time, IL-10 did not change in cardiac tissue but increased by 70% during the next 50 min of perfusion. Conclusion: RIPC activates NOX2 which upregulates the heart's antioxidant defenses and activates the NLRP3 inflammasome which stimulates a cardiac anti-inflammatory response. These changes may underlie the decrease in the infarct size induced by RIPC.

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.

Role of cyclophilin A in aggravation of myocardial ischemia reperfusion injury via regulation of apoptosis mediated by thioredoxin-interacting protein

BACKGROUND

The progression and persistence of myocardial ischemia/reperfusion injury (MI/RI) are strongly linked to local inflammatory responses and oxidative stress. Cyclophilin A (CypA), a pro-inflammatory factor, is involved in various cardiovascular diseases. However, the role and mechanism of action of CypA in MI/RI are still not fully understood.

METHODS

We used the Gene Expression Omnibus (GEO) database for bioinformatic analysis. We collected blood samples from patients and controls for detecting the levels of serum CypA using enzyme-linked immunosorbent assay (ELISA) kits. We then developed a myocardial ischemia/reperfusion (I/R) injury model in wild-type (WT) mice and Ppia-/- mice. We utilized echocardiography, hemodynamic measurements, hematoxylin and eosin (H&E) staining, immunohistochemistry, enzyme-linked immunosorbent assay, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining to determine the role of CypA in myocardial I/R injury. Finally, we conducted an in vitrostudy, cell transfection, flow cytometry, RNA interference, and a co-immunoprecipitation assay to clarify the mechanism of CypA in aggravating cardiomyocyte apoptosis.

RESULTS

We found that CypA inhibited TXNIP degradation to enhance oxidative stress-induced cardiomyocyte apoptosis during MI/RI. By comparing and analyzing CypA expression in patients with coronary atherosclerotic heart disease and in healthy controls, we found that CypA was upregulated in patients with Coronary Atmospheric Heart Disease, and its expression was positively correlated with Gensini scores. In addition, CypA deficiency decreased cytokine expression, oxidative stress, and cardiomyocyte apoptosis in I/R-treated mice, eventually alleviating cardiac dysfunction. CypA knockdown also reduced H2O2-induced apoptosis in H9c2 cells. Mechanistically, we found that CypA inhibited K48-linked ubiquitination mediated by atrophin-interacting protein 4 (AIP4) and proteasomal degradation of TXNIP, a thioredoxin-binding protein that mediates oxidative stress and induces apoptosis.

CONCLUSION

These findings highlight the critical role CypA plays in myocardial injury caused by oxidative stress-induced apoptosis, indicating that CypA can be a viable biomarker and a therapeutic target candidate for MI/RI.

Cardioprotective Strategies After Ischemia-Reperfusion Injury

Acute myocardial infarction (AMI) is associated with high morbidity and mortality worldwide. Although early reperfusion is the most effective strategy to salvage ischemic myocardium, reperfusion injury can develop with the restoration of blood flow. Therefore, it is important to identify protection mechanisms and strategies for the heart after myocardial infarction. Recent studies have shown that multiple intracellular molecules and signaling pathways are involved in cardioprotection. Meanwhile, device-based cardioprotective modalities such as cardiac left ventricular unloading, hypothermia, coronary sinus intervention, supersaturated oxygen (SSO2), and remote ischemic conditioning (RIC) have become important areas of research. Herein, we review the molecular mechanisms of cardioprotection and cardioprotective modalities after ischemia-reperfusion injury (IRI) to identify potential approaches to reduce mortality and improve prognosis in patients with AMI.

Empagliflozin reduces endoplasmic reticulum stress associated TXNIP/NLRP3 activation in tunicamycin-stimulated aortic endothelial cells

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) have proven to be of therapeutic significance for cardiovascular diseases beyond the treatment of type 2 diabetes. Recent studies have demonstrated the beneficial effects of SGLT2i on endothelial cell (EC) dysfunction, but the underlying cellular mechanisms remain to be clarified. In this study, we sought to understand the effect of empagliflozin (EMPA; Jardiance®) on cell homeostasis and endoplasmic reticulum (ER) stress signaling. ER stress was induced by tunicamycin (Tm) in human abdominal aortic ECs treated with EMPA over 24 h. Tm-induced ER stress caused increases in the protein expression of thioredoxin interacting protein (TXNIP), NLR-family pyrin domain-containing protein 3 (NLRP3), C/EBP homologous protein (CHOP), and in the ratio of phospho-eIF2α/eIF2α. EMPA (50-100 µM) resulted in a dampened downstream activation of ER stress as seen by the reduced expression of CHOP and TXNIP/NLRP3 in a dose-dependent manner. Nuclear factor erythroid 2-related factor 2 (nrf2) translocation was also attenuated in EMPA-treated ECs. These results suggest that EMPA improves redox signaling under ER stress which in turn attenuates the activation of TXNIP/NLRP3.

Protective effects of compound M01 on retinal ganglion cells in experimental anterior ischemic optic neuropathy by inhibiting TXNIP/NLRP3 inflammasome pathway

Apoptotic death of retinal ganglion cells (RGCs) is a common pathologic feature in different types of optic neuropathy, including ischemic optic neuropathy and glaucoma, ultimately leading to irreversible visual function loss. Potent and effective protection against RGC death is determinative in developing a successful treatment for these optic neuropathies. This study evaluated the neuroprotective effect of a HECT domain-E3 ubiquitin ligase inhibitor, M01, on retinal ganglion cells after ischemic injury. Experimental anterior ischemic optic neuropathy (AION) was induced by photothrombotic occlusion of microvessels supplying optic nerve in rats. M01 was administered (100 mg/Kg and 200 mg/Kg) subcutaneously for three consecutive days after AION induction. Administration of M01 (100 mg/Kg) significantly increased RGC survival and preserved visual function after AION induction. The number of TUNEL-positive cells and ED1-positive cells was significantly decreased, and optic disc edema was reduced considerably after ischemic infarction with M01 treatment. Moreover, M01 effectively ameliorated optic nerve demyelination and enhanced M2 microglial polarization after AION induction. M01 enhanced the expression of nuclear factor erythroid 2-related factor (Nrf2); subsequently, downregulated Thioredoxin interacting protein (TXNIP) expression, inhibited NLR family pyrin domain containing 3 (NLRP3) activation, and further decreased inflammatory factors, interleukin (IL)-1β and IL-6 in the retina after ischemic injury. These findings suggested that M01 has therapeutic potential by modulating Nrf2 and TXNIP/NLRP3 inflammasome pathways in the retina and optic nerve ischemic damage-related diseases.

Protein-protein interactions and related inhibitors involved in the NLRP3 inflammasome pathway

NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) receptor serves as the central node of immune sensing in the innate immune system, and plays an important role in the initiation and progression of chronic diseases. Cryo-electron microscopy (cryo-EM) has provided insights into the conformation of various oligomers within the NLRP3 activation pathway, significantly advancing our understanding of the mechanisms underlying NLRP3 inflammasome activation. Despite the extensive network of protein-protein interactions (PPIs) involved in the assembly and activation of NLRP3 inflammasome, the utilization of protein-protein interactions has been relatively overlooked in the development of NLRP3 inhibitors. This review focuses on summarizing PPIs within the NLRP3 inflammasome activation pathway and small molecule inhibitors capable of interfering with PPIs to counteract the NLRP3 overactivation. Small molecule NLRP3 inhibitors have been gained significant attention owing to their remarkable efficacy, excellent safety profiles, and unique mechanisms of action.

Tongguan capsule for treating myocardial ischemia-reperfusion injury: integrating network pharmacology and mechanism study

CONTEXT

Although Tongguan capsule (TGC) is used in the treatment of coronary atherosclerotic disease, the exact mechanism remains unclear.

OBJECTIVE

Network pharmacology and experimental validation were applied to examine the mechanism of TGC for treating myocardial ischemia-reperfusion injury (MIRI).

MATERIALS AND METHODS

The components and candidate targets were searched based on various databases such as TCMSP, TCMID, BATMAN-TCM. The binding ability was determined by molecular docking. The ischemia-reperfusion (I/R) model was constructed by ligating the left anterior descending (LAD) coronary artery. APOE^-/- mice were divided into three groups (n = 6): Sham group, I/R group, and TGC group (1 g/kg/d). To further verification, HCAEC cells were subjected to hypoxia-reoxygenation (H/R) to establish in vitro model.

RESULTS

The compounds, such as quercetin, luteolin, tanshinone IIA, kaempferol and bifendate, were obtained after screening. The affinity values of the components with GSK-3β, mTOR, Beclin-1, and LC3 were all <-5 kcal/mol. In vivo, TGC improved LVEF and FS, reducing infarct size. In vitro, Hoechst 33258 staining result showed TGC inhibited apoptosis. Compare with the H/R model, TGC treatment increased the levels of GSK-3β, LC3, and Beclin1, while decreasing the expression of mTOR and p62 (p < 0.05).

DISCUSSION AND CONCLUSION

The findings revealed that TGC exerted a cardioprotective effect by up regulating autophagy-related proteins through the mTOR pathway, which may be a therapeutic option for MIRI. However, there are still some limitations in this research. It is necessary to search more databases to obtain information and further demonstrated through randomized controlled trials for generalization.

Magnetic vagus nerve stimulation alleviates myocardial ischemia-reperfusion injury by the inhibition of pyroptosis through the M2AChR/OGDHL/ROS axis in rats

BACKGROUND

Myocardial ischemia-reperfusion (I/R) injury is accompanied by an imbalance in the cardiac autonomic nervous system, characterized by over-activated sympathetic tone and reduced vagal nerve activity. In our preceding study, we pioneered the development of the magnetic vagus nerve stimulation (mVNS) system. This system showcased precise vagus nerve stimulation, demonstrating remarkable effectiveness and safety in treating myocardial infarction. However, it remains uncertain whether mVNS can mitigate myocardial I/R injury and its specific underlying mechanisms. In this study, we utilized a rat model of myocardial I/R injury to delve into the therapeutic potential of mVNS against this type of injury.

RESULTS

Our findings revealed that mVNS treatment led to a reduction in myocardial infarct size, a decrease in ventricular fibrillation (VF) incidence and a curbing of inflammatory cytokine release. Mechanistically, mVNS demonstrated beneficial effects on myocardial I/R injury by inhibiting NLRP3-mediated pyroptosis through the M2AChR/OGDHL/ROS axis.

CONCLUSIONS

Collectively, these outcomes highlight the promising potential of mVNS as a treatment strategy for myocardial I/R injury.

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.

NLRP3 inflammasome involves in the pathophysiology of sepsis-induced myocardial dysfunction by multiple mechanisms

Sepsis-induced myocardial dysfunction (SIMD) is one of the serious health-affecting problems worldwide. At present, the mechanisms of SIMD are still not clearly elucidated. The NOD-like receptor protein 3 (NLRP3) inflammasome has been assumed to be involved in the pathophysiology of SIMD by regulating multiple biological processes. NLRP3 inflammasome and its related signaling pathways might affect the regulation of inflammation, autophagy, apoptosis, and pyroptosis in SIMD. A few molecular specific inhibitors of NLRP3 inflammasome (e.g., Melatonin, Ulinastatin, Irisin, Nifuroxazide, and Ginsenoside Rg1, etc.) have been developed, which showed a promising anti-inflammatory effect in a cellular or animal model of SIMD. These experimental findings indicated that NLRP3 inflammasome could be a promising therapeutic target for SIMD treatment. However, the clinical translation of NLRP3 inhibitors for treating SIMD still requires robust in vivo and preclinical trials.

Inflammation in Myocardial Ischemia/Reperfusion Injury: Underlying Mechanisms and Therapeutic Potential

Acute myocardial infarction (MI) occurs when blood flow to the myocardium is restricted, leading to cardiac damage and massive loss of viable cardiomyocytes. Timely restoration of coronary flow is considered the gold standard treatment for MI patients and limits infarct size; however, this intervention, known as reperfusion, initiates a complex pathological process that somewhat paradoxically also contributes to cardiac injury. Despite being a sterile environment, ischemia/reperfusion (I/R) injury triggers inflammation, which contributes to infarct expansion and subsequent cardiac remodeling and wound healing. The immune response is comprised of subsets of both myeloid and lymphoid-derived cells that act in concert to modulate the pathogenesis and resolution of I/R injury. Multiple mechanisms, including altered metabolic status, regulate immune cell activation and function in the setting of acute MI, yet our understanding remains incomplete. While numerous studies demonstrated cardiac benefit following strategies that target inflammation in preclinical models, therapeutic attempts to mitigate I/R injury in patients were less successful. Therefore, further investigation leveraging emerging technologies is needed to better characterize this intricate inflammatory response and elucidate its influence on cardiac injury and the progression to heart failure.

Sterile inflammation and the NLRP3 inflammasome in cardiometabolic disease

Inflammation plays an important role in the pathophysiology of cardiometabolic diseases. Sterile inflammation, a non-infectious and damage-associated molecular pattern (DAMP)-induced innate response, is now well-established to be closely associated with development and progression of cardiometabolic diseases. The NOD-like receptor (NLR) family pyrin domain-containing 3 (NLRP3) inflammasome is well-established as a major player in sterile inflammatory responses. It is a multimeric cytosolic protein complex which regulates the activation of caspase-1 and subsequently promotes cleavage and release of interleukin (IL)-1 family cytokines, which have a deleterious impact on the development of cardiometabolic diseases. Therefore, targeting NLRP3 itself or the downstream consequences of NLRP3 activation represent excellent potential therapeutic targets in inflammatory cardiometabolic diseases. Here, we review our current understanding of the role which NLRP3 inflammasome regulation plays in cardiometabolic diseases such as obesity, diabetes, non-alcoholic steatohepatitis (NASH), atherosclerosis, ischemic heart disease and cardiomyopathy. Finally, we highlight the potential of targeting NLPR3 or related signaling molecules as a therapeutic approach.

Progress in molecular mechanisms of coronary microvascular dysfunction

Coronary microvascular dysfunction is a high-risk factor for many cardiovascular events. However, because of multiple risk factors and limited understanding about its underlying pathophysiological mechanisms, it was easily misdiagnosed. Therefore, its clinical diagnosis and treatment were greatly restricted. Coronary microcirculation refers to microvessels that play an important role in the physiological regulation of myocardial perfusion and regulating blood flow distribution, fulfilling myocardial metabolic needs and moderating peripheral vascular resistance. In coronary microvascular dysfunction, vascular endothelial celldamage is a critical link. The main feature of early coronary microvascular dysfunction is the impairment of endothelial cell proliferation, adhesion, migration, apoptosis, and secretion. Moreover, coronary microvascular dysfunction risk factors include hyperglycemia, lipid metabolism disorders, ischemia-reperfusion injury, aging, and hypertension, similar to coronary atherosclerosis. There are various mechanisms by which these risk factors harm endothelial function and cause microcirculatory disturbances. Therefore, we reviewed coronary microvascular dysfunction's risk factors and pathogenesis in this article.

Phloretin ameliorates heart function after myocardial infarction via NLRP3/Caspase-1/IL-1β signaling

OBJECTIVES/AIMS

Inflammation is crucial in structural and electrical remodeling after myocardial infarction (MI), affecting cardiac pump function and conduction pathways. Phloretin possesses an anti-inflammation role by inhibiting the NLRP3/Caspase-1/IL-1β pathway. However, the effects of Phloretin on cardiac contractile and electrical conduction function after MI remained unclear. Therefore, we aimed to investigate the potential role of Phloretin in a rat model of MI.

METHODS

Rats were assigned into four groups: Sham, Sham+Phloretin, MI and MI+Phloretin, with ad libitum food and water. In the MI and MI+Phloretin groups, the left anterior descending coronary artery was occluded for 4 weeks, while the Sham and Sham+Phloretin groups received sham operation. The Sham+Phloretin group and the MI+Phloretin group received oral administration of Phloretin. In vitro, H9c2 cells were subjected to hypoxic conditions to simulate an MI model, with Phloretin for 24 h. Cardiac electrophysiological properties were assessed following MI, including the effective refractory period (ERP), action potential duration (APD)90 and ventricular fibrillation (VF) incidence. Echocardiography evaluated left ventricular ejection fraction (LVEF), left ventricular fraction shortening (LVFS), left ventricular internal diameter at end-diastole (LVIDd), left ventricular internal diameter at end-systole (LVIDs), left ventricular end-systolic volume (LVESV) and left ventricular end-diastolic volume (LVEDV) to assess cardiac function. Serum type B natriuretic peptide (BNP) level was applied to evaluate the degree of Heart failure (HF). The fibrosis area and severity were assessed by Masson staining and protein expression levels of collagen 3, collagen 1, TGF-β and α-SMA. Western blot analysis estimated the protein expression levels of NLRP3, Pro Caspase-1, Caspase-1, ASC, IL-18, IL-1β, pp38, p38, and Connexin43(Cx43) to elucidate the influence of inflammation on electrical remodeling after MI.

RESULTS

Our findings demonstrate that Phloretin inhibits the NLRP3/Caspase-1/IL-1β pathway, leading to the upregulation of Cx43 by limiting p38 phosphorylation, which further decreases susceptibility to ventricular arrhythmias (VAs). Additionally, Phloretin attenuated fibrosis by inhibiting inflammation to prevent HF. In vitro experiments also provided strong evidence supporting the inhibitory effects of Phloretin on the NLRP3/Caspase-1/IL-1β pathway.

CONCLUSION

Our results suggest that Phloretin could suppress the NLRP3/Caspase-1/IL-1β pathway to reverse structural and electrical remodeling after MI to prevent the occurrence of VAs and HF.

A historical literature review of coronary microvascular obstruction and intra-myocardial hemorrhage as functional/structural phenomena

The analysis of experimental data demonstrates that platelets and neutrophils are involved in the no-reflow phenomenon, also known as microvascular obstruction (MVO). However, studies performed in the isolated perfused hearts subjected to ischemia/reperfusion (I/R) do not suggest the involvement of microembolization and microthrombi in this phenomenon. The intracoronary administration of alteplase has been found to have no effect on the occurrence of MVO in patients with acute myocardial infarction. Consequently, the major events preceding the appearance of MVO in coronary arteries are independent of microthrombi, platelets, and neutrophils. Endothelial cells appear to be the target where ischemia can disrupt the endothelium-dependent vasodilation of coronary arteries. However, reperfusion triggers more pronounced damage, possibly mediated by pyroptosis. MVO and intra-myocardial hemorrhage contribute to the adverse post-infarction myocardial remodeling. Therefore, pharmacological agents used to treat MVO should prevent endothelial injury and induce relaxation of smooth muscles. Ischemic conditioning protocols have been shown to prevent MVO, with L-type Ca ²⁺ channel blockers appearing the most effective in treating MVO.

Involvement of the SIRT1-NLRP3 pathway in the inflammatory response

The silent information regulator 2 homolog 1-NACHT, LRR and PYD domains-containing protein 3 (SIRT1-NLRP3) pathway has a crucial role in regulation of the inflammatory response, and is closely related to the occurrence and development of several inflammation-related diseases. NLRP3 is activated to produce the NLRP3 inflammasome, which leads to activation of caspase-1 and cleavage of pro-interleukin (IL)-1β and pro-IL-18 to their active forms: IL-1β and IL-18, respectively. They are proinflammatory cytokines which then cause an inflammatory response.SIRT1 can inhibit this inflammatory response through nuclear factor erythroid 2-related factor 2 and nuclear factor-kappa B pathways. This review article focuses mainly on how the SIRT1-NLRP3 pathway influences the inflammatory response and its relationship with melatonin, traumatic brain injury, neuroinflammation, depression, atherosclerosis, and liver damage. Video Abstract.

Acid-sensing ion channel 1a exacerbates renal ischemia-reperfusion injury through the NF-κB/NLRP3 inflammasome pathway

Ischemia-reperfusion injury (IRI) is the main cause of acute kidney injury (AKI), and there is no effective therapy. Microenvironmental acidification is generally observed in ischemic tissues. Acid-sensing ion channel 1a (ASIC1a) can be activated by a decrease in extracellular pH which mediates neuronal IRI. Our previous study demonstrated that, ASIC1a inhibition alleviates renal IRI. However, the underlying mechanisms have not been fully elucidated. In this study, we determined that renal tubule-specific deletion of ASIC1a in mice (ASIC1afl/fl/CDH16cre) attenuated renal IRI, and reduced the expression of NLRP3, ASC, cleaved-caspase-1, GSDMD-N, and IL-1β. Consistent with these in vivo results, inhibition of ASIC1a by the specific inhibitor PcTx-1 protected HK-2 cells from hypoxia/reoxygenation (H/R) injury, and suppressed H/R-induced NLRP3 inflammasome activation. Mechanistically, the activation of ASIC1a by either IRI or H/R induced the phosphorylation of NF-κB p65, which translocates to the nucleus and promotes the transcription of NLRP3 and pro-IL-1β. Blocking NF-κB by treatment with BAY 11-7082 validated the roles of H/R and acidosis in NLRP3 inflammasome activation. This further confirmed that ASIC1a promotes NLRP3 inflammasome activation, which requires the NF-κB pathway. In conclusion, our study suggests that ASIC1a contributes to renal IRI by affecting the NF-κB/NLRP3 inflammasome pathway. Therefore, ASIC1a may be a potential therapeutic target for AKI. KEY MESSAGES: Knockout of ASIC1a attenuated renal ischemia-reperfusion injury. ASIC1a promoted the NF-κB pathway and NLRP3 inflammasome activation. Inhibition of the NF-κB mitigated the NLRP3 inflammasome activation induced by ASIC1a.

Myocardial Glutathione Synthase and TRXIP Expression Are Significantly Elevated in Hypertension and Diabetes: Influence of Stress on Antioxidant Pathways

Antioxidant protection is one of the key reactions of cardiomyocytes (CMCs) in response to myocardial damage of various origins. The thioredoxin interacting protein (TXNIP) is an inhibitor of thioredoxin (TXN). Over the recent few years, TXNIP has received significant attention due to its wide range of functions in energy metabolism. In the present work, we studied the features of the redox-thiol systems, in particular, the amount of TXNIP and glutathione synthetase (GS) as markers of oxidative damage to CMCs and antioxidant protection, respectively. This study was carried out on 38-week-old Wistar-Kyoto rats with insulin-dependent diabetes mellitus (DM) induced by streptozotocin, on 38- and 57-week-old hypertensive SHR rats and on a model of combined hypertension and DM (38-week-old SHR rats with DM). It was found that the amount of TXNIP increased in 57-week-old SHR rats, in diabetic rats and in SHR rats with DM. In 38-week-old SHR rats, the expression of TXNIP significantly decreased. The expression of GS was significantly higher compared with the controls in 57-week-old SHR rats, in DM rats and in the case of the combination of hypertension and DM. The obtained data show that myocardial damage caused by DM and hypertension are accompanied by the activation of oxidative stress and antioxidant protection.

Discovery of a novel 1,3,4-oxadiazol-2-one-based NLRP3 inhibitor as a pharmacological agent to mitigate cardiac and metabolic complications in an experimental model of diet-induced metaflammation

Inspired by the recent advancements in understanding the binding mode of sulfonylurea-based NLRP3 inhibitors to the NLRP3 sensor protein, we developed new NLRP3 inhibitors by replacing the central sulfonylurea moiety with different heterocycles. Computational studies evidenced that some of the designed compounds were able to maintain important interaction within the NACHT domain of the target protein similarly to the most active sulfonylurea-based NLRP3 inhibitors. Among the studied compounds, the 1,3,4-oxadiazol-2-one derivative 5 (INF200) showed the most promising results being able to prevent NLRP3-dependent pyroptosis triggered by LPS/ATP and LPS/MSU by 66.3 ± 6.6% and 61.6 ± 11.5% and to reduce IL-1β release (35.5 ± 8.8% μM) at 10 μM in human macrophages. The selected compound INF200 (20 mg/kg/day) was then tested in an in vivo rat model of high-fat diet (HFD)-induced metaflammation to evaluate its beneficial cardiometabolic effects. INF200 significantly counteracted HFD-dependent "anthropometric" changes, improved glucose and lipid profiles, and attenuated systemic inflammation and biomarkers of cardiac dysfunction (particularly BNP). Hemodynamic evaluation on Langendorff model indicate that INF200 limited myocardial damage-dependent ischemia/reperfusion injury (IRI) by improving post-ischemic systolic recovery and attenuating cardiac contracture, infarct size, and LDH release, thus reversing the exacerbation of obesity-associated damage. Mechanistically, in post-ischemic hearts, IFN200 reduced IRI-dependent NLRP3 activation, inflammation, and oxidative stress. These results highlight the potential of the novel NLRP3 inhibitor, INF200, and its ability to reverse the unfavorable cardio-metabolic dysfunction associated with obesity.

Tanshinone IIA mediates protection from diabetes kidney disease by inhibiting oxidative stress induced pyroptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Salvia miltiorrhiza is widely used traditional Chinese medicine in the treatment of diabetes kidney disease (DKD). Tanshinone IIA (Tan IIA) are one of the main components of the root of red-rooted Salvia miltiorrhiza Bunge. However, whether tanshinones delay the progression of DKD and the underlying mechanisms are unknown.

AIM OF THE STUDY

Clarify the mechanisms underlying the occurrence and progression of DKDs from a novel viewpoint and confirm the function and mechanism of Tan IIA.

MATERIALS AND METHODS

We experimented with models of DKD (db/db mice) and cultured human renal glomerular endothelial cells (HRGECs). We measured the biochemical indicators of mouse blood and urine to confirmed that Tan IIA exerted protective effects on the kidneys of db/db mice. Renal histopathology and immunohistochemical staining were used to determine the role of Tan IIA. High glucose-induced HRGECs pyroptosis based on the results of Western blot, CCK-8 cell viability test, calcein/PI staining, ROS/superoxide anion generation and transmission electron microscope. We also confirmed that Tan IIA alleviated HRGEC pyroptosis through the same methods. The relationships between oxidative induction and regulation of NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome activation were investigated using Western blot following the application of an NLRP3 inhibitor and oxidative stress inhibitor.

RESULTS

Tan IIA alleviated kidney injury and improved the levels of urine, blood indicators, the expression of NLRP3 and thioredoxin-interacting protein (Txnip) in db/db mice kidney. In vitro, high glucose inhibited HRGECs viability, increased ROS generation, enhanced the proportion of propidium iodide-stained cells. In addition, we discovered the expression of GSDMD-NT, NLRP3, cleaved IL-1β, cleaved caspase-1, and Txnip increased, but the expression of Trx1 decreased after treated by high glucose. These changes were partially ameliorated by Tan IIA.

CONCLUSION

Hyperglycemia could induce pyroptosis in renal glomerular endothelial cells. However, Tan IIA could delay the progression of DKD by inhibiting pyroptosis by regulating the Txnip/NLRP3 inflammasome.

ENPP2 alleviates hypoxia/reoxygenation injury and ferroptosis by regulating oxidative stress and mitochondrial function in human cardiac microvascular endothelial cells

This study aimed to elucidate the molecular mechanisms of hypoxia/reoxygenation (H/R) injury in human cardiac microvascular endothelial cells (HCMECs) by regulating ferroptosis. H/R model was established with HCMECs and before the reperfusion, ferroptosis inhibitor ferrostatin-1 or ferroptosis inducer erastin was all administered. Wound-healing assay was performed to detect the migration ability of cells in each group, and the angiogenesis ability was determined by tube formation assay. The level of reactive oxygen species (ROS) was detected by flow cytometry. Transmission electron microscopy (TEM) was used to observe the state of mitochondria. The expressions of related proteins in HCMECs were assessed by Western blot. From the results, H/R injury could inhibit the migration and angiogenesis, induce the ROS production, and cause the mitochondrial damage of HCMECs. Ferroptosis activator erastin could aggravate H/R injury in HCMECs, while the ferroptosis inhibitor ferrostatin-1 could reverse the effects of H/R on HCMECs. Western blot results showed that H/R or/and erastin treatment could significantly induce ACSL4, HGF, VEGF, p-ERK, and uPA protein expression and inhibit GPX4 expression. The addition of ferrostatin-1 resulted in the opposite trend of the proteins expression above to erastin treatment. What is more, overexpression of ENPP2 markedly suppressed the damaging effect of H/R on HCMECs and reversed the effects of H/R or erastin treatment on the expression of related proteins. These results demonstrated a great therapeutic efficacy of ENPP2 overexpression in preventing the development of H/R injury through inhibiting oxidative stress and ferroptosis.

Innate Immunity System in Patients With Cardiovascular and Kidney Disease

With a global burden of 844 million, chronic kidney disease (CKD) is now considered a public health priority. Cardiovascular risk is pervasive in this population, and low-grade systemic inflammation is an established driver of adverse cardiovascular outcomes in these patients. Accelerated cellular senescence, gut microbiota-dependent immune activation, posttranslational lipoprotein modifications, neuroimmune interactions, osmotic and nonosmotic sodium accumulation, acute kidney injury, and precipitation of crystals in the kidney and the vascular system all concur in determining the unique severity of inflammation in CKD. Cohort studies documented a strong link between various biomarkers of inflammation and the risk of progression to kidney failure and cardiovascular events in patients with CKD. Interventions targeting diverse steps of the innate immune response may reduce the risk of cardiovascular and kidney disease. Among these, inhibition of IL-1β (interleukin-1 beta) signaling by canakinumab reduced the risk for cardiovascular events in patients with coronary heart disease, and this protection was equally strong in patients with and without CKD. Several old (colchicine) and new drugs targeting the innate immune system, like the IL-6 (interleukin 6) antagonist ziltivekimab, are being tested in large randomized clinical trials to thoroughly test the hypothesis that mitigating inflammation may translate into better cardiovascular and kidney outcomes in patients with CKD.

Atmospheric PM2.5 induce autophagy and autophagic flux blockage in HUVEC cells via ROS/TXNIP signaling: Important role of metal components

Autophagy was involved in vascular endothelial injury caused by PM_2.5, which aggravated the pathogenesis of cardiovascular diseases. However, major toxic components and underlying mechanism responsible for PM_2.5-induced autophagy remain unclear. In this study, the effects of water-extracted PM_2.5 (WE-PM_2.5) on autophagy in human umbilical vein endothelial cells (HUVEC) were studied. Our results showed WE-PM_2.5 promoted autophagosome initiation and formation, meanwhile, lysosomal function was impaired, which further caused autophagic flux blockage in HUVEC cells. Furthermore, removal of metals alleviated WE-PM_2.5-induced autophagic flux blockage, while the artificial metal mixture reproduced the WE-PM_2.5 response. Mechanistically, ROS regulated autophagy-related proteins evidenced by BECN1, LC3B and p62 expression reversed by NAC pretreatment in WE-PM_2.5-exposed cells. WE-PM_2.5 also increased TXNIP expression mediated by ROS; moreover, knockdown of TXNIP in WE-PM_2.5-exposed cells decreased BECN1 and LC3B expression, but had little effects on the expression of p62, CTSB, and CTSD, indicating WE-PM_2.5-induced TXNIP was involved in autophagosome initiation and formation rather than autophagic degradation. Collectively, WE-PM_2.5-induced ROS not only promoted autophagosome initiation and formation, but also inhibited autophagic degradation. However, as the downstream molecule of ROS, TXNIP was only involved in autophagosome initiation and formation. Importantly, WE-PM_2.5-bound metals were largely responsible for autophagic flux blockage in HUVEC cells.

Mitochondria-derived damage-associated molecular patterns and inflammation in the ischemic-reperfused heart

Cardiac cell death after myocardial infarction release endogenous structures termed damage-associated molecular patterns (DAMPs) that trigger the innate immune system and initiate a sterile inflammation in the myocardium. Cardiomyocytes are energy demanding cells and 30% of their volume are mitochondria. Mitochondria are evolutionary endosymbionts originating from bacteria containing molecular patterns similar to bacteria, termed mitochondrial DAMPs (mDAMPs). Consequently, mitochondrial debris may be particularly immunogenic and damaging. However, the role of mDAMPs in myocardial infarction is not clarified. Identifying the most harmful mDAMPs and inhibiting their early inflammatory signaling may reduce infarct size and the risk of developing post-infarct heart failure. The focus of this review is the role of mDAMPs in the immediate pro-inflammatory phase after myocardial infarction before arrival of immune cells in the myocardium. We discuss different mDAMPs, their role in physiology and present knowledge regarding their role in the inflammatory response of acute myocardial infarction.

Regulating the microenvironment with nanomaterials: Potential strategies to ameliorate COVID-19

COVID-19, caused by SARS-CoV-2, has resulted in serious economic and health burdens. Current treatments remain inadequate to extinguish the epidemic, and efficient therapeutic approaches for COVID-19 are urgently being sought. Interestingly, accumulating evidence suggests that microenvironmental disorder plays an important role in the progression of COVID-19 in patients. In addition, recent advances in nanomaterial technologies provide promising opportunities for alleviating the altered homeostasis induced by a viral infection, providing new insight into COVID-19 treatment. Most literature reviews focus only on certain aspects of microenvironment alterations and fail to provide a comprehensive overview of the changes in homeostasis in COVID-19 patients. To fill this gap, this review systematically discusses alterations of homeostasis in COVID-19 patients and potential mechanisms. Next, advances in nanotechnology-based strategies for promoting homeostasis restoration are summarized. Finally, we discuss the challenges and prospects of using nanomaterials for COVID-19 management. This review provides a new strategy and insights into treating COVID-19 and other diseases associated with microenvironment disorders.

Various Expressions of PIK3C2A and TXNIP Genes and Their Potential Role as Independent Risk Factors for Chronic Stable Angina and Acute Coronary Syndrome

BACKGROUND AND AIM

Genetic factors play a significant role in the onset and progression of coronary artery disease (CAD). PIK3C2A may contribute to the development of acute coronary syndrome (ACS) by affecting blood glucose levels and oxidative stress. The expression levels of TXNIP were significantly higher in patients with unstable angina pectoris. However, the situation is different in ACS. In the current study, we aim to investigate the role of PIK3C2A and TXNIP as independent risk factors for chronic stable angina (CSA) and ACS.

SUBJECTS AND METHODS

This study involved 215 subjects (60 patients with CSA, 55 patients with ACS, and 100 controls). All subjects were exposed for assaying gene expressions of PIK3C2A and TXNIP by quantitative real-time polymerase chain reaction.

RESULTS

It was found that TXNIP was upregulated, whereas PIK3C2A was downregulated in patients with CAD compared to the control group. PIK3C2A was significantly downregulated in patients with ACS compared to that in patients with CSA (p < 0.001), but TXNIP was not (p = 0.7). TXNIP was significantly upregulated in STEMI-ACS patients compared to CSA (p = 0.045) and NSTEMI ACS (p = 0.046), among non-diabetic (p = 0.023) smokers (p = 0.036) with hypertension (p = 0.005) and hypercholesterolemia (p = 0.001). ROC (receiver operating characteristic) curve analysis revealed that PIK3C2A (0.981; p < 0.001; 98.18) was the most sensitive mRNA for discriminating ACS from control, followed by TXNIP (0.775; p < 0.001; 70.91). However, for discriminating ACS from CSA combined mRNAs, (PIK3C2A + TXNIP) (0.893; p < 0.001; 98.18) and PIK3C2A (0.892; p < 0.001; 81.82) are promising biomarkers. On the other hand, the most sensitive mRNA for differentiating CSA from control is mRNAs (PIK3C2A + TXNIP) (0.963; p < 0.001; 95), then TXINP (81.3; p < 0.001; 93.33), and finally, PIK3C2A (0.782; p < 0.001; 81.67). In the multivariate regression model, PIK3C2A ((p = 0.002), 0.118 (0.031-0.445)) and smoking status ((p = 0.034); 0.151 (0.026-0.866)) were independent variables for ACS. Moreover, PIK3C2A ((p < 0.013); 0.706 (0.614-0.812)), Hb ((p = 0.013); 0.525 (0.317-0.871)), and total cholesterol ((p = 0.04); 0.865 (0.784-0.955)) were significantly (p < 0.05) and independently related to the prognosis of CSA. Furthermore, PIK3C2A ((p = 0.002), 0.923 (0.877-0.971)), TXNIP ((p = 0.001); 2.809 (1.558-5.064)) the body weight ((p = 0.033); 1.254 (1.018-1.544)) were independently associated with CSA.

CONCLUSIONS

Our study concluded that the dysregulated mRNA PIK3C2A and TXNIP gene expressions may be useful in diagnosis of CAD and prediction of ACS development.

Upregulation of TXNIP contributes to granulosa cell dysfunction in polycystic ovary syndrome via activation of the NLRP3 inflammasome

Polycystic ovary syndrome (PCOS) is a complex endocrine disease. Thioredoxin-interacting protein (TXNIP) promotes oxidative stress and triggers inflammation. Herein, we investigated the role and potential mechanism of TXNIP in PCOS. In a mouse model of dehydroepiandrosterone (DHEA)-induced PCOS, we found that TXNIP was upregulated in the ovaries, especially in granulosa cells (GCs). TXNIP was also upregulated in testosterone (T)-treated GCs in vitro. Knockdown of TXNIP by lentivirus-constructed shRNA attenuated T-induced GC injury and oxidative stress, as well as inflammation and the NLRP3 inflammasome. The mechanism by which TXNIP promotes inflammation may involve TXNIP dissociation from the TXNIP-TRX complex and binding to NLRP3 to form the inflammasome. Additionally, we verified that knockdown of TXNIP ameliorated ovarian injury and inflammation in mice with DHEA-induced PCOS in vivo. Collectively, we demonstrated that TXNIP is involved in GC inflammation by promoting NLRP3 inflammasome activation in PCOS.

Cellular mechanisms and molecular pathways linking bitter taste receptor signalling to cardiac inflammation, oxidative stress, arrhythmia and contractile dysfunction in heart diseases

Heart diseases and related complications constitute a leading cause of death and socioeconomic threat worldwide. Despite intense efforts and research on the pathogenetic mechanisms of these diseases, the underlying cellular and molecular mechanisms are yet to be completely understood. Several lines of evidence indicate a critical role of inflammatory and oxidative stress responses in the development and progression of heart diseases. Nevertheless, the molecular machinery that drives cardiac inflammation and oxidative stress is not completely known. Recent data suggest an important role of cardiac bitter taste receptors (TAS2Rs) in the pathogenetic mechanism of heart diseases. Independent groups of researchers have demonstrated a central role of TAS2Rs in mediating inflammatory, oxidative stress responses, autophagy, impulse generation/propagation and contractile activities in the heart, suggesting that dysfunctional TAS2R signalling may predispose to cardiac inflammatory and oxidative stress disorders, characterised by contractile dysfunction and arrhythmia. Moreover, cardiac TAS2Rs act as gateway surveillance units that monitor and detect toxigenic or pathogenic molecules, including microbial components, and initiate responses that ultimately culminate in protection of the host against the aggression. Unfortunately, however, the molecular mechanisms that link TAS2R sensing of the cardiac milieu to inflammatory and oxidative stress responses are not clearly known. Therefore, we sought to review the possible role of TAS2R signalling in the pathophysiology of cardiac inflammation, oxidative stress, arrhythmia and contractile dysfunction in heart diseases. Potential therapeutic significance of targeting TAS2R or its downstream signalling molecules in cardiac inflammation, oxidative stress, arrhythmia and contractile dysfunction is also discussed.