Inflammasome, pyroptosis, and cytokines in myocardial ischemia-reperfusion injury

The cardioprotective effects of acteoside in myocardial ischemia reperfusion injury and the underlying mechanism

INTRODUCTION

We observed the cardioprotective effects of Acteoside (AC) on myocardial ischemia reperfusion injury (MIRI) and discussed the possible mechanisms.

METHODS

Before MIRI model was established successfully, AC was administrated to SD rats by gastric route for 7 d. Punctuate paw withdrawal threshold (PWT) was recorded to reflect the pain threshold. Blood samples were collected to measure the levels of oxidative stress, myocardial enzymes and Norepinephrine (NE). Hematoxylin and eosin (HE) staining was performed to observe the pathological changes of myocardial tissues. Apoptosis of myocardial cell was determined by transferase-mediated dUTP nick end labeling (TUNEL) assay, and the expressions of Bcl-2 and Bax were determined by Western blotting. Using network pharmacological analysis, the PI3K/Akt signaling pathway was screened to be associated with both AC and MIRI. Subsequently, the expressions of PI3K, p-Akt and caspase-3 were detected by immunochemistry in myocardial tissues.

RESULTS

We found that pre-administration of AC improved pain threshold and pathological change of myocardial structure caused by MIRI. AC reduced serum levels of myocardial enzymes and NE in MIRI. Compared with the Sham group, rats in MIRI group showed enhanced oxidative stress levels. These changes were partly reversed by AC. In addition, AC inhibited apoptosis, regulated the expression of apoptosis-related proteins. Immunochemistry analysis confirmed that AC increased the expressions of PI3K and p-Akt in myocardial tissue.

CONCLUSION

The cardioprotective effects of AC in MIRI were related with pain alleviation, oxidative stress, apoptosis and sympathetic nerve activity inhibition, the PI3K/Akt signal pathway activation.

CLINICAL TRIAL NUMBER

Not applicable.

E3 ubiquitin ligase CHIP alleviates H/R-induced myocardial injury by inhibiting pyroptosis

BACKGROUND

Hypoxia/Reoxygenation (H/R) injury to cardiomyocytes has adverse effects on the function, structure and prognosis of the heart. Studies have shown that H/R injury is closely related to pyroptosis. The inflammatory response induced by pyroptosis, leading to the death of cardiomyocytes. However, the specific mechanism of pyroptosis in myocardial H/R injury is not fully understood. In recent years, the important role of CHIP proteins in cardiovascular diseases has gradually attracted attention. Studies have found that CHIP protein can play an important role in the regulation of pyroptosis. However, its role in ameliorating H/R injury in cardiomyocytes has not been fully studied.

METHODS

An in vitro H/R model was constructed, and CHIP was knockdown and overexpression interfered simultaneously. The effect of CHIP on pyroptosis and its reduction of H/R-induced myocardial injury were verified by detection of cell viability, LDH, cell membrane integrity, ROS production, inflammatory factors (NLRP3, Caspase-1, ASC, IL-1β) and β-catenin/HSF1 signaling pathway.

RESULTS

In our study, we verified that the occurrence of oxidative stress and pyroptosis as well as cell damage was significantly increased in cardiomyocytes after H/R stimulation in vitro. After CHIP knockdown, pyroptosis of cardiomyocytes was further aggravated, accompanied by the down-regulation of HSF1/β-catenin signaling axis. These adverse changes were ameliorated after CHIP overexpression.

CONCLUSION

Our study confirmed that CHIP can alleviate H/R-induced myocardial injury by mediating pyroptosis, which may be achieved by regulating HSF1/β-catenin signaling pathway.

Inhibition of BRD4 alleviates pyroptosis induced by testicular ischemia/reperfusion injury through the NLRP3 pathway

BACKGROUND

Testicular ischemia/reperfusion injury (IRI) represents a significant contributor to male infertility. BRD4, an epigenetic regulator, is involved in various inflammatory responses and cell death processes. Nevertheless, its function in testicular IRI remains unclear.

METHODS

We employed animal models and the GC-1 cell line to assess tissue damage via HE staining, monitored oxidative stress levels using ROS detection kits, and quantified the key proteins and mRNAs including BRD4, NLRP3, caspase-1, and GSDMD expression through WB alongside qRT-PCR. The secretion of IL-1β/18 was determined by ELISA. Additionally, we utilized the BRD4 inhibitor JQ1 and the NLRP3 inhibitor MCC950, along with siRNA, to knock down BRD4 to investigate their impacts on testicular IRI and pyroptosis.

RESULTS

Our findings indicate that testicular IRI significantly enhances inflammatory responses and pyroptosis. BRD4 expression is significantly upregulated during IRI, and the BRD4 inhibitor JQ1 effectively mitigates testicular IRI by reducing the pyroptosis-related proteins and inflammatory cytokines levels. In cell experiments, knocking down BRD4 improved the survival rate of GC-1 cells, alleviated oxidative stress, lowered the pyroptosis-related protein expression, and reduced the IL-1β/18 secretion. Furthermore, our experiments suggest that BRD4 may promote pyroptosis by modulating the NLRP3 inflammasome pathway.

CONCLUSION

BRD4 exacerbates pyroptosis induced by testicular IRI through the NLRP3 pathway. Inhibition of BRD4 expression or activity may present new therapeutic approaches and targets for testicular IRI prevention and treatment.

A comprehensive review of m6 A methylation in coronary heart disease

The morbidity and mortality rates of coronary heart disease (CHD) are high worldwide. The primary pathological changes in CHD involve stenosis and ischemia caused by coronary atherosclerosis (AS). Extensive research on the pathogenesis of AS has revealed chronic immunoinflammatory processes and cell proliferation in all layers of coronary vessels, including endothelial cells (ECs), vascular smooth muscle cells, and macrophages. m6 A methylation is a common posttranscriptional modification of RNA that is coordinated by a variety of regulators (writers, readers, erasers) to maintain the functional stability of modified mRNAs and ncRNAs. In recent years, there has been increasing focus on the involvement of m6 A methylation in the incidence and progression of CHD, which starts with atherosclerotic plaque formation, leads to myocardial ischemia, and ultimately results in the occurrence of myocardial infarction (MI). m6 A regulators modulate relevant signaling pathways to participate in the inflammatory response, programmed death of cardiomyocytes, and fibrosis. Therefore, diagnostic models based on m6 A profiling are helpful for the early detection of CHD, and m6 A methylation shows promise as a sensitive target for new drugs to treat CHD in the future.

Kaempferol inhibits cardiomyocyte pyroptosis via promoting O-GlcNAcylation of GSDME and improved acute myocardial infarction

Acute myocardial infarction (AMI) is a leading fatal cardiovascular disease and poses a major threat to human health. Pyroptosis, an inflammation-related programmed cell death, plays a critical role in the progression of AMI. Kaempferol is a natural flavonoid compound with a variety of pharmacological effects, which exerts a significant cardioprotective function. The role of O-GlcNAcylation, a post-translation modification, has received attention in diseases including AMI. In this research, we explored the therapeutic potential of Kaempferol to AMI due to its well-known cardioprotective effect, including its antioxidant and anti-inflammatory properties. Hypoxia/reoxygenation (H/R) model was adopted to provoke myocardial injury and AMI mice model was established. Our findings indicated that H/R lessened cell viability and contributed to the release of LDH, IL-1β and IL-18, cell pyroptosis rate, and the expression of NLRP3, active caspase 1 and GSDMD-N-terminal domain (GSDMD-N). Kaempferol mitigated myocardial damage caused by H/R through repressing cell pyroptosis. Besides, we discovered that Kaempferol restored the levels of O-GlcNAcylation by regulating the activity of OGT (O-GlcNAc transferase) and OGA (O-GlcNAcase) in H/R-treated H9c2 cells. Notably, molecular docking revealed the binding relationship between Kaempferol and OGT. Further, we proved that knockdown of OGT abrogated the function of Kaempferol in H/R-induced pyroptosis. In AMI mice, Kaempferol relieved the myocardial tissue injury and decreased the NLRP3 and GSDME-N protein levels. More importantly, our results illustrated that OGT was responsible for the O-GlcNAcylation of GSDME at T94 site and acted as an inducing factor for GSDME phosphorylation. Namely, this study validated that Kaempferol facilitated GSDME O-GlcNAcylation to inhibit H/R-induced pyroptosis in an OGT-dependent manner.

Remimazolam alleviates myocardial ischemia/reperfusion injury and inflammation via inhibition of the NLRP3/IL‑1β pathway in mice

Remimazolam (Rema) is a novel anesthetic that is widely used in anesthesia and sedation in critically ill patients. Notably, Rema exerts effects in patients through activation of the γ‑aminobutyric acid (GABA) receptor. GABA may alleviate myocardial ischemia/reperfusion (I/R) injury; however, the impact of Rema and underlying molecular mechanism in myocardial I/R injury remain to be fully understood. Therefore, the present study aimed to investigate the effects of Rema on cardiac I/R injury and to determine the underlying mechanisms. An acute myocardial I/R model was established by ligating the left anterior descending artery in adult male C57BL/6 mice (8‑10 weeks). Cultured Raw264.7 cells treated with lipopolysaccharide (LPS) were also used to investigate the effect of Rema on macrophages. The results of the present study revealed that Rema improved I/R‑induced cardiac dysfunction by increasing the ejection fraction value and reducing the myocardial infarction area. In addition, Rema also alleviated I/R‑induced cardiac inflammatory cell infiltration based on H&E and immunofluorescence staining. Transmission electron microscopy and ROS measurements showed that Rema improved I/R‑induced mitochondrial structural disruption and oxidative stress in cardiomyocytes. Transcriptomics analysis and reverse transcription‑quantitative PCR revealed that Rema alleviated I/R‑induced release of inflammatory factors and cytokines by inhibiting the expression of IL‑1β, IL‑6, C‑C chemokine receptor 2 and C‑X‑C motif chemokine ligand 5. Rema also inhibited I/R‑induced CD68+ cell proliferation, IL‑1β release, and NOD‑like receptor thermal protein domain associated protein 3 (NLRP3) and IL‑1β expression. The results of in vitro assays revealed that Rema inhibited LPS‑induced increases in IL‑1β, IL‑6 and TNF‑α expression and release in cultured RAW264.7 macrophages. In conclusion, the present study revealed that Rema may alleviate I/R‑induced cardiac dysfunction and myocardial injury by inhibiting oxidative stress and inflammatory responses via the NLRP3/IL‑1β pathway.

Bufalin Ameliorates Myocardial Ischemia/Reperfusion Injury by Suppressing Macrophage Pyroptosis via P62 Pathway

Bufalin, which is isolated from toad venom, exerts positive effects on hearts under pathological circumstance. We aimed to investigate the effects and mechanisms of bufalin on myocardial I/R injury. In vivo, bufalin ameliorated myocardial I/R injury, which characteristics with better ejection function, decreased infarct size and less apoptosis. The levels of pyroptotic proteins were increased in I/R-treated macrophages and inflammatory cytokines expressed more in I/R-induced mouse, which could be attenuated by bufalin. Bufalin also reduced H/R-treated macrophage pyroptosis in vitro. Autophagic flux blockage and ROS accumulation were reduced by bufalin in impaired macrophages. Overexpression of p62 abrogated the anti-proptosis and anti-oxidative effects of bufalin. The levels of apoptosis related proteins were changed and TUNEL-positive ratio was raised in cardiomyocytes that received conditioned medium treatment with H/R-treated macrophages, while bufalin pretreatment could reduce apoptosis. These findings indicate that bufalin may attenuate myocardial I/R injury by suppressing macrophage pyroptosis via P62 pathway.

Electroacupuncture Preconditioning Attenuates Myocardial Ischemia-Reperfusion Injury in Rats Partially Through Nrf2-Mediated Reduction of Oxidative Stress and Pyroptosis

Oxidative stress and pyroptosis have been established as key contributors to myocardial ischemia-reperfusion injury (MIRI). While previous studies reported that electroacupuncture (EA) preconditioning exerted cardioprotective effects, the underlying mechanisms remain elusive. Thus, this study aimed to investigate the effects of EA preconditioning on oxidative stress and pyroptosis in MIRI rats, and explore the role of nuclear factor E2-associated factor 2 (Nrf2) throughout that process. A MIRI model was constructed by ligating the left anterior descending coronary artery for 30 min, followed by 4 h of reperfusion in rats. Prior to modeling, rats were subjected to EA at the Neiguan Point for three days. Furthermore, ML385, a Nrf2 inhibitor, was administered in order to examine the role of Nrf2 in regulating oxidative stress and pyroptosis following EA preconditioning. The results revealed that EA preconditioning improved left ventricular function after MIRI and reduced both the myocardial infarction area and cTnT levels. Meanwhile, EA preconditioning alleviated MIRI-induced oxidative stress and pyroptosis, as evidenced by the downregulation of ROS, MDA, NF-κB p65, caspase-1, IL-1β, and GSDMD-N, and the upregulation of SOD and HO-1. Mechanistically, EA up-regulated enhanced the expression of Nrf2. However, its cardioprotective effects and ability to attenuate oxidative stress and pyroptosis were suppressed by the inhibition of Nrf2. Taken together, our study indicated that EA preconditioning attenuated MIRI in rats by mitigating oxidative stress and pyroptosis, with Nrf2 playing a vital role in this protective mechanism.

Preconditioning with acteoside ameliorates myocardial ischemia‑reperfusion injury by targeting HSP90AA1 and the PI3K/Akt signaling pathway

The present study aimed to investigate the cardioprotective effects of acteoside (AC) on myocardial ischemia‑reperfusion injury (MIRI). To meet this aim, a network pharmacological analysis was conducted to search for key genes and signaling pathways associated with AC and MIRI. The infarct size of the rat heart was evaluated using 2,3,5‑triphenyltetrazolium chloride staining, and the serum levels of creatine kinase MB isoenzyme, cardiac troponin I, malondialdehyde and superoxide dismutase were subsequently detected in an in vivo experiment. The inhibitory effect of AC on oxidative stress was further confirmed by assessing the intracellular accumulation of reactive oxygen species (ROS). Hematoxylin and eosin staining was subsequently carried out to observe cardiac histopathological damage. The anti‑apoptotic effects of AC were determined using terminal deoxynucleotidyl‑transferase‑mediated dUTP nick end labeling assay and Hoechst 33342 staining, and the expression levels of apoptosis‑associated proteins in the myocardial tissue were assessed using immunohistochemical analysis. In addition, cell viability was determined using a Cell Counting Kit‑8 assay, and the expression levels of key target proteins associated with AC and MIRI were detected by western blot analysis. The results suggested that pretreatment with AC could mitigate MIRI‑induced myocardial damage, oxidative stress and apoptosis. The anti‑apoptotic effects of AC were associated with elevated Bcl‑2 levels, and reduced caspase‑3 and Bax expression levels in myocardial tissue. In vitro, AC pretreatment both led to an increased rate of cell survival and alleviated oxidative stress, as demonstrated by a decreased level of intracellular ROS accumulation. Moreover, guided by the network pharmacological analysis, heat‑shock protein 90AA1 (HSP90AA1) and the phosphoinositide 3‑kinase (PI3K)/serine‑threonine protein kinase (Akt) signaling pathway emerged as key targets for the action of AC against MIRI. Furthermore, the western blot analysis results showed that pretreatment with AC led to a significant increase in the activity of the PI3K/Akt signaling pathway, in addition to increased expression levels of glycogen synthase kinase‑3β and HSP90AA1. Taken together, the findings of the present study revealed that AC may exert cardioprotective effects on MIRI through suppressing apoptosis and oxidative stress by regulating the expression and activity of key proteins.

Taohong Siwu Decoction Combined With the LncRNA H19/miR-675-5p Axis Repairs Limb Ischemia-Reperfusion Injury Through the Regulation of the Wnt3a/Ca2+ Signaling Pathway

Background: Taohong Siwu decoction (THSWT) has shown therapeutic effects on ischemia/reperfusion injury (IRI). This study tended to investigate the role of THSWT combined with the long non-coding RNA (LncRNA) H19 (H19)/miR-675-5p axis in improving limb IRI (LIRI). Methods: Hind LIRI rats and simulated IRI skeletal myoblasts models were constructed to evaluate the therapeutic effects of THSWT. The mechanism of THSWT treatment on LIRI was investigated by the regulation of the H19/miR-675-5p axis and the wingless/integrated (Wnt)/Ca2+ signaling pathway. Various assessments, such as H&E staining, TUNEL staining, flow cytometry, cell counting kit-8 (CCK-8) assay, quantitative real-time polymerase chain reaction (qRT-PCR), western blot, immunohistochemistry (IHC) staining, enzyme-linked immunosorbent assay (ELISA), biochemical assay, and calcium fluorescence imaging, were conducted to observe skeletal muscle injury, cell apoptosis, skeletal myoblast proliferation, gene and protein expressions, cytokine levels, glucose (Glu) uptake, and Ca2+ concentration. Results: THSWT intervention effectively improved skeletal muscle injury in LIRI rats, as evidenced by reduced muscle fiber damage and decreased cell apoptosis, accompanied by downregulation of H19, miR-675-5p, cleaved-Caspase3, Bax, PLC, and PKC expressions and upregulation of Bcl2 expression. Furthermore, silencing of H19 inhibited cell apoptosis of skeletal muscle and reduced IL-1β, IL-6, and TNF-α levels in LIRI rats. Notably, THSWT intervention combined with the silencing of H19 synergistically promoted the repair of skeletal muscle injury in LIRI rats. Mechanistically, THSWT intervention combined with regulation of the H19/miR-675-5p axis promoted the proliferation of skeletal myoblasts damaged by IRI through the Wnt3a/Ca2+ signaling pathway, increasing the levels of intracellular Bcl2, while decreasing the levels of Ca2+, CaMKⅡ, PLC, PKC, cleaved-Caspase3, Bax, TNF-α, IL-1β, IL-6, Wnt3a, and β-catenin. Conclusions: THSWT combined with the regulation of the H19/miR-675-5p axis effectively improved LIRI by modulating the Wnt3a/Ca2+ signaling pathway, providing insights for potential therapeutic strategies for LIRI.

ncRNAs-Mediated Pyroptosis in Cerebral Ischemia-Reperfusion Injury: Pathophysiology, Mechanisms, and Therapeutic Perspectives

Cerebral ischemia-reperfusion injury (CIRI) is a complex pathological process triggered by transient obstruction of blood flow and subsequent reperfusion, ultimately leading to intracellular disturbances such as oxidative stress, inflammatory responses, and programmed cell death. Among the various types of cell death, pyroptosis (an inflammatory kind of regulated cell death) has received increasing attention due to its involvement in key neurovascular unit cells, including endothelial cells, neurons, microglia, and astrocytes. Intriguingly, accumulating evidence demonstrates that non-coding RNAs (ncRNAs), including long non-coding RNAs, microRNAs, and circular RNAs, can modulate multiple stages of pyroptosis in CIRI. This review synthesizes recent findings on the ncRNAs-regulated pyroptosis in CIRI. We highlight the molecular underpinnings of pyroptotic activation following ischemic injury and discuss how ncRNAs shape these mechanisms. By elucidating the interactions between ncRNAs and pyroptosis-related pathways, we intend to present innovative viewpoints for early diagnosis and the development of potential therapeutic strategies to mitigate CIRI.

Frontiers and Hotspot Evolution of NLRP3 Inflammasome in Myocardial Infarction Research: A Bibliometric Analysis From 2013 to 2024

The NACHT, leucine-rich repeat, and pyrin domain-containing protein 3 (NLRP3) inflammasome plays an essential role in myocardial infarction (MI) development. Up to now, no bibliometric analyses of NLRP3 in MI have been performed. Publications related to NLRP3 in MI from 1 January 2013 to 20 August 2024 were extracted from the Web of Science Core Collection (WoSCC). HistCite Pro, CiteSpace, VOSviewer, Scimago Graphica, and bibliometric online analysis program were used for bibliometric analysis and visualization. The impact of publications was assessed using the total global citation score (TGCS). A total of 324 articles (284 articles and 40 reviews) were included. China has published the most in this field, followed by the United States. Harbin Medical University was the leading institution for research related to NLRP3 in MI. Professor Abbate A. from the United States has made significant achievements in this field. International Immunopharmacology was the most active journal and Journal of Cardiovascular Pharmacology was the most cited journal. This study systematically summarizes the research results of NLRP3 in MI over the past 12 years. NLRP3 in myocardial ischemia-reperfusion injury (MIRI) will become a hot research topic, and translational research on NLRP3 inhibitors in MIRI will benefit a greater number of patients.

Inhibition of mir-155-5p alleviates cardiomyocyte pyroptosis induced by hypoxia/reoxygenation via targeting SIRT1-mediated activation of the NLRP3 inflammasome

OBJECTIVE

The hypoxia/reoxygenation (H/R)-induced pyroptosis of cardiomyocytes plays a crucial role in the pathogenesis of myocardial infarction (MI). miR-155-5p represents a promising target for MI therapy. However, its involvement in H/R-induced pyroptosis remains unclear.

METHODS

The H/R exposed rat cardiomyocyte H9c2 was utilized as in vitro model, and the expression levels of miR-155-5p and SIRT1 in cells were modulated through cell transfection experiments. Cell proliferative activity was assessed using the Cell counting kit-8 assay. Supernatant lactate dehydrogenase (LDH) activity was determined through colorimetry. The levels of living and dead cell were observed via Calcin-AM/PI staining. Levels of supernatant interleukin (IL)-1β and IL-18 were measured using ELISA assay. The expression levels of miR-155-5p and silent information regulator 1 (SIRT1) mRNA were detected by qRT-PCR. The protein expression levels of SIRT1, NLRP3, N-terminal gasdermin D (GSDMD-N), and Cleaved caspase-1 were evaluated using Western blot analysis. The targeted regulatory relationship between miR-155-5p and SIRT1 was verified using dual luciferase reporter gene assay.

RESULTS

The proliferation activity of H9c2 cells induced by H/R was attenuated, accompanied by severe injury, increased cell death, and the release of a substantial amount of pro-inflammatory cytokines IL-1β and IL-18. In addition, H/R stimulation resulted in the upregulation of miR-155-5p expression and downregulation of SIRT1 expression in H9c2 cells. Suppression of miR-155-5p or overexpression of SIRT1 exhibited ameliorative effects on H/R-induced cellular injury in H9c2 cells and inhibited NLRP3 inflammasome-mediated pyroptosis. The dual-luciferase assay confirmed the direct targeting of SIRT1 by miR-155-5p in H9c2 cells. Furthermore, partial reversal of the inhibitory effect of miR-155-5p inhibitor on H/R-induced NLRP3 inflammasome-mediated pyroptosis in H9c2 cells was observed upon interference with SIRT1 expression.

CONCLUSION

Inhibition of miR-155-5p alleviates cardiomyocyte pyroptosis induced by H/R via targeting SIRT1-mediated activation of the NLRP3 inflammasome.

Loss of Type 2 Bone Morphogenetic Protein Receptor Activates NOD-Like Receptor Family Protein 3/Gasdermin E-Mediated Pyroptosis in Pulmonary Arterial Hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is an incurable disease initiated by endothelial dysfunction, secondary to vascular inflammation and occlusive pulmonary arterial vascular remodeling, resulting in elevated pulmonary arterial pressure and right heart failure. Previous research has reported that dysfunction of type 2 bone morphogenetic protein receptor (BMPR2) signaling pathway in endothelium is inclined to prompt inflammation in PAH models, but the underlying mechanism of BMPR2 deficiency-mediated inflammation needs further investigation. This study was designed to investigate whether BMPR2 deficiency contributes to pulmonary arterial hypertension via the NLRP3 (NOD-like receptor family protein 3)/GSDME (gasdermin E)-mediated pyroptosis pathway.

METHODS AND RESULTS

NLRP3 knockout or short hairpin RNA interference of GSDME was performed in PAH animal models to investigate its effect on PAH progression. In addition, the effects of BMPR2 deficiency and restoration of BMPR2 by BMP9 (bone morphogenetic protein 9) or FK506 on pyroptosis were explored both in animal and cell models. Knockout of NLRP3 or short hairpin RNA interference of GSDME in animal models can alleviate the development of pyroptosis, accompanied with improved endothelial integrity, vascular remodeling, and right ventricular systolic pressure. Blocking BMPR2 is sufficient to induce NLRP3 upregulation and release of inflammatory factor IL-1β (interleukin-1β) in pulmonary arterial endothelial cells. Moreover, BMPR2 deficiency can induce GSDME-mediated pyroptosis through NLRP3 activation in 2 animal models, whereas activation of BMPR2 signaling by FK506 or BMP9 can reverse these phenotypes.

CONCLUSIONS

These findings provide evidence that loss of BMPR2 signaling promotes endothelial cell pyroptosis by enhancing NLRP3/GSDME signaling in PAH. Our findings may provide new insights to explore the inflammatory mechanism of PAH treatment.

Therapeutic Potential of Gasdermin D-Mediated Myocardial Pyroptosis in Ischaemic Heart Disease: Expanding the Paradigm From Bench to Clinical Insights

Ischaemic heart disease (IHD) remains a leading cause of global morbidity and mortality. One significant contributor to the pathology of IHD is the excessive release of inflammatory mediators during the disease progression. Pyroptosis is a form of programmed cell death (PCD) triggered by the activation of inflammasomes and caspase 1. The activation of inflammatory caspase 1 proteolytically cleaves gasdermin D (GSDMD) to the activated form amino acid terminus (GSDMD-NT), leading to disruption of the plasma membrane. This cascade of events is considered the canonical pathway of pyroptosis. IHD also caused oxidative stress, thereby triggering noncanonical pyroptosis via the activation of caspases 4/5/11. Previous studies have provided compelling evidence of the close relationship between pyroptosis and the aetiology of IHD (e.g., acute myocardial infarction, myocardial ischaemia and reperfusion injury and chronic myocardial infarction), as well as the association of pyroptosis with unfavourable clinical outcomes. Several interventions aimed at targeting pyroptosis have demonstrated promising therapeutic benefits against IHD-related pathologies. This review provides mechanistic insights into the roles of pyroptosis in IHD from in vitro, in vivo and clinical perspectives. In-depth understanding into this area could also pave the way for the future development of novel therapeutic strategies targeting pyroptosis in IHD.

The Role of P53 in Myocardial Ischemia-Reperfusion Injury

PURPOSE

P53 is one of the key tumor suppressors. In normal cells, p53 is maintained at low levels by the ubiquitination of the ubiquitinated ligase MDM2. In contrast, under stress conditions such as DNA damage and ischemia, the interaction between p53 and MDM2 is blocked and activated by phosphorylation and acetylation, thereby mediating the trans-activation of p53 through its target genes to regulate a variety of cellular responses. Previous studies have shown that the expression of p53 is negligible in normal myocardium, tends to increase in myocardial ischemia and is maximally induced in ischemia-reperfused myocardium, demonstrating a possible key role of p53 in the development of MIRI. In this review, we detail and summarize recent studies on the mechanism of action of p53 in MIRI and describe the therapeutic agents targeting the relevant targets to provide new strategies for the prevention and treatment of MIRI.

METHODS

We collected 161 relevant papers mainly from Pubmed and Web of Science (search terms "p53" and "myocardial ischemia-reperfusion injury"). After that, we selected pathway studies related to p53 and classified them according to their contents. We eventually analyzed and summarized them.

RESULTS AND CONCLUSION

In this review, we detail and summarize recent studies on the mechanism of action of p53 in MIRI and validate its status as an important intermediate affecting MIRI. On the one hand, p53 is regulated and modified by multiple factors, especially non-coding RNAs; on the other hand, p53 regulates apoptosis, programmed necrosis, autophagy, iron death and oxidative stress in MIRI through multiple pathways. More importantly, several studies have reported medications targeting p53-related therapeutic targets. These medications are expected to be effective options for the alleviation of MIRI, but further safety and clinical studies are needed to convert them into clinical applications.

Enhanced Parkin-mediated mitophagy mitigates adverse left ventricular remodelling after myocardial infarction: role of PR-364

BACKGROUND AND AIMS

Almost 30% of survivors of myocardial infarction (MI) develop heart failure (HF), in part due to damage caused by the accumulation of dysfunctional mitochondria. Organelle quality control through Parkin-mediated mitochondrial autophagy (mitophagy) is known to play a role in mediating protection against HF damage post-ischaemic injury and remodelling of the subsequent deteriorated myocardium.

METHODS

This study has shown that a single i.p. dose (2 h post-MI) of the selective small molecule Parkin activator PR-364 reduced mortality, preserved cardiac ejection fraction, and mitigated the progression of HF. To reveal the mechanism of PR-364, a multi-omic strategy was deployed in combination with classical functional assays using in vivo MI and in vitro cardiomyocyte models.

RESULTS

In vitro cell data indicated that Parkin activation by PR-364 increased mitophagy and mitochondrial biogenesis, enhanced adenosine triphosphate production via improved citric acid cycle, altered accumulation of calcium localization to the mitochondria, and initiated translational reprogramming with increased expression of mitochondrial translational proteins. In mice, PR-364 administered post-MI resulted in widespread proteome changes, indicating an up-regulation of mitochondrial metabolism and mitochondrial translation in the surviving myocardium.

CONCLUSIONS

This study demonstrates the therapeutic potential of targeting Parkin-mediated mitophagy using PR-364 to protect surviving cardiac tissue post-MI from progression to HF.

Inhibition of p70 Ribosomal S6K1 Protects the Myocardium against Ischemia/Reperfusion-Induced Necrosis through Downregulation of RIP3

BACKGROUND

Myocardial ischemia-reperfusion (I/R) injury refers to cell damage that occurs as a consequence of the restoration of blood circulation following reperfusion therapy for cardiovascular diseases, and it is a primary cause of myocardial infarction. The search for nove therapeutic targets in the context of I/R injury is currently a highly active area of research. p70 ribosomal S6 kinase (S6K1) plays an important role in I/R induced necrosis, although the specific mechanisms remain unclear.

OBJECTIVE

This study aims to explore the effects of inhibiting S6K1 on myocardial I/R injury and its potential mechanisms.

METHODS

A rat myocardial I/R model was created and treated with the S6K1-specific inhibitor PF-4708671. Hematoxylin-eosin (H&E) staining was applied to evaluate the pathological changes in cardiac tissues. 2,3,5-triphenyltetrazolium chloride (TTC) staining was used to measure the area of myocardial infarction (MI). Left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), the maximum rate of increase in left ventricular pressure (+dp/dtmax), and the maximum rate of the decrease in left ventricular pressure (-dp/dtmax) were measured using ultrasonic echocardiography. The expression levels of cardiac troponin-1 (cTn-1), lactate dehydrogenase (LDH), creatine kinase MB (CK-MB), and aspartate aminotransferase (AST) were determined by enzyme-linked immunosorbent assay (ELISA). Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining and propidium iodide (PI) staining were used to examine the apoptosis and necrosis of myocardial tissues. The expressions of apoptotic-related proteins, and key molecules of necrosis were detected by western blot. The relationship between S6K1 and receptor-interacting protein kinase 3 (RIP3) was analyzed by immunoprecipitation.

RESULTS

Inhibition of S6K1 reduces I/R-induced myocardial tissue damage, improves myocardial function, and inhibits myocardial tissue necrosis (p < 0.05). In addition, RIP3 is a direct target of S6K1, and activation of RIP3 blocked the protective effect of the S6K1 inhibitor PF-4708671 against myocardial I/R injury (p < 0.05).

CONCLUSION

Inhibition of S6K1 protects against myocardial I/R injury by down-regulating RIP3, suggesting that targeting S6K1 may offer a novel approach for intervention in myocardial I/R injury.

Therapeutic Potential of Curcumin in Diabetic Cardiomyopathy: Modulation of Pyroptosis Pathways

PURPOSE

Cardiac inflammation is a basic pathological process of diabetic cardiomyopathy (DCM). Inflammatory response is closely related to pyroptosis, which is a recently identified programmed cell death type. Curcumin (CUR) is a polyphenol extracted from turmeric and has been reported to be crucial in alleviating pyroptosis in DCM. However, the exact mechanism by which CUR improves pyroptosis remains unclear. Therefore, we aimed to investigate the effect of CUR on pyroptosis in DCM and explore the potential mechanisms.

METHODS

The molecular docking (MOD) analysis was performed using AutoDock Tools to evaluate the binding patterns and affinities between CUR and tripartite motif containing 21 (TRIM21), as well as between TRIM21 and gasdermin D (GSDMD). Subsequently, DCM models were established in Sprague-Dawley (SD) rats (in vivo) by administering streptozotocin (STZ) and feeding them a high-fat diet. In addition, H9C2 cells were cultured in a high glucose and palmitate environment to construct in vitro models of DCM. Rats or cells were treated by CUR directly. Subsequently, body weight (BW), heart weight (HW)/BW ratio, fasting blood glucose level, and lipid metabolism were measured. Pathological changes were analyzed using hematoxylin and eosin (H&E) and Masson staining. Small interfering RNA (si-RNA) was used to knockdown TRIM21 expression, and the pyroptosis protein expression and cellular activity were evaluated in different groups.

RESULTS

MOD analysis revealed that CUR had a strong binding affinity with TRIM21, and TRIM21 showed a robust interaction with GSDMD. STZ-induced diabetic SD rats showed metabolic abnormalities, structural changes in the ventricle, and the expression of TRIM21 and pyroptosis markers, including nod-like receptor protein-3 (NLRP3), Caspase-1, and GSDMD, were upregulated. CUR reduced cardiac remodeling and improved cardiac function in vivo. CUR inhibited pyroptosis by regulating TRIM21 through in vivo and in vitro studies.

CONCLUSION

CUR improves DCM by regulating TRIM21 expression to inhibit pyroptosis. Furthermore, this study provides novel approaches and experimental evidence for the research and treatment of DCM and presents new insights into its potential mechanisms.

E3 ubiquitin ligase Smurf1 promotes cardiomyocyte pyroptosis by mediating ubiquitin-dependent degradation of TRIB2 in a rat model of heart failure

OBJECTIVE

Heart failure (HF) causes structural and functional changes in the heart, with the pyroptosis-mediated inflammatory response as the core link in HF pathogenesis. E3 ubiquitin ligases participate in cardiovascular disease progression. Here, we explored the underlying molecular mechanisms of E3 ubiquitin ligase Smurf1 in governing HF.

METHODS

HF rat/H9C2 cell models were established by doxorubicin intraperitoneal injections/hypoxia-reoxygenation (H/R), and treated with Smurf1 siRNA and oe-TRIB2 lentivirus plasmids or the NF-κB pathway inhibitor PDTC/si-smurf1, si-TRIB2, protease inhibitor MG132, or lysosomal inhibitor NH4Cl. The cardiac function/cardiac tissue pathological changes/fibrosis in HF rats were evaluated by echocardiography/H&E and Masson staining. GSDMD-N expression was determined by immunohistochemistry. Cell viability/lactate dehydrogenase (LDH) activity/IL-1β and IL-18 levels were measured by CCK-8/LDH kit/ELISA. The interaction between TRIB2 and Smurf1/TRIB2 ubiquitination levels was assessed by co-immunoprecipitation assay. The expression levels of Smurf1 and TRIB2 messenger RNA (mRNA) were determined by RT-qPCR. Levels of Smurf1/TRIB2/the NF-κB pathway-related factors/pyroptosis-related factors and TRIB2 mRNA were determined by Western blot/RT-qPCR.

RESULTS

Smurf1 was highly expressed in H/R-induced H9C2 cells/HF rats, while its knockdown up-regulated TRIB2 and repressed the NF-κB pathway, reduced cardiomyocyte pyroptosis, and attenuated HF. Mechanistically, Smurf1 promoted TRIB2 degradation through an ubiquitin-dependent manner and activated the NF-κB pathway under H/R conditions. TRIB2 silencing annulled Smurf1 knockdown-regulated NF-κB pathway and cardiomyocyte pyroptosis. TRIB2 overexpression inactivated the NF-κB pathway and reduced cardiomyocyte pyroptosis, thus retarding HF.

CONCLUSION

Smurf1 was highly expressed in HF rats, which promoted TRIB2 ubiquitination degradation and activated the NF-κB pathway, thereby promoting cardiomyocyte pyroptosis in HF rats.

Inhibition of Taurine-upregulated Gene 1 Upregulates MiR-34a-5p to Protect against Myocardial Ischemia/Reperfusion via Autophagy Regulation

BACKGROUND

Taurine upregulated gene 1 (TUG1) has been identified on long noncoding RNA (lncRNA); however, its function in myocardial cells following ischemia/ reperfusion (I/R) injury has not been explored. This study aimed to investigate the role of LncTUG1 in I/R injury by focusing on its relationship with autophagy induction by regulating miR-34a-5p expression.

METHODS

We established a myocardial I/R model and H9C2 hypoxia-ischemic and reoxygenation (HI/R) conditions to induce I/R injury. TTC, Western blot, CCK-8 assay, quantitative reverse transcription PCR, flow cytometry, and confocal microscopy were used to assess the size of myocardial infarct, level of some apoptotic-related and autophagy-associated proteins, cell viability, the level of LncRNA TUG1, apoptosis, and autophagy, respectively.

RESULTS

The results revealed that a TUG1 knockdown protected against I/R-induced myocardial injury by decreasing the impairment in cardiac function. LncRNA TUG1 expression was increased in a myocardial I/R model and HI/R in H9C2 cells. Moreover, inhibition of LncTUG1 enhanced H9C2 cell viability and protected the cells from HI/R-induced apoptosis. Silencing LncRNA TUG1 promoted HI/R-induced autophagy. Furthermore, TUG1 siRNA upregulated the level of miR-34a-5p compared to the HI/R group. The protective effect of LncRNA TUG1 inhibition on H9C2 cells following HI/R was eliminated by blocking autophagy with an miR-34a-5p inhibitor.

CONCLUSION

These findings indicated that inhibiting TUG1 may reduce the extent of myocardial I/R injury by regulating miR-34a-5p. Taken together, these results suggest that LncRNA TUG1 may represent a novel therapeutic target for myocardial I/R injury.

Interleukin-38 ameliorates myocardial Ischemia-Reperfusion injury via inhibition of NLRP3 inflammasome activation in fibroblasts through the IL-1R8/SYK axis

OBJECTIVE

Although IL-38 is recognized for its regulatory role in a spectrum of chronic inflammatory diseases, investigations into its cardiac physiological and pathophysiological functions are nascent. Our aim was to delineate the biological impact of IL-38 in the context of myocardial ischemia-reperfusion injury (MIRI) and to uncover the mechanisms through which it exerts its effects.

METHODS AND RESULTS

In this study, we used an MIRI mouse model, LPS/ATP stimulation, and a hypoxia/reoxygenation cell model to determine the regulatory influence of IL-38 on MIRI. We observed that the administration of recombinant IL-38 to mice led to a reduction in infarct size, an enhancement in cardiac function, and a suppression of NLRP3 inflammasome activation. In contrast, genetic deletion of IL-38 was associated with an increase in infarct size, worsening of cardiac function, and upregulation of NLRP3 inflammasome activity. The detrimental effects associated with the absence of IL-38 were mitigated by the administration of a specific NLRP3 inhibitor, suggesting that the inhibition of NLRP3 is a critical component of the protective effect mediated by IL-38 in MIRI. In vitro assays revealed that IL-38 inhibited NLRP3 inflammasome activation in cardiac fibroblasts through the engagement of IL-1R8 and the modulation of SYK phosphorylation. Silencing of IL-1R8 negated the suppressive effect of IL-38 on the NLRP3 inflammasome.

CONCLUSION

IL-38 acts as a potent negative regulator of inflammasome activation after MIRI. It achieves this regulatory effect within cardiac fibroblasts by inhibiting SYK phosphorylation, a process mediated by IL-1R8.

Mechanistic analysis of Tanshinone IIA's regulation of the ATM/GADD45/ORC signaling pathway to reduce myocardial ischemia-reperfusion injury

Background

By far, one of the best treatments for myocardial ischemia is reperfusion therapy. The primary liposoluble component of Danshen, a traditional Chinese herbal remedy, Tanshinone ⅡA, has been shown to have cardiac healing properties. The purpose of this work is to investigate the processes by which Tanshinone ⅡA influences myocardial ischemia-reperfusion injury (MIRI) in the H9C2 cardiac myoblast cell line, as well as the association between Tanshinone ⅡA and MIRI.

Methods and results

The cardiac cells were divided into a normal group, a model group and Tanshinone ⅡA treatment groups. After 4 h of culture with the deprivation of oxygen and glucose, the cells were incubated normally for 2 h. The success of the model and the capacity of Tanshinone ⅡA to heal cardiac damage were validated by the outcomes of cell viability, morphology, and proliferation. The efficacy of Tanshinone ⅡA in treating MIRI was further confirmed by the scratch assay and biomarker measurement. The differentially expressed genes were examined using transcriptome sequencing. The Ataxia-Telangiectasia Mutated (ATM)/Growth Arrest and DNA Damage (GADD45)/Origin Recognition Complex (ORC) signaling pathway was identified as being crucial to this process by KEGG pathway analysis and GO enrichment. Molecular docking and RT-qPCR were used to confirm our results. The crucial function of the ATM/GADD45/ORC pathway was further confirmed by the addition of an ATM inhibitor, which inhibited the expression of ATM.

Conclusion

Tanshinone ⅡA can relieve the myocardial ischemia-reperfusion injury in cardiac cells by activating the ATM/GADD45/ORC pathway.

METTL3, m6A modification, and EGR1: interplay affecting myocardial I/R injury outcomes

The occurrence of severe myocardial ischemia/reperfusion (I/R) injury is associated with the clinical application of reestablishment technique for heart disease, and understanding its underlying mechanisms is currently an urgent issue. Prior investigations have demonstrated the potential enhancement of MIRI through EGR1 suppression, although the precise underlying regulatory pathways require further elucidation. The core focus of this investigation is to examine the molecular pathways through EGR1 regulates mitophagy-mediated myocardial cell pyroptosis and its impact on MIRI. Cardiomyocyte hypoxia/reoxygenation (H/R) injury models and mouse models of myocardial I/R injury were used to investigate the involvement of EGR1 in regulating mitophagy-mediated myocardial cell pyroptosis in myocardial I/R injury. The research outcomes demonstrated that under H/R conditions, EGR1 expression was upregulated and inhibited the JAK2/STAT3 pathway, leading to enhanced mitophagy and disrupted mitochondrial fusion/fission dynamics, ultimately resulting in myocardial cell pyroptosis. Further research revealed that the upregulation of EGR1 expression was mediated by methyltransferase like 3 (METTL3)-mediated m6A modification of EGR1 mRNA and depended on the binding of insulin like growth factor 2 mrna binding protein 2 (IGF2BP2) to the N6-methyladenosine (m6A) modification site to enhance mRNA stability. In vivo animal experiments confirmed that METTL3 upregulated EGR1 expression through IGF2BP2 and suppressed activation of the janus kinase 2 (JAK2) /signal transducer and activator of transcription 3 (STAT3) pathway, thereby inhibiting mitophagy, disrupting mitochondrial dynamics, promoting myocardial cell pyroptosis, and exacerbating I/R injury.

A combined AI and cell biology approach surfaces targets and mechanistically distinct Inflammasome inhibitors

Inflammasomes are protein complexes that mediate innate immune responses whose dysregulation has been linked to a spectrum of acute and chronic human conditions, which dictates therapeutic development that is aligned with disease variability. We designed a scalable, physiologic high-content imaging assay in human PBMCs that we analyzed using a combination of machine-learning and cell biology methods. This resulted in a set of biologically interpretable readouts that can resolve a spectrum of cellular states associated with inflammasome activation and inhibition. These methods were applied to a phenotypic screen that surfaced mechanistically distinct inflammasome inhibitors from an annotated 12,000 compound library. A set of over 100 inhibitors, including an array of Raf-pathway inhibitors, were validated in downstream functional assays. This approach demonstrates how complementary machine learning-based methods can be used to generate profiles of cellular states associated with different stages of complex biological pathways and yield compound and target discovery.

The therapeutic potential of Honeysuckle in cardiovascular disease: an anti-inflammatory intervention strategy

Honeysuckle is a conventional Chinese medicine with several therapeutic applications. With the advancement of modern scientific technologies, Honeysuckle's pharmacological effects and medicinal properties have been investigated more thoroughly. Studies demonstrate that the bioactive compounds in Honeysuckle possess anti-inflammatory effects via several mechanisms, protecting the cardiovascular system. This article provides a reference for the clinical use of Honeysuckle by reviewing research on the therapeutic impact of Honeysuckle and its active constituents on cardiovascular diseases, such as coronary atherosclerotic heart disease (CHD), myocardial ischemia-reperfusion (MI/R), acute myocardial infarction (AMI), hypertension, arrhythmia, and heart failure, through the inhibition of inflammatory responses.

The serum levels of gasdermin D in uremic patients and its relationship with the prognosis: a prospective observational cohort study

OBJECTIVE

This study aimed to explore the serum levels of gasdermin D (GSDMD) in uremic (end-stage kidney disease, ESKD) patients and their correlation with vascular calcification (VC) and clinical results.

METHODS

This prospective observational cohort study enrolled 213 ESKD patients who were undergoing regular maintenance hemodialysis (MHD) for > 3 months in our hospital from August 2019 to July 2022. The abdominal aortic calcification score (AACS) was used to assess the VC condition of patients with ESKD. Serum GSDMD, caspase-1, interleukin (IL)-6, IL-1β, IL-18 and C-reactive protein (CRP) levels were measured using enzyme-linked immunosorbent assay (ELISA). Demographic and clinical data were obtained. All patients were followed up for 1 year, and patients with major adverse cardiovascular events (MACE) were defined as having a poor prognosis. All data used SPSS 26.0 to statistical analyses.

RESULTS

The serum total cholesterol (TC) levels of patients in the AACS > 4 group were significantly elevated compared with those in the AACS ≤ 4 group. In addition, ESKD patients with an AACS > 4 had significantly higher serum levels of GSDMD, caspase-1, IL-6, IL-18 and IL-1β. Moreover, Pearson's analysis supported a positive correlation between GSDMD and caspase-1, IL-6, and IL-1β. In addition, we found that GSDMD levels were positively correlated with the clinical data (AACS scores and serum TC levels) of patients with ERSD. Additionally, ROC curves showed that the serum levels of GSDMD could be a potential predictive biomarker of moderate/severe VC and prognosis in patients with ESKD. Finally, the results of logistic regression indicated that GSDMD and AACS scores were risk factors for poor prognosis in patients with ESKD.

CONCLUSION

Serum GSDMD levels were remarkably elevated in patients with ESKD with moderate/severe calcification. In addition, serum levels of GSDMD could be a potential predictive biomarker of moderate/severe VC and prognosis in patients with ESKD.

Central role of Galectin-3 at the cross-roads of cardiac inflammation and fibrosis: Implications for heart failure and transplantation

Cardiac inflammation and fibrosis are central pathogenic mechanisms leading to heart failure. Transplantation is still the treatment of choice for many patients undergoing end-stage heart failure who remain symptomatic despite optimal medical therapy. In spite of considerable progress, the molecular mechanisms linking inflammation, fibrosis and heart failure remain poorly understood. Galectin-3 (GAL3), a chimera-type member of the galectin family, has emerged as a critical mediator implicated in cardiac inflammatory, vascular and fibrotic processes through modulation of different cellular compartments including monocytes and macrophages, fibroblasts, endothelial cells and vascular smooth muscle cells via glycan-dependent or independent mechanisms. GAL3-driven circuits may hierarchically amplify cytokine production and function, immune cell activation and fibrosis cascades, influencing a wide range of cardiovascular disorders. Thus, GAL3 emerges as a potential therapeutic target to counteract aberrant inflammation and fibrosis during heart failure and a potential biomarker of heart failure and clinical outcome of heart transplantation.

Unraveling the complex interplay between Mitochondria-Associated Membranes (MAMs) and cardiovascular Inflammation: Molecular mechanisms and therapeutic implications

Cardiovascular diseases (CVDs) represent a significant public health concern because of their associations with inflammation, oxidative stress, and abnormal remodeling of the heart and blood vessels. In this review, we discuss the intricate interplay between mitochondria-associated membranes (MAMs) and cardiovascular inflammation, highlighting their role in key cellular processes such as calcium homeostasis, lipid metabolism, oxidative stress management, and ERS. We explored how these functions impact the pathogenesis and progression of various CVDs, including myocardial ischemia-reperfusion injury, atherosclerosis, diabetic cardiomyopathy, cardiovascular aging, heart failure, and pulmonary hypertension. Additionally, we examined current therapeutic strategies targeting MAM-related pathways and proteins, emphasizing the potential of MAMs as therapeutic targets. Our review aims to provide new insights into the mechanisms of cardiovascular inflammation and propose novel therapeutic approaches to improve cardiovascular health outcomes.

Inhibition of Sat1 alleviates myocardial ischemia-reperfusion injury through regulation of ferroptosis via MAPK/ERK pathway

Introduction

Myocardial ischemia-reperfusion injury (MIRI) is a prevalent complication in patients with myocardial infarction. The pathological mechanism of MIRI remains elusive. Ferroptosis plays a critical role in MIRI. This study aimed to investigate the role of spermidine/spermine N1-acetyltransferase 1 (Sat1) in MIRI by regulation of ferroptosis.

Methods

Rats and H9C2 cells were used to perform MIRI model. The extent of myocardial damage and associated pathological changes were evaluated. Protein expression was detected by western blot. Then we observed the mitochondrial morphology and measured cell viability and damage. The levels of lipid peroxide and glutathione were measured, and lipid reactive oxygen species (ROS) was quantified. Differentially expressed genes (DEGs) in MIRI were analyzed. Moreover, to explore the role of Sat1 in MIRI, this study utilized adeno-associated virus 9 and lentiviral transduction to modulate Sat1 expression in rats and H9C2 cells, respectively. The transcription factor that regulates Sat1 expression was predicated. Luciferase reporter gene experiment was conducted to reveal the potential sites of Sox2 binding to Sat1.

Results

This study revealed that ferroptosis was involved in MIRI. Through bioinformatic analysis, Sat1 was identified as a significant gene in MIRI, which has been reported as an inducer of ferroptosis. Our results showed that Sat1 expression was significantly increased in MIRI. Next, the study showed that inhibition of Sat1 alleviated MIRI by suppressing ferroptosis in vivo and in vitro, and over-expression of Sat1 promoted MIRI via activation of ferroptosis. Furthermore, Sat1 and its interacting genes were enriched in several signaling pathways, including ferroptosis and the MAPK signaling pathway. The results showed that Sat1 regulated MIRI through ferroptosis via MAPK/ERK pathway. Moreover, it is found that Sox2 can suppress Sat1 expression at the transcriptional level. The potential binding site was TAACAAAGGAA.

Conclusion

In sum, this study demonstrated Sat1 expression was increased in MIRI, inhibition of Sat1 can alleviate MIRI by regulating ferroptosis via MAPK/ERK pathway, and Sat1 was negatively regulated by Sox2. These findings suggested that Sat1 may serve as a potential therapeutic target for the treatment of MIRI.

Hydroxysafflor Yellow A Inhibits Pyroptosis and Protecting HUVECs from OGD/R via NLRP3/Caspase-1/GSDMD Pathway

OBJECTIVE

To observe the protective effect and mechanism of hydroxyl safflower yellow A (HSYA) from myocardial ischemia-reperfusion injury on human umbilical vein endothelial cells (HUVECs).

METHODS

HUVECs were treated with oxygen-glucose deprivation reperfusion (OGD/R) to simulate the ischemia reperfusion model, and cell counting kit-8 was used to detect the protective effect of different concentrations (1.25-160 µ mol/L) of HSYA on HUVECs after OGD/R. HSYA 80 µ mol/L was used for follow-up experiments. The contents of inflammatory cytokines interleukin (IL)-18, IL-1 β, monocyte chemotactic protein 1 (MCP-1), tumor necrosis factor α (TNF-α) and IL-6 before and after administration were measured by enzyme-linked immunosorbent assay. The protein expressions of toll-like receptor, NOD-like receptor containing pyrin domain 3 (NLRP3), gasdermin D (GSDMD) and GSDMD-N-terminal domain (GSDMD-N) before and after administration were detected by Western blot. NLRP3 inflammasome inhibitor cytokine release inhibitory drug 3 sodium salt (CRID3 sodium salt, also known as MCC950) and agonist were added, and the changes of NLRP3, cysteine-aspartic acid protease 1 (Caspase-1), GSDMD and GSDMD-N protein expressions were detected by Western blot.

RESULTS

HSYA inhibited OGD/R-induced inflammation and significantly decreased the contents of inflammatory cytokines IL-18, IL-1 β, MCP-1, TNF-α and IL-6 (P<0.01 or P<0.05). At the same time, by inhibiting NLRP3/Caspase-1/GSDMD pathway, HSYA can reduce the occurrence of pyroptosis after OGD/R and reduce the expression of NLRP3, Caspase-1, GSDMD and GSDMD-N proteins (P<0.01).

CONCLUSIONS

The protective effect of HSYA on HUVECs after OGD/R is related to down-regulating the expression of NLRP3 inflammasome and inhibiting pyroptosis.

Tilianin suppresses NLRP3 inflammasome activation in myocardial ischemia/reperfusion injury via inhibition of TLR4/NF-κB and NEK7/NLRP3

Tilianin, a flavonoid compound derived from Dracocephalum moldavica L., is recognized for its diverse biological functionalities, in particular alleviating myocardial ischemia-reperfusion injury (MIRI). There is ample evidence suggesting that the NLRP3 inflammasome has a significant impact on the development of MIRI. In this study, rats undergoing the ligation and subsequent release of the left anterior descending (LAD) coronary artery and H9c2 cardiomyocytes subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) were used to investigate the effects of tilianin on NLRP3 inflammasome and its anti-MIRI mechanisms. Upon reperfusion, the rats were intraperitoneally injected with tilianin at doses of 3, 10, 30 mg/kg. H9c2 cells were treated with tilianin at concentrations of 10, 30, and 50 μg/mL. Echocardiography, TTC staining and TUNEL staining demonstrated that tilianin remarkably improved cardiac function and mitigated myocardial damage in MIRI rats. Additionally, notable inflammatory response reduction by tilianin was evidenced by subsequent hematatoxylin-eosin (HE) staining, inflammatory cytokines assay, and quantitative proteomics. Further western blotting analysis and immunofluorescence staining showed tilianin decreased the levels of TLR4, p-NF-κB, NLRP3, and ASC in MIRI rats and H9c2 cells exposed to OGD/R, alongside a significant reduction in cleaved gasdermin D, mature IL-1β and IL-18. Molecular docking, cellular thermal shift assay (CETSA) and co-immunoprecipitation (co-IP) assay revealed that tilianin impeded the interaction between NLRP3 and NEK7. Taken together, tilianin protects cardiomyocytes from MIRI by suppressing NLRP3 inflammasome through the inhibition of the TLR4/NF-κB signaling pathway and the disruption of the NEK7/NLRP3 interface. These findings underscore the potential of tilianin as a promising therapeutic candidate for MIRI.

Advancing Roles and Therapeutic Potentials of Pyroptosis in Host Immune Defenses against Tuberculosis

Tuberculosis (TB), an infectious disease caused by Mycobacterium tuberculosis (Mtb) infection, remains a deadly global public health burden. The use of recommended drug combinations in clinic has seen an increasing prevalence of drug-resistant TB, adding to the impediments to global control of TB. Therefore, control of TB and drug-resistant TB has become one of the most pressing issues in global public health, which urges the exploration of potential therapeutic targets in TB and drug-resistant TB. Pyroptosis, a form of programmed cell death characterized by cell swelling and rupture, release of cellular contents and inflammatory responses, has been found to promote pathogen clearance and adopt crucial roles in the control of bacterial infections. It has been demonstrated that Mtb can cause host cell pyroptosis, and these host cells, which are infected by Mtb, can kill Mtb accompanied by pyroptosis, while, at the same time, pyroptosis can also release intracellular Mtb, which may potentially worsen the infection by exacerbating the inflammation. Here, we describe the main pathways of pyroptosis during Mtb infection and summarize the identified effectors of Mtb that regulate pyroptosis to achieve immune evasion. Moreover, we also discuss the potentials of pyroptosis to serve as an anti-TB therapeutic target, with the aim of providing new ideas for the development of TB treatments.

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.

Di(2-ethylhexyl) phthalate exposure aggravates hypoxia/reoxygenation injury in cerebral endothelial cells by downregulating epithelial cadherin expression

Di-(2-ethylhexyl) phthalate (DEHP) is a widely used plasticizer that has adverse health effects. Most phthalates exhibit reproductive toxicity and are associated with diseases such as cardiovascular disorders. However, the effect of DEHP exposure on acute hypoxia/reperfusion injury remains unknown. Therefore, we assessed whether hypoxia/reperfusion injury is aggravated by exposure to DEHP and investigated plausible underlying mechanisms, including oxidative stress and expression of cyclooxygenase-2 (COX-2)/prostaglandin E2 (PGE2) and endothelial junctional proteins. bEnd.3 cells were exposed to DEHP and subsequently subjected to oxygen-glucose deprivation (OGD). Cell viability was analyzed using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) proliferation assay. The effect of DEHP/OGD/reoxygenation (R) was evaluated by assessing the levels of NO, reactive oxygen species (ROS), and PGE2. The expression of COX-2, cleaved caspase-3, cleaved PARP, inducible nitric oxide synthase (iNOS), and the endothelial tight junction proteins claudin-5 and ZO-1 was evaluated using quantitative polymerase chain reaction and western blotting. OGD/R decreased cell viability, and DEHP exposure before OGD/R further aggravated cell viability. DEHP/OGD/R significantly increased NO, PGE2, and ROS production following OGD/R. In the DEHP/OGD/R group, iNOS, COX-2, cleaved caspase-3, and cleaved PARP expression increased, and claudin-5 and ZO-1 levels decreased compared with those in the OGD/R group. E-Cadherin expression decreased significantly after DEHP/OGD/R exposure compared with that after OGD/R; this decrease in expression was recovered by treatment with the COX-2 inhibitor indomethacin and antioxidant N-acetylcysteine. Exposure to DEHP exacerbated hypoxia-reoxygenation injury. The enhanced damage upon DEHP exposure was associated with increased oxidative stress and COX-2 expression, leading to E-cadherin downregulation and increased apoptosis.

Single-Cell WGCNA Combined with Transcriptome Sequencing to Study the Molecular Mechanisms of Inflammation-Related Ferroptosis in Myocardial Ischemia-Reperfusion Injury

Purpose

Myocardial ischemia-reperfusion injury (MIRI) is characterized by inflammation and ferroptosis, but the precise mechanisms remain unknown. This study used single-cell transcriptomics technology to investigate the changes in various cell subtypes during MIRI and the regulatory network of ferroptosis-related genes and immune infiltration.

Methods

Datasets GSE146285, GSE83472, GSE61592, and GSE160516 were obtained from Gene Expression Omnibus. Each cell subtype in the tissue samples was documented. The Seurat package was used for data preprocessing, standardization, and clustering. Cellphonedb was used to investigate the ligand-receptor interactions between cells. The hdWGCNA analysis was used to create a gene co-expression network. GSVA and GSEA were combined to perform functional enrichment and pathway analysis on the gene set. Furthermore, characteristic genes of the disease were identified using Lasso regression and SVM algorithms. Immune cell infiltration analysis was also performed. MIRI rat models were created, and samples were taken for RT-qPCR and Western blot validation.

Results

The proportion of MIRI samples in the C2, C6, and C11 subtypes was significantly higher than that of control samples. Three genes associated with ferroptosis (CD44, Cfl1, and Zfp36) were identified as MIRI core genes. The expression of these core genes was significantly correlated with mast cells and monocyte immune infiltrating cells. The experimental validation confirmed the upregulation of Cd44 and Zfp36 expression levels in MIRI, consistent with current study trends.

Conclusion

This study used single-cell transcriptomics technology to investigate the molecular mechanisms underpinning MIRI. Numerous important cell subtypes, gene regulatory networks, and disease-associated immune infiltration were also discovered. These findings provide new information and potential therapeutic targets for MIRI diagnosis and treatment.

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.

ZBP1-mediated PANoptosis: A possible novel mechanism underlying the therapeutic effects of penehyclidine hydrochloride on myocardial ischemia-reperfusion injury

Although penehyclidine hydrochloride (PHC) has been identified to alleviate myocardial injury induced by ischemia/reperfusion (I/R), the regulatory molecules and related mechanisms are unknown. In this study, bioinformatics, molecular biology, and biochemistry methods were used to explore the molecular mechanisms and targets of PHC. In the myocardial ischemia-reperfusion injury (MIRI)-induced rat model, PHC pretreatment significantly improved cardiac function (p < 0.01). Multiple differentially expressed genes, including Z-DNA binding protein 1 (ZBP1), were identified through mRNA sequencing analysis of myocardial ischemic penumbra tissue in MIRI rats. The transduction of the ZBP1 adenovirus vector (Ad-Zbp1) in PHC-pretreated rats exhibited a reversible augmentation in myocardial infarct size (p < 0.01), pronounced pathological damage to the myocardial tissue, as well as a significant elevation of serum myocardial enzymes (p < 0.05). The interaction among ZBP1, fas-associating via death domain (FADD), and receptor-interacting serine/threonine-protein kinase 3 (RIPK3) leads to a remarkable up-regulation of cleaved-Caspase-1 (Cl-Casp-1), N-terminal gasdermin D (N-GSDMD), phospho-mixed lineage kinase domain-like Ser358 (p-MLKLS358), and other regulatory proteins, thereby triggering pyroptosis, apoptosis, and necroptosis (PANoptosis) in cardiomyocytes of MIRI rats. Moreover, the transduction of Ad-Zbp1 in the oxygen-glucose deprivation/re-oxygenation (OGD/R)-induced H9c2 cell model also dramatically augmented the number of cell deaths. However, the intervention of PHC considerably enhanced cell viability (p < 0.01), effectively mitigated the release of myocardial enzymes (p < 0.05), and markedly attenuated the expression levels of PANoptosis regulatory proteins through restraint of ZBP1 expression. Therefore, the therapeutic efficacy of PHC in improving MIRI might be attributed to targeting ZBP1-mediated PANoptosis.

Molecular probes for monitoring pyroptosis: design, imaging and theranostic application

Pyroptosis is a recently discovered process of programmed cell death that is linked with tumor progression and potential treatment strategies. Unlike other forms of programmed cell death, such as apoptosis or necrosis, pyroptosis is associated with pore-forming proteins gasdermin D (GSDMD), which are cleaved by caspase enzymes to form oligomers. These oligomers are then inserted into the cell surface membrane, causing pores to consequently result in rapid cell death. Pyroptosis, in conjunction with immunotherapy, represents a promising avenue for prognostication and antitumor therapy, providing a more precise direction for disease treatment. To gain deeper insight into the mechanisms underlying pyroptosis in real-time, non-invasive and live cell imaging techniques are urgently needed. Non-invasive imaging techniques can enhance future diagnostic and therapeutic approaches for inflammatory diseases, including different types of tumors. This review article discusses various non-invasive molecular probes for detecting pyroptosis, including genetic reporters and nanomaterials. These strategies can enhance scientists' understanding of pyroptosis and help discover personalized and effective ways to treat inflammatory diseases, particularly tumors.

IL-1 signaling pathway, an important target for inflammation surrounding in myocardial infarction

Acute myocardial infarction is an important cardiovascular disease worldwide. Although the mortality rate of myocardial infarction (MI) has improved dramatically in recent years due to timely treatment, adverse remodeling of the left ventricle continues to affect cardiac function. Various immune cells are involved in this process to induce inflammation and amplification. The infiltration of inflammatory cells in the infarcted myocardium is induced by various cytokines and chemokines, and the recruitment of leukocytes further amplifies the inflammatory response. As an increasing number of clinical anti-inflammatory therapies have achieved significant success in recent years, treating myocardial infarction by targeting inflammation may become a novel therapeutic option. In particular, successful clinical trials of canakinumab have demonstrated the important role of the inflammatory factor interleukin-1 (IL-1) in atherosclerosis. Targeted IL-1 therapy may decrease inflammation levels and improve cardiac function in patients after myocardial infarction. This article reviews the complex series of responses after myocardial infarction, including the involvement of inflammatory cells and the role of cytokines and chemokines, focusing on the progression of the IL-1 family in myocardial infarction as well as the performance of current targeted therapy drugs in experiments.

Inflammation in cerebral ischemia reperfusion improved by avanafil via nod-like receptor protein-3 inflammasome: an experimental study in rats

OBJECTIVE

The aim of study was to investigate the effect of avanafil, a second-generation phosphodiesterase-5 (PDE5) inhibitor, on cerebral ischemia reperfusion (CI/R) model.

METHODS

32 male albino Wistar rats were used. Four groups were constituted, as I: the healthy (sham), II: the CI/R group, III: the CI/R +I 10 mg/kg avanafil group, and IV: the CI/R + 20 mg/kg avanafil group. Avanafil was administered twice via oral gavage, first shortly after ischemia reperfusion and once more after 12 h. The rats were euthanized after 24 h. Histopathological and Real Time PCR analyzes were performed on cerebral tissues.

RESULTS

IL-1β, NLRP3 and TNF-α mRNA expressions were statistically higher in the CI/R group when compared to healthy (sham) group. Conversely, the IL-1β, NLRP3, and TNF-α mRNA expressions were significantly decreased in both of the avanafil-treated groups when compared to CI/R group. Histopathological results showed that both doses of avanafil also decreased cellular damage in cerebral tissue that occurred after CI/R.

CONCLUSION

Avanafil, was found to have ameliorated inflammatory response and cellular injury caused by CI/R. The mRNA expression of IL-1β, NLRP3, and TNF-α decreased in the I/R groups and approached the control group levels with a high dose of avanafil.

Unraveling the differential mechanisms of revascularization promoted by MSCs & ECFCs from adipose tissue or umbilical cord in a murine model of critical limb-threatening ischemia

BACKGROUND

Critical limb-threatening ischemia (CLTI) constitutes the most severe manifestation of peripheral artery disease, usually induced by atherosclerosis. CLTI patients suffer from high risk of amputation of the lower extremities and elevated mortality rates, while they have low options for surgical revascularization due to associated comorbidities. Alternatively, cell-based therapeutic strategies represent an effective and safe approach to promote revascularization. However, the variability seen in several factors such as cell combinations or doses applied, have limited their success in clinical trials, being necessary to reach a consensus regarding the optimal "cellular-cocktail" prior further application into the clinic. To achieve so, it is essential to understand the mechanisms by which these cells exert their regenerative properties. Herein, we have evaluated, for the first time, the regenerative and vasculogenic potential of a combination of endothelial colony forming cells (ECFCs) and mesenchymal stem cells (MSCs) isolated from adipose-tissue (AT), compared with ECFCs from umbilical cord blood (CB-ECFCs) and AT-MSCs, in a murine model of CLTI.

METHODS

Balb-c nude mice (n:32) were distributed in four different groups (n:8/group): control shams, and ischemic mice (after femoral ligation) that received 50 µl of physiological serum alone or a cellular combination of AT-MSCs with either CB-ECFCs or AT-ECFCs. Follow-up of blood flow reperfusion and ischemic symptoms was carried out for 21 days, when mice were sacrificed to evaluate vascular density formation. Moreover, the long-term molecular changes in response to CLTI and both cell combinations were analyzed in a proteomic quantitative approach.

RESULTS

AT-MSCs with either AT- or CB-ECFCs, promoted a significant recovery of blood flow in CLTI mice 21 days post-ischemia. Besides, they modulated the inflammatory and necrotic related processes, although the CB group presented the slowest ischemic progression along the assay. Moreover, many proteins involved in the repairing mechanisms promoted by cell treatments were identified.

CONCLUSIONS

The combination of AT-MSCs with AT-ECFCs or with CB-ECFCs promoted similar revascularization in CLTI mice, by restoring blood flow levels, together with the modulation of the inflammatory and necrotic processes, and reduction of muscle damage. The protein changes identified are representative of the molecular mechanisms involved in ECFCs and MSCs-induced revascularization (immune response, vascular repair, muscle regeneration, etc.).

circMIRIAF aggravates myocardial ischemia-reperfusion injury via targeting miR-544/WDR12 axis

Exploring and discovering novel circRNAs is one of the ways to develop innovative drugs for the diagnosis and treatment of myocardial ischemia-reperfusion injury (MI/RI). In the work, some dysregulated circRNAs were found by microarray screening analysis in AC16 cells, and hsa_circRNA_104852 named circMIRIAF was screened, which was up-regulated in AC16 cells damaged by hypoxia-reoxygenation injury (H/RI). The comprehensive analysis of ceRNA network revealed the potential relationship of circMIRIAF/miR-544/WDR12. Then, the results of interaction research confirmed that circMIRIAF acted as sponge of miR-544 to positively regulate WDR12 protein expression. Further, the validation results indicate that miR-544 silencing increased the expression of WDR12, and WDR12 activated Notch1 signal to aggravate H/RI of AC16 cells and MI/RI of mice via regulating oxidative stress and inflammation. Furthermore, silencing circMIRIAF caused the decreased circMIRIAF levels and the increased miR-544 levels in cardiomyocytes, while excessive miR-544 inhibited WDR12 expression to alleviate the disorder. On the contrary, excessive circMIRIAF increased WDR12 expression by adsorbing miR-544 to exacerbate H/RI in AC16 cells. In addition, circMIRIAF siRNA reversed the aggravation of H/RI in cells caused by WDR12 overexpression. Overall, circMIRIAF can serve as a drug target or treating MI/RI, and circMIRIAF could sponge miR-544 and enhance WDR12 expression to aggravate MI/RI, which may provide a novel therapeutic strategy for MI/RI treatment.

Escherichia coli K88 activates NLRP3 inflammasome-mediated pyroptosis in vitro and in vivo

Pyroptosis induced by lipopolysaccharide (LPS) has an obvious impact on intestinal inflammation and immune regulation. Enterotoxigenic Escherichia coli (ETEC) K88 has been proved to induce inflammatory responses in several models, but whether E. coli K88 participates in the same process of pyroptotic cell death as LPS remains to be identified. We conducted a pilot experiment to confirm that E. coli K88, instead of Escherichia coli O157 and Salmonella typhimurium, promotes the secretion of interleukin-1 beta (IL-1β) and interleukin-18 (IL-18) in macrophages. Further experiments were carried out to dissect the molecular mechanism both in vitro and in vivo. The Enzyme-Linked Immunosorbent Assay (ELISA) results suggested that E. coli K88 treatment increased the expression of pro-inflammatory cytokines IL-18 and IL-1β in both C57BL/6 mice and the supernatant of J774A.1 cells. Intestinal morphology observations revealed that E. coli K88 treatment mainly induced inflammation in the colon. Real-time PCR and Western blot analysis showed that the mRNA and protein expressions of pyroptosis-related factors, such as NLRP3, ASC, and Caspase1, were significantly upregulated by E. coli K88 treatment. The RNA-seq results confirmed that the effect was associated with the activation of NLRP3, ASC, Caspase1, GSDMD, IL-18, and IL-1β, and might also be related to inflammatory bowel disease and the tumor necrosis factor pathway. The pyroptosis-activated effect of E. coli K88 was significantly blocked by NLRP3 siRNA. Our data suggested that E. coli K88 caused inflammation by triggering pyroptosis, which provides a theoretical basis for the prevention and treatment of ETEC in intestinal infection.

Research progress of cGAS-STING signaling pathway in intestinal diseases

The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signal has drawn much consideration due to its sensitivity to DNA in innate immune mechanisms. Activation of the cGAS-STIN signaling pathway induces the production of interferon and inflammatory cytokines, resulting in immune responses, or inflammatory diseases. The intestinal tract is a vital organ for the body's nutrition absorption, recent studies have had various points of view on the job of cGAS-STING pathway in various intestinal sicknesses. Therefore, understanding its role and mechanism in the intestinal environment can help to develop new strategies for the treatment of intestinal diseases. This article examines the mechanism of the cGAS-STING pathway and its function in inflammatory bowel disease, intestinal cancer, and long-injury ischemia-reperfusion, lists the current medications that target it for the treatment of intestinal diseases, and discusses the impact of intestinal flora on this signaling pathway, to offer a theoretical and scientific foundation for upcoming targeted therapies for intestinal disorders via the cGAS-STING pathway.

Reperfusion Injury in Patients With Acute Myocardial Infarction: JACC Scientific Statement

Despite impressive improvements in the care of patients with ST-segment elevation myocardial infarction, mortality remains high. Reperfusion is necessary for myocardial salvage, but the abrupt return of flow sets off a cascade of injurious processes that can lead to further necrosis. This has been termed myocardial ischemia-reperfusion injury and is the subject of this review. The pathologic and molecular bases for myocardial ischemia-reperfusion injury are increasingly understood and include injury from reactive oxygen species, inflammation, calcium overload, endothelial dysfunction, and impaired microvascular flow. A variety of pharmacologic strategies have been developed that have worked well in preclinical models and some have shown promise in the clinical setting. In addition, there are newer mechanical approaches including mechanical unloading of the heart prior to reperfusion that are in current clinical trials.

Ginsenoside Rb2 Inhibits the Pyroptosis in Myocardial Ischemia Progression Through Regulating the SIRT1 Mediated Deacetylation of ASC

Myocardial ischemic (MI) injury is a common cardiovascular disease, and the potential therapeutic effects of ginsenoside Rb2 (Rb2) have been lately the focus of interest. Therefore, this study aimed to investigate the effects of Rb2 on pyroptosis of cardiomyocytes in MI progression. An in vitro MI model was developed by subjecting rat's cardiomyocytes (H9c2) to hypoxia/reoxygenation (H/R). The cell viability was determined by CCK-8 assay, while cell death was analyzed by propidium iodide staining. Similarly, pyroptosis-related protein levels and acetylation levels of apoptosis-associated speck-like protein containing a CARD (ASC) were detected by western blotting, and the relationship between Sirtuin 1 (SIRT1) and ASC was confirmed by co-immunoprecipitation (Co-IP) assay. Moreover, hematoxylin-eosin (H&E) and triphenyl tetrazolium chloride staining were used to study pathological structure and infarct size. It was found that post-Rb2 treatment significantly increased the cell viability and decreased the cell death and lactic dehydrogenase release, while the increased gasdermin D-N, NOD-like receptor thermal protein domain-associated protein 3, ASC, and cleaved-caspase-1 protein levels were significantly decreased in H/R-stimulated H9c2 cells. Moreover, the acetylation levels of H92c cells were decreased post-Rb2 treatment via increasing SIRT1 levels, while knocking down SIRT1, translated into an increase in ASC acetylation levels, leading to the increase in ASC protein stability and expressions. Additionally, the Rb2 effects on pyroptosis in H/R-stimulated H92c cells were reversed by overexpressing ASC, while reduced myocardial tissue damage was observed in MI rats following in vivo Rb2 treatment. Rb2 treatment inhibited pyroptosis in MI progression by decreasing the ASC levels. Mechanistically, Rb2 treatment increased the SIRT1 levels, further increasing the acetylation levels of ASC and decreasing the protein stability of ASC.

Therapy-naïve malignancy causes cardiovascular disease: a state-of-the-art cardio-oncology perspective

Cardiovascular disease (CVD) and cancer are the leading causes of mortality worldwide. Although generally thought of as distinct diseases, the intersectional overlap between CVD and cancer is increasingly evident in both causal and mechanistic relationships. The field of cardio-oncology is largely focused on the cardiotoxic effects of cancer therapies (e.g., chemotherapy, radiation). Furthermore, the cumulative effects of cardiotoxic therapy exposure and the prevalence of CVD risk factors in patients with cancer lead to long-term morbidity and poor quality of life in this patient population, even when patients are cancer-free. Evidence from patients with cancer and animal models demonstrates that the presence of malignancy itself, independent of cardiotoxic therapy exposure or CVD risk factors, negatively impacts cardiac structure and function. As such, the primary focus of this review is the cardiac pathophysiological and molecular features of therapy-naïve cancer. We also summarize the strengths and limitations of preclinical cancer models for cardio-oncology research and discuss therapeutic strategies that have been tested experimentally for the treatment of cancer-induced cardiac atrophy and dysfunction. Finally, we explore an adjacent area of interest, called "reverse cardio-oncology," where the sequelae of heart failure augment cancer progression. Here, we emphasize the cross-disease communication between malignancy and the injured heart and discuss the importance of chronic low-grade inflammation and endocrine factors in the progression of both diseases.

Effects of a novel regimen of repetitive transcranial magnetic stimulation (rTMS) on neural remodeling and motor function in adult male mice with ischemic stroke

Neuroinflammation caused by excessive microglial activation plays a key role in the pathogenesis of ischemic stroke. Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive neuromodulatory technique that has recently been reported to regulate microglial functions and exert anti-inflammatory effects. The intermittent burst stimulation (iTBS) regimen in rTMS improves neuronal excitability. However, whether iTBS exerts its anti-inflammatory effects by stimulating neurons and thereby modulating microglial polarization remains unclear. Motor function was assessed after 1 week of rTMS (iTBS regimen) treatment in adult male mice with occlusion/reperfusion of the middle cerebral artery (MCAO/r) injury. We also investigated the molecular biological alterations associated with microglial polarization using a cell proliferation assay, multiplex cytokine bioassays, and immunofluorescence staining. iTBS regimen can improve balance and motor coordination function, increase spontaneous movement, and improve walking function in mice with early cerebral ischemia injury. Expression levels of IL-1β, TNF-α, and IL-10 increased significantly in mice with MCAO injury. Especially, rTMS significantly increased the number of proliferating cells in the infarcted cortex. The fluorescence intensity of MAP2 in the peri-infarct area of MCAO injured mice was low, but the signal was broader. Compared with MCAO group, the fluorescence intensity of MAP2 in rTMS group was significantly increased. rTMS inhibited pro-inflammatory M1 activation (Iba1+/CD86+) and improved anti-inflammatory M2 activation (Iba1+/CD206+) in the peri-infarct zone, thus significantly changing the phenotypic ratio M1/M2. rTMS improves motor dysfunction and neuroinflammation after cerebral I/R injury in mice by regulating microglial polarization.

The m6A methylation enzyme METTL14 regulates myocardial ischemia/reperfusion injury through the Akt/mTOR signaling pathway

Herein, we investigated the role of the m6A methylation enzyme METTL14 in regulating myocardial ischemia/reperfusion injury (IR/I) through the Akt/mTOR signaling pathway and related biological mechanisms. Enzyme-linked immunosorbent assay (ELISA) and fluorescence quantitative polymerase chain reaction (qPCR) were performed to detect the m6A mRNA and METTL3, METTL14, WTAP, and KIAA1429 levels in a mouse myocardial IR/I model. An oxygen-glucose deprivation/reperfusion (OGD/R) model was constructed by transfecting neonatal rat cardiomyocytes (NRCM) with METTL14-knockdown lentivirus. METTL14, Bax, and cleaved-caspase3 mRNA expression levels were detected using fluorescence qPCR. Apoptosis was detected using TUNEL staining. After the IR/I surgery following the adeno-associated virus injection, the METTL14 mRNA and apoptosis-related BAX/BCL2 protein expression was detected using fluorescence qPCR and western blotting, respectively. Degree of cell necrosis was detected using an LDH assay. The oxidative stress response of the myocardial tissue was detected, and IL-6 and IL-1β serum levels were detected using ELISAs. The mice injected with METTL14-knockdown AAV9 adeno-associated virus underwent IR/I surgery after the injection of an Akt/mTOR pathway inhibitor (MK2206) into the myocardial layer. Elevated mRNA m6A modification and m6A methyltransferase METTL14 levels were observed in the IR/I-injured mouse heart tissues. METTL14 knockdown significantly inhibited the OGD/R- and IR/I-induced apoptosis and necrosis in cardiac myocytes, inhibited IR/I-induced oxidative stress and inflammatory factor secretion, and activated the Akt/ mTOR pathway in vitro and in vivo. Akt/mTOR pathway inhibition significantly attenuated the alleviating effect of METTL14 knockdown on myocardial IR/I injury-induced apoptosis. Knocking down m6A methylase METTL14 inhibits IR/I-induced myocardial apoptosis and necrosis, inhibits myocardial oxidative stress and secretion of inflammatory cytokines, and activates the Akt/mTOR signaling pathway. Hence, METTL14 regulated myocardial apoptosis and necrosis in mice with IR/I through the Akt/mTOR signaling pathway.