NLRP3 Inflammasome Activation-Mediated Pyroptosis Aggravates Myocardial Ischemia/Reperfusion Injury in Diabetic Rats

Shikonin from lithospermum erythrorhizon induces pyroptosis in trophoblast cells by activating the CTSB-NLRP3 inflammasome

BACKGROUND

With the decline of global fertility, drug therapeutic of ectopic pregnancy is of great significance. Lithospermum erythrorhizon is using for embryo killing as herbal medicine. Shikonin is the critical nucleus of Lithospermum erythrorhizon; however, the mechanism is still unclear. The study aimed to explore the mechanism of shikonin against ectopic pregnancy.

MATERIAL AND METHODS

In this study, we examined the viability and LDH release of HTR-8/SVneo cells by assays, observed pore formation in cell membranes by microscopy imaging and PI staining, and IL-1β release by WB and ELISA assay kit. Then, we used network pharmacology to analyse the potential interaction between shikonin, ectopic pregnancy and pyroptosis and used molecular docking techniques to verify interactions between shikonin and core common targets. Finally, western blotting and immunofluorescence assay were used to explore the mechanism of shikonin-inducing pyroptosis of HTR-8/SVneo cells.

RESULTS

Shikonin could cause a significant inhibition of HTR-8/SVneo cell viability in a concentration- and time-dependent manner. In HTR-8/SVneo cells, shikonin-induced cell swelling, bubble formation, an increase in the release of lactate dehydrogenase (LDH) and up-regulation of several pyroptosis-associated factors. And network pharmacology showed that The main targets of shikonin-ectopic pregnancy-pyroptosis were IL-1β and caspase-1, and molecular docking results showed that shikonin can closely bind to IL-1β, caspase-1 and GSDMD. Additionally, the necroptosis inhibitor GSK'872 could not suppress the expression of mature-IL-1β and prevent the pyroptosis phenotype from developing. However, the nucleotide oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inhibitor MCC-950 could downregulate the expression of pyroptosis-associated factors and prevent the pyroptosis phenotype from developing. Shikonin led to an elevation in the expression of cathepsin B (CTSB), and the CTSB inhibitor CA-074 abolished pyroptosis induced by shikonin; however, the NLRP3 inhibitor MCC-950 could not inhibit the expression of CTSB.

CONCLUSIONS

Our results suggest that shikonin activates CTSB to induce NLRP3-dependent pyroptosis in HTR-8/SVneo cells. This study has important clinical implications for the treatment of ectopic pregnancy.

TRPC5-mediated NLRP3 inflammasome activation contributes to myocardial cell pyroptosis in chronic intermittent hypoxia rats

BACKGROUND

Chronic intermittent hypoxia (CIH) is the primary cause of myocardial inflammation in obstructive sleep apnea-hypopnea syndrome (OSAHS). Pyroptosis is a newly discovered form of programmed cell death accompanying inflammatory reactions. Our previous study showed that TRPC5 is upregulated in the myocardial injury of CIH rats. The present study aimed to explore the role of TRPC5 in CIH-induced myocardial cell pyroptosis.

METHODS

A model of CIH in OSA rats was established. SD rats were randomly divided into control group(8rats) and OSA group(8rats). Scanning electron microscope(SEM) was performed on left ventricular tissues slides. Western blot were used to detect the expression levels of pyroptosis-related factors and TRPC5 and its downstream proteins in myocardia tissue.

RESULTS

The pyroptosis of myocardial cells by SEM revealed damaged cell membrane integrity of OSA group rats, with fibrous tissue attached to the cell membrane surface, and vesicular protrusions and pyroptotic bodies were observed.Compared to the control group, the expression of pyroptosis-related proteins, such as caspase1, pro-IL-1β, IL-1β, IL-18, GSDMD, and GSDMD-N was upregulated in the OSA group (p < 0.05). Compared to the control group, the expression of TRPC5, NLPR3, p-CaMKIIβ + δ+γ, and HDAC4 was higher in the OSA group (p < 0.05).

CONCLUSIONS

These findings indicated that the pyroptosis response increases in CIH-induced myocardial injury, and the mechanism that TRPC5 is upregulated, promoting the expression of NLRP3 and inflammasome formation through CaMKII phosphorylation and HDAC4 cytoplasmic translocation. This might be a potential target for the treatment of OSA-induced myocardial injury.

Glibenclamide reverses cardiac damage and NLRP3 inflammasome activation associated with a high refined sugar diet

Increased energy intake from carbohydrates has been associated with major cardiovascular outcomes. Mice fed a highly-refined carbohydrate (HC) diet develop cardiac hypertrophy and inflammation. During cardiac injury, NLRP3 inflammasome is activated which results in a local inflammatory response. In this study, we hypothesized that a nom-hypoglycemic dose of glibenclamide may reverses sugar diet-induced cardiac damage by NRLP3 inflammasome inhibition. Mice were fed the HC diet for eight weeks and divided into a group treated with glibenclamide (20 mg/kg, gavage) and another with vehicle for four weeks. Afterward, hearts were excised for morphometric analysis and ex vivo function determination. NLRP3 inflammasome activation was investigated by western blotting and in situ fluorescent detection of reactive oxygen species (ROS) and active caspase-1. The HC diet promotes heart hypertrophy and collagen deposition, which were reverted by glibenclamide without ameliorating HC diet-induced insulin resistance. Changes in cardiac performance were observed in vivo by invasive catheterization and in Langendorff-perfused hearts due to the HC diet, which were prevented by glibenclamide. Hearts from HC diet mice had increased levels of NLRP3 and cleaved IL-1β. Glibenclamide reversed ROS production and caspase-1 activity induced by HC diet. These findings suggest glibenclamide's cardioprotective effects on heart damage caused by the HC diet are related to its inhibitory action on the NLRP3 inflammasome.

Inhibition of circDGKZ ameliorates myocardial ischemia/reperfusion injury by targeting miR-345-5p/TLR4

AIMS

This study aims to explore the molecular mechanism of circular RNAs' (circRNAs) potential involvement in myocardial ischaemia-reperfusion injury (MIRI).

METHODS AND RESULTS

Differently expressed genes in myocardial infarction (MI) were identified by screening the GEO database. Serum was collected from MI patients and healthy volunteers (n = 5 for each group). AC16 cells were cultured and exposed to hypoxia/reperfusion (H/R) treatment for the cell experiments. Then candidate genes were validated in human serum and the H/R model. Quantitative real-time PCR and western blot were used to detect expression of key molecules such as circDGKZ, miR-345-5p, and Toll-like receptor 4 (TLR4), as well as pyroptosis markers such as NOD-like receptor thermal protein domain-associated protein 3 (NLRP3), ASC, C-caspase1, interleukin (IL)-1β, and IL-18. CircDGKZ was positively correlated in human serum (P < 0.05) and in AC16 cells (P < 0.01). Knockdown of circDGKZ inhibited cardiomyocyte pyroptosis and the TLR4/nuclear factor kappa B (NF-κB) signalling pathway (all P < 0.05). A luciferase assay was used to detect the molecule interaction. MiR-345-5p was regulated by circDGKZ and regulated TLR4 in cardiomyocytes both through direct interaction (P < 0.01). The stability and distribution of circRNA or linear RNA were examined by subcellular localization and RNA decay assays. CircDGKZ was stably expressed in cardiomyocytes and mainly distributed in the cytoplasm (P < 0.01). Knockdown of circDGKZ also promoted the degradation of NLRP3 by inducing autophagy (P < 0.05). MIRI rat models were constructed (n = 5 for each group), and the cellular results were further confirmed in rat models (P < 0.05).

CONCLUSIONS

Knockdown of circDGKZ interrupted pyroptosis and induced autophagy of cardiomyocytes via regulating miR-345-5p/TLR4/NF-κB.

Review of research progress on different modalities of Macrophage death in Mycobacterium leprae infection

Leprosy, caused by Mycobacterium leprae (M. leprae), is a chronic infectious disease primarily affecting the skin and peripheral nerves. The interaction between M. leprae and macrophages, its primary host cell, plays a critical role in disease progression. This review explores the various forms of macrophage cell death induced by M. leprae infection, including apoptosis, autophagy, necroptosis, pyroptosis, ferroptosis and necrosis. The regulation and implications of these cell death pathways on the host immune response are discussed. Apoptosis and autophagy are highlighted as mechanisms that may limit M. leprae proliferation, while necroptosis and pyroptosis contribute to inflammation and immune response. Notably, recent studies have identified CYBB-mediated ferroptosis as essential for macrophages infected with M. leprae to polarize towards the M2 phenotype, facilitating immune evasion by the pathogen. This review underscores the complexity of macrophage cell death in leprosy, and summarize their corresponding molecular mechanisms and potential impact on the host immunity.

Preconditioning with β-hydroxybutyrate attenuates lung ischemia-reperfusion injury by suppressing alveolar macrophage pyroptosis through the SIRT1-FOXO3 signaling pathway

The complex pathogenesis of lung ischemia-reperfusion injury (LIRI) was examined in a murine model, focusing on the role of pyroptosis and its exacerbation of lung injury. We specifically examined the levels and cellular localization of pyroptosis within the lung, which revealed alveolar macrophages as the primary site. The inhibition of pyroptosis by VX-765 reduced the severity of lung injury, underscoring its significant role in LIRI. Furthermore, the therapeutic potential of β-hydroxybutyrate (β-OHB) in ameliorating LIRI was examined. Modulation of β-OHB levels was evaluated by ketone ester supplementation and 3-hydroxybutyrate dehydrogenase 1 (BDH-1) gene knockout, along with the manipulation of the SIRT1-FOXO3 signaling pathway using EX-527 and pCMV-SIRT1 plasmid transfection. This revealed that β-OHB exerts lung-protective and anti-pyroptotic effects, which were mediated through the upregulation of SIRT1 and the enhancement of FOXO3 deacetylation, leading to decreased pyroptosis markers and lung injury. In addition, β-OHB treatment of MH-S cells in vitro showed a concentration-dependent improvement in pyroptosis, linking its therapeutic benefits to specific cell mechanisms. Overall, this study highlights the significance of alveolar macrophage pyroptosis in the exacerbation of LIRI and indicates the potential of β-OHB in mitigating injury by modulating the SIRT1-FOXO3 signaling pathway.

Acetate attenuates hypothalamic pyroptosis in experimentally induced polycystic ovarian syndrome

This study hypothesized that SCFA, acetate impacts positively on hypothalamic pyroptosis and its related abnormalities in experimentally induced PCOS rat model, possibly through NrF2/HIF1-α modulation. Eight-week-old female Wister rats were divided into groups (n = 5), namely control, PCOS, acetate and PCOS + acetate groups. Induction of PCOS was performed by administering 1 mg/kg body weight of letrozole for 21 days. After PCOS confirmation, the animals were treated with 200 mg/kg of acetate for 6 weeks. Rats with PCOS were characterized with insulin resistance, leptin resistance, increased plasma testosterone as well as degenerated ovarian follicles. There was also a significant increase in hypothalamic triglyceride level, triglyceride-glucose index, inflammatory biomarkers (SDF-1 and NF-kB) and caspase-6 as well as plasma LH and triglyceride. A decrease was observed in plasma adiponectin, GnRH, FSH, and hypothalamic GABA with severe inflammasome expression in PCOS rats. These were accompanied by decreased level of NrF2/HIF1-α, and the alterations were reversed when treated with acetate. Collectively, the present results suggest the therapeutic impact of acetate on hypothalamic pyroptosis and its related comorbidity in PCOS, a beneficial effect that is accompanied by modulation of NrF2/HIF1-α.

MicroRNA dysregulation and its impact on apoptosis-related signaling pathways in myelodysplastic syndrome

Myelodysplastic syndrome (MDS) holds a unique position among blood cancers, encompassing a spectrum of blood-related disorders marked by impaired maturation of blood cell precursors, bone marrow abnormalities, genetic instability, and a higher likelihood of progressing to acute myeloid leukemia. MicroRNAs (miRNAs), short non-coding RNA molecules typically 18-24 nucleotides in length, are known to regulate gene expression and contribute to various biological processes, including cellular differentiation and programmed cell death. Additionally, miRNAs are involved in many aspects of cancer development, influencing cell growth, transformation, and apoptosis. In this study, we explore the impact of microRNAs on cellular apoptosis in MDS.

ACTIVATION OF KLOTHO/SIRT1 SIGNALING PATHWAY ATTENUATES MYOCARDIAL ISCHEMIA REPERFUSION INJURY IN DIABETIC RATS

ABSTRACT

Diabetes and myocardial ischemia reperfusion (MIR) injury are characterized by oxidative stress, inflammation, autophagy disorders, and cardiac contractile dysfunction. Klotho and SIRT1 regulate the level of oxidative stress to participate in the regulation of many physiological functions such as cell survival, aging, apoptosis, autophagy, mitochondrial biogenesis, and inflammation. We hypothesized that the activation of Klotho/SIRT1 signaling pathway could attenuate MIR in diabetic rats. Type 1 diabetes and MIR injury model were established to examine this hypothesis in vivo . Primary rat cardiomyocytes and H9c2 cells were exposed to high glucose conditions and hypoxia/reoxygenation (H/R) insult in vitro . Hemodynamic parameters of heart function, myocardial infarct size, oxidative stress, markers of MIR injury or cell viability, and the mRNA and protein expression of Klotho and SIRT1 were measured. There was lower expression of Klotho and SIRT1 in diabetic MIR hearts than in nondiabetic rats, as well as significantly increased oxidative stress levels and decreased autophagy levels. Recombinant Klotho (rKlotho) protein and the SIRT1 agonist SRT1720 could significantly attenuate MIR injury in diabetes by activating Klotho/SIRT1 signaling pathway to reduce oxidative stress and restore autophagy levels. These findings suggest that the Klotho/SIRT1 pathway plays an important role in MIR injury in diabetic rats, and rKlotho protein and agonist SRT1720 have therapeutic potential for alleviating diabetic myocardial IR injury by activating Klotho/SIRT1 to reduce oxidative stress and restore autophagy levels.

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.

Inhibition of Caspase-1-dependent pyroptosis alleviates myocardial ischemia/reperfusion injury during cardiopulmonary bypass (CPB) in type 2 diabetic rats

Cardiovascular complications pose a significant burden in type 2 diabetes mellitus (T2DM), driven by the intricate interplay of chronic hyperglycemia, insulin resistance, and lipid metabolism disturbances. Myocardial ischemia/reperfusion (MI/R) injury during cardiopulmonary bypass (CPB) exacerbates cardiac vulnerability. This study aims to probe the role of Caspase-1-dependent pyroptosis in global ischemia/reperfusion injury among T2DM rats undergoing CPB, elucidating the mechanisms underlying heightened myocardial injury in T2DM. This study established a rat model of T2DM and compared Mean arterial pressure (MAP), heart rate (HR), and hematocrit (Hct) between T2DM and normal rats. Myocardial cell morphology, infarction area, mitochondrial ROS and caspase-1 levels, NLRP3, pro-caspase-1, caspase-1 p10, GSDMD expressions, plasma CK-MB, cTnI, IL-1β, and IL-18 levels were assessed after reperfusion in both T2DM and normal rats. The role of Caspase-1-dependent pyroptosis in myocardial ischemia/reperfusion injury during CPB in T2DM rats was examined using the caspase-1 inhibitor VX-765 and the ROS scavenger NAC. T2DM rats demonstrated impaired glucose tolerance but stable hemodynamics during CPB, while showing heightened vulnerability to MI/R injury. This was marked by substantial lipid deposition, disrupted myocardial fibers, and intensified cellular apoptosis. The activation of caspase-1-mediated pyroptosis and increased reactive oxygen species (ROS) production further contributed to tissue damage and the ensuing inflammatory response. Notably, myocardial injury was mitigated by inhibiting caspase-1 through VX-765, which also attenuated the inflammatory cascade. Likewise, NAC treatment reduced oxidative stress and partially suppressed ROS-mediated caspase-1 activation, resulting in diminished myocardial injury. This study proved that Caspase-1-dependent pyroptosis significantly contributes to the inflammation and injury stemming from global MI/R in T2DM rats under CPB, which correlate with the surplus ROS generated by oxidative stress during reperfusion.

LPS-LBP complex induced endothelial cell pyroptosis in aortic dissection is associated with gut dysbiosis

Acute aortic dissection (AAD) is the most severe traumatic disease affecting the aorta. Pyroptosis-mediated vascular wall inflammation is a crucial trigger for AAD, and the exact mechanism requires further investigation. In this study, our proteomic analysis showed that Lipopolysaccharide (LPS)-binding protein (LBP) was significantly upregulated in the plasma and aortic tissue of patients with AAD. Further, 16S rRNA sequencing of stool samples suggested that patients with AAD exhibit gut dysbiosis, which may lead to an impaired intestinal barrier and LPS leakage. By comparing with control mice, we found that LBP, including Pyrin Domain Containing Protein3 (NLRP3), the CARD-containing adapter apoptosis-associated speck-like protein (ASC), and Cleaved caspase-1, were upregulated in the AAD aorta, whereas gut intestinal barrier-related proteins were downregulated. Moreover, treated with LBPK95A (an LBP inhibitor) attenuated the incidence of AAD, the expression levels of pyroptosis-related factors, and the extent of vascular pathological changes compared to those in AAD mice. In addition, LPS and LBP treatment of human umbilical vein endothelial cells (HUVECs) activated TLR4 signaling and intracellular reactive oxygen species (ROS) production, which stimulated NLRP3 inflammasome formation and mediated pyroptosis in endothelial cells. Our findings showed that gut dysbiosis mediates pyroptosis by the LPS-LBP complex, thus providing new insights into developing AAD.

PRG4 mitigates hemorrhagic shock-induced cardiac injury by inhibiting mitochondrial dysregulation, oxidative stress and NLRP3-mediated pyroptosis

Hemorrhagic shock (HS) is one of the main causes of morbidity and death in patients with trauma or major surgery. Cardiac dysfunction is a well-known complication of HS. PRG4, also known as lubricin, is a mucin-like glycoprotein that plays anti-inflammatory and anti-apoptotic roles in a variety of diseases. In this study, we aimed to explore the cardioprotective efficacy of PRG4 in HS-induced cardiac injury. Employing the HS model and RNA-seq, we found that PRG4 was increased in the myocardial tissue of rats after HS. In vivo studies suggested that HS led to abnormal hemodynamic parameters and increased cTnI levels, and PRG4 overexpression effectively reversed these changes. PRG4 also suppressed HS-induced mitochondrial disorders, as reflected by increased mitochondrial membrane potential (MMP), ATP and mitochondria cytochrome c, COXIV and TOM20, as well as decreased BNIP3L and cytoplasmic cytochrome c. Furthermore, HS led to enhanced oxidative stress, as evidenced by upregulated ROS and MDA contents, and downregulated SOD and CAT activities, and these alterations were negated by PRG4 overexpression. Notably, PRG4 repressed the NLRP3-mediated pyroptosis pathway, as illustrated by decreased NLRP3 levels, caspase-1 activity and GSDMD-NT levels. In summary, these observations indicate that PRG4 overexpression protects against HS-induced cardiac dysfunction by inhibiting mitochondrial dysregulation, oxidative stress and NLRP3-mediated pyroptosis.

Lead exposure induces neurodysfunction through caspase-1-mediated neuronal pyroptosis

Chronic lead (Pb) exposure causes neurodysfunction and contributes to the development of neurodegenerative disease. However, the mechanism of Pb-induced neurological dysfunction have yet to be fully elucidated. This study determined the role pyroptosis plays in Pb-induced neurodysfunction in neurons. We used both in vitro and in vivo approaches to explore whether Pb exposure induces caspase-1-mediated pyroptosis in neurons and its relationship to Pb-induced neurological disorders. Our findings showed that caspase-1-mediated pyroptosis in Pb-exposed neurons activated glycogen synthase kinase 3 protease activity by disrupting Ca2+/calmodulin-dependent protein kinase II/cAMP-response element binding protein pathway, leading to neurological disorders. Moreover, the caspase-1 inhibition VX-765 or the non-steroidal anti-inflammatory drug sodium para-aminosalicylic acid (PAS-Na) attenuated the Pb-induced neurological disorders by alleviating caspase-1 mediated neuronal pyroptosis. Our novel studies suggest that caspase-1-mediated pyroptosis in neurons represents a potential mechanism for Pb-induced neurodysfunction, identifying a putative target for attenuating the neurodegenerative effects induced by this metal.

Unraveling the Triad: Hypoxia, Oxidative Stress and Inflammation in Neurodegenerative Disorders

The mammalian brain's complete dependence on oxygen for ATP production makes it highly susceptible to hypoxia, at high altitudes or in clinical scenarios including anemia or pulmonary disease. Hypoxia plays a crucial role in the development of various brain disorders, such as Alzheimer's, Parkinson's, and other age-related neurodegenerative diseases. On the other hand, a decrease in environmental oxygen levels, such as prolonged stays at high elevations, may have beneficial impacts on the process of ageing and the likelihood of death. Additionally, the utilization of controlled hypoxia exposure could potentially serve as a therapeutic approach for age-related brain diseases. Recent findings indicate that the involvement of HIF-1α and the NLRP3 inflammasome is of significant importance in the development of Alzheimer's disease. HIF-1α serves as a pivotal controller of various cellular reactions to oxygen deprivation, exerting influence on a multitude of physiological mechanisms such as energy metabolism and inflammatory responses. The NLRP3 plays a crucial role in the innate immune system by coordinating the initiation of inflammatory reactions through the assembly of the inflammasome complex. This review examines the information pertaining to the contrasting effects of hypoxia on the brain, highlighting both its positive and deleterious effects and molecular pathways that are involved in mediating these different effects. This study explores potential strategies for therapeutic intervention that focus on restoring cellular balance and reducing neuroinflammation, which are critical aspects in addressing this severe neurodegenerative condition and addresses crucial inquiries that warrant further future investigations.

Baicalin-loaded Polydopamine modified ZIF-8 NPs inhibits myocardial ischemia/reperfusion injury in rats

Baicalin (BAN) has shown promise in alleviating myocardial ischemia/reperfusion (I/R) injury, yet its limited solubility and biocompatibility have hindered its application. Developing drug delivery systems is a promising strategy to enhance the therapeutic potential of BAN in the context of I/R injury. This study aims to prepare a BAN-loaded nanodrug system using polydopamine (PDA)-modified Zeolitic imidazolate framework-8 (ZIF-8) as a carrier, with the goal of improving BAN's mitigating effects on I/R injury. We prepared the BAN nanoparticles (NPs) system, PZB NPs, using ZIF-8 as the carrier. The system was characterized in terms of morphology, particle size, zeta potential, and X-ray diffraction (XRD). We assessed the cytotoxicity of PZB NPs in H9c2 cells, investigated its effects and mechanisms in H/R-induced H9c2 cells, and evaluated its ability to alleviate myocardial I/R injury in rats. PZB NPs exhibited good dispersion, with a BAN loading efficiency of 26.43 ± 1.55%, a hydrated particle size of 102.21 ± 1.19 nm, and a zeta potential of -24.84 ± 0.07 mV. It displayed slow and sustained drug release in an acidic environment (pH 5.5). In vitro studies revealed that PZB NPs was non-cytotoxic and significantly enhanced the recovery of H/R injury H9c2 cell viability. PZB NPs suppressed cell apoptosis, activated the Nrf2/HO-1 pathway, and cleared ROS. In vivo study demonstrated that PZB NPs significantly reduced infarct size, ameliorated fibrosis and improved heart function. The PZB NPs markedly enhances BAN's ability to alleviate I/R injury, both in vitro and in vivo, offering a promising drug delivery system for clinical applications.

Hyperglycemia induces microglial pyroptosis by increasing oxygen extraction rate: Implication in neurological impairment during ischemic stroke

Elevated levels of blood glucose in patients with ischemic stroke are associated with a worse prognosis. The present study aimed to explore whether hyperglycemia promotes microglial pyroptosis by increasing the oxygen extraction rate in an acute ischemic stroke model. C57BL/6 mice that underwent middle cerebral artery occlusion were used for assessment of blood glucose level and neurological function. The cerebral oxygen extraction ratio (CERO2), oxygen consumption rate (OCR) and partial pressure of brain tissue oxygen (PbtO2) were measured. To investigate the significance of the NOD‑like receptor protein 3 (NLRP3) inflammasome, NLRP3‑/‑ mice were used, and the expression levels of NLRP3, caspase‑1, full‑length gasdermin D (GSDMD‑FL), GSDMD‑N domain (GSDMD‑N), IL‑1β and IL‑18 were evaluated. In addition, Z‑YVAD‑FMK, a caspase‑1 inhibitor, was used to treat microglia to determine whether activation of the NLRP3 inflammasome was required for the enhancing effect of hyperglycemia on pyroptosis. It was revealed that hyperglycemia accelerated cerebral injury in the acute ischemic stroke model, as evidenced by decreased latency to fall and the percentage of foot fault. Hyperglycemia aggravated hypoxia by increasing the oxygen extraction rate, as evidenced by increased CERO2 and OCR, and decreased PbtO2 in response to high glucose treatment. Furthermore, hyperglycemia‑induced microglial pyroptosis was confirmed by detection of increased levels of caspase‑1, GSDMD‑N, IL‑1β and IL‑18 and a decreased level of GSDMD‑FL. However, the knockout of NLRP3 attenuated these effects. Pharmacological inhibition of caspase‑1 also reduced the expression levels of GSDMD‑N, IL‑1β and IL‑18 in microglial cells. These results suggested that hyperglycemia stimulated NLRP3 inflammasome activation by increasing the oxygen extraction rate, thus leading to the aggravation of pyroptosis following ischemic stroke.

The interplay between T lymphocytes and macrophages in myocardial ischemia/reperfusion injury

Acute myocardial infarction is one of the most important causes of death in the world, causing a huge health and economic burden to the world. It is still a ticklish problem how to effectively prevent reperfusion injury while recovering the blood flow of ischemic myocardium. During the process of myocardial ischemia/reperfusion injury (MI/RI), the modulation of immune cells plays an important role. Monocyte/macrophage, neutrophils and endothelial cells initiate the inflammatory response and induce the release of various inflammatory cytokines, resulting in increased vascular permeability, tissue edema and damage. Meanwhile, T cells were recruited to impaired myocardium and release pro-inflammatory and anti-inflammatory cytokines. T cells and macrophages play important roles in keeping cardiac homeostasis and orchestrate tissue repair. T cells differentiation and macrophages polarization precisely regulates the tissue microenvironment in MI/RI, and shows cross action, but the mechanism is unclear. To identify potential intervention targets and propose ideas for treatment and prevention of MI/RI, this review explores the crosstalk between T lymphocytes and macrophages in MI/RI.

Advancements in the study of acute lung injury resulting from intestinal ischemia/reperfusion

Intestinal ischemia/reperfusion is a prevalent pathological process that can result in intestinal dysfunction, bacterial translocation, energy metabolism disturbances, and subsequent harm to distal tissues and organs via the circulatory system. Acute lung injury frequently arises as a complication of intestinal ischemia/reperfusion, exhibiting early onset and a grim prognosis. Without appropriate preventative measures and efficacious interventions, this condition may progress to acute respiratory distress syndrome and elevate mortality rates. Nonetheless, the precise mechanisms and efficacious treatments remain elusive. This paper synthesizes recent research models and pertinent injury evaluation criteria within the realm of acute lung injury induced by intestinal ischemia/reperfusion. The objective is to investigate the roles of pathophysiological mechanisms like oxidative stress, inflammatory response, apoptosis, ferroptosis, and pyroptosis; and to assess the strengths and limitations of current therapeutic approaches for acute lung injury stemming from intestinal ischemia/reperfusion. The goal is to elucidate potential targets for enhancing recovery rates, identify suitable treatment modalities, and offer insights for translating fundamental research into clinical applications.

Benzoylaconine Protects Skeletal Muscle Against Ischemia-Reperfusion Injury Through Activation of IF1-Dependent AMPK/Nrf2 Axis

Background

Aconitum carmichaelii (Fuzi) has been conventionally used to cure a variety of ailments, such as pain, cold sensations, and numbness of limb muscles (Bi Zheng) in China. Our prior investigations identified Benzoylaconine (BAC) as a bioactive alkaloid derived from Aconitum carmichaelii, with other studies also demonstrating its significant pharmacological potential.

Purpose

This study aimed to explore the potential of BAC as a protective agent against skeletal muscle ischemia-reperfusion (I/R) injury and to elucidate the underlying mechanisms.

Methods

In vivo models involved subjecting Sprague-Dawley rats to I/R through femoral artery ligation followed by reperfusion, while in vitro models utilized C2C12 cells subjected to hypoxia/reoxygenation (H/R). CCK-8 assay was used to assess cell viability. TUNEL staining and flow cytometric analysis were used to measure cell apoptosis. Biochemical assay was used to assess skeletal muscle injury and oxidative stress. Immunofluorescence and Western blot were performed to determine protein levels.

Results

BAC effectively protected muscle tissue from I/R injury, enhancing cell viability (p<0.01), elevating SOD levels (p<0.05), and reducing CK (p<0.01), LDH (p<0.01), ROS (p<0.01), MDA (p<0.01), and apoptosis-related molecules in vivo and in vitro (p<0.05, p<0.01). Mechanistically, BAC increased the expression of IF1, phosphorylated AMPK, facilitated the translocation of nuclear Nrf2, and induced the expression of HO-1 (p<0.01). Notably, AMPK inhibitor Compound C significantly hindered the ability of BAC to ameliorate H/R-induced cell injury (p<0.05), oxidative stress(p<0.01), and apoptosis (p<0.05), as well as promote Nrf2 nuclear translocation (p<0.01). Moreover, silencing of IF1 with siRNA abolished BAC-induced activation of AMPK/Nrf2 axis (p<0.01).

Conclusion

Our study provides novel evidence supporting the potential of BAC as a myocyte-protective agent against I/R injury, and we establish a previously unknown mechanism involving the activation of the IF1-dependent AMPK/Nrf2 axis in mediating the protective effects of BAC.

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.

Mechanistic study of Huangqi Guizhi Wuwu decoction amelioration of doxorubicin-induced cardiotoxicity by reducing oxidative stress and inhibiting cellular pyroptosis

Huangqi Guizhi Wuwu Decoction (HQGZWWD) has shown promising potential in treating various cardiovascular diseases. This study aimed to elucidate the molecular basis and therapeutic role of HQGZWWD in the treatment of doxorubicin (DOX)-induced myocardial injury. The HPLC fingerprint of HQGZWWD was used to analyze the active components. A DOX-induced myocardial damage rat model was developed, and the therapeutic effects of HQGZWWD were evaluated using echocardiography, myocardial enzyme levels, and hematoxylin and eosin staining. Network pharmacology was used to screen treatment targets, and western blotting and immunohistochemistry were performed to assess cellular pyroptosis levels. Oxidative stress levels were measured using assay kits, and mitochondrial damage was examined using transmission electron microscopy. An in vitro model of DOX-induced cell damage was established, and treatment was administered using serum containing HQGZWWD and N-acetylcysteine (NAC). Oxidative stress levels were detected using assay kits and DCFH-DA, whereas cellular pyroptosis levels were assessed through WB, immunofluorescence, and ELISA assays. HQGZWWD ameliorated DOX-induced myocardial injury. Network pharmacology identified IL-1β and IL-18 as crucial targets. HQGZWWD downregulated the protein levels of the inflammatory factors IL-1β and IL-18, inhibited the expression of GSDMD-NT, and simultaneously suppressed the synthesis of Caspase-1, ASC, NLRP3, and Caspase-11. Additionally, HQGZWWD inhibited oxidative stress, and the use of NAC as an oxidative stress inhibitor resulted in significant inhibition of the GSDMD-NT protein in H9C2 cells. These findings highlight the myocardial protective effects of HQGZWWD by inhibiting oxidative stress and suppressing both canonical and non-canonical pyroptotic pathways.

Oxidative medicine and cellular longevity the role and mechanism of NCOA4 in ferroptosis induced by intestinal ischemia reperfusion

BACKGROUND

Ferroptosis is an iron-dependent and cystathione-non-dependent non-apoptotic cell death characterized by elevated intracellular free iron levels and reduced antioxidant capacity, leading to the accumulation of lipid peroxides. Nuclear receptor coactivator 4 (NCOA4) mediates ferritinophagy, increasing labile iron levels, which can result in oxidative damage. However, the specific mechanism of NCOA4-mediated ferritinophagy in intestinal ischemia-reperfusion and the underlying mechanisms have not been reported in detail.

OBJECT

1. To investigate the role of NCOA4 in ferroptosis of intestinal epithelial cells induced by II/R injury in mouse. 2. To investigate the mechanism of action of NCOA4-induced ferroptosis.

METHODS

1. Construct a mouse II/R injury model and detect ferroptosis related markers such as HE staining, immunohistochemistry, ELISA, and WB methods. 2. Detect expression of NCOA4 in the intestine of mouse with II/R injury model and analyze its correlation with intestinal ferroptosis in mouse with II/R injury model. 3. Construct an ischemia-reperfusion model at the cellular level through hypoxia and reoxygenation, and overexpress/knockdown NCOA4 to detect markers related to ferroptosis. Based on animal experimental results, analyze the correlation and mechanism of action between NCOA4 and intestinal epithelial ferroptosis induced by II/R injury in mouse.

RESULTS

1. Ferroptosis occurred in the intestinal epithelial cells of II/R-injured mouse, and the expression of critical factors of ferroptosis, ACSL4, MDA and 15-LOX, was significantly increased, while the levels of GPX4 and GSH were significantly decreased. 2. The expression of NCOA4 in the intestinal epithelium of mouse with II/R injure was significantly increased, the expression of ferritin was significantly decreased, and the level of free ferrous ions was significantly increased; the expression of autophagy-related proteins LC3 and Beclin-1 protein was increased, and the expression of P62 was decreased, and these changes were reversed by autophagy inhibitors. 3. Knockdown of NCOA4 at the cellular level resulted in increased ferritin expression and decreased ferroptosis, and CO-IP experiments suggested that NCOA4 can bind to ferritin, which suggests that NCOA4 most likely mediates ferritinophagy to induce ferroptosis.

CONCLUSION

This thesis explored the role of NCOA4 in II/R injury in mice and the mechanism of action. The research results suggest that NCOA4 can mediate ferritinophagy to induce ferroptosis during II/R injury. This experiment reveals the pathological mechanism of II/R injury and provides some scientific basis for the development of drugs for the treatment of II/R injury based on the purpose of alleviating ferroptosis.

Ac2-26 activated the AKT1/GSK3β pathway to reduce cerebral neurons pyroptosis and improve cerebral function in rats after cardiopulmonary bypass

BACKGROUND

Cardiopulmonary bypass (CPB) results in brain injury, which is primarily caused by inflammation. Ac2-26 protects against ischemic or hemorrhage brain injury. The present study was to explore the effect and mechanism of Ac2-26 on brain injury in CPB rats.

METHODS

Forty-eight rats were randomized into sham, CPB, Ac, Ac/AKT1, Ac/GSK3βi and Ac/AKT1/GSK3βa groups. Rats in sham group only received anesthesia and in the other groups received standard CPB surgery. Rats in the sham and CPB groups received saline, and rats in the Ac, Ac/AKT1, Ac/GSK3βi and Ac/AKT1/GSK3βa groups received Ac2-26 immediately after CPB. Rats in the Ac/AKT1, Ac/GSK3βi and Ac/AKT1/GSK3βa groups were injected with shRNA, inhibitor and agonist of GSK3β respectively. The neurological function score, brain edema and histological score were evaluated. The neuronal survival and hippocampal pyroptosis were assessed. The cytokines, activity of NF-κB, S100 calcium-binding protein β(S100β) and neuron-specific enolase (NSE), and oxidative were tested. The NLRP3, cleaved-caspase-1 and cleaved-gadermin D (GSDMD) in the brain were also detected.

RESULTS

Compared to the sham group, all indicators were aggravated in rats that underwent CPB. Compared to the CPB group, Ac2-26 significantly improved neurological scores and brain edema and ameliorated pathological injury. Ac2-26 reduced the local and systemic inflammation, oxidative stress response and promoted neuronal survival. Ac2-26 reduced hippocampal pyroptosis and decreased pyroptotic proteins in brain tissue. The protection of Ac2-26 was notably lessened by shRNA and inhibitor of GSK3β. The agonist of GSK3β recovered the protection of Ac2-26 in presence of shRNA.

CONCLUSIONS

Ac2-26 significantly improved neurological function, reduced brain injury via regulating inflammation, oxidative stress response and pyroptosis after CPB. The protective effect of Ac2-26 primarily depended on AKT1/ GSK3β pathway.

Initial Despair and Current Hope of Identifying a Clinically Useful Treatment of Myocardial Reperfusion Injury: Insights Derived from Studies of Platelet P2Y12 Antagonists and Interference with Inflammation and NLRP3 Assembly

Myocardial necrosis following the successful reperfusion of a coronary artery occluded by thrombus in a patient presenting with ST-elevation myocardial infarction (STEMI) continues to be a serious problem, despite the multiple attempts to attenuate the necrosis with agents that have shown promise in pre-clinical investigations. Possible reasons include confounding clinical risk factors, the delayed application of protective agents, poorly designed pre-clinical investigations, the possible effects of routinely administered agents that might unknowingly already have protected the myocardium or that might have blocked protection, and the biological differences of the myocardium in humans and experimental animals. A better understanding of the pathobiology of myocardial infarction is needed to stem this reperfusion injury. P2Y12 receptor antagonists minimize platelet aggregation and are currently part of the standard treatment to prevent thrombus formation and propagation in STEMI protocols. Serendipitously, these P2Y12 antagonists also dramatically attenuate reperfusion injury in experimental animals and are presumed to provide a similar protection in STEMI patients. However, additional protective agents are needed to further diminish reperfusion injury. It is possible to achieve additive protection if the added intervention protects by a mechanism different from that of P2Y12 antagonists. Inflammation is now recognized to be a critical factor in the complex intracellular response to ischemia and reperfusion that leads to tissue necrosis. Interference with cardiomyocyte inflammasome assembly and activation has shown great promise in attenuating reperfusion injury in pre-clinical animal models. And the blockade of the executioner protease caspase-1, indeed, supplements the protection already seen after the administration of P2Y12 antagonists. Importantly, protective interventions must be applied in the first minutes of reperfusion, if protection is to be achieved. The promise of such a combination of protective strategies provides hope that the successful attenuation of reperfusion injury is attainable.

The role of regulated necrosis in diabetes and its complications

Morphologically, cell death can be divided into apoptosis and necrosis. Apoptosis, which is a type of regulated cell death, is well tolerated by the immune system and is responsible for hemostasis and cellular turnover under physiological conditions. In contrast, necrosis is defined as a form of passive cell death that leads to a dramatic inflammatory response (also referred to as necroinflammation) and causes organ dysfunction under pathological conditions. Recently, a novel form of cell death named regulated necrosis (such as necroptosis, pyroptosis, and ferroptosis) was discovered. Distinct from apoptosis, regulated necrosis is modulated by multiple internal or external factors, but meanwhile, it results in inflammation and immune response. Accumulating evidence has indicated that regulated necrosis is associated with multiple diseases, including diabetes. Diabetes is characterized by hyperglycemia caused by insulin deficiency and/or insulin resistance, and long-term high glucose leads to various diabetes-related complications. Here, we summarize the mechanisms of necroptosis, pyroptosis, and ferroptosis, and introduce recent advances in characterizing the associations between these three types of regulated necrosis and diabetes and its complications.

CXCL4/CXCR3 axis regulates cardiac fibrosis by activating TGF-β1/Smad2/3 signaling in mouse viral myocarditis

BACKGROUND

Severe myocarditis is often accompanied by cardiac fibrosis, but the underlying mechanism has not been fully elucidated. CXCL4 is a chemokine that has been reported to have pro-inflammatory and profibrotic functions. The exact role of CXCL4 in cardiac fibrosis remains unclear.

METHODS

Viral myocarditis (VMC) models were induced by intraperitoneal injection of Coxsackie B Type 3 (CVB3). In vivo, CVB3 (100 TCID50) and CVB3-AMG487 (CVB3: 100 TCID50; AMG487: 5 mg/kg) combination were administered in the VMC and VMC+AMG487 groups, respectively. Hematoxylin and eosin staining, severity score, Masson staining, and immunofluorescence staining were performed to measure myocardial morphology in VMC. Enzyme-linked immunosorbent assay (ELISA) and quantitative reverse transcription polymerase chain reaction (qRT-PCR) were performed to quantify inflammatory factors (IL-1β, IL-6, TNF-α, and CXCL4). Aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and creatine kinase-myocardial band (CK-MB) levels were analyzed by commercial kits. CXCL4, CXCR3B, α-SMA, TGF-β1, Collagen I, and Collagen III were determined by Western blot and immunofluorescence staining.

RESULTS

In vivo, CVB3-AMG487 reduced cardiac injury, α-SMA, Collagen I and Collagen III levels, and collagen deposition in VMC+AMG487 group. Additionally, compared with VMC group, VMC+AMG group decreased the levels of inflammatory factors (IL-1β, IL-6, and TNF-α). In vitro, CXCL4/CXCR3B axis activation TGF-β1/Smad2/3 pathway promote mice cardiac fibroblasts differentiation.

CONCLUSION

CXCL4 acts as a profibrotic factor in TGF-β1/Smad2/3 pathway-induced cardiac fibroblast activation and ECM synthesis, and eventually progresses to cardiac fibrosis. Therefore, our findings revealed the role of CXCL4 in VMC and unveiled its underlying mechanism. CXCL4 appears to be a potential target for the treatment of VMC.

LncRNA SNHG1 alleviates myocardial ischaemia-reperfusion injury by regulating the miR-137-3p/KLF4/TRPV1 axis

AIMS

Myocardial ischaemia-reperfusion injury (MIRI) contributes to serious myocardial injury and even death. Long non-coding RNAs (lncRNAs) have been reported to play pivotal roles in the occurrence and development of MIRI. Here, the detailed molecular mechanism of lncRNA SNHG1 in MIRI was explored.

METHODS AND RESULTS

A cell model of MIRI was established through hypoxia/reoxygenation (H/R) stimulation. Cell viability and pyroptosis were evaluated utilizing MTT, PI staining, and flow cytometry. Interleukin (IL)-1β and IL-18 secretion levels were examined by ELISA. The gene and protein expression were detected by RT-qPCR and western blot, respectively. Dual luciferase reporter gene, RIP and ChIP assays were performed to analyse the molecular interactions. The results showed that lncRNA SNHG1 overexpression alleviated H/R-induced HL-1 cell pyroptosis (all P < 0.05). LncRNA SNHG1 promoted KLF4 expression by sponging miR-137-3p. miR-137-3p silencing alleviated H/R-induced pyroptosis in HL-1 cells (all P < 0.05), which was abolished by KLF4 knockdown (all P < 0.05). KLF4 activated the AKT pathway by transcriptionally activating TRPV1 in HL-1 cells (all P < 0.05). TRPV1 knockdown reversed the alleviation of SNHG1 upregulation on H/R-induced pyroptosis in HL-1 cells (all P < 0.05).

CONCLUSIONS

These results showed that lncRNA SNHG1 assuaged cardiomyocyte pyroptosis during MIRI progression by regulating the KLF4/TRPV1/AKT axis through sponging miR-137-3p. Our findings may provide novel therapeutic targets for MIRI.

P2Y13 receptor involved in HIV-1 gp120 induced neuropathy in superior cervical ganglia through NLRP3 inflammasome activation

Cardiac autonomic neuropathy resulting from human immunodeficiency virus (HIV) infection is common; however, its mechanism remains unknown. The current work attempted to explore the function and mechanism of the P2Y13 receptor in HIV-glycoprotein 120 (gp120)-induced neuropathy in cervical sympathetic ganglion. The superior cervical ganglion (SCG) of the male SD rat was coated with HIV-gp120 to establish a model of autonomic neuropathy. In each group, we measured heart rate, blood pressure, heart rate variability, sympathetic nerve discharge and cardiac function. The expression of P2Y13 mRNA and protein in the SCG was tested by real-time polymerase chain reaction and western blotting. Additionally, this study focused on identifying the protein levels of NOD-like receptor family pyrin domain-containing 3 (NLRP3), Caspase-1, Gasdermin D (GSDMD), interleukin (IL)-1β and IL-18 in the SCG using western blotting and immunofluorescence. In gp120 rats, increased blood pressure, heart rate, cardiac sympathetic nerve activity, P2Y13 receptor levels and decreased cardiac function could be found. P2Y13 shRNA or MRS2211 inhibited the above mentioned changes induced by gp120, suggesting that the P2Y13 receptor may be engaged in gp120-induced sympathetic nerve injury. Moreover, the levels of NLRP3, Caspase-1, GSDMD, IL-1β and IL-18 in the gp120 group were increased, while significantly decreased by P2Y13 shRNA or MRS2211. Therefore, the P2Y13 receptor is involved in gp120-induced sympathetic neuropathy, and its molecular mechanism shows an association with the activation of the NLRP3 inflammasome, followed by GSDMD formation along with the release of inflammatory factors including IL-1β and IL-18. This article is part of the Special Issue on "Purinergic Signaling: 50 years".

The role of ncRNAs-mediated pyroptosis in diabetes and its vascular complications

Over the past decade, the prevalence of diabetes has increased significantly worldwide, leading to an increase in vascular complications of diabetes (VCD), such as diabetic cardiomyopathy (DCM), diabetic nephropathy (DN), and diabetic retinopathy (DR). Noncoding RNAs (ncRNAs), such as microRNAs (miRNAs), long Noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), play a key role in cellular processes, including the pathophysiology of diabetes and VCD via pyroptosis. ncRNAs (e.g., miR-17, lnc-MEG3, and lnc-KCNQ1OT1) can regulate pyroptosis in pancreatic β cells. Some ncRNAs are involved in VCD progression. For example, miR-21, lnc-KCNQ1OT1, lnc-GAS5, and lnc-MALAT1 were reported in DN and DCM, and lnc-MIAT was identified in DCM and DR. Herein, this review aimed to summarize recent research findings related to ncRNAs-mediated pyroptosis at the onset and progression of diabetes and VCD.

Pharmacological inhibition of ICOS attenuates the protective effect of exercise on cardiac fibrosis induced by isoproterenol

AIMS

To investigate the cardioprotective mechanism of exercise or exercise combined with inducible costimulatory molecules (ICOS) monoclonal antibody (mAb) therapy against isoproterenol (ISO)-induced cardiac remodeling.

MAIN METHODS

Totally 24 male C57BL/6J mice were randomly divided into four groups: the control group (normal saline treatment), ISO group (subcutaneous injection of isoproterenol, 10 mg/kg/day, once daily for 5 consecutive days), the exercise with subcutaneous ISO injection group (EPI), and the exercise with injected with ISO and ICOS mAb group (EPII). The mice in EPI and EPII group were trained on a small animal treadmill for 4 weeks (13 m/min, 0% grade, 60min/day).

KEY FINDINGS

Exercise significantly attenuated CD45+, Mac-2 inflammatory cell infiltration, cardiac fibrosis and inhibited the RIPK1/RIPK3/MLKL/CaMKII and cardiomyocyte pyroptosis pathways to counter ISO-induced severe cardiac injury. The administration of the ICOS mAb may inhibit the cardioprotection of exercise against ISO-induced heart damage. Compared to those in EPI, our data showed that the increasing levels of myocardial fibrosis, the leukocyte infiltration of cardiac tissue and proteins expression of cardiac myocyte necrosis and pyroptosis signaling pathways in the EPII group.

SIGNIFICANCE

Our results demonstrated that exercise decreased leukocyte infiltration in heart, inhibited the cardiomyocyte pyroptosis and necroptosis signaling pathways, and attenuated inflammatory responses to alleviate ISO-induced cardiac fibrosis. However, the antifibrotic effects of combined treatment with exercise and ICOS mAb intervention did not exhibit synergistic enhancement.

Study on pyroptosis-related genes Casp8, Gsdmd and Trem2 in mice with cerebral infarction

Objective

Cerebral infarction is the main cause of death in patients with cerebrovascular diseases. Our research aimed to screen and validate pyroptosis-related genes in cerebral infarction for the targeted therapy of cerebral infarction.

Methods and results

A total of 1,517 differentially expressed genes (DEGs) were obtained by DESeq2 software analysis. Gene set enrichment analysis results indicated that genes of middle cerebral artery occlusion (MCAO) mice aged 3 months and 18 months were enriched in pyroptosis, respectively. Differentially expressed pyroptosis-related genes (including Aim2, Casp8, Gsdmd, Naip2, Naip5, Naip6 and Trem2) were obtained through intersection of DEGs and genes from pyroptosis Gene Ontology Term (GO:0070269), and they were up-regulated in the brain tissues of MCAO mice in GSE137482. In addition, Casp8, Gsdmd, and Trem2 were verified to be significantly up-regulated in MCAO mice in GSE93376. The evaluation of neurologic function and triphenyltetrazolium chloride staining showed that the MCAO mouse models were successfully constructed. Meanwhile, the expressions of TNF-α, pyroptosis-related proteins, Casp8, Gsdmd and Trem2 in MCAO mice were significantly up-regulated. We selected Trem2 for subsequent functional analysis. OGD treatment of BV2 cell in vitro significantly upregulated the expressions of Trem2. Subsequent downregulation of Trem2 expression in OGD-BV2 cells further increased the level of pyroptosis. Therefore, Trem2 is a protective factor regulating pyroptosis, thus influencing the progression of cerebral infarction.

Conclusions

Casp8, Gsdmd and Trem2 can regulate pyroptosis, thus affecting cerebral infarction.

Cuproptosis: Unraveling the Mechanisms of Copper-Induced Cell Death and Its Implication in Cancer Therapy

Copper, an essential element for various biological processes, demands precise regulation to avert detrimental health effects and potential cell toxicity. This paper explores the mechanisms of copper-induced cell death, known as cuproptosis, and its potential health and disease implications, including cancer therapy. Copper ionophores, such as elesclomol and disulfiram, increase intracellular copper levels. This elevation triggers oxidative stress and subsequent cell death, offering potential implications in cancer therapy. Additionally, copper ionophores disrupt mitochondrial respiration and protein lipoylation, further contributing to copper toxicity and cell death. Potential targets and biomarkers are identified, as copper can be targeted to those proteins to trigger cuproptosis. The role of copper in different cancers is discussed to understand targeted cancer therapies using copper nanomaterials, copper ionophores, and copper chelators. Furthermore, the role of copper is explored through diseases such as Wilson and Menkes disease to understand the physiological mechanisms of copper. Exploring cuproptosis presents an opportunity to improve treatments for copper-related disorders and various cancers, with the potential to bring significant advancements to modern medicine.

E2F1-mediated Up-regulation of NCAPG Promotes Hepatocellular Carcinoma Development by Inhibiting Pyroptosis

Background and Aims

As a subunit of the condensin complex, NCAPG has an important role in maintaining chromosome condensation, but its biological function and regulatory mechanism in hepatocellular carcinoma (HCC) remains undefined.

Methods

The prognostic ability of NCAPG in HCC patients was examined by univariate and multivariate Cox regression analysis. ROC curves were plotted to compare the predictive ability of NCAPG and AFP. Double luciferase reporter system, and ChIP were used to investigate transcriptional potential of E2F1 to NCAPG. Pyroptosis was observed by scanning electron microscopy. Protein expression of NCAPG, E2F1, and major proteins constituting NLRP3 inflammasome was determined by western blotting and ELISA. An in vivo tumor formation assay was conducted to verify the in vitro results.

Results

Up-regulated NCAPG was identified in HCC tissues compared with adjacent tissue and high NCAPG was positively correlated with poor prognosis. Serum NCAPG mRNA level was a prognostic factor in HCC patients and also a diagnostic factor with higher predictive ability compared with AFP [AUROC 0.766 (95% CI: 0.650-0.881) vs. 0.649 (95% CI 0.506-0.793)]. HBx transfection resulted in concomitant up-regulation of E2F1 and NCAPG. E2F1 significantly increased the activity of luciferase reporter fused with NCAPG reporter, and the interaction of E2F1 and NCAPG gene was confirmed by ChIP. Silencing of E2F1 resulted in significant down-regulation of NCAPG. Knockdown of NCAPG promote pyroptosis mediated by NLRP3 inflammasome activation in multiple HCC cell lines and also suppressed tumorigenesis in vitro.

Conclusions

We identified a novel role of NCAPG in the regulation of NLRP3 inflammasome-mediated pyroptosis, which was regulated by its upstream transactivator, E2F1. The role of E2F1-NCAPG-NLRP3 regulation of pyroptosis network may be a potential target in HCC treatment.

The Role of Pro-Inflammatory Cytokines in the Pathogenesis of Cardiovascular Disease

With cardiovascular disease (CVD) being a primary source of global morbidity and mortality, it is crucial that we understand the molecular pathophysiological mechanisms at play. Recently, numerous pro-inflammatory cytokines have been linked to several different CVDs, which are now often considered an adversely pro-inflammatory state. These cytokines most notably include interleukin-6 (IL-6),tumor necrosis factor (TNF)α, and the interleukin-1 (IL-1) family, amongst others. Not only does inflammation have intricate and complex interactions with pathophysiological processes such as oxidative stress and calcium mishandling, but it also plays a role in the balance between tissue repair and destruction. In this regard, pre-clinical and clinical evidence has clearly demonstrated the involvement and dynamic nature of pro-inflammatory cytokines in many heart conditions; however, the clinical utility of the findings so far remains unclear. Whether these cytokines can serve as markers or risk predictors of disease states or act as potential therapeutic targets, further extensive research is needed to fully understand the complex network of interactions that these molecules encompass in the context of heart disease. This review will highlight the significant advances in our understanding of the contributions of pro-inflammatory cytokines in CVDs, including ischemic heart disease (atherosclerosis, thrombosis, acute myocardial infarction, and ischemia-reperfusion injury), cardiac remodeling (hypertension, cardiac hypertrophy, cardiac fibrosis, cardiac apoptosis, and heart failure), different cardiomyopathies as well as ventricular arrhythmias and atrial fibrillation. In addition, this article is focused on discussing the shortcomings in both pathological and therapeutic aspects of pro-inflammatory cytokines in CVD that still need to be addressed by future studies.

Targeting HIF-1α alleviates the inflammatory responses and rebuilds the CD4+ T cell subsets balance in the experimental autoimmune myasthenia gravis inflammation model via regulating cellular and humoral immunity

BACKGROUND

Cells and tissues in an inflammatory state are usually hypoxic. The hypoxic environment can affect the differentiation of immune cells and produce Hypoxia-inducible Factor-1α (HIF-1α). Inflammation is also a major contributor to the development and deterioration of Myasthenia Gravis (MG). There are limited studies on the immunopathological mechanism and targeted therapy associated with MG exacerbated with inflammation. This research aimed to explore whether BAY 87-2243 (HIF-1α inhibitor) ameliorates the symptoms of the Experimental Autoimmune Myasthenia Gravis (EAMG) inflammation model and study its regulatory mechanism on cellular immunity and humoral immunity.

METHODS

We first establish the EAMG inflammation model using Lipopolysaccharide (LPS), BAY 87-2243 was applied to the EAMG inflammation model and its therapeutic effects were evaluated in vivo and in vitro experiments.

RESULTS

The proportion of Treg cells was increased whereas Th1, Th17, and Th1/17 cells were decreased in BAY 87-2243-treated EAMG inflammation model. BAY 87-2243 ameliorated the acetylcholine receptors (AChRs) loss and the complement deposited at the neuromuscular junction of the EAMG inflammation model, declined the levels of IFN-γ, IL-17, and IL-6 in serum, and further attenuated responses in the germinal center and reduced the antibody levels by inhibiting the IL-6-dependent STAT3 axis.

CONCLUSION

BAY 87-2243 restored the balance of CD4+T cell subsets and reduced the production of the pro-inflammatory cytokines, thus acting as both an immune imbalance regulator and anti-inflammatory. The current study suggests that HIF-1α might be a potential target for the treatment of MG exacerbated with inflammation.

Comprehensive viewpoints on heart rate variability at high altitude

OBJECTIVES

Hypoxia is a physiological state characterized by reduced oxygen levels in organs and tissues. It is a common clinicopathological process and a major cause of health problems in highland areas.  Heart rate variability (HRV) is a measure of the balance in autonomic innervation to the heart. It provides valuable information on the regulation of the cardiovascular system by neurohumoral factors, and changes in HRV reflect the complex interactions between multiple systems. In this review, we provide a comprehensive overview of the relationship between high-altitude hypoxia and HRV. We summarize the different mechanisms of diseases caused by hypoxia and explore the changes in HRV across various systems. Additionally, we discuss relevant pharmaceutical interventions. Overall, this review aims to provide research ideas and assistance for in-depth studies on HRV. By understanding the intricate relationship between high-altitude hypoxia and HRV, we can gain insights into the underlying mechanisms and potential therapeutic approaches to mitigate the effects of hypoxia on cardiovascular and other systems.

METHODS

The relevant literature was collected systematically from scientific database, including PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), Baidu Scholar, as well as other literature sources, such as classic books of hypoxia.

RESULTS

There is a close relationship between heart rate variability and high-altitude hypoxia. Heart rate variability is an indicator that evaluates the impact of hypoxia on the cardiovascular system and other related systems. By improving the observation of HRV, we can estimate the progress of cardiovascular diseases and predict the impact on other systems related to cardiovascular health. At the same time, changes in heart rate variability can be used to observe the efficacy of preventive drugs for altitude related diseases.

CONCLUSIONS

HRV can be used to assess autonomic nervous function under various systemic conditions, and can be used to predict and monitor diseases caused by hypoxia at high altitude. Investigating the correlation between high altitude hypoxia and heart rate variability can help make HRV more rapid, accurate, and effective for the diagnosis of plateau-related diseases.

The Effect of Sevoflurane and Fullerenol C 60 on the Liver and Kidney in Lower Extremity Ischemia-Reperfusion Injury in Mice with Streptozocin-Induced Diabetes

Objective

This study aimed to demonstrate whether fullerenol C60, sevoflurane anesthesia, or a combination of both had protective effects on the liver and kidneys in lower extremity ischemia-reperfusion injury (IRI) in mice with streptozocin-induced diabetes.

Methods

A total of 46 Swiss albino mice were divided into six groups as follows: control group (group C, n=7), diabetes group (group D, n=7), diabetes-ischemia/reperfusion (group DIR, n=8), diabetes-ischemia/reperfusion-fullerenol C60 (group DIR-FC60, n=8), diabetes-ischemia/reperfusion-sevoflurane (group DIR-S, n=8), and the diabetes-ischemia/reperfusion-fullerenol C60-sevoflurane (group DIR-S-FC60, n=8). Fullerenol C60 (100mg/kg) was administered intraperitoneally 30 min before the ischemia-reperfusion procedure to the fullerenol groups (DIR-FC60 and DIR-S-FC60). In the DIR groups, 2 hours (h) ischemia-2h reperfusion periods were performed. In the sevoflurane groups, sevoflurane was applied during the ischemia-reperfusion period with 100% O2. Liver and kidney tissues were removed at the end of the reperfusion procedure for biochemical and histopathological examinations.

Results

In liver tissue, hydropic degeneration, sinusoidal dilatation, pycnotic nuclei, prenecrotic cells, and mononuclear cell infiltration in parenchyma were significantly more frequent in group DIR than in groups D and group C. In terms of the histopathologic criteria examined, more positive results were seen in group DIR-FC60, and when group DIR-FC60 was compared with group DIR, the difference was significant. The best results in AST, ALT, glucose, TBARS levels, and SOD enzyme activities in liver tissue were in group DIR-FC60 compared with group DIR, followed by groups DIR-S-FC60 and DIR-S, respectively. Regarding TBARS levels and SOD enzyme activities in kidney tissue, the best results were in groups DIR-FC60, DIR-S-FC60, and DIR-S, respectively.

Conclusion

According to our findings, it is clear that fullerenol C60 administered intraperitoneally 30 min before ischemia, alone or together with sevoflurane, reduces oxidative stress in distant organ damage caused by lower extremity IRI, and reduces liver and kidney tissue damage in histopathologic examinations.

Huoxin Pill Reduces Myocardial Ischemia Reperfusion Injury in Rats via TLR4/NFκB/NLRP3 Signaling Pathway

OBJECTIVE

To explore the protective effect of Huoxin Pill (HXP) on acute myocardial ischemia-reperfusion (MIRI) injury in rats.

METHODS

Seventy-five adult SD rats were divided into the sham-operated group, model group, positive drug group (diltiazem hydrochloride, DH), high dose group (24 mg/kg, HXP-H) and low dose group (12 mg/kg, HXP-L) of Huoxin Pill (n=15 for every group) according to the complete randomization method. After 1 week of intragastric administration, the left anterior descending coronary artery of the rat's heart was ligated for 45 min and reperfused for 3 h. Serum was separated and the levels of creatine kinase (CK), creatine kinase isoenzyme (CK-MB) and lactate dehydrogenase (LDH), superoxide dismutase (SOD), and malondialdehyde (MDA), hypersensitive C-reactive protein (hs-CRP) and interleukin-1β (IL-1β) were measured. Myocardial ischemia rate, myocardial infarction rate and myocardial no-reflow rate were determined by staining with Evans blue and 2,3,5-triphenyltetrazolium chloride (TTC). Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) and Bioinformatics Analysis Tool for Molecular mechANism of Traditional Chinese Medicine (BATMAN) databases were used to screen for possible active compounds of HXP and their potential therapeutic targets; the results of anti-inflammatory genes associated with MIRI were obtained from GeneCards, Drugbank, Online Mendelian Inheritance in Man (OMIM), and Therapeutic Target Datebase (TTD) databases was performed; Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment were used to analyze the intersected targets; molecular docking was performed using AutoDock Tools. Western blot was used to detect the protein expression of Toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NFκB)/NOD-like receptor protein 3 (NLRP3).

RESULTS

Compared with the model group, all doses of HXP significantly reduced the levels of LDH, CK and CK-MB (P<0.05, P<0.01); HXP significantly increased serum activity of SOD (P<0.05, P<0.01); all doses of HXP significantly reduced the levels of hs-CRP and IL-1β (P<0.05, P<0.01) and the myocardial infarction rate and myocardial no-reflow rate (P<0.01). GO enrichment analysis mainly involved positive regulation of gene expression, extracellular space and identical protein binding, KEGG pathway enrichment mainly involved PI3K-Akt signaling pathway and lipid and atherosclerosis. Molecular docking results showed that kaempferol and luteolin had a better affinity with TLR4, NFκB and NLRP3 molecules. The protein expressions of TLR4, NFκB and NLRP3 were reduced in the HXP group (P<0.01).

CONCLUSIONS

HXP has a significant protective effect on myocardial ischemia-reperfusion injury in rats, and its effect may be related to the inhibition of redox response and reduction of the inflammatory response by inhibiting the TLR4NFκB/NLRP3 signaling pathway.

Exosomes derived from bone marrow mesenchymal stem cells regulate pyroptosis via the miR-143-3p/myeloid differentiation factor 88 axis to ameliorate intestinal ischemia-reperfusion injury

Intestinal ischemia-reperfusion (I/R) injury is a condition in which tissue injury is aggravated after ischemia due to recovery of blood supply. Bone marrow mesenchymal stem cell-derived exosome (BMSC-exo) showed a protective effect on I/R injury. This study aimed to investigate the possible mechanisms by which BMSC-exos ameliorate intestinal I/R injury. We isolated mouse BMSC-exos by super-centrifugation and found that they effectively increased cell viability in a cell model, alleviated intestinal barrier injury in a mouse model, and downregulated the expression of inflammatory cytokines and pyroptosis-related proteins, suggesting that BMSC-exos may alleviate intestinal I/R injury in vitro and in vivo by regulating pyroptosis. We identified miR-143-3p as a differentially expressed miRNA by microarray sequencing. Bioinformatic analysis predicted a binding site between miR-143-3p and myeloid differentiation factor 88 (MyD88); a dual-luciferase reporter assay confirmed that miR-143-3p could directly regulate the expression of MyD88. Our findings suggest that miR-143-3p regulates pyroptosis by regulating NOD-like receptor thermal protein domain associated protein 3 (NLRP3) through the toll-like receptor (TLR)-4/MyD88/nuclear factor kappa-B (NF-кB) pathway. This study describes a potential strategy for the treatment of intestinal I/R injury using BMSC-exos that act by regulating pyroptosis through the miR-143-3p mediated TLR4/MyD88/NF-кB pathway.

TAK1 Activation by NLRP3 Deficiency Confers Cardioprotection Against Pressure Overload-Induced Cardiomyocyte Pyroptosis and Hypertrophy

A comprehensive view of the role of NLRP3/caspase-1/GSDMD-mediated pyroptosis in pressure overload cardiac hypertrophy is presented in this study. Furthermore, mitigation of NLRP3 deficiency-induced pyroptosis confers cardioprotection against pressure overload through activation of TAK1, whereas this salutary effect is abolished by inhibition of TAK1 activity, highlighting a previously unrecognized reciprocally regulatory role of NLRP3-TAK1 governing inflammation-induced cell death and hypertrophic growth. Translationally, this study advocates strategies based on inflammation-induced cell death might be exploited therapeutically in other inflammatory and mechanical overload disorders, such as myocardial infarction and mitral regurgitation.

Advances in the mechanisms related to follicle loss after frozen-thawed ovarian tissue transplantation

Ovaries are important reproductive and endocrine organs in women. Ovarian tissue cryopreservation and transplantation technology can not only solve the fertility problems of patients, but also may improve female endocrine problems. This is particularly important for patients in urgent need of radiotherapy and chemotherapy, and for women with prepubertal malignant tumors. However, follicle loss after freeze-thawing is a key challenge for effective ovarian tissue transplantation and leads to poor transplant outcomes. Therefore, it is crucial to elucidate the mechanisms underlying follicle loss after transplantation. This paper reviews current research on the mechanisms of follicle loss after frozen-thawed ovarian tissue transplantation, including the activation, apoptosis, and pyroptosis mechanisms of primordialfollicles. Further, it highlights the requirement of more experimental studies for improving ovarian tissue transplantation methods.

Irisin suppresses pancreatic β cell pyroptosis in T2DM by inhibiting the NLRP3-GSDMD pathway and activating the Nrf2-TrX/TXNIP signaling axis

BACKGROUND

Irisin plays a key role in metabolic diseases, including type 2 diabetes mellitus (T2DM). However, the mechanism underlying the link between irisin and the development of T2DM, particularly in pancreatic islet β-cells, remains unknown.

METHODS

In vitro, Min6 cells were treated with high glucose (HG) to generate T2DM cell models. GSDMD-N staining, Western blotting assays, and ELISA were performed to measure the expression levels of GSDMD, caspase 1, IL-1β, and IL-18. Next, the NLRP3 stimulator, ATP, was used to assess the effect of irisin on NLRP3 inflammasome. To evaluate the function of the Nrf2-TrX/TXNIP signaling axis, the Nrf2 inhibitor ML385 was used. For in vivo assessment, we first established T2DM model mice. Then, hematoxylin and eosin (H&E) staining was performed to observe the islet morphology, and the immunofluorescence technique was used to examine the mass of α and β cells. To confirm the role of the Nrf2-TrX/TXNIP signaling axis, ML385 was injected into the mice. Immunofluorescence of Nrf2, caspase 1, and GSDMD was detected in the islet cells of the model mice to verify the results.

RESULTS

We found that irisin treatment significantly decreased the expression of GSDMD-N (P31) and cleaved caspase-1 (p20), decreased caspase1 activity, and inhibited the secretion of IL-1β and IL-18 in HG-treated Min6 cells. We also found that irisin inhibited oxidative stress and NLRP3 expression by activating the Nrf2-TrX/TXNIP signaling axis. Additionally, in the T2DM model mice, irisin enhanced the function of islet cells, decreased insulin resistance, and preserved the morphology of pancreatic islets.

CONCLUSION

We showed in this study that irisin can be used for treating pyroptosis in HG-induced islet β-cells and T2DM model mice. We also found that irisin inhibits pyroptosis and oxidative stress by inhibiting the NLRP3-GSDMD pathway and activating the Nrf2-TrX/TXNIP signaling axis.

Inhibiting Rev-erbα-mediated ferroptosis alleviates susceptibility to myocardial ischemia-reperfusion injury in type 2 diabetes

The complex progression of type-2 diabetes (T2DM) may result in increased susceptibility to myocardial ischemia-reperfusion (IR) injury. IR injuries in multiple organs involves ferroptosis. Recently, the clock gene Rev-erbα has aroused considerable interest as a novel therapeutic target for metabolic and ischemic heart diseases. Herein, we investigated the roles of Rev-erbα and ferroptosis in myocardial IR injury during T2DM and its potential mechanisms. A T2DM model, myocardial IR and a tissue-specific Rev-erbα-/- mouse in vivo were established, and a high-fat high glucose environment with hypoxia-reoxygenation (HFHG/HR) in H9c2 were also performed. After myocardial IR, glycolipid profiles, creatine kinase-MB, AI, and the expression of Rev-erbα and ferroptosis-related proteins were increased in diabetic rats with impaired cardiac function compared to non-diabetic rats, regardless of the time at which IR was induced. The ferroptosis inhibitor ferrostatin-1 decreased AI in diabetic rats given IR and LPO levels in cells treated with HFHG/HR, as well as the expression of Rev-erbα and ACSL4. The ferroptosis inducer erastin increased AI and LPO levels and ACSL4 expression. Treatment with the circadian regulator nobiletin and genetically targeting Rev-erbα via siRNA or CRISPR/Cas9 technology both protected against severe myocardial injury and decreased Rev-erbα and ACSL4 expression, compared to the respective controls. Taken together, these data suggest that ferroptosis is involved in the susceptibility to myocardial IR injury during T2DM, and that targeting Rev-erbα could alleviate myocardial IR injury by inhibiting ferroptosis.

Dexmedetomidine against intestinal ischemia/reperfusion injury: A systematic review and meta-analysis of preclinical studies

BACKGROUND

Intestinal ischemia/reperfusion injury (IRI) is a multifactorial, complex pathophysiological process in clinical settings. In recent years, intestinal IRI has received increasing attention due to increased morbidity and mortality. To date, there are no effective treatments. Dexmedetomidine (DEX), a highly selective α2-adrenergic receptor agonist, has been demonstrated to be effective against intestinal IRI. In this systematic review and meta-analysis, we evaluated the efficacy and potential mechanisms of DEX as a treatment for intestinal IRI in animal models.

METHODS

Five databases (PubMed, Embase, Web of Science, Cochrane Library, and Scopus) were searched until March 15, 2023. Using the SYRCLE risk bias tool, we assessed methodological quality. Statistical analysis was conducted using STATA 12 and R 4.2.2. We analyzed the related outcomes (mucosa damage-related indicators; inflammation-relevant markers, oxidative stress markers) relied on the fixed or random-effects models.

RESULTS

There were 15 articles including 18 studies included, and 309 animals were involved in the studies. Compared to the model groups, DEX improved intestinal IRI. DEX decreased Chiu's score and serum diamine oxidase (DAO) level. DEX reduced the level of inflammation-relevant markers (interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α). DEX also improved oxidative stress (decreased malondialdehyde (MDA), increased superoxide dismutase (SOD)).

CONCLUSIONS

DEX's effectiveness in ameliorating intestinal IRI has been demonstrated in animal models. Antioxidation, anti-inflammation, anti-apoptotic, anti-pyroptosis, anti-ferroptosis, enhancing mitophagy, reshaping the gut microbiota, and gut barrier protection are possible mechanisms. However, in light of the heterogeneity and methodological quality of these studies, further well-designed preclinical studies are warranted before clinical implication.

Inhibition of Caspase-1-mediated pyroptosis promotes osteogenic differentiation, offering a therapeutic target for osteoporosis

BACKGROUND

Pyroptosis, an emerging inflammatory form of cell death, has been previously demonstrated to stimulate a massive inflammatory response, thus hindering the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). Nevertheless, the impact of pyroptosis in thwarting osteogenic differentiation and exacerbating the advancement of osteoporosis (OP) remains enigmatic.

METHODS

We evaluated the expression levels of pyroptosis-associated indicators, including NOD-like receptor family pyrin domain-containing protein 3 (NLRP3), CASPASE-1, IL-1β, and IL-18, in specimens obtained from femoral heads of OP patients, as well as in an ovariectomy-induced mouse model of OP. Subsequently, the precise roles of pyroptosis in osteogenic differentiation were investigated using bioinformatics analysis, alongside morphological and biochemical assessments.

RESULTS

The pivotal pyroptotic proteins, including NLRP3, Caspase-1, IL-1β, and IL-18, exhibited significant upregulation within the bone tissue samples of clinical OP cases, as well as in the femoral tissues of ovariectomy (OVX)-induced mouse OP model, displaying a negatively associated with compromised osteogenic capacity, as represented by lessened bone mass, suppressed expression of osteogenic proteins such as Runt-related transcription factor 2 (RUNX2), Alkaline phosphatase (ALP), Osterix (OSX), and Osteopontin (OPN), and increased lipid droplets. Moreover, bioinformatics analysis substantiated shared gene expression patterns between pyroptosis and OP pathology, encompassing NLRP3, Caspase-1, IL-1β, IL-18, etc. Furthermore, our in vitro investigation using ST2 cells revealed that dexamethasone treatment prominently induced pyroptosis while impeding osteogenic differentiation. Notably, gene silencing of Caspase-1 effectively counteracted the inhibitory effects of dexamethasone on osteogenic differentiation, as manifested by increased ALP activity and enhanced expression of RUNX2, ALP, OSX, and OPN.

CONCLUSION

Our findings unequivocally underscore that inhibition of Caspase-1-mediated pyroptosis promotes osteogenic differentiation, providing a promising therapeutic target for managing OP.

Loganin alleviates myocardial ischemia-reperfusion injury through GLP-1R/NLRP3-mediated pyroptosis pathway

Myocardial ischemia-reperfusion (I/R) injury is one of main pathological manifestations of cardiovascular outcomes related to NLRP3 inflammasome-mediated pyroptosis pathway. Loganin is an iridoid glycoside extracted from traditional Chinese medicines, which has multiple activities. However, the roles and mechanism of loganin in myocardial I/R injury remain largely unknown. The models of myocardial I/R injury were established using I/R-treated rats or OGD/R-treated H9C2 cardiomyocytes. Myocardial damage was assessed by TTC and hematoxylin-eosin staining. Pyroptosis-related marker levels were detected by immunohistochemistry, immunofluorescence and western blotting assays. Cell proliferation was examined via EdU assay. Cell apoptosis was investigated by LDH release and flow cytometry. The integrity of cell membrane was analyzed via Dil staining. GLP-1R and NLRP3 levels were detected by immunofluorescence and western blotting assays. Our results showed that loganin suppressed I/R-induced myocardial damage in rats by reducing myocardial infarct, injury and pyroptosis. In addition, loganin attenuated OGD/R-induced cardiomyocyte apoptosis through increasing cell proliferation and reducing LDH release and apoptotic rate. Loganin also mitigated OGD/R-induced cardiomyocyte pyroptosis by reducing cell membrane damage and levels of cleaved caspase-1, IL-1β and IL-18. Furthermore, loganin repressed GLP-1R/NLRP3 pathway activation in OGD/R-treated H9C2 cardiomyocytes by enhancing GLP-1R expression and decreasing NLRP3 level. GLP-1R/NLRP3 activation by GLP-1R inhibition or NLRP3 overexpression reversed the suppressive effects of loganin on OGD/R-induced cardiomyocyte pyroptosis. These data indicated that loganin prevented OGD/R-induced proliferation inhibition, apoptosis and pyroptosis in OGD/R-treated cardiomyocytes by inhibiting GLP-1R/NLRP3 activity, indicating the therapeutic potential of loganin in myocardial I/R injury.

Astragaloside IV restrains pyroptosis and fibrotic development of pulmonary artery smooth muscle cells to ameliorate pulmonary artery hypertension through the PHD2/HIF1α signaling pathway

BACKGROUND

Astragaloside (AS)-IV, extracted from traditional Chinese medicine Astragalus mongholicus, has been widely used in the anti-inflammatory treatment for cardiovascular disease. However, the mechanism by which AS-IV affects pulmonary artery hypertension (PAH) development remains largely unknown.

METHODS

Monocrotaline (MCT)-induced PAH model rats were administered with AS-IV, and hematoxylin-eosin staining and Masson staining were performed to evaluate the histological change in pulmonary tissues of rats. Pulmonary artery smooth muscle cells (PASMCs) were treated by hypoxia and AS-IV. Pyroptosis and fibrosis were assessed by immunofluorescence, western blot and enzyme-linked immunosorbent assay.

RESULTS

AS-IV treatment alleviated pulmonary artery structural remodeling and pulmonary hypertension progression induced by MCT in rats. AS-IV suppressed the expression of pyroptosis-related markers, the release of pro-inflammatory cytokine interleukin (IL)-1β and IL-18 and fibrosis development in pulmonary tissues of PAH rats and in hypoxic PAMSCs. Interestingly, the expression of prolyl-4-hydroxylase 2 (PHD2) was restored by AS-IV administration in PAH model in vivo and in vitro, while hypoxia inducible factor 1α (HIF1α) was restrained by AS-IV. Mechanistically, silencing PHD2 reversed the inhibitory effect of AS-IV on pyroptosis, fibrosis trend and pyroptotic necrosis in hypoxia-cultured PASMCs, while the HIF1α inhibitor could prevent these PAH-like phenomena.

CONCLUSION

Collectively, AS-IV elevates PHD2 expression to alleviate pyroptosis and fibrosis development during PAH through downregulating HIF1α. These findings may provide a better understanding of AS-IV preventing PAH, and the PHD2/HIF1α axis may be a potential anti-pyroptosis target during PAH.

Polydatin improves vascular endothelial function by maintaining mitochondrial homeostasis under high glucose conditions

Previous studies have shown that polydatin (Poly) confer cardioprotective effects. However, its underlying mechanisms remain elusive. This study showed that Poly (10 µM) treatment reversed the high glucose (HG)-induced decrease in acetylcholine-elicited vasodilation in aortas. Poly also improved the acetylcholine-induced vasodilation of aortic vessels isolated from diabetic rats. Meanwhile, Poly ameliorated the morphological damage of the thoracic aorta and improved the viability of HUVECs under HG conditions. Furthermore, analysis of the vasoprotective effect of Poly under HG conditions by transmission electron microscopy, Western blotting, and qPCR revealed that Poly improved endothelial pyroptosis through the NLRP3/Caspase/1-IL-1β pathway, enhanced dynamin-related protein 1-mediated mitochondrial fission, and increased the mitochondrial membrane potential under HG conditions. In conclusion, Poly restored acetylcholine-induced vasodilation impaired by HG incubation, which was associated with reduced oxidation, inflammation, and pyroptosis, the recovery of the mitochondrial membrane potential and maintenance of mitochondrial dynamic homeostasis of endothelial cells in the aortas.

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.