Possible protective effect of resolvin D1 on inflammation in atrial fibrillation: involvement of ER stress mediated the NLRP3 inflammasome pathway

GTS-21 alleviates sepsis-induced atrial fibrillation susceptibility by modulating macrophage polarization and Neuregulin-1 secretion

OBJECTIVE

Sepsis-induced atrial fibrillation (AF) is driven by systemic inflammation and macrophage-mediated atrial remodeling, with proinflammatory M1 macrophages playing a key role. This study investigates whether GTS-21, an α7nAChR agonist, can reduce AF susceptibility by promoting macrophage polarization towards the anti-inflammatory M2 phenotype.

METHODS

A mouse model of lipopolysaccharide (LPS) (10 mg/kg)-induced sepsis was used to explore the relationship between atrial inflammation and AF. GTS-21 (20 mg/kg) was administered to assess its impact on 48-h survival and AF incidence. Cardiac function was evaluated using echocardiography. Markers of myocardial injury, including CK-MB, LDH, and cTnI, were measured. Macrophage polarization and atrial inflammation were assessed using immunofluorescence, flow cytometry, RT-qPCR, and western blotting. Oxidative stress and mitochondrial function were evaluated using reactive oxygen species (ROS) measurements, electron microscopy, and mitochondrial protein expression analysis. Calcium dynamics were studied using western blotting and confocal microscopy.

RESULTS

In LPS-induced septic mice, GTS-21 improved 48-h survival rates and reduced the induction rate and duration of AF (P < 0.05). Echocardiography showed a preserved left ventricular ejection fraction and enhanced diastolic function. Mechanistically, it promoted M2 macrophage polarization, inhibited the NF-κB P65/NLRP3/C-caspase 1 pathway to reduce IL-1β release, and alleviated oxidative stress. Additionally, mitochondrial structure was restored by reversing fission and promoting fusion, while calcium-handling proteins (NCX-1, RYR2, and SERCA2a) were regulated to prevent intracellular calcium overload, reducing AF susceptibility.

CONCLUSION

GTS-21 mitigated atrial inflammation and reduced the incidence of AF in mice with sepsis by regulating macrophage polarization, reducing oxidative stress, and preserving mitochondrial and calcium dynamics in cardiomyocytes. These findings highlight the therapeutic potential of GTS-21 in treating sepsis-induced AF.

A short history of the atrial NLRP3 inflammasome and its distinct role in atrial fibrillation

Inflammasomes are multiprotein complexes of the innate immune system that mediate inflammatory responses to infection and to local and systemic stress and tissue injury. The principal function is to facilitate caspase-1 auto-activation and subsequently maturation and release of the effectors interleukin (IL)-1β and IL-18. The atrial-specific NLRP3 inflammasome is a unifying causal feature of atrial fibrillation (AF) development, progression and recurrence after ablation. Many AF-associated risk factors and co-morbidities converge mechanistically on the activation of this central inflammatory signaling platform. This review presents the historical conceptual development of a distinct atrial inflammasome and its potential causal involvement in AF. We follow the early observations linking systemic and local inflammation with AF, to the emergence of an atrial-intrinsic NLRP3 inflammasome operating within not just immune cells but also in resident atrial fibroblasts and cardiomyocytes. We outline the key developments in understanding how the atrial NLRP3 inflammasome and its effector IL-1β contribute causally to cellular and tissue-level arrhythmogenesis in different pathological settings, and outline candidate therapeutic concepts verified in preclinical models of atrial cardiomyopathy and AF.

17(R)-Resolvin D1 protects against sickle cell-related inflammatory cardiomyopathy in humanized mice

ABSTRACT

Cardiovascular disease has been recognized as the main cause of death in adults with sickle cell disease (SCD). Although the exact mechanism linking SCD to cardiomyopathy remains elusive, a possible role of subclinical acute transient myocardial ischemia during acute sickle cell-related vaso-occlusive crises (VOCs) has been suggested. We approached SCD cardiomyopathy by integrated omics using humanized SS mice exposed to hypoxia/reoxygenation (H/R; 10 hours hypoxia followed by 3 hours reoxygenation) stress, mimicking acute VOCs. In sickle cell (SS) mice exposed to H/R, a neutrophil-driven cardiac hypertrophic response is initiated by cardiac proinflammatory pathways, intersecting proteins and micro RNA involved in profibrotic signaling. This response may be facilitated by local unresolved inflammation. We then examined the effect of 17(R)-resolvin D1 (17R-RvD1), a member of the specialized proresolving lipid mediator superfamily, administration on H/R-activated profibrotic and proangiogenic pathways. In SS mice, we found that 17R-RvD1 (1) modulates miRNAome; (2) prevents the activation of NF-κB p65; (3) protects against the H/R-induced activation of both platelet derived growth factor receptor and transforming growth factor (TGF)-β1/Smad2-3 canonical pathways; (4) reduces the expression of hypoxia-inducible factor-dependent proangiogenic signaling; and (5) decreases the H/R-induced proapoptotic cell signature. The protective role of 17R-RvD1 against H/R-induced maladaptive heart remodeling was supported by the reduction of galectin-3, procollagen C-proteinase enhancer-1, and endothelin-1 expression and perivascular fibrosis in SS mice at 3 days after H/R stress compared with vehicle-treated SS animals. Collectively, our data support the novel role of unresolved inflammation in pathologic heart remodeling in SCD mice in response to H/R stress. Our study provides new evidence for protective effects of 17R-RvD1 against SCD-related cardiovascular disease.

ANXA1-FPR2 axis mitigates the susceptibility to atrial fibrillation in obesity via rescuing AMPK activity in response to lipid overload

Atrial fibrillation (AF) is the most prevalent arrhythmia in clinical practice, and obesity serves as a significant risk factor for its development. The underlying mechanisms of obesity-related AF remain intricate and have yet to be fully elucidated. We have identified FPR2 as a potential hub gene involved in obesity-related AF through comprehensive analysis of four transcriptome datasets from AF patients and one transcriptome dataset from obese individuals, and its expression is up-regulated in both AF and obese individuals. Interestingly, ANXA1, the endogenous ligand of FPR2, was found to exhibit differential expression with AF and obesity. Specifically, it was observed to be down-regulated in AF patients but up-regulated in obese individuals. The susceptibility to AF in obese mice induced by high-fat diet (HFD) was increased following with the FPR2 blocker Boc-2.The administration of exogenous ANXA1 active peptide chain Ac2-26 can mitigate the susceptibility to AF in obese mice by attenuating atrial fibrosis, lipid deposition, oxidative stress injury, and myocardial cell apoptosis. However, this protective effect against AF susceptibility is reversed by AAV9-shAMPK-mediated AMPK specific knockdown in the myocardium. The vitro experiments demonstrated that silencing ANXA1 exacerbated lipid deposition, oxidative stress injury, and apoptosis induced by palmitic acid (PA) in cardiomyocytes. Additionally, Ac2-26 effectively mitigated myocardial lipid deposition, oxidative stress injury, and apoptosis induced by PA. These effects were impeded by FPR2 inhibitors Boc-2 and WRW4. The main mechanism involves the activation of AMPK by ANXA1 through FPR2 in order to enhance fatty acid oxidation in cardiomyocytes, thereby ultimately leading to a reduction in lipid accumulation and associated lipotoxicity. Our findings demonstrate that the ANXA1-FPR2 axis plays a protective role in obesity-associated AF by alleviating metabolic stress in the atria of obese mice, thereby emphasizing its potential as a promising therapeutic target for AF.

Serum and glucocorticoid-regulated kinase 1 (SGK1) as an emerging therapeutic target for cardiac diseases

Cardiac diseases encompass a wide range of conditions that affect the structure and function of the heart. These conditions are a leading cause of morbidity and mortality worldwide. The serum- and glucocorticoid-inducible kinase 1 (SGK1) is a serine/threonine kinase that plays a significant role in various cellular processes, including cell survival and stress response. Alterations in SGK1 activity can have significant impacts on health and disease. Multiple research findings have indicated that SGK1 is associated with heart disease due to its involvement in cardiac hypertrophy and fibrosis. This article reviews different signaling pathways associated with SGK1 activity in various heart conditions, including the SGK1/NF-κB and PI3K/SGK1 pathways.

Emerging insights into the role of NLRP3 inflammasome and endoplasmic reticulum stress in renal diseases

NLRP3 inflammasome is a key component of the innate immune system, mediating the activation of caspase-1, and the maturity and secretion of the pro-inflammatory cytokine interleukin (IL)-1beta (IL-1β) and IL-18 to cope with microbial infections and cell injury. The NLRP3 inflammasome is activated by various endogenous danger signals, microorganisms and environmental stimuli, including urate, extracellular adenosine triphosphate (ATP) and cholesterol crystals. Increasing evidence indicates that the abnormal activation of NLRP3 is involved in multiple diseases including renal diseases. Hence, clarifying the mechanism of action of NLRP3 inflammasome in different diseases can help prevent and treat various diseases. Endoplasmic reticulum (ER) is an important organelle which participates in cell homeostasis maintenance and protein quality control. The unfolded protein response (UPR) and ER stress are caused by the excessive accumulation of unfolded or misfolded proteins in ER to recover ER homeostasis. Many factors can cause ER stress, including inflammation, hypoxia, environmental toxins, viral infections, glucose deficiency, changes in Ca2+ level and oxidative stress. The dysfunction of ER stress participates in multiple diseases, such as renal diseases. Many previous studies have shown that NLRP3 inflammasome and ER stress play an important role in renal diseases. However, the relevant mechanisms are not yet fully clear. Herein, we focus on the current understanding of the role and mechanism of ER stress and NLRP3 inflammasome in renal diseases, hoping to provide theoretical references for future related researches.

C-Phycocyanin Prevents Oxidative Stress, Inflammation, and Lung Remodeling in an Ovalbumin-Induced Rat Asthma Model

Asthma is a chronic immunological disease related to oxidative stress and chronic inflammation; both processes promote airway remodeling with collagen deposition and matrix thickening, causing pulmonary damage and lost function. This study investigates the immunomodulation of C-phycocyanin (CPC), a natural blue pigment purified from cyanobacteria, as a potential alternative treatment to prevent the remodeling process against asthma. We conducted experiments using ovalbumin (OVA) to induce asthma in Sprague Dawley rats. Animals were divided into five groups: (1) sham + vehicle, (2) sham + CPC, (3) asthma + vehicle, (4) asthma + CPC, and (5) asthma + methylprednisolone (MP). Our findings reveal that asthma promotes hypoxemia, leukocytosis, and pulmonary myeloperoxidase (MPO) activity by increasing lipid peroxidation, reactive oxygen and nitrogen species, inflammation associated with Th2 response, and airway remodeling in the lungs. CPC and MP treatment partially prevented these physiological processes with similar action on the biomarkers evaluated. In conclusion, CPC treatment enhanced the antioxidant defense system, thereby preventing oxidative stress and reducing airway inflammation by regulating pro-inflammatory and anti-inflammatory cytokines, consequently avoiding asthma-induced airway remodeling.

The relationship between atrial fibrillation and NLRP3 inflammasome: a gut microbiota perspective

Atrial fibrillation (AF) is a common clinical arrhythmia whose pathogenesis has not been fully elucidated, and the inflammatory response plays an important role in the development of AF. The inflammasome is an important component of innate immunity and is involved in a variety of pathophysiologic processes. The NLRP3 inflammasome is by far the best studied and validated inflammasome that recognizes multiple pathogens through pattern recognition receptors of innate immunity and mediates inflammatory responses through activation of Caspase-1. Several studies have shown that NLRP3 inflammasome activation contributes to the onset and development of AF. Ecological dysregulation of the gut microbiota has been associated with the development of AF, and some evidence suggests that gut microbiota components, functional byproducts, or metabolites may induce or exacerbate the development of AF by directly or indirectly modulating the NLRP3 inflammasome. In this review, we report on the interconnection of NLRP3 inflammasomes and gut microbiota and whether this association is related to the onset and persistence of AF. We discuss the potential value of pharmacological and dietary induction in the management of AF in the context of the association between the NLRP3 inflammasome and gut microbiota. It is hoped that this review will lead to new therapeutic targets for the future management of AF.

Resolvin D1 Attenuates Inflammation and Pelvic Pain Associated with EAP by Inhibiting Oxidative Stress and NLRP3 Inflammasome Activation via the Nrf2/HO-1 Pathway

Background

Resolvin D1 (RvD1), a member of the specialized pro-resolving lipid mediators family, has a potent anti-inflammatory effect and alleviates tissue damage. The purpose of the current research was to study the effect of RvD1 on CP/CPPS and the underlying mechanisms using a mouse model of experimental autoimmune prostatitis (EAP) mice.

Materials and Methods

The EAP mouse model was successfully established, and was used to test the therapeutic effect of RvD1. Hematoxylin-eosin staining and dihydroethidium staining were used to evaluate the histological changes and oxidative stress levels of prostate tissues. Chronic pelvic pain was assessed by applying von Frey filaments to the lower abdomen. The superoxide dismutase enzyme and malondialdehyde levels were detected using enzyme-linked immunosorbent assay (ELISA). The levels of inflammation-related cytokines, including IL-1β, IL-6, and TNF-α were detected by ELISA.

Results

RvD1 treatment ameliorated prostatic inflammation and the pelvic pain of EAP mice. RvD1 treatment could inhibit activation of the NLRP3 inflammasome and oxidative stress. RvD1 treatment could activate Nrf2/HO-1 signaling in mice with EAP. Blockade of Nrf2/HO-1 signaling abolished the RvD1-mediated inhibition of oxidative stress, NLRP3 inflammasome activation and the anti-inflammatory effect of RvD1 in EAP.

Conclusion

RvD1 treatment can reduce inflammatory cell infiltration in prostate tissue and attenuate pelvic pain associated with EAP by inhibiting oxidative stress and NLRP3 inflammasome activation via the Nrf2/HO-1 pathway. These results provide new insights that RvD1 has the potential as an effective agent in the treatment of EAP.

Atrial Fibrillation and Diabetes Mellitus: Dangerous Liaisons or Innocent Bystanders?

Atrial fibrillation (AF) is the most common arrhythmia in adults and diabetes mellitus (DM) is a major risk factor for cardiovascular diseases. However, the relationship between both pathologies has not been fully documented and new evidence supports the existence of direct and independent links. In the myocardium, a combination of structural, electrical, and autonomic remodeling may lead to AF. Importantly, patients with AF and DM showed more dramatic alterations than those with AF or DM alone, particularly in mitochondrial respiration and atrial remodeling, which alters conductivity, thrombogenesis, and contractile function. In AF and DM, elevations of cytosolic Ca²⁺ and accumulation of extra cellular matrix (ECM) proteins at the interstitium can promote delayed afterdepolarizations. The DM-associated low-grade inflammation and deposition/infiltration of epicardial adipose tissue (EAT) enforce abnormalities in Ca²⁺ handling and in excitation-contraction coupling, leading to atrial myopathy. This atrial enlargement and the reduction in passive emptying volume and fraction can be key for AF maintenance and re-entry. Moreover, the stored EAT can prolong action of potential durations and progression from paroxysmal to persistent AF. In this way, DM may increase the risk of thrombogenesis as a consequence of increased glycation and oxidation of fibrinogen and plasminogen, impairing plasmin conversion and resistance to fibrinolysis. Additionally, the DM-associated autonomic remodeling may also initiate AF and its re-entry. Finally, further evidence of DM influence on AF development and maintenance are based on the anti-arrhythmogenic effects of certain anti-diabetic drugs like SGLT2 inhibitors. Therefore, AF and DM may share molecular alterations related to Ca²⁺ mobility, mitochondrial function and ECM composition that induce atrial remodeling and defects in autonomic stimulation and conductivity. Likely, some specific therapies could work against the associated cardiac damage to AF and/or DM.

Pretreatment of the ROS Inhibitor Phenyl-N-tert-butylnitrone Alleviates Sleep Deprivation-Induced Hyperalgesia by Suppressing Microglia Activation and NLRP3 Inflammasome Activity in the Spinal Dorsal Cord

Sleep deprivation, a common perioperative period health problem, causes ocular discomfort and affects postsurgical pain. However, the mechanism of sleep deprivation-induced increased pain sensitivity is elusive. This study aims to explore the role of ROS in sleep deprivation (SD)-induced hyperalgesia and the underlying mechanism. A 48-h continuous SD was performed prior to the hind paw incision pain modeling in mice. We measured ROS levels, microglial activation, DNA damage and protein levels of iNOS, NLRP3, p-P65 and P65 in mouse spinal dorsal cord. The involvement of ROS in SD-induced prolongation of postsurgical pain was further confirmed by intrathecal injection of ROS inhibitor, phenyl-N-tert-butylnitrone (PBN). Pretreatment of 48-h SD in mice significantly prolonged postsurgical pain recovery, manifesting as lowered paw withdrawal mechanical threshold and paw withdrawal thermal latency. It caused ROS increase and upregulation of iNOS on both Day 1 and 7 in mouse spinal dorsal cord. In addition, upregulation of NLRP3 and p-P65, microglial activation and DNA damage were observed in mice pretreated with 48-h SD prior to the incision. Notably, intrathecal injection of PBN significantly reversed the harmful effects of SD on postsurgical pain recovery, hyperalgesia, microglial activation and DNA damage via the NF-κB signaling pathway. Collectively, ROS increase is responsible for SD-induced hyperalgesia through activating microglial, triggering DNA damage and enhancing NLRP3 inflammasome activity in the spinal dorsal cord.

Protective effect of berberine against LPS-induced injury in the intestine: a review

Sepsis is a systemic inflammatory condition caused by an unbalanced immunological response to infection, which affects numerous organs, including the intestines. Lipopolysaccharide (LPS; also known as endotoxin), a substance found in Gram-negative bacteria, plays a major role in sepsis and is mostly responsible for the disease's morbidity and mortality. Berberine is an isoquinoline alkaloid found in a variety of plant species that has anti-inflammatory properties. For many years, berberine has been used to treat intestinal inflammation and infection. Berberine has been reported to reduce LPS-induced intestinal damage. The potential pathways through which berberine protects against LPS-induced intestinal damage by inhibiting NF-κB, suppressing MAPK, modulating ApoM/S1P pathway, inhibiting COX-2, modulating Wnt/Beta-Catenin signaling pathway, and/or increasing ZIP14 expression are reviewed.Abbreviations: LPS, lipopolysaccharide; TLR, Toll-like receptor; MD-2, myeloid differentiation factor 2; CD14, cluster of differentiation 14; LBP, lipopolysaccharide-binding protein; MYD88, myeloid differentiation primary response 88; NF-κB, nuclear factor kappa light-chain enhancer of activated B cells; MAPK, mitogen-activated protein kinase; IL, interleukin; TNFα, tumor necrosis factor-alpha; Caco-2, cyanocobalamin uptake by human colon adenocarcinoma cell line; MLCK, myosin light-chain kinase; TJ, tight junction; IκBα, nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha; IBS, irritable bowel syndrome; ERK, extracellular signal-regulated kinase; JNK, c-Jun N-terminal kinase (JNK; GVB, gut-vascular barrier; ApoM, apolipoprotein M; S1P, sphingosine-1-phosphate; VE-cadherin, vascular endothelial cadherin; AJ, adherens junction; PV1, plasmalemma vesicle-associated protein-1; HDL, high-density lipoprotein; Wnt, wingless-related integration site; Fzd, 7-span transmembrane protein Frizzled; LRP, low-density lipoprotein receptor-related protein; TEER, transendothelial/transepithelial electrical resistance; COX-2, cyclooxygenase-2; iNOS, inducible nitric oxide synthase; IGF, insulin-like growth factor; IGFBP, insulin-like growth factor-binding protein; ZIP, Zrt-Irt-like protein; PPAR, peroxisome proliferator-activated receptors; p-PPAR, phosphorylated-peroxisome proliferator-activated receptors; ATF, activating transcription factors; SOD, superoxide dismutase; GSH-Px, glutathione peroxidase; SARA, subacute ruminal acidosis; IPEC-J2, porcine intestinal epithelial cells; ALI, acute lung injury; ARDS, acute respiratory distress syndrome.

Sorting nexins as a promising therapeutic target for cardiovascular disorders: An updated overview

Sorting nexins (SNXs) are involved in sorting the protein cargo within the endolysosomal system. Recently, several studies have shown the role of SNXs in cardiovascular pathology. SNXs exert both physiologic and pathologic functions in the cardiovascular system by regulating protein sorting and trafficking, maintaining protein homeostasis, and participating in multiple signaling pathways. SNX deficiency results in blood pressure response to dopamine 5 receptor [D5R] stimulation. SNX knockout protected against atherosclerosis lesions by suppressing foam cell formation. Moreover, SNXs can act as endogenous anti-arrhythmic agents via maintenance of calcium homeostasis. Overexpression SNXs also can reduce cardiac fibrosis in atrial fibrillation. The SNX-STAT3 interaction in cardiac cells promoted heart failure. SNXs may have the potential to act as a pharmacological target against specific cardiovascular diseases.

NF-κB and its crosstalk with endoplasmic reticulum stress in atherosclerosis

Atherosclerosis (AS) is a common cardiovascular disease with complex pathogenesis, in which multiple pathways and their interweaving regulatory mechanism remain unclear. The primary transcription factor NF-κB plays a critical role in AS via modulating the expression of a series of inflammatory mediators under various stimuli such as cytokines, microbial antigens, and intracellular stresses. Endoplasmic reticulum (ER) stress, caused by the disrupted synthesis and secretion of protein, links inflammation, metabolic signals, and other cellular processes via the unfolded protein response (UPR). Both NF-κB and ER stress share the intersection regarding their molecular regulation and function and are regarded as critical individual contributors to AS. In this review, we summarize the multiple interactions between NF-κB and ER stress activation, including the UPR, NLRP3 inflammasome, and reactive oxygen species (ROS) generation, which have been ignored in the pathogenesis of AS. Given the multiple links between NF-κB and ER stress, we speculate that the integrated network contributes to the understanding of molecular mechanisms of AS. This review aims to provide an insight into these interactions and their underlying roles in the progression of AS, highlighting potential pharmacological targets against the atherosclerotic inflammatory process.

Resolution-promoting autacoids demonstrate promising cardioprotective effects against heart diseases

Chronic heart diseases have in common an unresolved inflammatory status. In atherosclerosis, myocarditis, myocardial infarction, or atrial fibrillation, mounting evidence suggests that unresolved inflammation contributes to the chronicity, aggravation, and morbidity of the disease. Following cardiac injury or infection, acute inflammation is a normal and required process to repair damaged tissues or eliminate pathogens and promote restoration of normal functions and structures. However, if acute inflammation is not followed by resolution, a chronic and deleterious inflammatory status may occur, characterized by the persistence of inflammatory biomarkers, promoting aggravation of myocardial pathogenesis, abnormal structural remodeling, development of cardiac fibrosis, and loss of function. Although traditional antiinflammatory strategies, including the use of COX-inhibitors, to inhibit the production of inflammation promotors failed to promote homeostasis, mounting evidence suggests that activation of specific endogenous autacoids may promote resolution and perpetuate cardioprotective effects. The recent discovery of the active mechanism of resolution suggests that proresolving signals and cellular processes may help to terminate inflammation and combat the development of its chronic profile in cardiac diseases. This review discussed (I) the preclinical and clinical evidence of inflammation-resolution in cardiac disorders including atrial fibrillation; (II) how and why many traditional antiinflammatory treatments failed to prevent or cure cardiac inflammation and fibrosis; and (III) whether new therapeutic strategies may interact with the resolution machinery to have cardioprotective effects. RvD D-series resolving, RvE E-series resolving, LXA4 lipoxin A4, MaR1 maresin-1.

Circulating Galectin-3 and Aldosterone for Predicting Atrial Fibrillation Recurrence after Radiofrequency Catheter Ablation

Background

Circulating galectin-3 (Gal-3) and aldosterone (ALD) are involved in fibrosis and inflammation. However, their potential value as predictors of atrial fibrillation (AF) recurrence after radiofrequency catheter ablation (RFCA) is unknown or controversial. Therefore, the aim of this study was to assess the relationship between baseline Gal-3, ALD levels, and AF recurrence in patients performing RFCA.

Methods

153 consecutive patients undergoing RFCA were included. Gal-3 and ALD were measured at baseline. Univariate and multivariate Cox regressions were performed to determine the predictors of AF recurrence. Receiver operating characteristic (ROC) curve and Kaplan-Meier (K-M) curve were used to assess the value of predictors.

Results

There were 35 (22.88%) cases of AF recurrence after RFCA. The recurrence group had significantly higher preoperative serum levels of Gal-3 and ALD than the nonrecurrence group. Univariate and multivariate analysis showed that Gal-3 (HR = 1.28, 95% CI: 1.04-1.56, p = 0.02) and ALD (OR = 1.02, 95% CI: 1.00-1.03, p < 0.03) were significantly associated with AF recurrence after RFCA. The area under the curve (AUC) of preoperative serum Gal-3, ALD, and 2 combined to predict the recurrence of AF patients after RFCA was 0.636, 0.798, and 0.893, respectively, while sensitivity was 65.32%, 71.69%, and 88.61%, respectively and specificity was 77.46%, 78.53%, and 86.0%, respectively. Patients with Gal-3 above the cutoff value of 14.57 pg/ml had higher frequent AF recurrence than the patients with Gal − 3 ≤ 14.57 pg/ml (35% vs. 12%, p < 0.001) during a follow-up. Meanwhile, patients with ALD above the cutoff value of 243.61 pg/ml also had a higher AF recurrence rate than those with ALD ≤ 243.61 pg/ml (37% vs. 11%, p < 0.001) during a follow-up. The recurrence rate in patients with Gal − 3 > 14.57 pg/ml + ALD > 243.61 pg/ml was higher than that in patients with baseline Gal − 3 > 14.57 pg/ml or ALD > 243.61 pg/ml and patients with Gal − 3 ≤ 14.57 pg/ml + ALD ≤ 243.61 pg/ml (57% vs. 14% vs. 9%, p < 0.01, respectively).

Conclusion

AF recurrence after RFCA had higher baseline Gal-3 and ALD levels, and higher preoperative circulating Gal-3 and ALD levels were independent predictors of AF recurrence for patients undergoing RFCA, while combination of preoperative Gal-3 and ALD levels has higher prediction accuracy.

RESOLVIN E1 ATTENUATES DOXORUBICIN-INDUCED ENDOTHELIAL SENESCENCE BY MODULATING NLRP3 INFLAMMASOME ACTIVATION

Endothelial cell senescence contributes to chronic inflammation and endothelial dysfunction, while favoring cardiovascular disorders and frailty. Senescent cells acquire a pro-inflammatory secretory phenotype that further propagates inflammation and senescence to neighboring cells. Cell senescence can be provoked by plethora of stressors, including inflammatory molecules and chemotherapeutic drugs. Doxorubicin (Doxo) is a powerful anthracycline anticancer drug whose clinical application is constrained by a dose-limiting cardiovascular toxicity. We here investigated whether cell senescence can contribute to the vascular damage elicited by Doxo. In human umbilical vein endothelial cells (HUVEC) cultures, Doxo (10-100 nM) increased the number of SA-β-gal positive cells and the levels of γH2AX, p21 and p53, used as markers of senescence. Moreover, we identified Doxo-induced senescence to be mediated by the nucleotide-binding domain-like receptor protein 3 (NLRP3) inflammasome, a key player of the immune innate system capable of releasing interleukin (IL)-1β. In fact, IL-1β itself mimicked the stimulatory action of Doxo on both NLRP3 activation and cellular senescence, while the pharmacological blockade of IL-1 receptors markedly attenuated the pro-senescence effects of Doxo. In search of additional pharmacological strategies to attenuate Doxo-induced endothelial senescence, we identified resolvin E1 (RvE1), an endogenous pro-resolving mediator, as capable of reducing cell senescence induced by both Doxo and IL-1β by interfering with the increased expression of pP65, NLRP3, and pro-IL-1β proteins and with the formation of active NLRP3 inflammasome complexes. Overall, RvE1 and the blockade of the NLRP3 inflammasome-IL-1β axis may offer a novel therapeutic approach against Doxo-induced cardiovascular toxicity and subsequent sequelae.

Exosomes from Bone Marrow Mesenchymal Stem Cells with Overexpressed Nrf2 Inhibit Cardiac Fibrosis in Rats with Atrial Fibrillation

Background

Even though nuclear factor-erythroid 2-related factor 2 (Nrf2) signaling has been associated with the pathogenesis of multiple heart conditions, data on roles of Nrf2 within atrial fibrillation (AF) still remain scant. The present investigation had the aim of analyzing Nrf2-overexpressing role/s upon bone mesenchymal stem cell- (BMSC-) derived exosomes in rats with AF.

Methods

Exosomes were collected from control or Nrf2 lentivirus-transduced BMSCs and then injected into rats with AF through the tail vein. AF duration was observed using electrocardiography. Immunohistochemical staining was then employed for assessing Nrf2, HO-1, α-SMA, collagen I, or TGF-β1 expression profiles within atrial myocardium tissues. Conversely, Masson staining was utilized to evaluate atrial fibrosis whereas apoptosis within myocardia was evaluated through TUNEL assays. In addition, TNF-α, IL-1β, IL-4, or IL-10 serum expression was assessed through ELISA.

Results

Results of the current study showed significant downregulation of Nrf2/HO-1 within AF rat myocardia. It was found that injection of the control or Lv-Nrf2 exosomes significantly alleviated and lowered AF timespans together with reducing cardiomyocyte apoptosis. Moreover, injection of Lv-Nrf2 exosomes essentially lowered AF-driven atrial fibrosis and also inhibited inflammatory responses in the rats with AF.

Conclusion

Delivery of BMSC-derived exosomes using overexpressed Nrf2 inhibited AF-induced arrhythmias, myocardial fibrosis, apoptosis, and inflammation via Nrf2/HO-1 pathway triggering.

AIM2 inflammasome contributes to aldosterone-induced renal injury via endoplasmic reticulum stress

Inflammatory response and renal fibrosis are the hallmarks of chronic kidney disease (CKD). However, the specific mechanism of aldosterone-induced renal injury in the progress of CKD requires elucidation. Emerging evidence has demonstrated that absent in melanoma 2 (AIM2)-mediated inflammasome activation and endoplasmic reticulum stress (ERS) play a pivotal role in the renal fibrosis. Here, we investigated whether overexpression or deficiency of AIM2 affects ERS and fibrosis in aldosterone-infused renal injury. Interestingly, we found that AIM2 was markedly expressed in the diseased proximal tubules from human and experimental CKD. Mechanically, overactivation of AIM2 aggravated aldosterone-induced ERS and fibrotic changes in vitro while knockdown of AIM2 blunted these effects in vivo and in vitro. By contrast, AIM2 deficiency ameliorated renal structure and function deterioration, decreased proteinuria levels and lowered systolic blood pressure in vivo; silencing of AIM2 blocked inflammasome-mediated signaling pathway, relieved ERS and fibrotic changes in vivo. Furthermore, mineralocorticoid receptor (MR) antagonist eplerenone and ERS inhibitor tauroursodeoxycholic acid (TUDCA) had nephroprotective effects on the basis of AIM2 overactivation in vitro, while they failed to produce a more remarkable renoprotective effect on the treatment of AIM2 silence in vitro. Notably, the combination of TUDCA with AIM2 knockdown significantly reduced proteinuria levels in vivo. Additionally, immunofluorescence assay identified that apoptosis-associated speck-like protein (ASC) recruitment and Gasdermin-D (GSDMD) cleavage respectively occurred in the glomeruli and tubules in vivo. These findings establish a crucial role for AIM2 inflammasome in aldosterone-induced renal injury, which may provide a novel therapeutic target for the pathogenesis of CKD.