The Anti-inflammatory Mediator Resolvin E1 Protects Mice Against Lipopolysaccharide-Induced Heart Injury

Cardiac macrophage metabolism in health and disease

Cardiac macrophages are essential mediators of cardiac development, tissue homeostasis, and response to injury. Cell-intrinsic shifts in metabolism and availability of metabolites regulate macrophage function. The human and mouse heart contain a heterogeneous compilation of cardiac macrophages that are derived from at least two distinct lineages. In this review, we detail the unique functional roles and metabolic profiles of tissue-resident and monocyte-derived cardiac macrophages during embryonic development and adult tissue homeostasis and in response to pathologic and physiologic stressors. We discuss the metabolic preferences of each macrophage lineage and how metabolism influences monocyte fate specification. Finally, we highlight the contribution of cardiac macrophages and derived metabolites on cell-cell communication, metabolic health, and disease pathogenesis.

Resolvin D1 attenuates Ang II-induced hypertension in mice by inhibiting the proliferation, migration and phenotypic transformation of vascular smooth muscle cells by blocking the RhoA/mitogen-activated protein kinase pathway

The proliferation, migration and phenotypic transformation of vascular smooth muscle cells contribute to vascular remodeling and hypertension. Resolvin D1 (RvD1) is a specialized pro-resolving lipid mediator that has been shown to have anti-inflammatory effects and can protect against different cardiovascular diseases. However, the role and mechanism of RvD1 in hypertension are not clear. The current study investigated the role of RvD1 in Ang II-induced hypertensive mice and Ang II-stimulated rat vascular smooth muscle cells. The results showed that RvD1 treatment significantly attenuated hypertension and vascular remodeling, as indicated by decreases in blood pressure, aortic media thickness and collagen deposition. In addition, RvD1 inhibited the proliferation, migration and phenotypic transformation of vascular smooth muscle cells (VSMCs) in vivo and in vitro . Notably, the protective effects of RvD1 were mediated by the Ras homolog gene family member A (RhoA)/mitogen-activated protein kinase (MAPK) signaling pathway. In conclusion, our findings demonstrated the potential benefits of RvD1 as a promising therapeutic agent in the treatment of vascular remodeling and hypertension.

Maresin-1 ameliorates hypertensive vascular remodeling through its receptor LGR6

Hypertensive vascular remodeling is defined as the changes in vascular function and structure induced by persistent hypertension. Maresin-1 (MaR1), one of metabolites from Omega-3 fatty acids, has been reported to promote inflammation resolution in several inflammatory diseases. This study aims to investigate the effect of MaR1 on hypertensive vascular remodeling. Here, we found serum MaR1 levels were reduced in hypertensive patients and was negatively correlated with systolic blood pressure (SBP). The treatment of MaR1 reduced the elevation of blood pressure and alleviated vascular remodeling in the angiotensin II (AngII)-infused mouse model. In addition, MaR1-treated vascular smooth muscle cells (VSMCs) exhibited reduced excessive proliferation, migration, and phenotype switching, as well as impaired pyroptosis. However, the knockout of the receptor of MaR1, leucine-rich repeat-containing G protein-coupled receptor 6 (LGR6), was seen to aggravate pathological vascular remodeling, which could not be reversed by additional MaR1 treatment. The mechanisms by which MaR1 regulates vascular remodeling through LGR6 involves the Ca2+/calmodulin-dependent protein kinase II/nuclear factor erythroid 2-related factor 2/heme oxygenase-1 signaling pathway. Overall, supplementing MaR1 may be a novel therapeutic strategy for the prevention and treatment of hypertension.

Resolvin E1/ChemR23 Protects Against Hypertension and Vascular Remodeling in Angiotensin II-Induced Hypertensive Mice

BACKGROUND

Inflammation plays a critical role in the development of hypertension and vascular remodeling. Resolvin E1 (RvE1), as one of the specialized proresolving lipid mediators, promotes inflammation resolution by binding with a G protein-coupled receptor, ChemR23 (chemerin receptor 23). However, whether RvE1/ChemR23 regulates hypertension and vascular remodeling is unknown.

METHODS

Hypertension in mice was induced by Ang II (angiotensin II) infusion (750 ng/kg per minute), and RvE1 (2 µg/kg per day) was administered through intraperitoneal injection. Loss of ChemR23 was achieved by mice receiving intravenous injection of adeno-associated virus 9-encoding shRNA against ChemR23.

RESULTS

Aortic ChemR23 expression was increased in Ang II-induced hypertensive mice and that ChemR23 was mainly expressed on vascular smooth muscle cells (VSMCs). RvE1 lowered blood pressure, reduced aortic media thickness, attenuated aortic fibrosis, and mitigated VSMC phenotypic transformation and proliferation in hypertensive mice, which were all reversed by the knockdown of ChemR23. Moreover, RvE1 reduced the aortic infiltration of macrophages and T cells, which was also reversed by ChemR23 knockdown. RvE1 inhibited Ccl5 expression in VSMCs via the AMPKα (AMP-activated protein kinase α)/Nrf2 (nuclear factor E2-related factor 2)/canonical NF-κB (nuclear factor κB) pathway, thereby reducing the infiltration of macrophages and T cells. The AMPKα/Nrf2 pathway also mediated the effects of RvE1 on VSMC phenotypic transformation and proliferation. In patients with hypertension, the serum levels of RvE1 and other eicosapentaenoic acid-derived metabolites were significantly decreased.

CONCLUSIONS

RvE1/ChemR23 ameliorated hypertension and vascular remodeling by activating AMPKα/Nrf2 signaling, which mediated immune cell infiltration by inhibiting the canonical NF-κB/Ccl5 pathway, and regulated VSMC proliferation and phenotypic transformation. RvE1/ChemR23 may be a potential therapeutic target for hypertension.

Serinc2 deficiency exacerbates sepsis-induced cardiomyopathy by enhancing necroptosis and apoptosis

In critical care medicine, sepsis is a potentially fatal syndrome characterized by multi-organ dysfunction and eventual failure. Sepsis-induced cardiomyopathy (SIC) is characterized by decreased venstricular contractility. Serine incorporator 2 (Serinc2) is a protein involved in phosphatidylserine biosynthesis and membrane incorporation. It may also be a protective factor in septic lung injury. However, it is unknown whether Serinc2 influences SIC onset or progression. In the present study, we found that Serinc2 was downregulated in the cardiomyocytes of cecal ligation and puncture (CLP)-induced SIC and in neonatal rat cardiomyocytes (NRCMs) exposed to lipopolysaccharides (LPS). Serinc2 knockout (KO) exacerbated sepsis-induced myocardial inflammation, necroptosis, apoptosis, myocardial damage, and contractility impairment. Furthermore, the lack of Serinc2 in cardiomyocytes aggravated LPS-induced cardiomyopathic inflammation, necroptosis, and apoptosis. An adenovirus overexpressing Serinc2 inhibited the inflammatory response and favored cardiomyocyte survival. A mechanistic analysis revealed that Serinc2 deficiency exacerbated LPS-induced cardiac dysfunction by inhibiting the protein kinase B (Akt)/glycogen synthase kinase 3 beta (GSK-3β) signaling pathway that regulates necrotic complex formation and apoptotic pathways in cardiomyopathy. The findings of the present work demonstrated that Serinc2 plays an essential role in SIC and is, therefore, promising as a prophylactic and therapeutic target for this condition.

DEL-1 deficiency aggravates pressure overload-induced heart failure by promoting neutrophil infiltration and neutrophil extracellular traps formation

Recent studies have shown that neutrophils play an important role in the development and progression of heart failure. Developmental endothelial locus-1 (DEL-1) is an anti-inflammatory glycoprotein that has been found to have protective effects in various cardiovascular diseases. However, the role of DEL-1 in chronic heart failure is not well understood. In a mouse model of pressure overload-induced non-ischemic cardiac failure, we found that neutrophil infiltration in the heart increased and DEL-1 levels decreased in the early stages of heart failure. DEL-1 deficiency worsened pressure overload-induced cardiac dysfunction and remodeling in mice. Mechanistically, DEL-1 deficiency promotes neutrophil infiltration and the formation of neutrophil extracellular traps (NETs) through the regulation of P38 signaling. In vitro experiments showed that DEL-1 can inhibit P38 signaling and NETs formation in mouse neutrophils in a MAC-1-dependent manner. Depleting neutrophils, inhibiting NETs formation, and inhibiting P38 signaling all reduced the exacerbation of heart failure caused by DEL-1 deletion. Overall, our findings suggest that DEL-1 deficiency worsens pressure overload-induced heart failure by promoting neutrophil infiltration and NETs formation.

Macrophage neogenin deficiency exacerbates myocardial remodeling and inflammation after acute myocardial infarction through JAK1-STAT1 signaling

Immune response plays a crucial role in post-myocardial infarction (MI) myocardial remodeling. Neogenin (Neo1), a multifunctional transmembrane receptor, plays a critical role in the immune response; however, whether Neo1 participates in pathological myocardial remodeling after MI is unclear. Our study found that Neo1 expression changed significantly after MI in vivo and after LPS + IFN-γ stimulation in bone marrow-derived macrophages (BMDMs) in vitro. Neo1 functional deficiency (using a neutralizing antibody) and macrophage-specific Neo1 deficiency (induced by Neo1flox/flox;Cx3cr1cre mice) increased infarction size, enhanced cardiac fibrosis and cardiomyocyte apoptosis, and exacerbated left ventricular dysfunction post-MI in mice. Mechanistically, Neo1 deficiency promoted macrophage infiltration into the ischemic myocardium and transformation to a proinflammatory phenotype, subsequently exacerbating the inflammatory response and impairing inflammation resolution post-MI. Neo1 deficiency regulated macrophage phenotype and function, possibly through the JAK1-STAT1 pathway, as confirmed in BMDMs in vitro. Blocking the JAK1-STAT1 pathway with fludarabine phosphate abolished the impact of Neo1 on macrophage phenotype and function, inflammatory response, inflammation resolution, cardiomyocyte apoptosis, cardiac fibrosis, infarction size and cardiac function. In conclusion, Neo1 deficiency aggravates inflammation and left ventricular remodeling post-MI by modulating macrophage phenotypes and functions via the JAK1-STAT1 signaling pathway. These findings highlight the anti-inflammatory potential of Neo1, offering new perspectives for therapeutic targets in MI treatment. Neo1 deficiency aggravated inflammation and left ventricular remodeling after MI by modulating macrophage phenotypes and functions via the JAK1-STAT1 signaling pathway.

Resolvin E1 heals injured cardiomyocytes: Therapeutic implications and H-FABP as a readout for cardiovascular disease & systemic inflammation

The purpose of this study is to investigate heart-fatty acid binding protein (H-FABP) leakage from cardiomyocytes as a quantitative measure of cell membrane damage and to test healing by Resolvin E1 (RVE1) as a potential therapeutic for patients with inflammatory diseases (cardiovascular disease and comorbidities) with high morbidity and mortality. Our quantitative ELISA assays demonstrated H-FABP as a sensitive and reliable biomarker for measuring cardiomyocyte damage induced by lipopolysaccharide (LPS) and healing by RvE1, a specialized pro-resolving mediator (SPM) derived from the Omega-3 fatty acid, eicosapentaenoic acid (EPA), a dietary nutrient that balances inflammation to restore homeostasis. RvE1 reduced leakage of H-FABP by up to 86%, which supports our hypothesis that inflammation as a mechanism of injury can be targeted for therapy. H-FABP as a blood biomarker was tested in 40 patients admitted to Boston Medical Center for respiratory distress, (20 patients with and 20 patients without COVID infection). High levels of H-FABP correlated with clinically diagnosed CVD, diabetes, and end-stage renal disease (ESRD) in both patient groups. The level of H-FABP indicates not only CVD damage but is a valuable measure for patients with increased inflammation disease comorbidities.

IL-30 protects against sepsis-induced myocardial dysfunction by inhibiting pro-inflammatory macrophage polarization and pyroptosis

Cardiac dysfunction is a well-recognized complication of sepsis and seriously affects the prognosis of sepsis patients. IL-30 has been reported to exert anti-inflammatory effects in various diseases. However, the role of IL-30 in sepsis-induced myocardial dysfunction (SIMD) remains unclear. Here, we explored the protective role of IL-30 in cecum ligation and puncture (CLP)-induced SIMD mice. IL-30 expression increased in the cardiac tissues of septic mice and was mainly derived from macrophages. IL-30 deletion or neutralization aggravated sepsis-induced cardiac dysfunction and injury, whereas recombinant IL-30 treatment significantly ameliorated it. Mechanistically, IL-30 deficiency exerts pro-inflammatory effects by promoting Ly6Chigh macrophage polarization and pyroptosis. Inhibiting NLRP3 with MCC950 significantly reversed cardiac dysfunction, macrophage polarization and pyroptosis aggravated by IL-30 deficiency. Recombinant IL-30 inhibited pro-inflammatory macrophage polarization and pyroptosis in vivo and vitro. Taken together, these results suggest that IL-30 protects against SIMD by inhibiting pro-inflammatory macrophage polarization and pyroptosis.

Resolvin D2 and its receptor GPR18 in cardiovascular and metabolic diseases: A promising biomarker and therapeutic target

Accumulating evidence suggests that inflammation plays an important role in the pathophysiology of the initiation and progression of cardiovascular and metabolic diseases (CVMDs). Anti-inflammation strategies and those that promote inflammation resolution have gradually become potential therapeutic approaches for CVMDs. Resolvin D2 (RvD2), a specialized pro-resolving mediator, exerts anti-inflammatory and pro-resolution effects through its receptor GPR18, a G protein-coupled receptor. Recently, the RvD2/GPR18 axis has received more attention due to its protective role in CVMDs, including atherosclerosis, hypertension, ischaemiareperfusion, and diabetes. Here, we introduce basic information about RvD2 and GPR18, summarize their roles in different immune cells, and review the therapeutic potential of the RvD2/GPR18 axis in CVMDs. In summary, RvD2 and its receptor GPR18 play an important role in the occurrence and development of CVMDs and are potential biomarkers and therapeutic targets.

Microglia-Mediated Neuroimmune Response Regulates Cardiac Remodeling After Myocardial Infarction

Background Sympathetic hyperactivity contributes to pathological remodeling after myocardial infarction (MI). However, the mechanisms underlying the increase in sympathetic activity remain unknown. Microglia are the predominant immune cells in the central nervous system and can regulate sympathetic neuron activity through neuroimmune response in the hypothalamic paraventricular nucleus. The present study aimed to investigate whether microglia-mediated neuroimmune response can regulate sympathetic activity and cardiac remodeling after MI. Methods and Results PLX3397 (pexidartinib) was used to deplete central microglia via intragastric injection or intracerebroventricular injection. After that, MI was induced by ligation of the left anterior descending coronary artery. Our study showed that MI resulted in the activation of microglia in the paraventricular nucleus. Microglia depletion, which was induced by PLX3397 treatment via intragastric injection or intracerebroventricular injection, improved cardiac function, reduced infarction size, and attenuated cardiomyocyte apoptosis, fibrosis, pathological electrical remodeling, and myocardial inflammation after MI. Mechanistically, these protective effects were associated with an attenuated neuroimmune response in the paraventricular nucleus, which contributed to the decrease of sympathetic activity and attenuation of sympathetic remodeling in the heart. However, intragastric injection with PLX3397 obviously depleted macrophages and induced neutrophil and T-lymphocyte disorders in the heart, blood, and spleen. Conclusions Microglia depletion in the central nervous system attenuates pathological cardiac remodeling after MI by inhibiting neuroimmune response and sympathetic activity. Intragastric administration of PLX3397 leads to serious deleterious effects in peripheral immune cells, especially macrophages, which should be a cause for concern in animal experiments and clinical practice.

Inflammatory signalling in atrial cardiomyocytes: a novel unifying principle in atrial fibrillation pathophysiology

Inflammation has been implicated in atrial fibrillation (AF), a very common and clinically significant cardiac rhythm disturbance, but its precise role remains poorly understood. Work performed over the past 5 years suggests that atrial cardiomyocytes have inflammatory signalling machinery - in particular, components of the NLRP3 (NACHT-, LRR- and pyrin domain-containing 3) inflammasome - that is activated in animal models and patients with AF. Furthermore, work in animal models suggests that NLRP3 inflammasome activation in atrial cardiomyocytes might be a sufficient and necessary condition for AF occurrence. In this Review, we evaluate the evidence for the role and pathophysiological significance of cardiomyocyte NLRP3 signalling in AF. We first summarize the evidence for a role of inflammation in AF and review the biochemical properties of the NLRP3 inflammasome, as defined primarily in studies of classic inflammation. We then briefly consider the broader evidence for a role of inflammatory signalling in heart disease, particularly conditions that predispose individuals to develop AF. We provide a detailed discussion of the available information about atrial cardiomyocyte NLRP3 inflammasome signalling in AF and related conditions and evaluate the possibility that similar signalling might be important in non-myocyte cardiac cells. We then review the evidence on the role of active resolution of inflammation and its potential importance in suppressing AF-related inflammatory signalling. Finally, we consider the therapeutic potential and broader implications of this new knowledge and highlight crucial questions to be addressed in future research.

Type I Cystatin Derived from Fasciola gigantica Suppresses Macrophage-Mediated Inflammatory Responses

There is an inverse relationship between the high incidence of helminth infection and the low incidence of inflammatory disease. Hence, it may be that helminth molecules have anti-inflammatory effects. Helminth cystatins are being extensively studied for anti-inflammatory potential. Therefore, in this study, the recombinant type I cystatin (stefin-1) of Fasciola gigantica (rFgCyst) was verified to have LPS-activated anti-inflammatory potential, including in human THP-1-derived macrophages and RAW 264.7 murine macrophages. The results from the MTT assay suggest that rFgCyst did not alter cell viability; moreover, it exerted anti-inflammatory activity by decreasing the production of proinflammatory cytokines and mediators, including IL-1β, IL-6, IL-8, TNF-α, iNOS, and COX-2 at the gene transcription and protein expression levels, as determined by qRT-PCR and Western blot analysis, respectively. Further, the secretion levels of IL-1β, IL-6, and TNF-α determined by ELISA and the NO production level determined by the Griess test were decreased. Furthermore, in Western blot analysis, the anti-inflammatory effects involved the downregulation of pIKKα/β, pIκBα, and pNF-κB in the NF-κB signaling pathway, hence reducing the translocation from the cytosol into the nucleus of pNF-κB, which subsequently turned on the gene of proinflammatory molecules. Therefore, cystatin type 1 of F. gigantica is a potential candidate for inflammatory disease treatment.

Specialized pro-resolving lipid mediators regulate inflammatory macrophages: A paradigm shift from antibiotics to immunotherapy for mitigating COVID-19 pandemic

The most severe clinical manifestations of the horrifying COVID-19 disease, that claimed millions of lives during the pandemic time, were Acute respiratory distress syndrome (ARDS), Coagulopathies, septic shock leading eventually to death. ARDS was a consequence of Cytokine storm. The viral SARS-COV2infection lead to avalanche of cytokines and eicosanoids causing "cytokine storm" and "eicosanoid storm." Cytokine storm is one of the macrophage-derived inflammatory responses triggered by binding of virus particles to ACE2 receptors of alveolar macrophages, arise mainly due to over production of various pro-inflammatory mediators like cytokines, e.g., interleukin (IL)-1, IL-2, and tumor necrosis factor (TNF)- α, causing pulmonary edema, acute respiratory distress, and multi-organ failure. Cytokine storm was regarded as the predictor of severity of the disease and was deemed one of the causes of the high mortality rates due to the COVID-19. The basis of cytokine storm is imbalanced switching between an inflammation increasing - pro-inflammatory (M1) and an inflammation regulating-anti-inflammatory (M2) forms of alveolar macrophages which further deteriorates if opportunistic secondary bacterial infections prevail in the lungs. Lack of sufficient knowledge regarding the virus and its influence on co-morbidities, clinical treatment of the diseases included exorbitant use of antibiotics to mitigate secondary bacterial infections, which led to the unwarranted development of multidrug resistance (MDR) among the population across the globe. Antimicrobial resistance (AMR) needs to be addressed from various perspectives as it may deprive future generations of the basic health immunity. Specialized pro-resolving mediators (SPMs) are generated from the stereoselective enzymatic conversions of essential fatty acids that serve as immune resolvents in controlling acute inflammatory responses. SPMs facilitate the clearance of injured tissue and cell debris, the removal of pathogens, and augment the concentration of anti-inflammatory lipid mediators. The SPMs, e.g., lipoxins, protectins, and resolvins have been implicated in exerting inhibitory influence on with cytokine storm. Experimental evidence suggests that SPMS lower antibiotic requirement. Therefore, in this review potential roles of SPMs in enhancing macrophage polarization, triggering immunological functions, hastening inflammation resolution, subsiding cytokine storm and decreasing antibiotic requirement that can reduce AMR load are discussed.

Angiotensin-(1-7) ameliorates sepsis-induced cardiomyopathy by alleviating inflammatory response and mitochondrial damage through the NF-κB and MAPK pathways

BACKGROUND

There is no available viable treatment for Sepsis-Induced Cardiomyopathy (SIC), a common sepsis complication with a higher fatality risk. The septic patients showed an abnormal activation of the renin angiotensin (Ang) aldosterone system (RAAS). However, it is not known how the Ang II and Ang-(1-7) affect SIC.

METHODS

Peripheral plasma was collected from the Healthy Control (HC) and septic patients and Ang II and Ang-(1-7) protein concentrations were measured. The in vitro and in vivo models of SIC were developed using Lipopolysaccharide (LPS) to preliminarily explore the relationship between the SIC state, Ang II, and Ang-(1-7) levels, along with the protective function of exogenous Ang-(1-7) on SIC.

RESULTS

Peripheral plasma Ang II and the Ang II/Ang-(1-7) levels in SIC-affected patients were elevated compared to the levels in HC and non-SIC patients, however, the HC showed higher Ang-(1-7) levels. Furthermore, peripheral plasma Ang II, Ang II/Ang-(1-7), and Ang-(1-7) levels in SIC patients were significantly correlated with the degree of myocardial injury. Additionally, exogenous Ang-(1-7) can attenuate inflammatory response, reduce oxidative stress, maintain mitochondrial dynamics homeostasis, and alleviate mitochondrial structural and functional damage by inhibiting nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways, thus alleviating SIC.

CONCLUSIONS

Plasma Ang-(1-7), Ang II, and Ang II/Ang-(1-7) levels were regarded as significant SIC biomarkers. In SIC, therapeutic targeting of RAAS, for example with Ang-(1-7), may exert protective roles against myocardial damage.

Exploring Dysregulated Ferroptosis-Related Genes in Septic Myocardial Injury Based on Human Heart Transcriptomes: Evidence and New Insights

Introduction

Sepsis is currently a common condition in emergency and intensive care units, and is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Cardiac dysfunction caused by septic myocardial injury (SMI) is associated with adverse prognosis and has significant economic and human costs. The pathophysiological mechanisms underlying SMI have long been a subject of interest. Recent studies have identified ferroptosis, a form of programmed cell death associated with iron accumulation and lipid peroxidation, as a pathological factor in the development of SMI. However, the current understanding of how ferroptosis functions and regulates in SMI remains limited, particularly in the absence of direct evidence from human heart.

Methods

We performed a sequential comprehensive bioinformatics analysis of human sepsis cardiac transcriptome data obtained through the GEO database. The lipopolysaccharide-induced mouse SMI model was used to validate the ferroptosis features and transcriptional expression of key genes.

Results

We identified widespread dysregulation of ferroptosis-related genes (FRGs) in SMI based on the human septic heart transcriptomes, deeply explored the underlying biological mechanisms and crosstalks, followed by the identification of key functional modules and hub genes through the construction of protein-protein interaction network. Eight key FRGs that regulate ferroptosis in SMI, including HIF1A, MAPK3, NOX4, PPARA, PTEN, RELA, STAT3 and TP53, were identified, as well as the ferroptosis features. All the key FRGs showed excellent diagnostic capability for SMI, part of them was associated with the prognosis of sepsis patients and the immune infiltration in the septic hearts, and potential ferroptosis-modulating drugs for SMI were predicted based on key FRGs.

Conclusion

This study provides human septic heart transcriptome-based evidence and brings new insights into the role of ferroptosis in SMI, which is significant for expanding the understanding of the pathobiological mechanisms of SMI and exploring promising diagnostic and therapeutic targets for SMI.

PKM2 deficiency exacerbates gram-negative sepsis-induced cardiomyopathy via disrupting cardiac calcium homeostasis

Sepsis is a life-threatening syndrome with multi-organ dysfunction in critical care medicine. With the occurrence of sepsis-induced cardiomyopathy (SIC), characterized by reduced ventricular contractility, the mortality of sepsis is boosted to 70-90%. Pyruvate kinase M2 (PKM2) functions in a variety of biological processes and diseases other than glycolysis, and has been documented as a cardioprotective factor in several heart diseases. It is currently unknown whether PKM2 influences the development of SIC. Here, we found that PKM2 was upregulated in cardiomyocytes treated with LPS both in vitro and in vivo. Pkm2 inhibition exacerbated the LPS-induced cardiac damage to neonatal rat cardiomyocytes (NRCMs). Furthermore, cardiomyocytes lacking PKM2 aggravated LPS-induced cardiomyopathy, including myocardial damage and impaired contractility, whereas PKM2 overexpression and activation mitigated SIC. Mechanism investigation revealed that PKM2 interacted with sarcoplasmic/endoplasmic reticulum calcium ATPase 2a (SERCA2a), a key regulator of the excitation-contraction coupling, to maintain calcium homeostasis, and PKM2 deficiency exacerbated LPS-induced cardiac systolic dysfunction by impairing SERCA2a expression. In conclusion, these findings highlight that PKM2 plays an essential role in gram-negative sepsis-induced cardiomyopathy, which provides an attractive target for the prevention and treatment of septic cardiomyopathy.

RvD1n-3 DPA Downregulates the Transcription of Pro-Inflammatory Genes in Oral Epithelial Cells and Reverses Nuclear Translocation of Transcription Factor p65 after TNF-α Stimulation

Specialized pro-resolving mediators (SPMs) are multifunctional lipid mediators that participate in the resolution of inflammation. We have recently described that oral epithelial cells (OECs) express receptors of the SPM resolvin RvD1_{n-3 DPA} and that cultured OECs respond to RvD1_{n-3 DPA} addition by intracellular calcium release, nuclear receptor translocation and transcription of genes coding for antimicrobial peptides. The aim of the present study was to assess the functional outcome of RvD1_{n-3 DPA}-signaling in OECs under inflammatory conditions. To this end, we performed transcriptomic analyses of TNF-α-stimulated cells that were subsequently treated with RvD1_{n-3 DPA} and found significant downregulation of pro-inflammatory nuclear factor kappa B (NF-κB) target genes. Further bioinformatics analyses showed that RvD1_{n-3 DPA} inhibited the expression of several genes involved in the NF-κB activation pathway. Confocal microscopy revealed that addition of RvD1_{n-3 DPA} to OECs reversed TNF-α-induced nuclear translocation of NF-κB p65. Co-treatment of the cells with the exportin 1 inhibitor leptomycin B indicated that RvD1_{n-3 DPA} increases nuclear export of p65. Taken together, our observations suggest that SPMs also have the potential to be used as a therapeutic aid when inflammation is established.

Losartan attenuates sepsis-induced cardiomyopathy by regulating macrophage polarization via TLR4-mediated NF-κB and MAPK signaling

Sepsis-induced cardiomyopathy (SIC) is a serious complication of sepsis with high mortality but no effective treatment. The renin angiotensin (Ang) aldosterone system (RAAS) is activated in patients with sepsis but it is unclear how the Ang II/Ang II type 1 receptor (AT1R) axis contributes to SIC. This study examined the link between the Ang II/AT1R axis and SIC as well as the protective effect of AT1R blockers (ARBs). The Ang II level in peripheral plasma and AT1R expression on monocytes were significantly higher in patients with SIC compared with those in non-SIC patients and healthy controls and were correlated with the degree of myocardial injury. The ARB losartan reduced the infiltration of neutrophils, monocytes, and macrophages into the heart and spleen of SIC mice. Additionally, losartan regulated macrophage polarization from the M1 to the M2 subtype via nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways, thereby maintaining the mitochondrial dynamics balance in cardiomyocytes and reducing oxidative stress and cardiomyocyte apoptosis. In conclusion, the plasma Ang II level and AT1R expression on plasma monocytes are an important biomarker in SIC. Therapeutic targeting of AT1R, for example with losartan, can potentially protect against myocardial injury in SIC.

IL-12p40 deletion aggravates lipopolysaccharide-induced cardiac dysfunction in mice

Background

Cardiac dysfunction is one of the most common complications of sepsis and is associated with the adverse outcomes and high mortality of sepsis patients. IL-12p40, the common subunit of IL-12 and IL-23, has been shown to be involved in a variety of inflammation-related diseases, such as psoriasis and inflammatory bowel disease. However, the role of IL-12p40 in lipopolysaccharide (LPS)-induced cardiac dysfunction remains obscure. This study aimed to explore the role of IL-12p40 in LPS-induced cardiac dysfunction and its potential mechanisms.

Methods

In this study, mice were treated with LPS and the cardiac expression of IL-12p40 was determined. Then, IL-12p40–/– mice were used to detect the role and mechanisms of IL-12p40 in LPS-induced cardiac injury. In addition, monocytes were adoptively transferred to IL-12p40–/– mice to explore their effects on LPS-induced cardiac dysfunction.

Results

The results showed that cardiac IL-12p40 expression was significantly increased after treated with LPS. In addition, IL-12p40 deletion significantly aggravated LPS-induced cardiac dysfunction, evidenced by the increased serum levels of cardiomyocyte injury markers and heart injury scores, as well as by the deteriorated cardiac function. Moreover, IL-12p40 deletion increased LPS-induced monocyte accumulation and cardiac expression of inflammatory cytokines, as well as enhanced the activation of the NF-κB and MAPK pathways. Furthermore, adoptive transfer WT mouse monocytes to IL-12p40−/− mice alleviated LPS-induced cardiac dysfunction and decreased the phosphorylation of p65.

Conclusion

IL-12p40 deletion significantly aggravated LPS-induced cardiac injury and cardiac dysfunction in mice by regulating the NF-κB and MAPK signaling pathways, and this process was related to monocytes. Therefore, IL-12p40 show a protective role in SIC, and IL-12p40 deficiency or anti-IL-12p40 monoclonal antibodies may be detrimental to patients with SIC.

Dysregulated autophagy-related genes in septic cardiomyopathy: Comprehensive bioinformatics analysis based on the human transcriptomes and experimental validation

Septic cardiomyopathy (SCM) is severe organ dysfunction caused by sepsis that is associated with poor prognosis, and its pathobiological mechanisms remain unclear. Autophagy is a biological process that has recently been focused on SCM, yet the current understanding of the role of dysregulated autophagy in the pathogenesis of SCM remains limited and uncertain. Exploring the molecular mechanisms of disease based on the transcriptomes of human pathological samples may bring the closest insights. In this study, we analyzed the differential expression of autophagy-related genes in SCM based on the transcriptomes of human septic hearts, and further explored their potential crosstalk and functional pathways. Key functional module and hub genes were identified by constructing a protein–protein interaction network. Eight key genes (CCL2, MYC, TP53, SOD2, HIF1A, CTNNB1, CAT, and ADIPOQ) that regulate autophagy in SCM were identified after validation in a lipopolysaccharide (LPS)-induced H9c2 cardiomyoblast injury model, as well as the autophagic characteristic features. Furthermore, we found that key genes were associated with abnormal immune infiltration in septic hearts and have the potential to serve as biomarkers. Finally, we predicted drugs that may play a protective role in SCM by regulating autophagy based on our results. Our study provides evidence and new insights into the role of autophagy in SCM based on human septic heart transcriptomes, which would be of great benefit to reveal the molecular pathological mechanisms and explore the diagnostic and therapeutic targets for SCM.

Research Progress on the Mechanism of Sepsis Induced Myocardial Injury

Sepsis is an abnormal condition with multiple organ dysfunctions caused by the uncontrolled infection response and one of the major diseases that seriously hang over global human health. Besides, sepsis is characterized by high morbidity and mortality, especially in intensive care unit (ICU). Among the numerous subsequent organ injuries of sepsis, myocardial injury is one of the most common complications and the main cause of death in septic patients. To better manage septic inpatients, it is necessary to understand the specific mechanisms of sepsis induced myocardial injury (SIMI). Therefore, this review will elucidate the pathophysiology of SIMI from the following certain mechanisms: apoptosis, mitochondrial damage, autophagy, excessive inflammatory response, oxidative stress and pyroptosis, and outline current therapeutic strategies and potential approaches in SIMI.

Maresin-1 and Its Receptors RORα/LGR6 as Potential Therapeutic Target for Respiratory Diseases

Maresin-1 is one of the representative specialized pro-resolving mediators that has shown beneficial effects in inflammatory disease models. Recently, two distinct types of receptor molecules were discovered as the targets of maresin-1, further revealing the pro-resolution mechanism of maresin-1. One is retinoic acid-related orphan receptor α (RORα) and the another one is leucine-rich repeat domain-containing G protein-coupled receptor 6 (LGR6). In this review, we summarized the detailed role of maresin-1 and its two different receptors in respiratory diseases. RORα and LGR6 are potential targets for the treatment of respiratory diseases. Future basic research and clinical trials on MaR1 and its receptors should provide useful information for the treatment of respiratory diseases.

Omega-3 fatty acids impair miR-1-3p-dependent Notch3 down-regulation and alleviate sepsis-induced intestinal injury

Background

Sepsis is a troublesome syndrome that can cause intestinal injury and even high mortality rates. Omega-3 fatty acids (FAs) are known to protect against intestinal damage. Accordingly, the current study set out to explore if omega-3 FAs could affect sepsis-induced intestinal injury with the involvement of the microRNA (miR)-1-3p/Notch3-Smad axis.

Methods

First, cecal ligation and perforation (CLP) was performed to establish septic mouse models in C57BL/6J mice, and mouse intestinal epithelial MODE-K cells were induced by lipopolysaccharide (LPS) to establish sepsis cell models. The CLP-induced septic mice or LPS-exposed cells were subjected to treatment with Omega-3 FAs and activin (Smad signaling activator), miR-1-3p inhibitor and over-expressed/short hairpin RNA (oe-/sh)-Notch3 to explore their roles in inflammation, intestinal oxidative stress and cell apoptosis. A dual-luciferase reporter gene assay was further performed to verify the regulatory relationship between miR-1-3p and Notch3.

Results

Omega-3 FAs inhibited CLP-induced intestinal injury and ameliorated LPS-induced intestinal epithelial cell injury by down-regulating miR-1-3p, as evidenced by decreased levels of tumor necrosis factor-α, interleukin-1β (IL-1β) and IL-6, in addition to diminished levels of reactive oxygen species, malondialdehyde levels and superoxide dismutase activity. Furthermore, miR-1-3p could down-regulate Notch3, which inactivated the Smad pathway.

Conclusion

Collectively, our findings indicated that omega-3 FAs elevate the expression of Notch3 by down-regulating miR-1-3p, and then blocking the Smad pathway to alleviate intestinal epithelial inflammation and oxidative stress injury caused by sepsis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-021-00425-w.

Resolvin E1-ChemR23 Axis Regulates the Hepatic Metabolic and Inflammatory Transcriptional Landscape in Obesity at the Whole Genome and Exon Level

Resolvin E1 (RvE1) is an immunoresolvent that is synthesized from eicosapentaenoic acid and can bind the receptor ERV1/ChemR23. We previously showed activation of the RvE1-ChemR23 axis improves hyperglycemia and hyperinsulinemia of obese mice; however, it remains unclear how RvE1 controls glucose homeostasis. Here we investigated hepatic metabolic and inflammatory transcriptional targets of the RvE1-ChemR23 axis using lean and obese wild type (WT) and ChemR23 knockout (KO) mice. We conducted an in-depth transcriptional study by preforming whole gene-level and exon-level analyses, which provide insight into alternative splicing variants and miRNA regulation. Compared to controls, WT and KO obese mice in the absence of RvE1 displayed similar gene-level profiles, which entailed dysregulated pathways related to glucose homeostasis. Notably, obese WT mice relative to lean controls showed a robust decrease in pathways related to the biosynthesis of unsaturated fatty acids. At the exon-level, obese ChemR23 KOs compared to obese WT mice displayed changes in pathways related to hepatic lipid transport, cholesterol metabolism, and immunological functions such as complement cascades and platelet activation. Importantly, upon RvE1 administration to WT obese mice, we discovered upregulated genes in pathways relating to insulin sensitivity and downregulated genes related to regulators of TGF-β signaling. This transcriptional profile was generally not recapitulated with obese ChemR23 KO mice administered RvE1. Collectively, gene and exon-level analyses suggest RvE1 controls the hepatic transcriptional profile related to glucose homeostasis, insulin sensitivity, and inflammation in a manner that is largely dependent on ChemR23. These studies will drive future mechanistic experiments on the RvE1-ChemR23 axis.

Let-7i-5p Mediates the Therapeutic Effects of Exosomes from Human Placenta Choriodecidual Membrane-Derived Mesenchymal Stem Cells on Mitigating Endotoxin-Induced Mortality and Liver Injury in High-Fat Diet-Induced Obese Mice

Obesity complicates sepsis and increases the mortality of sepsis. We examined the effects of exosomes (from human placenta choriodecidual membrane-derived mesenchymal stem cells, pcMSCs) on preventing sepsis in obesity and the mitigating role of hsa-let-7i-5p microRNA. Obese mice (adult male C57BL/6J mice fed a high-fat diet for 12 weeks) received normal saline (HFD), endotoxin (10 mg/kg, intraperitoneal (ip); HFDLPS), endotoxin with exosomes (1 × 10⁸ particles/mouse, ip; HLE), or endotoxin with let-7i-5p microRNA inhibitor-pretreated exosomes (1 × 10⁸ particles/mouse, ip; HLEi). Our data demonstrated that the 48-h survival rate in the HLE (100%) group was significantly higher than in the HFDLPS (50%) and HLEi (58.3%) groups (both p < 0.05). In the surviving mice, by contrast, levels of liver injury (injury score, plasma aspartate transaminase and alanine transaminase concentrations, tissue water content, and leukocyte infiltration in liver tissues; all p < 0.05), inflammation (nuclear factor-κB activation, hypoxia-inducible factor-1α activation, macrophage activation, and concentrations of tumor necrosis factor-α, interleukin-6, and leptin in liver tissues; all p < 0.05), and oxidation (malondialdehyde in liver tissues, with p < 0.001) in the HLE group were significantly lower than in the HFDLPS group. Levels of mitochondrial injury/dysfunction and apoptosis in liver tissues in the HLE group were also significantly lower than in the HFDLPS group (all p < 0.05). Inhibition of let-7i-5p microRNA offset the effects of the exosomes, with most of the aforementioned measurements in the HLEi group being significantly higher than in the HLE group (all p < 0.05). In conclusion, exosomes mitigated endotoxin-induced mortality and liver injury in obese mice, and these effects were mediated by let-7i-5p microRNA.

Cordycepin induces M1/M2 macrophage polarization to attenuate the liver and lung damage and immunodeficiency in immature mice with sepsis via NF-κB/p65 inhibition

OBJECTIVES

To explore the impacts of cordycepin and underlying mechanism on the sepsis.

METHODS

The sepsis mice model was built and treated with different concentrations of cordycepin. Then the liver and lung injury caused by cecal ligation and puncture (CLP) was assessed using H&E staining and TUNEL assay. The expression of relevant genes was detected using qRT-PCR analysis and ELISA assays. Besides, the macrophage polarization was checked by flow cytometry.

KEY FINDINGS

Cordycepin could significantly improve the liver and lung injury. Moreover, cordycepin increased the distribution of F4/80+ CD206+ M2-like macrophages and F4/80+ iNOS+ M1-like macrophages through down-regulating the expression of relevant genes. More importantly, cordycepin could monitor the protein expression of iNOS, Arg-1, TNF-α, MCP-1, IL-4 and IL-10 in CLP mice. Meanwhile, the elevated level of p65 induced by CLP was also repressed by the increase of the cordycepin. Moreover, cordycepin played a crucial part in CLP mice through modulating the NF-κB/p65 signalling pathway.

CONCLUSIONS

Cordycepin played an important role in mice with sepsis via reducing the M1/M2 macrophage polarization and modulating the NF-κB/p65 signalling pathway.

Paeoniflorin improves myocardial injury via p38 MAPK/NF-KB p65 inhibition in lipopolysaccharide-induced mouse

Background

Paeoniflorin (Pae) is an active compound with a variety of pharmacological effects. This aim was to investigate how Pae protects against myocardial injury and to explore its potential mechanism.

Methods

We established a BALB/c mouse model that was intraperitoneal injection (i.p.) of RvE1 (25 µg/kg) or Pae (20 mg/kg) for 3 days, and then treated with lipopolysaccharide (LPS, 10 mg/kg, i.p.). The mice were randomly divided into the sham group, the LPS group, the LPS + RvE1 group, the LPS + Pae group (n=8). Cardiac dysfunction was detected by HE staining and ELISA assay. The oxidative stress, mitochondrial membrane potential (MMP), mitochondrial permeability transition pore (mPTP) and apoptosis were assessed. Furthermore, western blotting (WB) assay were employed to analyze the protective mechanisms.

Results

Pae improved LPS-induced cardiac function and impeded apoptosis. Pae significantly reduced the release of inflammatory cytokines such as interleukin (IL)-6, tumor necrosis factor-α (TNF-α), and IL-1β. Furthermore, Pae decreased malondialdehyde (MDA), glutathione (GSH), and reactive oxygen species (ROS), and increased superoxide dismutase (SOD). In addition, Pae attenuated the mPTP opening and MMP depolarization. Notably, Pae treatment inhibited the activation of p38 MAPK and NF-κB p65.

Conclusions

It was confirmed that Pae alleviated LPS-induced myocardial injury. Pae might be as a new drug candidate for myocardial ischaemic complications.

Il12a Deletion Aggravates Sepsis-Induced Cardiac Dysfunction by Regulating Macrophage Polarization

Cardiac dysfunction is a well-recognized complication of sepsis and is associated with the outcome and prognosis of septic patients. Evidence suggests that Il12a participates in the regulation of various cardiovascular diseases, including heart failure, hypertension and acute myocardial infarction. However, the effects of Il12a in sepsis-induced cardiac dysfunction remain unknown. In our study, lipopolysaccharide (LPS) and cecal ligation and puncture (CLP) model were used to mimic sepsis, and cardiac Il12a expression was assessed. In addition, Il12a knockout mice were used to detect the role of Il12a in sepsis-related cardiac dysfunction. We observed for the first time that Il12a expression is upregulated in mice after LPS treatment and macrophages were the main sources of Il12a. In addition, our findings demonstrated that Il12a deletion aggravates LPS-induced cardiac dysfunction and injury, as evidenced by the increased serum and cardiac levels of lactate dehydrogenase (LDH) and cardiac creatine kinase-myocardial band (CK-MB). Moreover, Il12a deletion enhances LPS-induced macrophage accumulation and drives macrophages toward the M1 phenotype in LPS-treated mice. Il12a deletion also downregulated the activity of AMP-activated protein kinase (AMPK) but increased the phosphorylation levels of p65 (p-p65) and NF-κB inhibitor alpha (p-IκBα). In addition, Il12a deletion aggravates CLP-induced cardiac dysfunction and injury. Treatment with the AMPK activator AICAR abolishes the deterioration effect of Il12a deletion on LPS-induced cardiac dysfunction. In conclusion, Il12a deletion aggravated LPS-induced cardiac dysfunction and injury by exacerbating the imbalance of M1 and M2 macrophages. Our data provide evidence that Il12a may represent an attractive target for sepsis-induced cardiac dysfunction.

Interleukin-9 deficiency affects lipopolysaccharide-induced macrophage-related oxidative stress and myocardial cell apoptosis via the Nrf2 pathway both in vivo and in vitro

Previous studies showed that interleukin-9 (IL-9) is involved in cardiovascular diseases, including hypertension and cardiac fibrosis. This study aimed to investigate the role of IL-9 in lipopolysaccharide (LPS)-induced myocardial cell (MC) apoptosis. Mice were treated with LPS, and IL-9 expression was measured and the results showed that compared with WT mice, LPS-treated mice exhibited increased cardiac Mø-derived IL-9. Additionally, the effects of IL-9 deficiency (IL-9-/-) on macrophage (Mø)-related oxidative stress and MC apoptosis were evaluated, the results showed that IL-9 knockout significantly exacerbated cardiac dysfunction, inhibited Nrf2 nuclear transfer, promoted an imbalance in M1 and M2 Møs, and exacerbated oxidative stress and MC apoptosis in LPS-treated mice. Treatment with ML385, a specific nuclear factor erythroid-2 related factor 2 (Nrf2) pathway inhibitor significantly alleviated the above effects in LPS-treated IL-9-/- mice. Bone marrow-derived Møs from wild-type (WT) mice and IL-9-/- mice were treated with LPS, and the differentiation and oxidative stress levels of Møs were measured. The effect of Mø differentiation on mouse MC apoptosis was also analyzed in vitro. The results showed that LPS-induced M1 Mø/M2 Mø imbalance and Mø-related oxidative stress were alleviated by IL-9 knockout but were exacerbated by ML385 treatment. The protective effects of IL-9 deficiency on the MC apoptosis mediated by LPS-treated Møs were reversed by ML-385. Our results suggest that deletion of IL-9 decreased the nuclear translocation of Nrf2 in Møs, which further aggravated Mø-related oxidative stress and MC apoptosis. IL-9 may be a target for the prevention of LPS-induced cardiac injury.

Mediterranean Diet as an Antioxidant: The Impact on Metabolic Health and Overall Wellbeing

It has been established, worldwide, that non-communicable diseases such as obesity, diabetes, metabolic syndrome, and cardiovascular events account for a high percentage of morbidity and mortality in contemporary societies. Several modifiable risk factors, such as sedentary activities, sleep deprivation, smoking, and unhealthy dietary habits have contributed to this increase. Healthy nutrition in terms of adherence to the Mediterranean diet (MD), rich in fruits, legumes, vegetables, olive oil, herbs, spices, and high fiber intake may contribute to the decrease in this pandemic. The beneficial effects of the MD can be mainly attributed to its numerous components rich in anti-inflammatory and antioxidant properties. Moreover, the MD may further contribute to the improvement of reproductive health, modify the risk for neurodegenerative diseases, and protect against depression and psychosocial maladjustment. There is also evidence highlighting the impact of healthy nutrition in female people on the composition of the gut microbiota and future metabolic and overall health of their offspring. It is therefore important to highlight the beneficial effects of the MD on metabolic, reproductive, and mental health, while shaping the overall health of future generations. The beneficial effects of MD can be further enhanced by increased physical activity in the context of a well-balanced healthy lifestyle.

The roles of macrophage polarization in the host immune response to sepsis

Sepsis is a life-threatening clinical syndrome caused by infection. Its pathogenesis is complex and entails coagulation dysfunction, inflammation, and immune disorders. Macrophages are important components of innate and adaptive immunity that are highly heterogeneous and plastic. They can polarize into a multi-dimensional spectrum of phenotypes with different functions relating to immune regulation in response to changes in the microenvironment of specific tissues. We reviewed studies that examined the role of macrophage polarization with a focus on the classical activated (M1-like) and alternative activated (M2-like) macrophages as the two main phenotypes involved in the host immune response to sepsis. A complex regulatory network is involved in the process of macrophage polarization, which is influenced by a variety of signaling molecules, transcription factors, epigenetic modifications, and metabolic reprogramming. M1-like macrophages release large quantities of pro-inflammatory mediators, while M2-like macrophages release large quantities of anti-inflammatory mediators. An imbalance between M1-like and M2-like macrophages induces the occurrence and development of sepsis. Therefore, targeted regulation of the process of macrophage polarization could be a useful approach to normalize the immune balance of the host, offering a new treatment modality for different stages of sepsis.

4-OI Attenuates Carbon Tetrachloride-Induced Hepatic Injury via Regulating Oxidative Stress and the Inflammatory Response

The liver is an important metabolic organ, and acute liver injury (ALI) is potentially lethal. Itaconate, a metabolic intermediate from the tricarboxylic acid cycle, showed emerging anti-oxidative and anti-inflammation properties, and an accumulating protective effect in multiple diseases, but its role in ALI still needs to be further explored. Here we established an ALI model induced by carbon tetrachloride in mice. Our results showed that 4-Octyl itaconate (OI), a derivate of itaconate, mitigated hepatic damage by improving liver function, reducing histopathological damage, and decreasing the death of hepatocytes. Additionally, OI decreased myeloperoxidase and thiobarbituric acid reactive substances (TBARS) levels in the ALI model. OI also inhibited the inflammatory response by reducing pro-inflammatory cytokine secretion (IL-6, TNF-α, IL-1β, and MCP-1) and infiltration of macrophages and neutrophils in the ALI model. However, administration of ML385, a specified Nrf2 inhibitor, eliminated the protective properties of OI in the CCl4-induced liver injury model by increasing hepatic damage and oxidative stress. Furthermore, OI increased the expression and nuclear translocation of Nrf2 and elevated the expression of heme oxygenase-1 and NAD(P)H quinone oxidoreductase 1, while knockdown of Nrf2 eliminated these effects in murine hepatocyte NCTC 1469 under CCl4 treatment. Moreover, we found that OI reduced serum High-mobility group box 1 (HMGB1) levels in CCl4-treated mice. Finally, OI inhibited nuclear translocation of factor-kappa B (NF-𝜅B) and inflammatory cytokine production in murine macrophages. In conclusion, these results indicated that OI ameliorated CCl4-induced ALI by mitigating oxidative stress and the inflammatory response. The possible mechanism was associated with the elevation of Nrf2 nuclear translocation and inhibition of HMGB1 mediated the nuclear translocation of NF-𝜅B.

Selenium Supplementation Protects Against Lipopolysaccharide-Induced Heart Injury via Sting Pathway in Mice

Sepsis-induced myocardial dysfunctions are associated with high morbidity and mortality. Selenium, an essential trace element, has been reported to exert anti-inflammation, anti-oxidative stress, and anti-apoptosis. However, the protective effects of selenium on LPS-induced heart injury are still poorly illustrated. Therefore, in the present study, we sought to explore the effects of selenium pretreatment on LPS-induced myocardial injury in mice. We firstly found that selenium pretreatment significantly improved markers of myocardial injury and alleviated LPS-induced myocardial dysfunctions. Moreover, selenium supplementation reduced pro-inflammatory cytokines expression, decreased oxidative stress, and inhibited myocardial apoptosis. In addition, selenium supplementation inactivated the Sting pathway. In conclusion, our study suggests that selenium exerts protective effects on LPS-induced myocardial injury, and the underlying molecular mechanism may be related to the inactivation of Sting pathway, implying a potential therapy for sepsis-induced myocardial dysfunctions.

Endogenous conversion of n-6 to n-3 polyunsaturated fatty acids facilitates the repair of cardiotoxin-induced skeletal muscle injury in fat-1 mice

In this study, we investigated the beneficial effects of high endogenous levels of n-3 polyunsaturated fatty acids (PUFAs) on skeletal muscle repair and regeneration using a mouse cardiotoxin (CTX, 20 μM/200 μL) -induced gastrocnemius muscle injury model. Transgenic fat-1 mice expressing the Caenorhabditis elegans fat-1 gene, encoding n-3 fatty acid desaturase, showed higher n-3 PUFA levels and lower n-6/n-3 PUFA ratios in gastrocnemius muscle tissues. Hematoxylin and eosin and Masson’s trichrome staining of gastrocnemius sections revealed increased muscle fiber size and reduced fibrosis in fat-1 mice on days 7 and 14 after CTX injections. Gastrocnemius muscle tissues from fat-1 mice showed reduced inflammatory responses and increased muscle fiber regeneration reflecting enhanced activation of satellite cells on day 3 after cardiotoxin injections. Gastrocnemius muscle tissues from cardiotoxin-treated fat-1 mice showed reduced levels of pro-apoptotic proteins (Caspase 3 and Bax) and increased levels of anti-apoptotic proteins (Bcl-2 and Survivin). Moreover, eicosapentaenoic acid (EPA) reduced the incidence of apoptosis among cardiotoxin-treated C2C12 mouse myoblasts. These findings demonstrate that higher endogenous n-3 PUFA levels in fat-1 mice enhances skeletal muscle repair and regeneration following cardiotoxin-induced injury.

Omega 3 Fatty Acid and Skin Diseases

Humans are exposed to various external environmental factors. Food intake is one of the most influential factors impacting daily lifestyle. Among nutrients obtained from foods, omega-3 polyunsaturated fatty acids (PUFAs) have various beneficial effects on inflammatory diseases. Furthermore, omega-3 PUFA metabolites, including resolvins, are known to demonstrate strong anti-inflammatory effects during allergic and inflammatory diseases; however, little is known regarding the actual impact of these metabolites on skin diseases. In this review, we focused on metabolites that have strong anti-inflammatory actions in various inflammatory diseases, as well as those that present antitumor actions in malignancies, in addition to the actual effect of omega-3 PUFA metabolites on various cells.

Omega-3 Polyunsaturated Fatty Acids and the Resolution of Inflammation: Novel Therapeutic Opportunities for Aortic Valve Stenosis?

Inflammation is well-established in cardiovascular disease, including valvular heart disease. Inflammation is a key process in the fibrosis and calcification of the aortic valve leaflets, which ultimately clinically manifest as aortic valve stenosis characterized by valve dysfunction and cardiac obstruction. In the absence of pharmacological treatment, either surgical or transcatheter aortic valve replacement is currently the only available therapeutic strategy for patients with severe aortic valve stenosis. Omega-3 polyunsaturated fatty acids, which exert beneficial effects in several cardiovascular diseases, serve as the substrate for several bioactive lipid mediators that regulate inflammation. Recent findings point to the beneficial effects of omega-3 fatty acids in cardiac valves, being inversely associated with aortic valve calcification and contributing to the resolution of valvular inflammation by means of the pro-resolving mediator resolvin E1 and downstream signaling through its receptor ChemR23.

Pro-Resolving Lipid Mediator Resolvin E1 Mitigates the Progress of Diethylnitrosamine-Induced Liver Fibrosis in Sprague-Dawley Rats by Attenuating Fibrogenesis and Restricting Proliferation

Liver fibrosis is a complex process associated to most types of chronic liver disease, which is characterized by a disturbance of hepatic tissue architecture and the excessive accumulation of extracellular matrix. Resolvin E1 (RvE1) is a representative member of the eicosapentaenoic omega-3 lipid derivatives, and is a drug candidate of the growing family of endogenous resolvins. Considering the aforementioned, the main objective of this study was to analyze the hepatoprotective effect of RvE1 in a rat model of liver fibrosis. Male Sprague-Dawley rats received diethylnitrosamine (DEN, 70 mg/mg body weight intraperitoneally (i.p)) as an inductor of liver fibrosis once weekly and RvE1(100 ng/body weight i.p) twice weekly for four weeks. RvE1 suppressed the alterations induced by DEN, normalizing the levels of alanine aminotransferase (ALT), albumin, and lactate dehydrogenase (LDH), and ameliorated DEN injury by decreasing the architecture distortion, inflammatory infiltration, necrotic areas, and microsteatosis. RvE1 also limited DEN-induced proliferation through a decrease in Ki67-positive cells and cyclin D1 protein expression, which is related to an increase of the levels of cleaved caspase-3. Interestingly, we found that RvE1 promotes higher nuclear translocation of nuclear factor κB (NF-κB)p65 than DEN. RvE1 also increased the levels of nuclear the nuclear factor erythroid 2-related factor 2 (Nrf2), but with no antioxidant effect, measured as an increase in glutathione disulfide (GSSG) and a decrease in the ratio of glutathione (GSH)/GSSG. Taken together, these results suggest that RvE1 modulates the fibrogenesis, steatosis, and cell proliferation in a model of DEN induced fibrosis.

RvE1 Attenuates Polymicrobial Sepsis-Induced Cardiac Dysfunction and Enhances Bacterial Clearance

The development of cardiac dysfunction caused by microbial infection predicts high mortality in sepsis patients. Specialized pro-resolving mediators (SPMs) mediate resolution of inflammation in many inflammatory diseases, and are differentially expressed in plasma of sepsis patients. Here, we investigated whether the levels of SPMs are altered in the murine septic heart following polymicrobial sepsis-induced cardiac dysfunction. Ten weeks-old male C57BL/6 mice were subjected to polymicrobial sepsis induced by cecal ligation and puncture (CLP), which is a clinically relevant sepsis model receiving analgesics, antibiotics, and fluid resuscitation. CLP caused a significant systolic dysfunction assessed by echocardiography. The hearts were subjected to LC-MS/MS based lipid mediator profiling. Many SPMs were significantly reduced in septic hearts, among which RvE1 had a ~93-fold reduction. Treatment of CLP mice with synthetic RvE1 (1 μg/mouse i.v.) at 1 h after CLP increased peritoneal macrophages number, particularly MHC II^- macrophages. RvE1 reduced pro-inflammatory gene expression (interleukin-1β, interleukin-6, and CCL2) in lipopolysaccharide-stimulated bone marrow-derived macrophages (BMDMs) in vitro. RvE1 attenuated cardiac dysfunction in septic mice and increased cardiac phosphorylated Akt; decreased cardiac phosphorylated IκB kinase α/β, nuclear translocation of the NF-κB subunit p65, extracellular signal-regulated kinase 1/2, and c-Jun amino-terminal kinases 1/2. Most notably, RvE1 treatment reduced peritoneal bacterial load and promoted phagocytosis activity of BMDMs. In conclusion, cardiac SPMs, particularly RvE1, are substantially reduced in mice with polymicrobial sepsis. Delayed therapeutic administration of RvE1 to mice with polymicrobial sepsis attenuates the cardiac dysfunction through modulating immuno-inflammatory responses. In addition to the above effects, the ability to enhance bacterial clearance makes RvE1 an ideal therapeutic to reduce the sequalae of polymicrobial sepsis.

Interleukin-22 deficiency alleviates doxorubicin-induced oxidative stress and cardiac injury via the p38 MAPK/macrophage/Fizz3 axis in mice

Several interleukin (IL) family members have been demonstrated to be involved in doxorubicin (DOX)-induced cardiac injury. This study aimed to investigate the role of IL-22 in DOX-induced cardiac injury and explore its possible mechanisms. In this study, mice were given DOX, and the cardiac expression and sources of IL-22 were determined. Then, IL-22 was knocked out to observe the effects on DOX-induced cardiac injury in mice. In addition, the p38 mitogen-activated protein kinase (MAPK) pathway was inhibited, macrophages were depleted and adoptively transferred, and Fizz3 was up-regulated in mice to explore the mechanisms. The results showed that cardiac IL-22 expression was significantly increased by DOX treatment and was mostly derived from cardiac macrophages. IL-22 knockout significantly reduced cardiac vacuolization and the expression of cardiomyocyte injury markers in both serum and left ventricular tissue and improved cardiac function in DOX-treated mice. In addition, IL-22 knockout reversed DOX-induced cardiac M1 macrophage/M2 macrophage imbalance, reduced oxidative stress and protected against cardiomyocyte apoptosis. p38 MAPK pathway inhibition with SB203580 and macrophage depletion further alleviated the above effects in DOX-treated IL-22-knockout mice. The effects were stronger IL-22-knockout mice with adoptive transfer of WT macrophages than in those with adoptive transfer of IL-22-knockout macrophages. Furthermore, increasing the expression of Fizz3 reduced cardiomyocyte apoptosis and alleviated cardiac dysfunction. Our results may suggest that IL-22 knockout alleviate DOX-induced oxidative stress and cardiac injury by inhibiting macrophage differentiation and thereby increasing the expression of Fizz3. Reductions in IL-22 expression may be beneficial for clinical chemotherapy in tumor patients.

Resolvin E1 protects against doxorubicin-induced cardiotoxicity by inhibiting oxidative stress, autophagy and apoptosis by targeting AKT/mTOR signaling

Doxorubicin (DOX)-induced cardiotoxicity impairs the quality of life of cancer patients during or after DOX treatment, and it is imperative to explore a novel strategy to address this problem. Resolvin E1 (RvE1) is derived from eicosapentaenoic acid (EPA), which has been reported to exert beneficial effects on DOX-induced oxidative stress in cardiomyocytes. This study was designed to investigate whether RvE1 protects against DOX-induced cardiotoxicity, and the underlying mechanism was explored. DOX (20 mg/kg, one injection, i.p.) was used to induce DOX-induced cardiotoxicity in C57BL/6 mice. At 5 days after DOX administration, the effect of RvE1 was assessed by measuring cardiac function, oxidative stress, autophagy and apoptosis in cardiac tissue. We used an AKT inhibitor and rapamycin to investigate the underlying mechanisms. Our results showed that RvE1 inhibited the DOX-induced decrease in body weight and heart weight, the reduction in left ventricular ejection fraction and fractional shortening, and the increase in lactate dehydrogenase, creatine kinase myocardial bound and cardiomyocyte vacuolization. Compared to the control group, the DOX group exhibited increased oxidative stress, autophagy and apoptosis in cardiac tissue, which were alleviated by treatment with RvE1. The AKT/mTOR signaling pathways were responsible for RvE1-mediated regulation of DOX-induced oxidative stress, autophagy and myocardial apoptosis. In conclusion, RvE1 protected against DOX-induced cardiotoxicity via the regulation of AKT/mTOR signaling.