Myocardial Inflammatory Cytokines Research Articles

Geomagnetic activity affects animal myocardial ischemia/reperfusion injury: an experimental-simulated study

Numerous studies have shown that geomagnetic activity (GMA) contributes to the development and escalation of cardiovascular disease (CVD), as well as increased morbidity and mortality. However, the underlying molecular mechanisms and approaches for understanding GMA remain unclear. This study aimed to investigate the impact of GMA on oxidative stress and inflammatory responses. Myocardial ischemia/reperfusion injury (MI/RI) rat models were created under various geomagnetic field conditions. The range of cardiac function, markers of myocardial injury, inflammatory factors, and the TLR4/NF-κB signaling pathway were measured after the 24-h period. The findings showed that weak GMA significantly improved cardiac function in the MI/RI rat model and reduced the size of myocardial infarction and creatine kinase (CK) and lactic dehydrogenase (LDH) levels. Additionally, weak GMA enhanced superoxide dismutase (SOD) activity and decreased malondialdehyde (MDA) content. Furthermore, weak GMA significantly reduced the levels of the myocardial inflammatory cytokines interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). Conversely, the effects observed under severe GMA conditions were opposite to those observed under weak GMA. Western blot and qPCR analysis demonstrated that weak GMA led to a significant downregulation of TLR4, TRAF6, NF-κB, TNF-α, and MCP-1 in the MI/RI rat models. In contrast to weak GMA, severe GMA increased TLR4, TRAF6, NF-κB, and TNF-α expression. This study suggested that weak GMA had a limiting effect on MI/RI rat models, whereas severe GMA exacerbated injury in MI/RI rats. These effects were associated with oxidative stress and inflammatory responses and might potentially involve the TLR4/NF-κB signaling pathway.

Analysis of the improvement effect of Astragalus extract on oxidative stress injury in viral myocarditis through STAT3/IL-6.

The objective of this study was to investigate the improvement effect of Astragalus (AS) extract on oxidative stress (OS) and inflammatory response of myocarditis (MYO) cells through the STAT3/IL-6 axis. For this purpose, The MYO model cells prepared by intervening cardiomyocyte HL-1 with Coxsackievirus B3 (CVB3) were divided into four groups: model group, as well as high- (H-), medium- (M-) and low-dose (L-) AS groups treated by 80, 40, and 20 μg/mL AS, respectively. Conventionally cultured cells were set as the normal group. Cell multiplication and apoptosis, as well as levels of Myocardial injury markers (cTnT, BNP and CK), inflammatory cytokines (ICs; TNF-α, IL-1β and IL-6) and OS indices (SOD, GSH-Px and MDA), were measured. STAT3/IL-6 pathway expression was also observed. Results showed that the model group presented decreased cell multiplication than the normal group, but with increased myocardialinjury, apoptosis rate, Caspase3 protein, ICs and OS reaction (P < 0.05); In the three AS-intervened groups, enhanced cell multiplication, while reduced myocardialinjury, apoptosis rate, ICs and OS response were observed, especially in H-AS group (P < 0.05). Besides, STAT3 and IL-6 concentrations, statistically increased in the model group, were reduced by AS intervention (P < 0.05). Colivelin, a specific activator of STAT3, further aggravated the apoptosis, inflammatory reaction and OS response of MYO cells (P < 0.05), but its impacts on MYO cells could be reversed by AS. In conclusion, AS can ameliorate MYO, and its mechanism is related to the inhibition of cellular inflammatory response and OS response through the STAT3/IL-6 axis.

Activation of cannabinoid receptors 2 alleviates myocardial damage in cecal ligation and puncture-induced sepsis by inhibiting pyroptosis

BackgroundIt has been reported that cannabinoid receptors 2 (CB2 receptors) play an important role in the pathophysiological process of sepsis, which may also be associated with the regulation of pyroptosis, an inflammatory programmed cell death. The present study aimed to investigate the protective effect of CB2 receptors on myocardial damage in a model of septic mice by inhibiting pyroptosis. MethodsThe C57BL/6 mice underwent cecal ligation and puncture (CLP) to induce sepsis. All mice were randomly divided into the sham, CLP, or CLP+HU308 group. Blood and heart tissue samples were collected 12 h after surgery. Hematoxylin and eosin staining was used for analyzing histopathological results. Creatine kinase isoenzymes (CK-MB) and IL-1β were measured using ELISA, while lactate dehydrogenase (LDH) level was determined using photoelectric colorimetry. The expression levels of CB2 receptors and pyroptosis-associated proteins (NLRP3, caspase-1, and GSDMD) were measured using western blotting. The location and distribution of CB2 receptors and caspase-1 in myocardial tissues were assessed by immunofluorescence. TUNEL staining was used to quantify the number of dead cells in myocardial tissues. ResultsThe CLP procedure increased CB2 receptor expression in mice. CB2 receptors were located in myocardial macrophages. Activating CB2 receptors decreased the levels of myocardial damage mediator LDH, CK-MB, and inflammatory cytokine IL-1β. The results also showed that CLP increased the pyroptosis in myocardial tissues, while CB2 agonist HU308 inhibited pyroptosis by decreasing the level of NLRP3 and activating caspase-1 and GSDMD. ConclusionsCB2 receptor activation has a protective effect on the myocardium of mice with sepsis by inhibiting pyroptosis.

Evaluation of time-dependent phenotypes of myocardial ischemia-reperfusion in mice.

A mouse model of myocardial ischemia-reperfusion (I/R) is widely used to study myocardial ischemia-reperfusion injury (I/RI). However, few studies focus on the direct comparison of the extent of pathological events resulting from variant durations of ischemia and reperfusion process. A mouse model of I/RI was established by ligation and perfusion of the left anterior descending coronary artery (LAD), and the dynamic changes were recorded by electrocardiogram at different stages of I/R. Subsequently, reperfusion duration was used as a variable to directly compare the phenotypes of different myocardial injury degrees induced by 3 h, 6 h and 24 h reperfusion from myocardial infarct size, myocardial apoptosis, myocardial enzyme, and inflammatory cytokine levels. All mice subjected to myocardial I/R surgery showed obvious myocardial infarction, extensive myocardial apoptosis, dynamic changes in serum myocardial enzyme and inflammatory cytokines, at least for the first 24 h of reperfusion. The infarct size and apoptosis rates gradually increased with the extension of reperfusion time. The peaks of serum myocardial enzyme and inflammatory cytokines occurred at 6 h and 3 h of reperfusion, respectively. We also established I/R mice models with 30 and 60 mins of ischemia. After 21 days of remodeling, longer periods of ischemia increased the degree of fibrosis and reduced cardiac function. In summary, we conclude that reperfusion durations of 3 h, 6 h, and 24 h induces different injury phenotypes in ischemia-reperfusion mouse model. At the same time, the ischemia duration before reperfusion also affects the degree of cardiac remodeling.

Myocardial edema, inflammation, and injury in human heart donated after circulatory death are sensitive to warm ischemia and subsequent cold storage

BackgroundSingle-dose del Nido solution was recently used in human donation after circulatory death (DCD) heart procurement. We compared the effect of del Nido cardioplegia on myocardial edema, inflammatory response, and injury in human DCD hearts and human donation after brain death (DBD) hearts with different warm ischemic times (WIT) and subsequent cold saline storage times (CST). MethodsA total of 24 human hearts, including 6 in the DBD group and 18 in the DCD group—were procured for the research study. The DCD group was divided into 3 subgroups based on WIT: 20, 40, and ≥60 minutes. All hearts received 1 L of del Nido cardioplegia before being placed in cold saline for 6 hours. Left ventricular biopsies were performed at 0, 2, 4, and 6 hours. Temporal changes in myocardial edema, inflammatory cytokines (TNF-α, IL-6, and IL-1β), and histopathology injury scores were compared between the DBD and DCD groups. ResultsDCD hearts showed more profound changes in myocardial edema, inflammation, and injury than DBD hearts at baseline and subsequent CST. The DCD heart with WIT of 20 and 40 minutes with CST of 4 and 2 hours, respectively, appeared to have limited myocardial edema, inflammation, and injury. DCD hearts with WIT ≥60 minutes showed severe myocardial edema, inflammation, and injury at baseline and subsequent CST. ConclusionsSingle-dose cold del Nido cardioplegia and subsequent cold normal saline storage can preserve both DCD and DBD hearts. DCD hearts have been shown to be able to tolerate a WIT of 20 minutes and subsequent CST of 4 hours without experiencing significant myocardial edema, inflammation, and injury.

USF2 activates RhoB/ROCK pathway by transcriptional inhibition of miR-206 to promote pyroptosis in septic cardiomyocytes.

Septic cardiomyopathy (SCM) is one of the most serious complications of sepsis. The present study investigated the role and mechanism of upstream stimulatory factor 2 (USF2) in SCM. Serum samples were extracted from SCM patients and healthy individuals. A murine model of sepsis was induced by caecal ligation and puncture (CLP) surgery. Myocardial injury was examined by echocardiography and HE staining. ELISA assay evaluated myocardial markers (CK-MB, cTnI) and inflammatory cytokines (TNF-α, IL-1β, IL-18). Primary mouse cardiomyocytes were treated with lipopolysaccharide (LPS) to simulate sepsis in vitro. RT-qPCR and Western blot were used for analyzing gene and protein levels. CCK-8 assay assessed cell viability. NLRP3 was detected by immunofluorescence. ChIP, RIP and dual luciferase reporter assays were conducted to validate the molecular associations. USF2 was increased in serum from SCM patients, septic mice and primary cardiomyocytes. USF2 silencing improved the survival of septic mice and attenuated sepsis-induced myocardial pyroptosis and inflammation in vitro and in vivo. Mechanistically, USF2 could directly bind to the promoter of miR-206 to transcriptionally inhibit its expression. Moreover, RhoB was confirmed as a target of miR-206 and could promote ROCK activation and NLRP3 inflammasome formation. Moreover, overexpression of RhoB remarkably reversed the protection against LPS-induced inflammation and pyroptosis mediated by USF2 deletion or miR-206 overexpression in cardiomyocytes. The above findings elucidated that USF2 knockdown exerted a cardioprotective effect on sepsis by decreasing pyroptosis and inflammation via miR-206/RhoB/ROCK pathway, suggesting that USF2 may be a novel drug target in SCM.

Exercise protects aged mice against coronary endothelial senescence via FUNDC1-dependent mitophagy

Vascular aging contributes to adverse changes in organ function and is a significant indicator of major cardiac events. Endothelial cells (ECs) participate in aging-provoked coronary vascular pathology. Regular exercise is associated with preservation of arterial function with aging in humans. However, the molecular basis is not well understood. The present study was aimed to determine the effects of exercise on coronary endothelial senescence and whether mitochondrial clearance regulator FUN14 domain containing 1 (FUNDC1)-related mitophagy and mitochondrial homeostasis were involved. In mouse coronary arteries, FUNDC1 levels showed gradually decrease with age. Both FUNDC1 and mitophagy levels in cardiac microvascular endothelial cells (CMECs) were significantly reduced in aged mice and were rescued by exercise training. Exercise also alleviated CMECs senescence as evidenced by senescence associated β-galactosidase activity and aging markers, prevented endothelial abnormal cell migration, proliferation, and eNOS activation in CMECs from aged mice, and improved endothelium-dependent vasodilation of coronary artery, reduced myocardial neutrophil infiltration and inflammatory cytokines evoked by MI/R, restored angiogenesis and consequently alleviated MI/R injury in aging. Importantly, FUNDC1 deletion abolished the protective roles of exercise and FUNDC1 overexpression in ECs with adeno-associated virus (AAV) reversed endothelial senescence and prevented MI/R injury. Mechanistically, PPARγ played an important role in regulating FUNDC1 expressions in endothelium under exercise-induced laminar shear stress. In conclusion, exercise prevents endothelial senescence in coronary arteries via increasing FUNDC1 in a PPARγ-dependent manner, and subsequently protects aged mice against MI/R injury. These findings highlight FUNDC1-mediated mitophagy as potential therapeutic target that prevents endothelial senescence and myocardial vulnerability.

GAS-STING signaling plays an essential pathogenetic role in Doxorubicin-Induced Cardiotoxicity

BackgroundThe severe unfavorable effects of doxorubicin on the heart restrict its clinical usage. Numerous investigations document that cyclic GMP-AMP synthase (cGAS) activator of interferon genes (STING) cascade influences inflammation along with the immune response in a variety of diseases. The pathophysiological function of the cGAS-STING cascade in Doxorubicin-induced cardiomyopathy (DIC) is, nevertheless, unknown.MethodsIn vivo, cardiotoxicity was triggered by a single dose of intra-peritoneal inoculation of doxorubicin (15 mg/kg) in wild-type C57BL/6J mice and STING knockdown animals. Adeno-associated virus 9 (AAV9) was utilized to silence STING. qPCR along with Western blotting were adopted to assess alterations in the cGAS/STING cascade. To assess cardiac function, we employed echocardiography coupled with histology, as well as molecular phenotyping. In vitro, HL-1 cardiomyocytes were introduced as test models.ResultsIn wild type mice, doxorubicin stimulation significantly activated the cGAS/STING pathway. STING silencing increased rate of survival along with heart function in mice, as well as diminished myocardial inflammatory cytokines along with apoptosis. These observations were also confirmed by utilizing siRNA of STING in vitro studies.ConclusionThis research premise established that STING inhibition could alleviate Dox-triggered cardiotoxicity in mice. As a result, preventing DIC by repressing STING in cardiomyocytes might be a possible treatment approach.

Mice with endothelial cell-selective adhesion molecule deficiency develop coronary microvascular rarefaction and left ventricle diastolic dysfunction.

Endothelial cell-selective adhesion molecule (ESAM) regulates inflammatory cell adhesion and transmigration and promotes angiogenesis. Here, we examined the role of ESAM in cardiac vascularization, inflammatory cell infiltration, and left ventricle (LV) diastolic function under basal and hemodynamic stress conditions. We employed mice with homozygous genetic deletion of ESAM (ESAM-/- ) and also performed uninephrectomy and aldosterone infusion (UNX-Aldo) to induce volume and pressure overload. Using echocardiography, we found that ESAM-/- mice display no change in systolic function. However, they develop LV diastolic dysfunction, as indicated by a significantly reduced E/A ratio (E=early, A=late mitral inflow peak velocities), increased E/e' ratio, isovolumic relaxation time (IVRT), and E wave deceleration time. An unbiased automated tracing and 3D reconstruction of coronary vasculature revealed that ESAM-/- mice had reduced coronary vascular density. Arteries of ESAM-/- mice exhibited impaired endothelial sprouting and in cultured endothelial cells siRNA-mediated ESAM knockdown reduced tube formation. Changes in ESAM-/- mice were accompanied by elevated myocardial inflammatory cytokine and myeloperoxidase-positive neutrophil levels. Furthermore, UNX-Aldo procedure in wild type mice induced LV diastolic dysfunction, which was accompanied by significantly increased serum ESAM levels. When compared to wild types, ESAM-/- mice with UNX-Aldo displayed worsening of LV diastolic function, as indicated by increased IVRT and pulmonary edema. Thus, we propose that ESAM plays a mechanistic role in proper myocardial vascularization and the maintenance of LV diastolic function under basal and hemodynamic stress conditions.

Naltrexone-Induced Cardiac Function Improvement is Associated With an Attenuated Inflammatory Response and Lipid Perioxidation in Volume Overloaded Rats.

In previous studies, upregulation of myocardial opioid receptors as well as the precursors of their endogenous ligands were detected in the failing heart due to chronic volume overload. Moreover, opioid receptor blockade by naltrexone improved left ventricular function. In parallel, inflammatory processes through cytokines have been confirmed to play an important role in the pathogenesis of different forms of heart failure. Thus, the present study examined the systemic and myocardial inflammatory response to chronic volume overload and its modulation by chronic naltrexone therapy. Chronic volume overload was induced in male Wistar rats by applying an infrarenal aortocaval fistula (ACF) for 28 days during which the selective opioid receptor antagonist naltrexone (n = 6) or vehicle (n = 6) were administered via a subcutaneously implanted Alzet minipump. The ultrastructural, morphometric and hemodynamic characterization of ACF animals were performed using an intraventricular conductance catheter in vivo and electron microscopy in vitro. Co-localization of mu-, delta- and kappa-opioid receptor subtypes (MOR, DOR, and KOR respectively) with the voltage gated L-type Ca2+ channel (Cav1.2), the ryanodine receptor (RyR), and mitochondria in cardiomyocytes as well as IL-6, IL-12, TNF-alpha, and Malondialdehyde (MDA) were determined using double immunofluorescence confocal microscopy, RT-PCR and ELISA, respectively. In rat left ventricular myocardium, three opioid receptor subtypes MOR, DOR, and KOR colocalized with Cav1.2, RyR and mitochondria suggesting a modulatory role of the excitation-contraction coupling. In rats with ACF-induced volume overload, signs of heart failure and myocardial ultrastructural damage, chronic naltrexone therapy improved cardiac function and reversed the systemic and myocardial inflammatory cytokine expression as well as lipid peroxidation. In conclusion, antagonism of the cardiodepressive effects of the myocardial opioid system does not only improve left ventricular function but also blunts the inflammatory response and lipid peroxidation.

Shenfu injection attenuates cardiac dysfunction and inhibits apoptosis in septic mice.

BackgroundCardiac dysfunction frequently occurs after sepsis and septic shock and contributes to multiple organ failure. Shenfu injection, a well-known Chinese medicine formulation, has recently been demonstrated to possess potential cardio-protective effects, although its effect and mechanism in sepsis-induced myocardial dysfunction remains unclear.MethodsTo investigate whether Shenfu injection could alleviate myocardial injury and improve cardiac function, a model of sepsis was induced by cecal ligation and puncture (CLP) surgery in C57BL/6 mice. Cardiac function, inflammatory factors, and apoptosis were evaluated in the myocardium.ResultsOur results showed that the survival and left ventricular function markedly declined when exposed to CLP compared with the sham procedure. In contrast, Shenfu injection lowered mortality and prevented CLP from triggering left ventricular dysfunction. Moreover, mice treated with Shenfu injection exhibited noticeably decreased myocardial inflammatory cytokines [tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and monocytechemoattractantprotein-1 (MCP-1)] and reduced apoptotic myocardiocytes death compared with mice that had CLP. The activation of myocardial NF-кB detected in septic mice was suppressed by the presence of Shenfu injection, as evidenced by decreased nuclear translocation of the NF-кB p65 subunit. Moreover, Shenfu injection also prevented sepsis-caused decreases in myocardial phospho-Akt and phospho-GSK-3β in septic mice.ConclusionsThese data suggest that administration of Shenfu injection attenuates cardiac dysfunction, protects against inflammatory injury, and reduces apoptosis of myocardiocytes during sepsis by activating the AKT/GSK-3β pathway.

Levosimendan protects from sepsis-inducing cardiac dysfunction by suppressing inflammation, oxidative stress and regulating cardiac mitophagy via the PINK-1-Parkin pathway in mice.

BackgroundSepsis is a leading cause of death in China, the mortality rate of which is elevated when cardiac dysfunction is induced. Levosimendan is used for the treatment of decompensated cardiac failure. In this study, we sought to investigate the role of levosimendan in the inflammation, oxidative stress, and mitophagic response of the septic heart.MethodsA lipopolysaccharide (LPS)-induced septic myocardial dysfunction mouse model was established. To study the relationship between levosimendan and inflammation, oxidative stress, and mitophagy response, mice were pretreated with mdivi-1 (an inhibitor of mitophagy) prior to LPS administration. Levosimendan was given (24 µg/kg) via intraperitoneal injection 3 h after LPS had been administered. At 6 h after LPS injection, echocardiographic analysis, enzyme-linked immunosorbent assay (ELISA), oxidative stress index, myocardial pathological changes, transmission electron microscopy (TEM), immunofluorescence, and western blot were used to investigate the protective effects of levosimendan against LPS-induced myocardial dysfunction.ResultsIn the sepsis model, levosimendan markedly ameliorated myocardial dysfunction, decreased the release of myocardial enzymes and inflammatory cytokines, improved oxidative stress index and myocardial pathological changes, reduced mitochondrial division, and activated mitophagy. To confirm whether the protection of levosimendan was mediated by mitophagy, a mitophagy inhibitor-mdivi-1 was used in this study. It significantly impaired the protective effects of levosimendan. In addition, our studies further confirmed the protection of levosimendan against LPS-induced myocardial injury and the mechanisms involving PINK-1-Parkin mediated mitophagy signaling.ConclusionsLevosimendan was able to rescue the LPS-induced cardiac dysfunction mice, supporting its mechanism of action by suppressing inflammation, oxidative stress, and directly targeting the PINK-1-Parkin pathway.

Increased m6A-RNA methylation and FTO suppression is associated with myocardial inflammation and dysfunction during endotoxemia in mice.

Endotoxemia triggers life-threatening immune and cardiovascular response that leads to tissue damage, multi-organ failure, and death. The understanding of underlying molecular mechanisms is still evolving. N6-methyladenosine (m6A)-RNA modification plays key regulatory role in numerous biological processes. However, it remains unclear whether endotoxemia alters RNA methylation in the myocardium. In the current study, we investigated the effect of lipopolysaccharide (LPS)-induced endotoxemia on m6A-RNA methylation and its implications on myocardial inflammation and left ventricular (LV) function. Following LPS administration, mice showed increases in m6A-RNA methylation in the myocardium with a corresponding decrease in the expression of fat mass and obesity-associated protein (FTO, an m6A eraser/demethylase). The changes were associated with a significant increase in expression of myocardial inflammatory cytokine genes, such as IL-6, TNF-α, IL-1β, and reduced LV function. Moreover, rat cardiomyoblasts (H9c2) exposed to LPS showed similar changes (with increase in m6A-RNA methylation and inflammatory cytokine genes, whereas downregulation of FTO). Furthermore, methylated RNA immunoprecipitation assay showed hypermethylation and increase in the expression of IL-6 and TNF-α genes in LPS-treated H9c2 cells as compared to untreated cells. Interestingly, FTO knockdown in cardiomyocytes mimicked the above effects. Taken together, these data suggest that endotoxemia-induced m6A methylation might play a critical role in expression of cardiac proinflammatory cytokines, and modulation of m6A methylation might limit myocardial inflammation and dysfunction during endotoxemia.

The Effect of Resistance Exercise on Myocardial Inflammatory Cytokines and ERK1/2 Expression in Type 2 Diabetic Rats

PURPOSE: The purpose of this study was to investigate the effect of resistance ladder exercise on myocardial inflammatory cytokines and extracellular signal regulated kinase (ERK)1/2 expression in type 2 diabetic rats.METHODS: A total of 21 8-week-old male Long Evans Tokushima Otsuka (LETO) and Otsuka Long Evans Tokushima Fatty (OLETF) rats were divided into three groups: LETO group (CON, n=7), OLETF group (DM, n=7), and resistance exercise group (DM+EXE, n=7). Resistance exercise referred to a climbing exercise on a slope. The rats performed this exercise 3 full d per week, for 8 week. The expression of myocardial inflammatory cytokines and ERK1/2 was analyzed via western blotting after 8 week of exercise intervention.RESULTS: After 8 weeks of resistance exercise for the management of type 2 diabetes, the production of anti-inflammatory factor Interleukin (IL)-10 in the myocardium increased. This inhibited the production of pro-inflammatory factors IL-6 and tumor necrosis factor-alpha. However, resistance exercise did not affect the expression of ERK1 and ERK2, which are apoptosis regulatory proteins.CONCLUSIONS: In type 2 diabetes, resistance exercise is thought to be effective in reducing inflammatory factors by mediating cytokines. Although the effects of resistance ladder exercise were confirmed, further studies on a variety of exercise types and intensities should be conducted to prevent and improve the conditions of those with diabetes.

Prevention of endotoxin-induced cardiomyopathy using sodium tanshinone IIA sulfonate: Involvement of augmented autophagy and NLRP3 inflammasome suppression

Increasing evidence indicates that patients or experimental animals exposure to endotoxin (lipopolysaccharides, LPS) exert deleterious cardiac functions that greatly contribute to morbidity and mortality. The pathophysiologic processes, including NLRP3 inflammasome overactivation and cardiac inflammatory injury, are complicated. Sodium tanshinone IIA sulfonate (STS), a water-soluble derivative of tanshinone IIA, is a naturally occurring compound extracted from Salvia miltiorrhiza and has anti-inflammatory and cardioprotective properties. In this study we examined the effect of STS on endotoxin-induced cardiomyopathy and investigated the underlying mechanisms. An endotoxemic mouse model was established by injecting LPS (10 mg/kg). Different doses of STS were administered intraperitoneally (5, 10, or 50 mg/kg) at different time points (2/12 h, 4/12 h, and 8/12 h) after LPS challenge to assess its effect on survival of mice with endotoxemia. In parallel, cardiac function, myocardial inflammatory cytokines, cardiomyocyte pyroptosis and autophagy were evaluated to determine the extent of myocardial damage due to sepsis in the presence and absence of STS at the optimal dose (10 mg/kg) and time-point (2/12 h). The results demonstrated that STS increased the survival rates, improved the compromised cardiac function and reduced myocardial inflammatory injury associated with enhanced autophagy and mitigated NLRP3 inflammasome activation. Moreover, inhibiting of autophagy or blocking the AMPK pathway reversed STS-elicited prevention of cardiomyopathy and activated the NLRP3 inflammasome in endotoxemic mice. Collectively, our study demonstrates that STS attenuates endotoxemia-induced mortality and cardiomyopathy, which may be associated with promotion of autophagy and inhibition of NLRP3 inflammasome overactivation.

Amelioratory effect of neoandrographolide on myocardial ischemic-reperfusion injury by its anti-inflammatory and anti-apoptotic activities.

In the present study, we aimed to evaluate the cardioprotective effect of neoandrographolide (Neo) on myocardial ischemia/reperfusion injury (I/R) models and explore its possible mechanism. We randomly and equally divided male mice into sham-operation, I/R, and I/R + Neo groups. H9C2 cell line and primary neonatal rat cardiomyocytes were induced into the simulated I/R's status and used to further validate the Neo's role in vitro. Heart systolic function, indexes of myocardial injury (IMI), infarct size, pathological change, cell apoptosis, inflammatory cytokines, and indexes related to apoptotic and NF-κB signaling pathways were analyzed in vivo or in vitro after the Neo treatment. Compared to the I/R group, Neo significantly suppressed IMI, infarct size, inflammatory cell infiltration, cell apoptosis, inflammatory cytokines, bax, cleaved caspase-3, P-IKBa, and P-NF-κB protein expressions, and the translocation of NF-kB subunit p65 from the cytoplasm to the nucleus in vivo or in vitro. Still, ejected fraction, fractional shortening, and the bcl-2 protein expression were notably increased after the Neo treatment. Neo could be developed into a new drug for treating myocardial I/R by inhibiting myocardial inflammation and apoptosis, which was closely related to suppressing the activation of bax/bcl-2 and NF-κB signaling pathways.

Uncoupling protein 2 overexpression alleviates sepsis-induced myocardial injury via inhibiting reactive oxygen species production and inflammation

To investigate whether the overexpression of uncoupling protein 2 (UCP2) can protect myocardium from sepsis by inhibiting the production of reactive oxygen species (ROS) and inflammatory response. Forty Sprague-Dawley rats were divided into four groups according to random number table method (n = 10): sham transfection and sham surgery group (Sham group), sham transfection and cecal ligation and perforation (CLP) group (CLP group), simple adeno-associated virus (AAV) transfection surgery group (AAV group), and UCP2 overexpression surgery group (UCP2 group). In UCP2 group, UCP2 adeno-associated virus (AAV-UCP2; titer 1×1012 v.g/mL, 10 μL per site, 60 μL in total) was injected into myocardium, and CLP was performed 3 weeks later. In AAV group, the myocardium was transfected with AAV virus and CLP was performed 3 weeks later. Twenty-four hours after modeling, whether the model was successfully prepared was evaluated. The transfection effect of AAV virus on the frozen sections of myocardial tissue was observed under fluorescence microscope, the expression of UCP2 protein was detected by Western blotting, ROS production was detected by dihydroethidine (DHE) staining, and serum myocardial markers and inflammatory cytokines were detected by enzyme linked immunosorbent assay (ELISA). Twenty-four hours after CLP, the rats showed stiff hair, increased secretions from eyes, nose and mouth, and symptoms of pyuria, loose stools, and dyspnea. After laparotomy, the cecum showed purple and black, and there was purulent exudation around the intestinal cavity. The virus was successfully transfected on frozen section under the fluorescence microscope (the site of the transfection was green fluorescence), and further Western blotting revealed that the expression of UCP2 in the CLP group was higher than that in the Sham group (UCP2/β-tubulin: 1.53±0.06 vs. 1, P < 0.01). Compared with the AAV group, UCP2 expression was further increased in the UCP2 group (UCP2/β-tubulin: 1.96±0.22 vs. 1.59±0.07, P < 0.01). Under the fluorescence microscope, ROS production in the CLP and AAV groups were found significantly increased compared with that in the Sham group; when UCP2 was overexpressed, ROS production were significantly decreased compared with the CLP and AAV groups (A value: 1.03±0.10 vs. 1.81±0.13, 1.67±0.08, both P < 0.01). ELISA showed that compared with the Sham group, the levels of lactate dehydrogenase (LDH), creatine kinase (CK), cardiac troponin I (cTnI), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were significantly increased in the CLP and AAV groups; when UCP2 was overexpressed, the above myocardial enzymes and inflammatory cytokines secretion were significantly decreased compared with the CLP group and AAV group [LDH (ng/L): 48.97±1.04 vs. 56.85±1.36, 57.08±1.54; CK (ng/L): 235.23±20.33 vs. 306.34±25.93, 304.76±25.29; cTnI (ng/L): 199.79±18.27 vs. 241.88±14.32, 243.33±23.79; TNF-α (ng/L): 385.71±20.09 vs. 488.92±26.92, 489.03±33.37; IL-6 (ng/L): 121.12±7.61 vs. 159.07±17.65, 157.61±15.13; all P < 0.01]. Kaplan-Meier survival curve showed that the survival rate of rats 36 hours after CLP was only 30.0%. When UCP2 overexpressed, the survival rate was significantly higher than that of the CLP group and AAV group (60.0% vs. 30.0%, 30.0%, both P < 0.05). There was no significant difference between the AAV group and CLP group. UCP2 overexpression can reduce myocardial injury and improve the survival rate of septic rats by reducing ROS production and inhibiting inflammatory reaction in septic myocardium.

Sophoridine Regulates the NADPH Oxidase-2 Pathway and Potentiates the Cardioprotective Effect of Dexmedetomidine Against Sepsis-Induced Cardiomyopathy

We have evaluated the protective effect of sophoridine and dexmedetomidine alone and in combination against lipopolysaccharides induced myocardial dysfunction. Mitochondrial reactive oxygen species, malondialdehyde and superoxide dismutase in the myocardial tissue and inflammatory cytokines served as markers of oxidative stress and mitochondrial dysfunction. Data of the study suggest that myocardial function was improved with sophoridine alone and in combination with dexmedetomidine in septic mice. Also, there was reduction in the expression of NADPH oxidase 2, NADPH oxidase 4, p-Extracellular signal-regulated kinase/Extracellular signal-regulated kinase, p-P38/P38 and caspase-3 protein in the myocardial tissues of sophoridine-treated group than sepsis group of mice. In conclusion, data of the report reveals that sophoridine alone and in combination with dexmedetomidine shows synergistic effect against the management of sepsis induced myocardial injured mice by modulating the expression of NADPH oxidase 2.

Inhibition of cathepsin S attenuates myocardial ischemia/reperfusion injury by suppressing inflammation and apoptosis.

Myocardial ischemia/reperfusion (I/R) injury leads to high mortality and morbidity due to the incomplete understanding of the underlying mechanism and the consequent lack of effective therapy. The present study revealed and validated key candidate genes in relation to inflammation and apoptosis pathways underlying myocardial I/R injury. Cathepsin S was identified as the top hub protein based on the protein-protein interaction analysis, and, thus, its role during myocardial I/R injury was further investigated. Myocardial I/R in mice resulted in significantly increased levels of myocardial injury biomarkers (cardiac troponin I, lactic dehydrogenase, and creatinine kinase-MB) and inflammatory cytokines (interleukin-1β [IL-1β], IL-6, and tumor necrosis factor-α), elevated apoptosis rate, and upregulated protein expression of cleaved caspase-8, cleaved caspase-3, and cleaved poly ADP-ribose polymerase. These abovementioned changes were blocked by two different selective cathepsin S inhibitors, LY3000328 or MIV-247. Moreover, Kaplan-Meier survival plot showed that cathepsin S inhibition improved 21-day survival rate following myocardial I/R injury. This study demonstrated that the inhibition of cathepsin S alleviated myocardial I/R-induced injury by suppressing inflammation and apoptosis, which may be used in clinical applications of cardioprotection.

Network pharmacology-based therapeutic mechanism of Kuanxiong aerosol for angina pectoris

Ethnopharmacological relevanceKuanxiong aerosol has been reported to be an effective and safe clinical treatment for angina pectoris (AP). Aim of the studyTo explore the potential pharmacological mechanism of Kuanxiong aerosol by combined methods of network pharmacology prediction and experimental verification. Materials and methodsNetworks of Kuanxiong aerosol-associated targets and AP-related genes were constructed through STRING database. Potential targets and pathway enrichment analysis related to the therapeutic efficacy of Kuanxiong aerosol were identified using Cytoscape and Database for Annotation, Visualization and Integrated Discovery (DAVID). To explore the mechanism of action of Kuanxiong aerosol, its in vitro effects on myocardial hypoxia, inflammatory cytokines, and oxidative injury, and its in vivo pharmacological effects on myocardial ischemia and cardiac fibrosis were studied in rat models. ResultsNetwork pharmacology analysis revealed that the potential targets mainly include the Fas ligand (FASLG), interleukin 4 (IL4), and catalase (CAT), which mediated the processes of apoptosis, and cellular responses to hypoxia, lipopolysaccharide (LPS), reactive oxygen species (ROS), and mechanical stimulus. Multiple pathways, such as the hypoxia-inducible factor 1 (HIF1) and tumor necrosis factor (TNF) pathways were found to be closely related to the pharmacological protective mechanism of Kuanxiong aerosol against AP. In addition, Kuanxiong aerosol suppressed the hypoxia, LPS, and hydrogen peroxide (H2O2)-induced injuries of H9c2 cardiomyocytes through the regulation of HIF1A, suppressed expression of IL6 and TNF, and antioxidant property. In the rat model of myocardial ischemia, Kuanxiong aerosol was found to lower the creatine kinase (CK), creatine kinase-myocardial band (CK-MB), and lactate dehydrogenase (LDH) levels, without altering the hemodynamic function. Kuanxiong aerosol was capable of attenuating cardiac fibrosis and improving cardiac function in a cardiac fibrosis rat model. ConclusionsThis study revealed that the pharmacological mechanisms of Kuanxiong aerosol for AP therapy were related to anti-myocardial ischemia, anti-inflammation, and anti-oxidation via a non-hemodynamic manner, indicating that Kuanxiong aerosol is a preferable drug clinically for AP treatment due to its both preventive and protective effects.