Effects of levo- and dextrosimendan on NF-kappaB-mediated transcription, iNOS expression and NO production in response to inflammatory stimuli

Challenging and target-based shifting strategies for heart failure treatment: An update from the last decades

Heart failure (HF) is a major global health problem afflicting millions worldwide. Despite the significant advances in therapies and prevention, HF still carries very high morbidity and mortality, requiring enormous healthcare-related expenditure, and the search for new weapons goes on. Following initial treatment strategies targeting inotropism and congestion, attention has focused on offsetting the neurohormonal overactivation and three main therapies, including angiotensin-converting enzyme inhibitors or angiotensin II type 1 receptor antagonists, β-adrenoceptor antagonists, and mineralocorticoid receptor antagonists, have been the foundation of standard treatment for patients with HF. Recently, a paradigm shift, including angiotensin receptor-neprilysin inhibitor, sodium glucose co-transporter 2 inhibitor, and ivabradine, has been added. Moreover, soluble guanylate cyclase stimulator, elamipretide, and omecamtiv mecarbil have come out as a next-generation therapeutic agent for patients with HF. Although these pharmacologic therapies have been significantly successful in relieving symptoms, there is still no complete cure for HF. We may be currently entering a new era of treatment for HF with animal experiments and human clinical trials assessing the value of antibody-based immunotherapy and gene therapy as a novel therapeutic strategy. Such tempting therapies still have some challenges to be addressed but may become a weighty option for treatment of HF. This review article will compile the paradigm shifts in HF treatment over the past dozen years or so and illustrate current landscape of antibody-based immunotherapy and gene therapy as a new therapeutic algorithm for patients with HF.

Levosimendan and Dobutamin Attenuate LPS-Induced Inflammation in Microglia by Inhibiting the NF-κB Pathway and NLRP3 Inflammasome Activation via Nrf2/HO-1 Signalling

Hypovolemic shock is a circulatory failure, due to a loss in the effective circulating blood volume, that causes tissue hypoperfusion and hypoxia. This condition stimulates reactive oxygen species (ROS) and pro-inflammatory cytokine production in different organs and also in the central nervous system (CNS). Levosimendan, a cardioprotective inodilator, and dobutamine, a β1-adrenergic agonist, are commonly used for the treatment of hypovolemic shock, thanks to their anti-inflammatory and antioxidant effects. For this reason, we aimed at investigating levosimendan and dobutamine's neuroprotective effects in an "in vitro" model of lipopolysaccharide (LPS)-induced neuroinflammation. Human microglial cells (HMC3) were challenged with LPS (0.1 µg/mL) to induce an inflammatory phenotype and then treated with levosimendan (10 µM) or dobutamine (50 µM) for 24 h. Levosimendan and dobutamine significantly reduced the ROS levels and markedly increased Nrf2 and HO-1 protein expression in LPS-challenged cells. Levosimendan and dobutamine also decreased p-NF-κB expression and turned off the NLRP3 inflammasome together with its downstream signals, caspase-1 and IL-1β. Moreover, a reduction in TNF-α and IL-6 expression and an increase in IL-10 levels in LPS-stimulated HMC3 cells was observed following treatment. In conclusion, levosimendan and dobutamine attenuated LPS-induced neuroinflammation through NF-κB pathway inhibition and NLRP3 inflammasome activation via Nrf2/HO-1 signalling, suggesting that these drugs could represent a promising therapeutic approach for the treatment of neuroinflammation consequent to hypovolemic shock.

Efficacy and safety of levosimendan in patients with sepsis: a systematic review and network meta-analysis

Objective: We conducted a systematic review to assess the advantages and disadvantages of levosimendan in patients with sepsis compared with placebo, milrinone, and dobutamine and to explore the clinical efficacy of different concentrations of levosimendan. Methods: PubMed, Web of Science, Cochrane Library, Embase, CNKI, Wanfang data, VIP, and CBM databases were searched using such keywords as simendan, levosimendan, and sepsis. The search time was from the establishment of the database to July 2023. Two researchers were responsible for literature screening and data collection respectively. After the risk of bias in the included studies was evaluated, network meta-analysis was performed using R software gemtc and rjags package. Results: Thirty-two randomized controlled trials (RCTs) were included in the network meta-analysis. Meta-analysis results showed that while levosimendan significantly improved CI levels at either 0.1 µg/kg/min (mean difference [MD] [95%CrI] = 0.41 [-0.43, 1.4]) or 0.2 µg/kg/min (MD [95%CrI] =0.54 [0.12, 0.99]). Levosimendan, at either 0.075 µg/kg/min (MD [95% CrI] =0.033 [-0.75, 0.82]) or 0.2 µg/kg/min (MD [95% CrI] = -0.014 [-0.26, 0.23]), had no significant advantage in improving Lac levels. Levosimendan, at either 0.1 µg/kg/min (RR [95% CrI] = 0.99 [0.73, 1.3]) or 0.2 µg/kg/min (RR [95% CrI] = 1.0 [0.88, 1.2]), did not have a significant advantage in reducing mortality. Conclusion: The existing evidence suggests that levosimendan can significantly improve CI and lactate levels in patients with sepsis, and levosimendan at 0.1 µg/kg/min might be the optimal dose. Unfortunately, all interventions in this study failed to reduce the 28-day mortality. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023441220.

Insampaedok-San Extract Exerts an Immune-Enhancing Effect through NF-κB p65 Pathway Activation

Insampaedok-san (IS) has traditionally been prescribed as a medication for cold-related symptoms in Northeast Asia, including Korea and China. In this study, we focused on elucidating the molecular mechanism underlying the immunomodulatory activity of IS water extract (ISE) in macrophages. ISE significantly enhanced the levels of nitric oxide (NO) and prostaglandin E2 (PGE2) by increasing the expression of inducible NO synthase and cyclooxygenase-2 (COX-2) in a dose-dependent manner. ISE, which consists of many herbs, contains a large number of active compounds whose pharmacological targets and mechanisms are complicated. Therefore, network pharmacology analysis was used to predict the potential key components, targets, and mechanisms of ISE as immunomodulators. Subsequently, the network pharmacology results were validated experimentally. Seven key components were identified through HPLC-QTOF-MS. As predicted by the network pharmacology analysis, ISE increased the mRNA expression of Tnf and Il6. Furthermore, ISE increased the phosphorylation, nuclear translocation, and transcriptional activity of the p65 subunit of the nuclear factor-κB (NF-κB) signaling pathway. In contrast, rapamycin, an NF-κB inhibitor, suppressed the ISE-induced mRNA expression of Tnf and Il6. In conclusion, ISE is an immune activator that can elevate the production of NO, PGE2, and proinflammatory cytokines mediated by NF-κB signaling.

Treatment with levosimendan in an experimental model of early ventilator-induced diaphragmatic dysfunction

Introduction

Mechanical ventilation (MV) is a life-saving approach in critically ill patients. However, it may affect the diaphragmatic structure and function, beyond the lungs. Levosimendan is a calcium sensitizer widely used in clinics to improve cardiac contractility in acute heart failure patients. In vitro studies have demonstrated that levosimendan increased force-generating capacity of the diaphragm in chronic obstructive pulmonary disease patients. Thus the aim of this study was to evaluate the effects of levosimendan administration in an animal model of ventilator-induced diaphragmatic dysfunction (VIDD) on muscle contraction and diaphragm muscle cell viability.

Methods

Sprague-Dawley rats underwent prolonged MV (5 hours). VIDD+Levo group received a starting bolus of levosimendan immediately after intratracheal intubation and then an intravenous infusion of levosimendan throughout the study. Diaphragms were collected for ex vivo contractility measurement (with electric stimulation), histological analysis and Western blot analysis. Healthy rats were used as the control.

Results

Levosimendan treatment maintained an adequate mean arterial pressure during the entire experimental protocol, preserved levels of autophagy-related proteins (LC3BI and LC3BII) and the muscular cell diameter demonstrated by histological analysis. Levosimendan did not affect the diaphragmatic contraction or the levels of proteins involved in the protein degradation (atrogin).

Conclusions

Our data suggest that levosimendan preserves muscular cell structure (cross-sectional area) and muscle autophagy after 5 hours of MV in a rat model of VIDD. However, levosimendan did not improve diaphragm contractile efficiency.

Levosimendan Increases Survival in a D-Galactosamine and Lipopolysaccharide Rat Model

Levosimendan, a calcium sensitizer, has an organ protective profile through the inhibition of inflammatory mediators and cytokines in critical conditions, such as heart failure, ischemia-reperfusion injury, and sepsis. The survival effect of levosimendan for acute liver failure has not been examined yet. Male Sprague-Dawley rats were examined in the D-galactosamine hydrochloride and lipopolysaccharide (GalN/LPS) model. Levosimendan was injected intraperitoneally before GalN/LPS treatment. Survival was monitored for 7 days. For biochemical analyses, liver and blood samples were collected from the rats at 1 and 8 h after GaIN/LPS treatment. The pretreatment of levosimendan at 4 mg/kg significantly increased survival in GalN/LPS rats. In the liver specimen, levosimendan significantly inhibited the activation of nuclear factor-κB (NF-κB) at 1 h, and significantly decreased the mRNA expression of inflammatory mediators, including inducible nitric oxide synthase and tumor necrosis factor-α (TNF-α), at 8 h. In serum, levosimendan decreased the levels of nitrite, a metabolite of nitric oxide, and TNF-α protein, as well as aspartate aminotransferase and alanine aminotransferase. These results indicated that Levosimendan ameliorated liver dysfunction and survival in acute liver failure model rats through the suppression of NF-κB activation.

Inodilators in septic shock: should these be used?

Septic shock involves a complex interaction between abnormal vasodilation, relative and/or absolute hypovolemia, myocardial dysfunction, and altered blood flow distribution to the tissues. Fluid administration, vasopressor support and inotropes, represent fundamental pieces of quantitative resuscitation protocols directed to assist the restoration of impaired tissue perfusion during septic shock. Indeed, current recommendations on sepsis management include the use of inotropes in the case of myocardial dysfunction, as suggested by a low cardiac output, increased filling pressures, or persisting signals of tissue hypoperfusion despite an adequate correction of intravascular volume and mean arterial pressure by fluid administration and vasopressor support. Evidence supporting the use of inotropes in sepsis and septic shock is mainly based on physiological studies. Most of them suggest a beneficial effect of inotropes on macro hemodynamics especially when sepsis coexists with myocardial dysfunction; others, however, have demonstrated variable results on regional splanchnic circulation, while others suggest favorable effects on microvascular distribution independently of its impact on cardiac output. Conversely, impact of inodilators on clinical outcomes in this context has been more controversial. Use of dobutamine has not been consistently related with more favorable clinical results, while systematic administration of levosimendan in sepsis do not prevent the development of multiorgan dysfunction, even in patients with evidence of myocardial dysfunction. Nevertheless, a recent metanalysis of clinical studies suggests that cardiovascular support regimens based on inodilators in sepsis and septic shock could provide some beneficial effect on mortality, while other one corroborated such effect on mortality specially in patients with proved lower cardiac output. Thus, using or not inotropes during sepsis and septic shock remains as controversy matter that deserves more research efforts.

Sepsis: From Historical Aspects to Novel Vistas. Pathogenic and Therapeutic Considerations

BACKGROUND

Sepsis is a clinical condition due to an infectious event which leads to an early hyper-inflammatory phase followed by a status of tolerance or immune paralysis. Hyper-inflammation derives from a massive activation of immune (neutrophils, monocytes/macrophages, dendritic cells and lymphocytes) and non-immune cells (platelets and endothelial cells) in response to Gram-negative and Gram-positive bacteria and fungi.

DISCUSSION

A storm of pro-inflammatory cytokines and reactive oxygen species accounts for the systemic inflammatory response syndrome. In this phase, bacterial clearance may be associated with a severe organ failure development. Tolerance or compensatory anti-inflammatory response syndrome (CARS) depends on the production of anti-inflammatory mediators, such as interleukin-10, secreted by T regulatory cells. However, once triggered, CARS, if prolonged, may also be detrimental to the host, thus reducing bacterial clearance.

CONCLUSION

In this review, the description of pathogenic mechanisms of sepsis is propaedeutic to the illustration of novel therapeutic attempts for the prevention or attenuation of experimental sepsis as well as of clinical trials. In this direction, inhibitors of NF-κB pathway, cell therapy and use of dietary products in sepsis will be described in detail.

Retracted Article: Anti-inflammatory potency of Locusta migratoria manilensis cyclopeptides in mast cells and macrophages

Locusts are esteemed as a traditional Chinese medicine, as well as tonic foods in Asian countries. While searching for natural anti-inflammatory agents in natural products, we isolated four novel locust cyclopeptides (LCPs) and the results show that [cyclo-(Trp-Leu-His-Thr)]∼LCP-3 has potent anti-inflammatory potency in RAW264.7 and HMC-1 cells under LPS (lipopolysaccharide) stimuli. Furthermore, mechanistic studies show that LCP-3 attenuates pro-inflammatory cytokine (TNF-α, IL-6, IL-1β, NO and PGE2) expression. Moreover, LCP-3 attenuates inflammatory damage associated with the direct inhibition of iNOS and COX-2 expression. LCP-3 also regulates the MAPK, PI3K/AKT and NF-κB pathways to attenuate LPS-induced damage. Of note, our study first reports the anti-inflammatory potency of LCPs and elucidates their underlying molecular mechanisms.

Levosimendan pretreatment improves survival of septic rats after partial hepatectomy and suppresses iNOS induction in cytokine-stimulated hepatocytes

We evaluated the survival effects and biochemical profiles of levosimendan in septic rats after partial hepatectomy and investigated its effects in cultured hepatocytes. Thirty-two rats underwent 70% hepatectomy and were randomised equally into four groups, followed by lipopolysaccharide (LPS) injection (250 µg/kg, i.v.) after 48 h. Levosimendan was given (i.p.) 1 h before LPS injection [group (A) levosimendan 2 mg/kg; (B) 1; (C) 0.5; (D) vehicle]. Survival at 7 days was increased significantly in group A compared with that in group D [A: 63%; B: 38%; C: 13%; D: 0%]. In serum, levosimendan decreased the level of tumour necrosis factor-α, interleukin (IL)-1β, IL-6 and nitric oxide (NO). In remnant livers, levosimendan inhibited inducible nitric oxide synthase (iNOS) gene expression. In primary cultured rat hepatocytes stimulated by IL-1β, levosimendan suppressed NO production by inhibiting iNOS promoter activity and stability of its mRNA.

Effects of Levosimendan on Inflammation and Oxidative Stress Pathways in a Lipopolysaccharide-Stimulated Human Endothelial Cell Model

Levosimendan is a myocardial Ca²⁺ sensitizer and opener of ATP-dependent potassium channels with inotropic, vasodilating, and cardioprotective properties. It was originally developed for the treatment of acute decompensated heart failure, but its complex mechanism of action means that it could also play a role in organ protection in response to infection. Using an in vitro approach, we explored whether levosimendan administration influenced cell responses to lipopolysaccharide (LPS). Primary human umbilical vein endothelial cells were stimulated with 1 µg/ml LPS from Escherichia coli (E. coli). Cells were treated with levosimendan at 0, 0.1, 1, or 10 µM 3 hr later. Samples were taken 24 hr after treatment to measure cell necrosis, apoptosis, pro-inflammatory mediators (interleukin 6 [IL-6] and toll-like receptor 4 [TLR4]), and oxidative stress (total reactive oxygen species/reactive nitrogen species [ROS/RNS]). Levosimendan at 1 and 10 µM protected against LPS-induced endothelial cell death and reduced TLR4 expression (p < .05). All doses reduced levels of IL-6 and ROS/RNS (p < .05). Findings suggest that levosimendan may exert protective effects against endothelial cell death in this model via attenuation of inflammation and oxidative stress pathways. Future studies might explore the potential beneficial role of levosimendan in modulating molecular mechanisms triggered by infections.

Cardioprotective and functional effects of levosimendan and milrinone in mice with cecal ligation and puncture-induced sepsis

Levosimendan and milrinone may be used in place of dobutamine to increase cardiac output in septic patients with a low cardiac output due to impaired cardiac function. The effects of the two inotropic agents on cardiac inflammation and left ventricular (LV) performance were examined in mice with cecal ligation and puncture (CLP)-induced sepsis. CLP mice displayed significant cardiac inflammation, as indicated by highly increased pro-inflammatory cytokines and neutrophil infiltration in myocardial tissues. When continuously given, levosimendan prevented but milrinone exaggerated cardiac inflammation, but they significantly reduced the elevations in plasma cardiac troponin-I and heart-type fatty acid-binding protein, clinical markers of cardiac injury. Echocardiographic assessment of cardiac function showed that the effect of levosimendan, given by an intravenous bolus injection, on LV performance was impaired in CLP mice, whereas milrinone produced inotropic responses equally in sham-operated and CLP mice. A lesser effect of levosimendan on LV performance after CLP was also found in spontaneously beating Langendorff-perfused hearts. In ventricular myocytes isolated from control and CLP mice, levosimendan, but not milrinone, caused a large increase in the L-type calcium current. This study represents that levosimendan and milrinone have cardioprotective properties but provide different advantages and drawbacks to cardiac inflammation/dysfunction in sepsis.

Cardioprotective and Anti-Aggregatory Effects of Levosimendan on Isoproterenol-Induced Myocardial Injury in High-Fat-Fed Rats Involves Modulation of PI3K/Akt/mTOR Signaling Pathway and Inhibition of Apoptosis

Hyperlipidemia and hypercoagulability states are linked with the increased risks of myocardial infarction (MI). Levosimendan has vasorelaxant and anti-aggregatory properties. The present study evaluated the anti-aggregatory and cardioprotective effects of levosimendan versus cilostazol in high-fat diet (HFD)-fed rats subjected to isoproterenol-induced MI. Rats were assigned to normal, HFD, HFD + isoproterenol, HFD + isoproterenol + cilostazol, and HFD + isoproterenol + levosimendan. The present study investigated the anti-aggregatory effect of both levosimendan and cilostazol and revealed that both drugs attenuated the severity of platelet aggregation. Moreover, both levosimendan and cilostazol revealed effectiveness in attenuating the severity of HFD/isoproterenol-induced myocardial injury as revealed by electrocardiogram signs, apoptotic markers, and histopathological score via counteracting the oxidative stress burden, increments in the expression of inflammatory mediators, and modulating nuclear factor kappa-B (NF-κB) and phosphatidylinositide 3-kinases (PI3K)/protein kinase B (Akt)/ mechanistic target of rapamycin (mTOR) pathway. It was obvious that levosimendan offered more cardioprotective properties than cilostazol. The study showed the relations between hyperlipedemia, hyperaggregability state, and myocardial injury with the modulation of NF-κB and PI3K/Akt/mTOR pathway.

Effect of levosimendan on mortality in severe sepsis and septic shock: a meta-analysis of randomised trials

OBJECTIVE

We aim to synthesise up-to-date randomised trials to investigate the effects of levosimendan on mortality and clinical outcomes in severe sepsis and septic shock.

METHODS

A collection of databases including PubMed, EMBASE, Cochrane Central Register and Web of Science were searched updated to August 2017. Randomised trials were included when they pertain to the use of levosimendan in severe sepsis or septic shock compared with any category of inotropes, or as an adjunct to standard therapy with mortality reported. The primary outcome was mortality, and the secondary outcomes were clinical performances including serum lactate, cardiac function, vasopressor requirement and fluid infusion.

RESULTS

A total of 10 studies with 1036 patients were included in this meta-analysis. The results revealed that levosimendan could not reduce mortality significantly in severe sepsis and septic shock (OR 0.89, 95% CI 0.69 to 1.16, P=0.39). Levosimendan use could reduce serum lactate more effectively, and enhance cardiac contractibility with increased cardiac index and left ventricular ejection fraction. However, its use could also increase fluid infusion but not reduce norepinephrine dose. No significant benefit in mortality could be observed of levosimendan versus dobutamine use, or in patients with proven cardiac dysfunction.

CONCLUSIONS

Current evidence is not sufficient to support levosimendan as superior to dobutamine or as an optimal adjunct in severe sepsis and septic shock. More large-scale randomised trials are necessary to validate levosimendan use in sepsis.

Impact of levosimendan on platelet function

Levosimendan has been developed for treatment of severe heart failure. The favorable hemodynamic effect of levosimendan is related to its unique dual mechanism of action - increase of the contractile force of the myocardium caused by enhanced sensitivity of myofilaments to calcium combined with vasodilatation caused by the opening of adenosine triphosphate - dependent potassium channels. Due to the structural similarities to phosphodiesterase inhibitors it may partly exert its action via inhibition of phosphodiesterase inhibitors III. Inhibition of the phosphodiesterase inhibitors III leads to an increase of intracellular concentration of cyclic adenosine monophosphate causing an anti-aggregatory effect. There are some contradictory or indirect and inconclusive reports related to the impact of levosimendan on platelet function. The aim of this systematic review was to critically discuss the impact of levosimendan on platelet function according to currently available knowledge based on the findings of experimental as well as observational and randomized clinical studies.

Screening of an FDA-approved compound library identifies levosimendan as a novel anti-HIV-1 agent that inhibits viral transcription

Combination antiretroviral therapy (cART) has been proven to efficiently inhibit ongoing replication of human immunodeficiency virus type 1 (HIV-1), and significantly improve the health outcome in patients of acquired immune deficiency syndrome (AIDS). However, cART is unable to cure HIV-1/AIDS. Even in presence of cART there exists a residual viremia, contributed from the viral reservoirs of latently infected HIV-1 proviruses; this constitutes a major hurdle. Currently, there are multiple strategies aimed at eliminating or permanently silence these HIV-1 latent reservoirs being intensely explored. One such strategy, a recently emerged "block and lock" approach is appealing. For this approach, so-called HIV-1 latency-promoting agents (LPAs) are used to reinforce viral latency and to prevent the low-level or sporadic transcription of integrated HIV-1 proviruses. Although several LPAs have been reported, there is still a question of their suitability to be further developed as a safe and valid therapeutic agent for the clinical use. In this study, we aimed to identify new potential LPAs through the screening an FDA-approved compound library. A new and promising anti-HIV-1 inhibitor, levosimendan, was identified from these screens. Levosimendan is currently used to treat heart failure in clinics, but it demonstrates strong inhibition of TNFα-induced HIV-1 reactivation in multiple cell lines of HIV-1 latency through affecting the HIV-1 Tat-LTR transcriptional axis. Furthermore, we confirmed that in primary CD4⁺ T cells levosimendan inhibits both the acute HIV-1 replication and the reactivation of latent HIV-1 proviruses. As a summary, our studies successfully identify levosimendan as a novel and promising anti-HIV-1 inhibitor, which should be immediately investigated in vivo given that it is already an FDA-approved drug.

Dose–Response Head-to-Head Comparison of Inodilators Dobutamine, Milrinone, and Levosimendan in Chronic Experimental Pulmonary Hypertension

The choice of inodilator drug in the acute management of patients with pulmonary hypertension (PH) having right ventricular (RV) failure remains unsettled and challenging. Comprehensive experimental evaluations may provide further insight and fundamental translational research clues to support inodilator selection and clinical trial design. Our aim was to compare acute dose–response hemodynamic effects of inodilators dobutamine (DOB), milrinone (MIL), and levosimendan (LEV) in chronic experimental PH. Seven-week-old male Wistar rats were randomly injected with 60 mg·kg−1 monocrotaline (MCT) or vehicle (Ctrl, n = 7) and underwent systemic and pulmonary artery (PA) pressure and RV pressure–volume (PV) hemodynamic evaluation under halogenate anesthesia 24 to 30 days after injection. The MCT-injected animals (n = 7 each) randomly received dose–response infusions of DOB (1, 3, 6 and 12 μg·kg−1·min−1), MIL (MIL: 1, 3, 6 and 12 μg·kg−1·min−1), or LEV (0.3, 0.6, 1.2 and 2.4 μg·kg−1·min−1). Load-independent indexes were obtained by inferior vena cava occlusion at baseline and after the last dose. All inodilators increased RV ejection fraction, preload recruitable stroke work, and ventricular–vascular coupling without jeopardizing perfusion pressure. Dobutamine raised heart rate and PA pressure. Only LEV increased cardiac index and decreased PA elastance and pulmonary vascular resistance (PVR). Moreover, only LEV downward-shifted the end-diastolic PV relationship, thereby improving RV compliance. Adding sildenafil to LEV further decreased PVR. Levosimendan had beneficial acute systolic and diastolic functional effects in experimental chronic PH and RV afterload compared to DOB and MIL. It should be further tested in clinical trials enrolling patients with PH in the perioperative and critical care settings.

Anti-thrombotic and pro-fibrinolytic effects of levosimendan in human endothelial cells in vitro

AIMS

Levosimendan is an inodilator for the treatment of acute decompensated heart failure (HF). Data from clinical studies suggest that levosimendan is particularly effective in HF due to myocardial infarction. After acute revascularization, no reflow-phenomenon is a common complication that may lead to pump failure and cardiogenic shock. Our aim was to examine whether levosimendan interferes with the pro-thrombotic phenotype of activated endothelial cells in vitro.

METHODS

Human heart microvascular endothelial cells (HHMEC) and human umbilical vein endothelial cells (HUVEC) were treated with interleukin-1β (IL-1β) (200U/mL) or thrombin (5U/mL) and co-treated with or without levosimendan (0.1-10μM) for 2-24h. In addition, flow experiments were performed. Effects on plasminogen activator inhibitor-1 (PAI-1) and tissue factor (TF) expression and activity were measured by rt-PCR, specific ELISA and flow cytometry.

RESULTS

Treatment with IL-1β or thrombin significantly increased the expression of PAI-1 and TF in endothelial cells. Co-treatment with levosimendan strongly attenuated the effects of IL-1β and thrombin on PAI-1 and TF mRNA by up to 50% and 45%, in a dose- and time-dependent manner. Similar results were obtained under flow conditions. Furthermore, co-treatment with levosimendan dampened the antigen production of PAI-1 and the surface expression of TF by 35% and 45%, respectively. Additionally, levosimendan diminished both TF and PAI-1 activity.

CONCLUSION

Levosimendan down-regulates the expression of the pro-thrombotic and anti-fibrinolytic biomolecules TF and PAI-1 in activated human endothelial cells. Our findings may, at least in part, explain some of the beneficial effects of levosimendan after myocardial reperfusion.

Levosimendan beyond inotropy and acute heart failure: Evidence of pleiotropic effects on the heart and other organs: An expert panel position paper

Levosimendan is a positive inotrope with vasodilating properties (inodilator) indicated for decompensated heart failure (HF) patients with low cardiac output. Accumulated evidence supports several pleiotropic effects of levosimendan beyond inotropy, the heart and decompensated HF. Those effects are not readily explained by cardiac function enhancement and seem to be related to additional properties of the drug such as anti-inflammatory, anti-oxidative and anti-apoptotic ones. Mechanistic and proof-of-concept studies are still required to clarify the underlying mechanisms involved, while properly designed clinical trials are warranted to translate preclinical or early-phase clinical data into more robust clinical evidence. The present position paper, derived by a panel of 35 experts in the field of cardiology, cardiac anesthesiology, intensive care medicine, cardiac physiology, and cardiovascular pharmacology from 22 European countries, compiles the existing evidence on the pleiotropic effects of levosimendan, identifies potential novel areas of clinical application and defines the corresponding gaps in evidence and the required research efforts to address those gaps.

Inotropes and inodilators for acute heart failure: sarcomere active drugs in focus

Acute heart failure (AHF) emerges as a major and growing epidemiological concern with high morbidity and mortality rates. Current therapies in patients with acute heart failure rely on different strategies. Patients with hypotension, hypoperfusion, or shock require inotropic support, whereas diuretics and vasodilators are recommended in patients with systemic or pulmonary congestion. Traditionally inotropic agents, referred to as Ca²⁺ mobilizers load the cardiomyocyte with Ca²⁺ and thereby increase oxygen consumption and risk for arrhythmias. These limitations of traditional inotropes may be avoided by sarcomere targeted agents. Direct activation of the cardiac sarcomere may be achieved by either sensitizing the cardiac myofilaments to Ca²⁺ or activating directly the cardiac myosin. In this review, we focus on sarcomere targeted inotropic agents, emphasizing their mechanisms of action and overview the most relevant clinical considerations.

Levosimendan affects oxidative and inflammatory pathways in the diaphragm of ventilated endotoxemic mice

INTRODUCTION

Controlled mechanical ventilation and endotoxemia are associated with diaphragm muscle atrophy and dysfunction. Oxidative stress and activation of inflammatory pathways are involved in the pathogenesis of diaphragmatic dysfunction. Levosimendan, a cardiac inotrope, has been reported to possess anti-oxidative and anti-inflammatory properties. The aim of the present study was to investigate the effects of levosimendan on markers for diaphragm nitrosative and oxidative stress, inflammation and proteolysis in a mouse model of endotoxemia and mechanical ventilation.

METHODS

Three groups were studied: (1) unventilated mice (CON, n =8), (2) mechanically ventilated endotoxemic mice (MV LPS, n =17) and (3) mechanically ventilated endotoxemic mice treated with levosimendan (MV LPS + L, n =17). Immediately after anesthesia (CON) or after 8 hours of mechanical ventilation, blood and diaphragm muscle were harvested for biochemical analysis.

RESULTS

Mechanical ventilation and endotoxemia increased expression of inducible nitric oxide synthase (iNOS) mRNA and cytokine levels of interleukin (IL)-1β, IL-6 and keratinocyte-derived chemokine, and decreased IL-10, in the diaphragm; however, they had no effect on protein nitrosylation and 4-hydroxy-2-nonenal protein concentrations. Levosimendan decreased nitrosylated proteins by 10% (P <0.05) and 4-hydroxy-2-nonenal protein concentrations by 13% (P <0.05), but it augmented the rise of iNOS mRNA by 47% (P <0.05). Levosimendan did not affect the inflammatory response in the diaphragm induced by mechanical ventilation and endotoxemia.

CONCLUSIONS

Mechanical ventilation in combination with endotoxemia results in systemic and diaphragmatic inflammation. Levosimendan partly decreased markers of nitrosative and oxidative stress, but did not affect the inflammatory response.

Levosimendan exerts anti-inflammatory effects on cardiac myocytes and endothelial cells in vitro

Levosimendan is a positive inotropic drug for the treatment of acute decompensated heart failure (HF). Clinical trials showed that levosimendan was particularly effective in HF due to myocardial infarction. Myocardial necrosis induces a strong inflammatory response, involving chemoattractants guiding polymorphonuclear neutrophils (PMN) into the infarcted myocardial tissue. Our aim was to examine whether levosimendan exhibits anti-inflammatory effects on human adult cardiac myocytes (HACM) and human heart microvascular endothelial cells (HHMEC). Cardiac myocytes and endothelial cells were stimulated with interleukin-1β (IL)-1β (200 U/ml) and treated with levosimendan (0.1-10 µM) for 2-48 hours. IL-1β strongly induced expression of IL-6 and IL-8 in HACM and E-selectin and intercellular adhesion molecule-1 (ICAM-1) in HHMEC and human umbilical vein endothelial cells (HUVEC). Treatment with levosimendan strongly attenuated IL-1β-induced expression of IL-6 and IL-8 in HACM as well as E-selectin and ICAM-1 in ECs. Levosimendan treatment further reduced adhesion of PMN to activated endothelial cells under both static and flow conditions by approximately 50 %. Incubation with 5-hydroxydecanoic acid, a selective blocker of mitochondrial ATP-dependent potassium channels, partly abolished the above seen anti-inflammatory effects. Additionally, levosimendan strongly diminished IL-1β-induced reactive oxygen species and nuclear factor-κB (NF-κB) activity through inhibition of S536 phosphorylation. In conclusion, levosimendan exhibits anti-inflammatory effects on cardiac myocytes and endothelial cells in vitro. These findings could explain, at least in part, the beneficial effects of levosimendan after myocardial infarction.

Levosimendan in critical illness: a literature review

Levosimendan, the active enantiomer of simendan, is a calcium sensitizer developed for treatment of decompensated heart failure, exerts its effects independently of the beta adrenergic receptor and seems beneficial in cases of severe, intractable heart failure. Levosimendan is usually administered as 24-h infusion, with or without a loading dose, but dosing needs adjustment in patients with severe liver or renal dysfunction. Despite several promising reports, the role of levosimendan in critical illness has not been thoroughly evaluated. Available evidence suggests that levosimendan is a safe treatment option in critically ill patients and may reduce mortality from cardiac failure. However, data from well-designed randomized controlled trials in critically ill patients are needed to validate or refute these preliminary conclusions. This literature review is an attempt to synthesize available evidence on the role and possible benefits of levosimendan in critically ill patients with severe heart failure.

Eosinophil apoptosis as a therapeutic target in allergic asthma

Asthma is a chronic inflammatory disease of the airways manifesting in many different phenotypes. Allergic asthma, comprising approximately half of patients with asthma, is characterized by the accumulation of eosinophils into the lungs. Eosinophils release factors that damage the surrounding cells and participate in the maintenance and exacerbation of inflammation. In the absence of any inflammatory survival-prolonging factors, eosinophils die by apoptosis in few days but in inflamed airways, eosinophil survival is thought to be prolonged due to the surrounding pro-inflammatory factors such as IL-5, IL-3 and GM-CSF. Resolution of eosinophilic inflammation is an important goal in the treatment of allergic asthma. Apoptosis is a physiological and non-inflammatory way to eliminate these harmful cells, and development of drugs targeting eosinophil apoptosis is one possible strategy for the therapy of allergic asthma. Importance of this strategy is supported by the fact that promotion of eosinophil apoptosis is a property of many anti-asthmatic agents such as glucocorticoids, the current main anti-inflammatory therapy of asthma, theophylline and leukotriene modifiers. β2 agonists have been shown to modulate eosinophil longevity by increasing survival. Also, anti-IL-5 antibody mesolizumab has shown efficacy in reducing asthma exacerbations in patients with severe eosinophilic asthma. Many potential future anti-asthmatic agents, such as Siglec-8 activating antibody and novel humanized anti-IL-5 antibody MEDI-563, have the property of inducing eosinophil apoptosis. This MiniReview aims to present eosinophil apoptosis as a therapeutic target in the treatment of allergic asthma. We summarize the effects and mechanisms of current and potential future anti-asthmatic drugs on eosinophil apoptosis and additionally, discuss the potential factors that promote eosinophil longevity in the lungs.

Anti-inflammatory Potential of Silk Sericin

Silk sericin was found to suppress the production of pro-inflammatory cytokines, which are related to the inflammatory reaction. The objectives of this study were to investigate the anti-inflammatory effect of sericin in vivo using the carrageenan-induced rat edema model and changes in the histology of tissues. The effects of sericin on the expression of COX-2 and iNOS were also evaluated. Sericin solutions at 0.004-0.080 mg/mL were applied topically to the top of the hind paw and carrageenan (1.0 mg) was injected subcutaneously to the plantar surface of the right hind paw. Our results indicated that sericin significantly reduced the inflammation in rats’ paw compared with the negative control (water and acetone) and its effect at 0.080 mg/mL was only slightly lower than that of 1.0% w/v indomethacin. Similar numbers of polymorphonuclear and macrophage cells were found in rats’ tissue treated with indomethacin and sericin solution, while the numbers were significantly higher in their absence. The gene expression results by RT-PCR showed that the COX-2 and iNOS genes were down-regulated in samples treated with sericin in a dose dependent manner. These data indicated that the anti-inflammatory properties of sericin may be partly attributable to the suppression of the COX-2 enzyme and nitric oxide production.

No beneficial effects of levosimendan in acute porcine endotoxaemia

BACKGROUND

Levosimendan has been proposed as an attractive alternative to adrenergic agents for the treatment of sepsis-induced heart failure and haemodynamic derangements. Its use in this setting is, however, still not well investigated. The aim of this study was to test the hypothesis that levosimendan is able to attenuate endotoxin-induced pulmonary hypertension and improve myocardial function in a porcine model. The secondary aims were to investigate its effect on renal and liver function, and the plasma cytokine response.

METHODS

Endotoxaemia was induced in 18 pigs, randomized to placebo and Levosimendan groups. All pigs were fluid resuscitated and Noradrenalin infusion was given according to a predefined protocol. Systemic haemodynamics and myocardial function were measured using pulmonary artery catheterization and transthoracic echocardiography. Renal and liver function tests and cytokine concentrations were measured in plasma.

RESULTS

Levosimendan did not attenuate endotoxin-induced pulmonary hypertension and did not improve myocardial function. There were no differences in renal or liver function. Increases in arterial lactate and decreases in base excess were observed in the Levosimendan group, as well as significant increases in plasma interleukin (IL)-6 and IL-8.

CONCLUSIONS

Contrary to our hypothesis, levosimendan given in conjunction with a protocolized vasopressor and fluid resuscitation did not improve cardiac, renal or liver function in this model of acute porcine endotoxaemia. Hyperlactataemia, acidosis and increases in plasma pro-inflammatory cytokines were observed, the mechanisms and implications of which remain unclear.

TNFα in myocardial ischemia/reperfusion, remodeling and heart failure

TNFα is crucially involved in the pathogenesis and progression of myocardial ischemia/reperfusion injury and heart failure. The formation and release of TNFα and its downstream signal transduction cascade following activation of its two receptor subtypes are characterized. Myocardial TNFα and TNF receptor activation have an ambivalent role in myocardial ischemia/reperfusion injury and protection from it. Excessive TNFα expression and subsequent cardiomyocyte TNF receptor type 1 stimulation induce contractile dysfunction, hypertrophy, fibrosis and cell death, while a lower TNFα concentration and subsequent cardiomyocyte TNF receptor type 2 stimulation are protective. Apart from its concentration and receptor subtype, the myocardial action of TNFα depends on the duration of its exposure and its localization. While detrimental during sustained ischemia, TNFα contributes to ischemic preconditioning protection, no matter whether it is the first, second or third window of protection, and both TNF receptors are involved in the protective signal transduction cascade. Finally, the available clinical attempts to antagonize TNFα in cardiovascular disease, notably heart failure, are critically discussed.

Levosimendan: calcium sensitizer and inodilator

Levosimendan is a unique therapeutic agent that decreases mortality in acute episodes of decompensated heart failure by increasing myocardial contractility without increasing oxygen consumption or ATP demands, decreasing preload, or decreasing afterload. The mechanism for each accomplishment is novel. The drug is a calcium sensitizer, which increases myocyte contractility by stabilizing troponin C rather than by increasing intracellular calcium. The drug may have implications in numerous other common and chronic medical ailments, even in overdoses of drugs that stun and depress the myocardium.