Mitochondrial abnormalities in septic cardiomyopathy

Septic cardiomyopathy is a common complication in patients with sepsis, and is one of the indicators of poor prognosis. Its pathogenesis is complex, involving calcium ion imbalance in cardiomyocytes, nitric oxide (NO) synthesis disorder, mitochondrial abnormalities and immune inflammatory reaction, especially mitochondrial abnormalities. In this paper, the mechanism of mitochondrial abnormalities causing septic cardiomyopathy was discussed from the aspects of mitochondrial structure change, mitochondrial energy metabolism disorder, redox imbalance, mitochondrial calcium overload, mitochondrial biosynthesis and autophagy abnormalities.

How to use echocardiography to manage patients with shock?

Echocardiography enables the intensivist to assess the patient with circulatory failure. It allows the clinician to identify rapidly the type and the cause of shock in order to develop an effective management strategy. Important characteristics in the setting of shock are that it is non-invasive and can be rapidly applied. Early and repeated echocardiography is a valuable tool for the management of shock in the intensive care unit. Competency in basic critical care echocardiography is now regarded as a mandatory part of critical care training with clear guidelines available. The majority of pathologies found in shocked patients are readily identified using basic level 2D and M-mode echocardiography. The four core types of shock (cardiogenic, hypovolemic, obstructive, and septic) can readily be identified by echocardiography. Echocardiography can differentiate the different pathologies that may be the cause of each type of shock. More importantly, as a result of more complex and elderly patients, the shock may be multifactorial, such as a combination of cardiogenic and septic shock, which emphasises on the added value of transthoracic echocardiography (TTE) in such population of patients. In this review we aimed to provide to clinicians a bedside strategy of the use of TTE parameters to manage patients with shock. In the first part of this overview, we detailed the different TTE parameters and how to use them to identify the type of shock. And in the second part, we focused on the use of these parameters to evaluate the effect of treatments, in different types of shock.

Efficacy of antibiotic combinations in an experimental sepsis model with Pseudomonas aeruginosa

This study aimed to compare the efficacy of fosfomycin, colistin, tobramycin and their dual combinations in an experimental sepsis model. After sepsis was established with a Pseudomonas aeruginosa isolate (P1), antibiotic-administered rats were divided into six groups: Fosfomycin, tobramycin, colistin and their dual combinations were administered by the intravenous or intraperitoneal route to the groups. The brain, heart, lung, liver, spleen and kidney tissues of rats were cultured to investigate bacterial translocation caused by P1. Given the antibiotics and their combinations, bacterial colony counts in liver tissues were decreased in colistin alone and colistin plus tobramycin groups compared with control group, but there were no significant differences. In addition, a non-statistical decrease was found in the spleen tissues of rats in the colistin plus tobramycin group. There was a > 2 log10 CFU/ml decrease in the number of bacterial colonies in the kidney tissues of the rats in the fosfomycin group alone, but the decrease was not statistically significant. However, there was an increase in the number of bacterial colonies in the spleen and kidney samples in the group treated with colistin as monotherapy compared to the control group. The number of bacterial colonies in the spleen samples in fosfomycin plus tobramycin groups increased compared to the control group. Bacterial colony numbers in all tissue samples in the fosfomycin plus colistin group were found to be close to those in the control group. Colistin plus tobramycin combinations are effective against P. aeruginosa in experimental sepsis, and clinical success may be achieved. New in vivo studies demonstrating the ability of P. aeruginosa to biofilm formation in tissues other than the lung are warranted in future.

Sepsis in the Pediatric Cardiac Intensive Care Unit: An Updated Review

Sepsis remains among the most common causes of mortality in children with congenital heart disease (CHD). Extensive literature is available regarding managing sepsis in pediatric patients without CHD. Because the cardiovascular pathophysiology of children with CHD differs entirely from their typical peers, the available diagnosis and management recommendations for sepsis cannot be implemented directly in children with CHD. This review discusses the risk factors, etiopathogenesis, available diagnostic tools, resuscitation protocols, and anesthetic management of pediatric patients suffering from various congenital cardiac lesions. Further research should focus on establishing a standard guideline for managing children with CHD with sepsis and septic shock admitted to the intensive care unit.

Modulation of the mTOR Pathway by Curcumin in the Heart of Septic Mice

mTOR is a signaling pathway involved in cell survival, cell stress response, and protein synthesis that may be a key point in sepsis-induced cardiac dysfunction. Curcumin has been reported in vitro as an mTOR inhibitor compound; however, there are no studies demonstrating this effect in experimental sepsis. Thus, this study aimed to evaluate the action of curcumin on the mTOR pathway in the heart of septic mice. Free curcumin (FC) and nanocurcumin (NC) were used, and samples were obtained at 24 and 120 h after sepsis. Histopathological and ultrastructural analysis showed that treatments with FC and NC reduced cardiac lesions caused by sepsis. Our main results demonstrated that curcumin reduced mTORC1 and Raptor mRNA at 24 and 120 h compared with the septic group; in contrast, mTORC2 mRNA increased at 24 h. Additionally, the total mTOR mRNA expression was reduced at 24 h compared with the septic group. Our results indicate that treatment with curcumin and nanocurcumin promoted a cardioprotective response that could be related to the modulation of the mTOR pathway.

Cardiomyocyte-specific disruption of soluble epoxide hydrolase limits inflammation to preserve cardiac function

Endotoxemia elicits a multiorgan inflammatory response that results in cardiac dysfunction and often leads to death. Inflammation-induced metabolism of endogenous N-3 and N-6 polyunsaturated fatty acids generates numerous lipid mediators, such as epoxy fatty acids (EpFAs), which protect the heart. However, EpFAs are hydrolyzed by soluble epoxide hydrolase (sEH), which attenuates their cardioprotective actions. Global genetic disruption of sEH preserves EpFA levels and attenuates cardiac dysfunction in mice following acute lipopolysaccharide (LPS)-induced inflammatory injury. In leukocytes, EpFAs modulate the innate immune system through the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome. However, the mechanisms by which both EpFAs and sEH inhibition exert their protective effects in the cardiomyocyte are still elusive. This study investigated whether cardiomyocyte-specific sEH disruption attenuates inflammation and cardiac dysfunction in acute LPS inflammatory injury via modulation of the NLRP3 inflammasome. We use tamoxifen-inducible CreER recombinase technology to target sEH genetic disruption to the cardiomyocyte. Primary cardiomyocyte studies provide mechanistic insight into inflammasome signaling. For the first time, we demonstrate that cardiomyocyte-specific sEH disruption preserves cardiac function and attenuates inflammatory responses by limiting local cardiac inflammation and activation of the systemic immune response. Mechanistically, inhibition of cardiomyocyte-specific sEH activity or exogenous EpFA treatment do not prevent upregulation of NLRP3 inflammasome machinery in neonatal rat cardiomyocytes. Rather, they limit downstream activation of the pathway leading to release of fewer chemoattractant factors and recruitment of immune cells to the heart. These data emphasize that cardiomyocyte sEH is vital for mediating detrimental systemic inflammation.NEW & NOTEWORTHY The cardioprotective effects of genetic disruption and pharmacological inhibition of sEH have been demonstrated in a variety of cardiac disease models, including acute LPS inflammatory injury. For the first time, it has been demonstrated that sEH genetic disruption limited to the cardiomyocyte profoundly preserves cardiac function and limits local and systemic inflammation following acute LPS exposure. Hence, cardiomyocytes serve a critical role in the innate immune response that can be modulated to protect the heart.

Risk of Permanent Pacemaker Implantation Following Bentall Operation

Conduction disorders following cardiac surgery are common complications with incidences of permanent pacemaker dependency up to 5%. However, data on pacemaker implantation rates in the long-term follow-up after Bentall operations are scarce. In a retrospective study, a mixed cohort of 260 patients including endocarditis and aortic dissection undergoing Bentall operation between March 1996 and December 2015 was analyzed. Median follow-up time was 60 (12-107) months. Early and late rates of permanent pacemaker implantation and associated risk factors were investigated. In the postoperative course 31 (11.9%) permanent pacemakers were implanted. The 30-day incidence of pacemaker implantations was 7.7% with operations performed after a median of 6 (3-12) days after the Bentall operation. After ten years, 21% of the Bentall patients were permanent pacemaker dependent. The risk factors for permanent pacemaker dependency included age above 75 years (16.1% vs 5.7%; P < 0.001), preoperative cardiac conduction disturbance (32.3% vs 22.7%, P = 0.018), aortic valve stenosis (38.7% vs 23.1, P = 0.008), infective endocarditis (19.4% vs 7.4%, P = 0.004), tricuspid valve reconstruction (6.5% vs 0.9%, P = 0.033), sepsis (12.9% vs 4.4%, P < 0.001) and non-cardiac reoperation (19.4% vs 8.7%, P = 0.004). Pacemaker implantation significantly increased the length of initial hospitalization (13 [8-26] days vs 8 [7-13] days; P = 0.003). In the long-term follow-up, mortality was not different between the groups. Permanent pacemaker dependency is a frequent complication in the short- and long-term follow-up after Bentall operations. Screening for cardiac conduction disturbances in the short- and long-term follow-up is recommended.

miR-340-5p Alleviates Oxidative Stress Injury by Targeting MyD88 in Sepsis-Induced Cardiomyopathy

BACKGROUND

Sepsis-induced cardiomyopathy (SIC) is a sort of severe disease in the intensive care unit. This research focuses on exploring the influence of miR-340-5p on SIC and its specific mechanism.

METHODS

Mice were administered with lipopolysaccharide (LPS) to construct a SIC animal model. Mice were intramyocardially injected with Adenoassociated Virus- (AAV-) 9 containing the miR-340-5p precursor to make the miR-340-5p overexpression in the myocardium. The expression level of myocardial miR-340-5p was evaluated by qRT-PCR. The cardiac function was measured by echocardiography, the myocardial morphology was observed by hematoxylin-eosin (HE) staining, and the oxidative stress level was detected by 4-hydroxynonenal (4-HNE) immunohistochemical staining and malondialdehyde (MDA) assay in mice. The cells were pretreated with miR-340-5p mimic, mimic-NC, miR-340-5p inhibitor, inhibitor-NC, MyD88 siRNA, or si-NC and then administered with LPS or PBS. The cell viability was measured with the CCK-8 assay. The level of intracellular oxidative stress was evaluated using reactive oxygen species (ROS), MDA, and glutathione (GSH) detection. The MyD88 level was assessed via Western blotting analysis. The interaction of miR-340-5p with the MyD88 mRNA was confirmed via dual-luciferase reporter assay and RNA pull-down assay.

RESULTS

The miR-340-5p overexpression partially alleviated the increase of the MyD88 level, impairment of cardiac function, and oxidative stress injury in the SIC animal model. In the SIC cell model, miR-340-5p mimic pretreatment partially relieved oxidative stress injury, while the miR-340-5p inhibitor had the opposite effect. Besides, the miR-340-5p mimic and inhibitor could reduce and further increase the MyD88 level in the SIC cell model, respectively. Dual-luciferase reporter and RNA pull-down experiments confirmed the interaction between the MyD88 mRNA and miR-340-5p. Finally, it was found that MyD88 siRNA pretreatment also partially alleviates the oxidative stress injury in the SIC cell model.

CONCLUSION

In sum, our study demonstrated that miR-340-5p can improve myocardial oxidative stress injury by targeting MyD88 in SIC.

Pyruvate-Driven Oxidative Phosphorylation is Downregulated in Sepsis-Induced Cardiomyopathy: A Study of Mitochondrial Proteome

BACKGROUND

Sepsis-induced cardiomyopathy (SIC) is a major contributing factor for morbidity and mortality in sepsis. Accumulative evidence has suggested that cardiac mitochondrial oxidative phosphorylation is attenuated in sepsis, but the underlying molecular mechanisms remain incompletely understood.

METHODS

Adult male mice of 9 to 12 weeks old were subjected to sham or cecal ligation and puncture procedure. Echocardiography in vivo and Langendorff-perfused hearts were used to assess cardiac function 24 h after the procedures. Unbiased proteomics analysis was performed to profile mitochondrial proteins in the hearts of both sham and SIC mice. Seahorse respirator technology was used to evaluate oxygen consumption in purified mitochondria.

RESULTS

Of the 665 mitochondrial proteins identified in the proteomics assay, 35 were altered in septic mice. The mitochondrial remodeling involved various energy metabolism pathways including subunits of the electron transport chain, fatty acid catabolism, and carbohydrate oxidative metabolism. We also identified a significant increase of pyruvate dehydrogenase (PDH) kinase 4 (PDK4) and inhibition of PDH activity in septic hearts. Furthermore, compared to sham mice, mitochondrial oxygen consumption of septic mice was significantly reduced when pyruvate was provided as a substrate. However, it was unchanged when PDH was bypassed by directly supplying the Complex I substrate NADH, or by using the Complex II substrate succinate, or using Complex IV substrate, or by providing the beta-oxidation substrate palmitoylcarnitine, neither of which require PDH for mitochondrial oxygen consumption.

CONCLUSIONS

These data demonstrate a broad mitochondrial protein remodeling, PDH inactivation and impaired pyruvate-fueled oxidative phosphorylation during SIC, and provide a molecular framework for further exploration.

Rapid and Direct Action of Lipopolysaccharide (LPS) on Skeletal Muscle of Larval Drosophila

The endotoxin lipopolysaccharide (LPS) from Gram-negative bacteria exerts a direct and rapid effect on tissues. While most attention is given to the downstream actions of the immune system in response to LPS, this study focuses on the direct actions of LPS on skeletal muscle in Drosophila melanogaster. It was noted in earlier studies that the membrane potential rapidly hyperpolarizes in a dose-dependent manner with exposure to LPS from Pseudomonas aeruginosa and Serratia marcescens. The response is transitory while exposed to LPS, and the effect does not appear to be due to calcium-activated potassium channels, activated nitric oxide synthase (NOS), or the opening of Cl- channels. The purpose of this study was to further investigate the mechanism of the hyperpolarization of the larval Drosophila muscle due to exposure of LPS using several different experimental paradigms. It appears this response is unlikely related to activation of the Na-K pump or Ca2+ influx. The unknown activation of a K+ efflux could be responsible. This will be an important factor to consider in treatments of bacterial septicemia and cellular energy demands.

Irisin Attenuates Oxidative Stress, Mitochondrial Dysfunction, and Apoptosis in the H9C2 Cellular Model of Septic Cardiomyopathy through Augmenting Fundc1-Dependent Mitophagy

In the present study, we used lipopolysaccharide- (LPS-) stimulated H9C2 cardiomyocytes to investigate whether irisin treatment attenuates septic cardiomyopathy via Fundc1-related mitophagy. Fundc1 levels and mitophagy were significantly reduced in LPS-stimulated H9C2 cardiomyocytes but were significantly increased by irisin treatment. Irisin significantly increased ATP production and the activities of mitochondrial complexes I and III in the LPS-stimulated cardiomyocytes. Irisin also improved glucose metabolism and significantly reduced LPS-induced levels of reactive oxygen species by increasing the activities of antioxidant enzymes, glutathione peroxidase (GPX), and superoxide dismutase (SOD), as well as levels of reduced glutathione (GSH). TUNEL assays showed that irisin significantly reduced LPS-stimulated cardiomyocyte apoptosis by suppressing the activation of caspase-3 and caspase-9. However, the beneficial effects of irisin on oxidative stress, mitochondrial metabolism, and viability of LPS-stimulated H9C2 cardiomyocytes were abolished by silencing Fundc1. These results demonstrate that irisin abrogates mitochondrial dysfunction, oxidative stress, and apoptosis through Fundc1-related mitophagy in LPS-stimulated H9C2 cardiomyocytes. This suggests irisin is a potentially useful treatment for septic cardiomyopathy, though further investigations are necessary to confirm our findings.

PINK1 contained in huMSC-derived exosomes prevents cardiomyocyte mitochondrial calcium overload in sepsis via recovery of mitochondrial Ca2+ efflux

Background

Sepsis is a systemic inflammatory response to a local severe infection that may lead to multiple organ failure and death. Previous studies have shown that 40–50% of patients with sepsis have diverse myocardial injuries and 70 to 90% mortality rates compared to 20% mortality in patients with sepsis without myocardial injury. Therefore, uncovering the mechanism of sepsis-induced myocardial injury and finding a target-based treatment are immensely important.

Objective

The present study elucidated the mechanism of sepsis-induced myocardial injury and examined the value of human umbilical cord mesenchymal stem cells (huMSCs) for protecting cardiac function in sepsis.

Methods

We used cecal ligation and puncture (CLP) to induce sepsis in mice and detect myocardial injury and cardiac function using serological markers and echocardiography. Cardiomyocyte apoptosis and heart tissue ultrastructure were detected using TdT-mediated dUTP Nick-End Labeling (TUNEL) and transmission electron microscopy (TEM), respectively. Fura-2 AM was used to monitor Ca²⁺ uptake and efflux in mitochondria. FQ-PCR and Western blotting detected expression of mitochondrial Ca²⁺ distribution regulators and PTEN-induced putative kinase 1 (PINK1). JC-1 was used to detect the mitochondrial membrane potential (Δψm) of cardiomyocytes.

Results

We found that expression of PINK1 decreased in mouse hearts during sepsis, which caused cardiomyocyte mitochondrial Ca²⁺ efflux disorder, mitochondrial calcium overload, and cardiomyocyte injury. In contrast, we found that exosomes isolated from huMSCs (huMSC-exo) carried Pink1 mRNA, which could be transferred to recipient cardiomyocytes to increase PINK1 expression. The reduction in cardiomyocyte mitochondrial calcium efflux was reversed, and cardiomyocytes recovered from injury. We confirmed the effect of the PINK1-PKA-NCLX axis on mitochondrial calcium homeostasis in cardiomyocytes during sepsis.

Conclusion

The PINK1-PKA-NCLX axis plays an important role in mitochondrial calcium efflux in cardiomyocytes. Therefore, PINK1 may be a therapeutic target to protect cardiomyocyte mitochondria, and the application of huMSC-exo is a promising strategy against sepsis-induced heart dysfunction.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02325-6.

Effect of Verapamil, an L-Type Calcium Channel Inhibitor, on Caveolin-3 Expression in Septic Mouse Hearts

Sepsis-induced myocardial dysfunction considerably increases mortality risk in patients with sepsis. Previous studies from our group have shown that sepsis alters the expression of structural proteins in cardiac cells, resulting in cardiomyocyte degeneration and impaired communication between cardiac cells. Caveolin-3 (CAV3) is a structural protein present in caveolae, located in the membrane of cardiac muscle cells, which regulates physiological processes such as calcium homeostasis. In sepsis, there is a disruption of calcium homeostasis, which increases the concentration of intracellular calcium, which can lead to the activation of potent cellular enzymes/proteases which cause severe cellular injury and death. The purpose of the present study was to test the hypotheses that sepsis induces CAV3 overexpression in the heart, and the regulation of L-type calcium channels directly relates to the regulation of CAV3 expression. Severe sepsis increases the expression of CAV3 in the heart, as immunostaining in our study showed CAV3 presence in the cardiomyocyte membrane and cytoplasm, in comparison with our control groups (without sepsis) that showed CAV3 presence predominantly in the plasma membrane. The administration of verapamil, an L-type calcium channel inhibitor, resulted in a decrease in mortality rates of septic mice. This effect was accompanied by a reduction in the expression of CAV3 and attenuation of cardiac lesions in septic mice treated with verapamil. Our results indicate that CAV3 has a vital role in cardiac dysfunction development in sepsis and that the regulation of L-type calcium channels may be related to its expression.

Laboratory Markers in the Management of Pediatric Polytrauma: Current Role and Areas of Future Research

Severe trauma is the most common cause of mortality in children and is associated with a high socioeconomic burden. The most frequently injured organs in children are the head and thorax, followed by the extremities and by abdominal injuries. The efficient and early assessment and management of these injuries is essential to improve patients' outcome. Physical examination as well as imaging techniques like ultrasound, X-ray and computer tomography are crucial for a valid early diagnosis. Furthermore, laboratory analyses constitute additional helpful tools for the detection and monitoring of pediatric injuries. Specific inflammatory markers correlate with post-traumatic complications, including the development of multiple organ failure. Other laboratory parameters, including lactate concentration, coagulation parameters and markers of organ injury, represent further clinical tools to identify trauma-induced disorders. In this review, we outline and evaluate specific biomarkers for inflammation, acid-base balance, blood coagulation and organ damage following pediatric polytrauma. The early use of relevant laboratory markers may assist decision making on imaging tools, thus contributing to minimize radiation-induced long-term consequences, while improving the outcome of children with multiple trauma.

A nanotrap improves survival in severe sepsis by attenuating hyperinflammation

Targeting single mediators has failed to reduce the mortality of sepsis. We developed a telodendrimer (TD) nanotrap (NT) to capture various biomolecules via multivalent, hybrid and synergistic interactions. Here, we report that the immobilization of TD-NTs in size-exclusive hydrogel resins simultaneously adsorbs septic molecules, e.g. lipopolysaccharides (LPS), cytokines and damage- or pathogen-associated molecular patterns (DAMPs/PAMPs) from blood with high efficiency (92-99%). Distinct surface charges displayed on the majority of pro-inflammatory cytokines (negative) and anti-inflammatory cytokines (positive) allow for the selective capture via TD NTs with different charge moieties. The efficacy of NT therapies in murine sepsis is both time-dependent and charge-dependent. The combination of the optimized NT therapy with a moderate antibiotic treatment results in a 100% survival in severe septic mice by controlling both infection and hyperinflammation, whereas survival are only 50-60% with the individual therapies. Cytokine analysis, inflammatory gene activation and tissue histopathology strongly support the survival benefits of treatments.

Endothelial HSPA12B Exerts Protection Against Sepsis-Induced Severe Cardiomyopathy via Suppression of Adhesion Molecule Expression by miR-126

Heat shock protein A12B (HSPA12B) is predominately expressed in endothelial cells (ECs) and has been reported to protect against cardiac dysfunction from endotoxemia or myocardial infarction. This study investigated the mechanisms by which endothelial HSPA12B protects polymicrobial sepsis–induced cardiomyopathy. Wild-type (WT) and endothelial HSPA12B knockout (HSPA12B^–/–) mice were subjected to polymicrobial sepsis induced by cecal ligation and puncture (CLP). Cecal ligation and puncture sepsis accelerated mortality and caused severe cardiac dysfunction in HSPA12B^–/– mice compared with WT septic mice. The levels of adhesion molecules and the infiltrated immune cells in the myocardium of HSPA12B^–/– septic mice were markedly greater than in WT septic mice. The levels of microRNA-126 (miR-126), which targets adhesion molecules, in serum exosomes from HSPA12B^–/– septic mice were significantly lower than in WT septic mice. Transfection of ECs with adenovirus expressing HSPA12B significantly increased miR-126 levels. Increased miR-126 levels in ECs prevented LPS-stimulated expression of adhesion molecules. In vivo delivery of miR-126 carried by exosomes into the myocardium of HSPA12B^–/– mice significantly attenuated CLP sepsis increased levels of adhesion molecules, and improved CLP sepsis–induced cardiac dysfunction. The data suggest that HSPA12B protects against sepsis-induced severe cardiomyopathy via regulating miR-126 expression which targets adhesion molecules, thus decreasing the accumulation of immune cells in the myocardium.

Factors associated with abnormal left ventricular ejection fraction (decreased or increased) in patients with sepsis in the intensive care unit

BACKGROUND

Sepsis-induced cardiomyopathy (SIC) is known to show cardiac dysfunction in patients with sepsis. Both a decrease or an increase in ejection fraction (EF), an indicator of cardiac function, can occur. The purpose of this study was to identify factors associated with abnormal left ventricular (LV) function measured by EF in patients with sepsis in the intensive care unit (ICU).

METHODS

This was a retrospective study performed from November 2016 to December 2018. Three-hundred and sixty-six patients (mean age, 73 ± 13 years; 191 [52%] men) admitted to the ICU with sepsis were included. Patients were classified into three categories according to LV EF (group 1 -[EF<50%, n = 36], group 2 -[50≤EF<70%, n = 252], and group 3 -[EF≥70%, n = 78]). Echocardiographic assessment was performed within 48 hours of diagnosis of sepsis. We analyzed clinical factors including mortality, echocardiographic findings, and laboratory parameters.

RESULTS

Decreased LV EF occurred in 36 (10%) patients and hyper-dynamic EF developed in 78 (21%) patients. Of 366 patients, 103 (28%) patients died. Baseline characteristics were similar in the three groups, except female sex an indicator of abnormal EF. Mortality rates were also similar in the three groups; however, mortality rates were significantly higher in patients with abnormal EF (decreased or increased vs. normal). Echocardiographic parameters were significantly different in the three groups, in terms of LV systolic parameters and chamber size. Small left atrium (LA) and small LV were significantly associated with abnormal EF (especially in patients with increased EF). High brain natriuretic peptide was associated with decreased EF. Among these factors, female sex and small LA were significantly associated with abnormal EF in the multiple regression analysis.

CONCLUSION

Our findings highlight that female sex and small cardiac size are associated with abnormal EF, and therefore, death. Therefore, female patients and patients with small LA should be monitored closely when they present with sepsis.

Mid-regional pro-atrial natriuretic peptide as a biomarker of left ventricular systolic dysfunction in patients with sepsis

BACKGROUND Releasing cytokine pro inflammation in patients with sepsis (tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β) and IL-6) with other factors (mid regional pro atrial natriuretic peptide [MR-proANP] and TNF-α) will cause left ventricular systolic dysfunction (LVSD). This research aimed to prove MR-proANP as a biomarker of LVSD in sepsis, area under the curve (AUC), sensitivity, specificity, cut-off point and probability of MR-proANP and TNF-α as a biomarker of LVSD. METHODS Non-experimental diagnostic test with cross sectional design and simple random sampling. Variable examined consisted of MR pro ANP, TNF-α and left ventricular ejection fraction (LVEF). LVSD if LVEF was ≤45%. Statistical analysis using 2 × 2 table and receiver operating characteristic curve using SPSS 22 for window. RESULTS There were examined 71 patients from November 2013 to March 2014 in tertiary ICU of Moewardi Hospital. There were 22 patients with mild sepsis (30.9%), 40 patients with severe sepsis (56.4%) and 9 patients with septic shock (12.7%). The AUC value of MR-proANP level was 0.84 (95% CI 0.73–0.95), p < 0.001. Optimal cut off point was ≥225.95 pmol/l and diagnostic odd ratio (DOR) was 12.11. The AUC value of TNF-α level was 0.73 (95% CI 0.60–0.86), p < 0.002. Optimal cut-off point was ≥7.36 pg/ml and DOR was 5.03. Multivariate analysis was resulted that MR-proANP was the best predictor of LVSD (AUC 0.78), and TNF-α (0.69). CONCLUSIONS MR-proANP could be used as a biomarker and the best diagnostic predictor of LVSD.

The effects of bacterial endotoxin LPS on synaptic transmission at the neuromuscular junction

The direct action of bacterial lipopolysaccharides (LPS) endotoxin was shown to enhance synaptic transmission and hyperpolarize the membrane potential at low doses, but block glutamatergic receptors and decrease observable spontaneous events at a high dosage. The dosage effects are LPS type specific. The hyperpolarization is not due to voltage-gated potassium channels or to activation of nitric oxide synthase (NOS). The effects are induced directly by LPS, independent of an immune response.

The effects of bacterial endotoxin (LPS) on cardiac function in a medicinal blow fly (Phaenicia sericata) and a fruit fly (Drosophila melanogaster)

The bacterial endotoxins, lipopolysaccharides (LPS), are known to have direct effects on mammalian heart cells; thus, LPS is likely to have some effects in other cardiac models. Drosophila melanogaster was used since it serves as a model for cardiac physiology. Larvae of blow flies (Phaenicia sericata) commonly used as therapy for debriding dead tissue, are exposed to high levels of bacterial endotoxins, but their mechanisms of LPS resistance are not entirely understood. Comparative effects of LPS on heart rate (HR) were examined for both Drosophila and blowfly larvae. Acute 10-min direct exposure of in situ heart tubes with saline containing 1, 100, and 500 μg/ml LPS from two common bacterial stains (Pseudomonas aeruginosa and Serratia marcescens) revealed a dose-dependent effect. The effects differed between the two fly models. Larval hearts of Drosophila stopped rapidly in low Ca²⁺ containing saline, but the hearts of blow flies appear unaffected for >30 min. S. marcescens increased HR initially in Drosophila followed by a reduction for low and high doses, but no change was observed in larvae of blow flies. Whereas P. aeruginosa at a high dose decreased HR in larvae of Drosophila but increased HR in larvae of blow flies. The goal of this study is to better the understanding in the direct action of LPS on HR. Knowing the acute and direct actions of LPS exposure on HR in different species of larvae may aid in understanding the underlying mechanisms in other animals during septicemia.

The Prognostic Value of Troponin in Pediatric Polytrauma

Introduction: Severe trauma accounts for a great number of deaths among children and adolescents. The diagnostic value of troponin serum levels of severely injured patients has been reported for adults, but data on pediatric polytrauma (PT) are scarce. Therefore, we conducted a retrospective monocentered study analyzing the prognostic value of troponin T (TnT) in pediatric trauma patients at the time point of hospital admission. Methods: Data of 88 polytraumatized pediatric patients admitted to the emergency room of the University Hospital of Ulm, Germany, between 2007 and 2016 were analyzed retrospectively. The data source was the written and digital patient records. Interleukin-6 (IL-6), creatine kinase activity (CK activity), and lactate and TnT levels were measured by a certified clinical diagnostic laboratory; and patients were stratified for the Injury Severity Score (ISS). The prognostic value for lung contusion, organ dysfunction, and fatal outcome was statistically explored. The study was approved by the independent ethical committee of the University of Ulm (#44/18). Results: TnT levels were significantly increased in patients after severe PT compared with mild or moderate trauma severity as assessed by ISS values. Patients with TnT levels above the cutoff showed significantly increased levels of IL-6 and CK activity and a significantly prolonged stay in the intensive care unit. However, TnT levels did not correlate with absolute ISS values. TnT levels were significantly increased in patients with chest trauma and lung contusion. The incidence of lung contusion was associated with elevation of TnT. So was the onset of organ dysfunction, defined as a Sequential Organ Failure Assessment (SOFA) score ≥ 2 and fatal outcome, with a significant enhancement of plasma levels in children with organ dysfunction and in non-survivors. Conclusion: These descriptive data suggest that evaluation of TnT on admission of multiply injured children may help in predicting severity of injury and mortality in the clinical course after trauma and thus may be a useful addition to established prognostic parameters in the future.

Evaluation of sepsis induced cardiac dysfunction as a predictor of mortality

Background

Sepsis is characterized by life threatening organ dysfunction with dysregulated immune response. Cardiac dysfunction seen in sepsis is unique as it is reversible within 7–10 days. Initial study by Parker et al. in 1984, showed, paradoxically lower ejection fraction in survivors of septic shock. Subsequent meta-analysis did not support that survivors had lower ejection fraction. Aim of our study was to assess the sepsis induced cardiac dysfunction by 2D echocardiography and Troponin I.

Methods

After obtaining institutional ethical committee approval (ref 125/2016), a prospective observational study was done in an university medical college from February 2016 to April 2016. Inclusion criteria were patients diagnosed with sepsis by new sepsis definition. Pregnant patients and patients with poor echo window were excluded. Echocardiographic assessment was done within 48 h of diagnosis of sepsis by standard methods. Primary outcome was ICU mortality and secondary outcome was ICU length of stay. Statistical analysis was done using STATA™ (Version14, College station TX).

Results

Fifty eight patients were screened, ten were excluded due to poor echo window. Baseline characteristics were similar in survivors and non survivors, except APACHE II, SOFA age and cumulative fluid balance. Echocardiographic parameters, mitral annular plane systolic excursion (MAPSE), E/e’ and LV systolic function assessed by visual gestalt method were found to be statistically significant. Parameters found significant in bivariate analysis were used as a covariate in logistic regression. APACHE II and MAPSE were significant co-variates in logistic regression with ROC (0.95) and calibration was satisfactory (chi2(df8),1.98, p = 0.98).

Conclusions

Sepsis induced cardiac dysfunction assessed by echocardiography showed measurement of MAPSE when combined with APACHE II was a good predictor of mortality. Among the echocardiographic parameters MAPSE alone was a good predictor of mortality. Results of this study need further validation from larger study.

Mechanisms of LPS-Induced Acute Kidney Injury in Neonatal and Adult Rats

Neonatal sepsis is one of the major causes of mortality and morbidity in newborns, greatly associated with severe acute kidney injury (AKI) and failure. Handling of newborns with kidney damage can be significantly different compared to adults, and it is necessary to consider the individuality of an organism's response to systemic inflammation. In this study, we used lipopolysaccharide (LPS)-mediated acute kidney injury model to study mechanisms of kidney cells damage in neonatal and adult rats. We found LPS-associated oxidative stress was more severe in adults compared to neonates, as judged by levels of carbonylated proteins and products of lipids peroxidation. In both models, LPS-mediated septic simulation caused apoptosis of kidney cells, albeit to a different degree. Elevated levels of proliferating cell nuclear antigen (PCNA) in the kidney dropped after LPS administration in neonates but increased in adults. Renal fibrosis, as estimated by smooth muscle actin levels, was significantly higher in adult kidneys, whereas these changes were less profound in LPS-treated neonatal kidneys. We concluded that in LPS-mediated AKI model, renal cells of neonatal rats were more tolerant to oxidative stress and suffered less from long-term pathological consequences, such as fibrosis. In addition, we assume that by some features LPS administration simulates the conditions of accelerated aging.

Septic cardiomyopathy: The value of lactoferrin and CD15 as specific markers to corroborate a definitive diagnosis

Current scientific consensus about the physiopathology in the progression from severe sepsis to septic shock and death focuses on myocardial contractile dysfunction. Nevertheless, objective parameters to establish a pathological correlate of a fatal outcome are lacking; then a cause of death due to sepsis can remain an unsolved problem. We first reviewed all death cases recorded at our institutions during the period from 2007 until 2015. Then, we conducted a retrospective study of a selected autopsy series of people who had received “sepsis” as cause of death. Two pathologists re-examined the heart sections while the most suitable myocardial sample for each case was stained for immunohistochemistry with antibodies targeted for specific inflammatory-related molecules. We used specific antibodies for the following markers: alpha-smooth muscle actin (alpha-SMA); fibronectin; matrix metallopeptidase 9 (MMP-9); intercellular adhesion molecule 1 (ICAM-1); caspase-3; lactoferrin (LF); cluster differentiation 15 (CD15). The statistical significance of differences was assessed using student’s t-test for unpaired data or non-parametric Mann–Whitney or Wilcoxon tests for skewed variables or one-way analysis of variance and post hoc Scheffe’s test for continuous variables and Pearson’s χ²-test for discrete variables. Linear regression analysis was used to determine the presence of a correlation between continuous variables. At our institutions, 2220 deaths have been recorded during the period study. Sepsis accounted as a cause of death for the 20% of total. We finally enrolled 56 cases; of these, only 20 were positive for microbiological analysis. At histological examination, clear inflammation was detectable in the 32% of cases; otherwise, immunohistochemical reaction showed a positive reaction for LF and CD15 in more than a half cases (56%). We still ignore all the underlying mechanisms of sepsis and all its pathophysiological connections with cardiac metabolism; in this sense, we aim to corroborate the diagnostic value of anti-LF and anti-CD15 staining for the post-mortem detection of myocardial inflammation.

Analysis on sarcoglycans expression as markers of septic cardiomyopathy in sepsis-related death

The post-mortem assessment of sepsis-related death can be carry out by many methods recently suggested as microbiological and biochemical investigations. In these cases, the cause of death is a multiple organ dysfunction due to a dysregulated inflammatory response occurring after the failure of infection control process. It was highlighted also that the heart can be a target organ in sepsis which determines the so-called septic cardiomyopathy characterized by myocardial depression. Several mechanisms to explain the pathophysiology of septic cardiomyopathy were suggested, but very few studies about the structural alterations of cardiac cells responsible for myocardial depression were carried out. The aim of this study was to evaluate whether sarcoglycans (SG) were involved in septic cardiac damage analyzing their expression in sepsis-related deaths and, particularly, if these proteins can be used as markers of septic myocardial dysfunction. Cases of septic-related death confirmed by clinical and autopsy records were investigated and compared to a control group of traumatic deaths. Indirect immunofluorescence analysis was performed to analyze α-SG, β-SG, δ-SG, ζ-SG, ε-SG, and γ-SG. Decrease of fluorescence staining pattern for all tested sarcoglycans was observed in the septic-related deaths compared to normal fluorescence staining pattern of control group. These results provide new findings about the myocytes structural alterations due to sepsis and suggest that these proteins could be used in forensic assessment of septic cardiomyopathy.

Myocardial strain/stress changes identified by echocardiography may reveal early sepsis-induced myocardial dysfunction

Objective

To perform early assessment of sepsis-induced myocardial dysfunction (SIMD) using strain/stress echocardiography.

Methods

A canine model of SIMD was established using intravenous injection of lipopolysaccharide (LPS, 2 mg/kg). Thirteen dogs were included, comprising an LPS-treated SIMD group (n = 7) and saline control group (n = 6). SIMD was assessed at various time-points using cardiac measurements including haemodynamics and echocardiography.

Results

Systolic and radial ventricular wall stress and circular ventricular wall stress (WSsc) were significantly lower in the sepsis group versus the control group at all time-points. Logistic regression analysis revealed an inverse correlation between stress rate of the front-posterior and bottom wall and left ventricle systolic wall strength. In contrast, a positive correlation was found between the mean velocity of circumferential fibre shortening (mVCF) or heart rate-adjusted mVCF (RVCF) and WSsc. Using regression equations, predicted values for mVCF and RVCF in animals with sepsis were significantly higher than measured values at 4- 5- and 6-h time-points.

Conclusions

These findings will further the understanding of pathophysiological alterations in SIMD at the early stage of sepsis, and suggest that strain rate may reflect the nature of myocardial contractility.

Early structural changes of the heart after experimental polytrauma and hemorrhagic shock

Evidence is emerging that systemic inflammation after trauma drives structural and functional impairment of cardiomyocytes and leads to cardiac dysfunction, thus worsening the outcome of polytrauma patients. This study investigates the structural and molecular changes in heart tissue 4 h after multiple injuries with additional hemorrhagic shock using a clinically relevant rodent model of polytrauma. We determined mediators of systemic inflammation (keratinocyte chemoattractant, macrophage chemotactic protein 1), activated complement component C3a and cardiac troponin I in plasma and assessed histological specimen of the mouse heart via standard histomorphology and immunohistochemistry for cellular and subcellular damage and ongoing apoptosis. Further we investigated spatial and quantitative changes of connexin 43 by immunohistochemistry and western blotting. Our results show significantly increased plasma levels of both keratinocyte chemoattractant and cardiac troponin I 4 h after polytrauma and 2 h after induction of hypovolemia. Although we could not detect any morphological changes, immunohistochemical evaluation showed increased level of tissue high-mobility group box 1, which is both a damage-associated molecule and actively released as a danger response signal. Additionally, there was marked lateralization of the cardiac gap-junction protein connexin 43 following combined polytrauma and hemorrhagic shock. These results demonstrate a molecular manifestation of remote injury of cardiac muscle cells in the early phase after polytrauma and hemorrhagic shock with marked disruption of the cardiac gap junction. This disruption of an important component of the electrical conduction system of the heart may lead to arrhythmia and consequently to cardiac dysfunction.

The Role of Endotoxin in the Setting of Cardiorenal Syndrome Type 5

Lipopolysaccharide or endotoxin, the major cell wall component of gram-negative bacteria, plays a pivotal role in the pathogenesis of sepsis. It is able to activate the host defense system through the interaction with Toll-like receptor 4, thus triggering pro-inflammatory mechanisms. When the production of inflammatory mediators becomes uncontrolled and excessive, septic shock develops with multiple organ dysfunction, such as myocardial and renal impairment, which are hallmarks of cardiorenal syndrome type 5. In this review, we will analyze the role of endotoxin in the pathogenesis of sepsis, its effects on cardiac and renal interactions in the setting of cardiorenal syndrome type 5 and the possible use of extracorporeal therapies in this clinical condition.

Human platelet interaction with E. coli O111 promotes tissue-factor-dependent procoagulant activity, involving Toll like receptor 4

Platelets have a major role in clotting activation and contribute to the innate immune response during systemic infections. Human platelets contain tissue factor (TF) and express functional Toll-like receptor 4 (TLR4). However, the role of TLR4 in triggering the procoagulant properties of platelets, upon challenge with bacteria, is yet unknown. Our hypothesis is that E. coli O111-TLR4 interaction activates platelets and elicits their procoagulant activity. We demonstrated that the strain, but not ultrapure LPS, increased surface P-selectin expression, platelet dependent TF procoagulant activity (TF-PCA) and prompted a faster thrombin generation (TG). Blockade of TLR4 resulted in decreased platelet activation, TF-PCA and TG, revealing the participation of this immune receptor on the procoagulant response of platelets. Our results provide a novel mechanism by which individuals with bacterial infections would have an increased incidence of blood clots. Furthermore, the identification of platelet TF and TLR4 as regulators of the effect of E. coli O111 might represent a novel therapeutic target to reduce the devastating consequences of the hemostatic disorder during sepsis.

Pathophysiology of the cardio-renal syndromes types 1-5: An uptodate

According to the recent definition proposed by the Consensus conference on Acute Dialysis Quality Initiative Group, the term cardio-renal syndrome (CRS) has been used to define different clinical conditions in which heart and kidney dysfunction overlap. Type 1 CRS (acute cardio- renal syndrome) is characterized by acute worsening of cardiac function leading to AKI (5, 6) in the setting of active cardiac disease such as ADHF, while type - 2 CRS occurs in a setting of chronic heart disease. Type 3 CRS is closely link to acute kidney injury (AKI), while type 4 represent cardiovascular involvement in chronic kidney disese (CKD) patients. Type 5 CRS represent cardiac and renal involvement in several diseases such as sepsis, hepato - renal syndrome and immune - mediated diseases.

Anti-Inflammatory Activity of the Essential Oil Citral in Experimental Infection with Staphylococcus aureus in a Model Air Pouch

This study proposes to implement an alternative and effective strategy for local treatment of disease provoked by S. aureus. For the analysis of possible anti-inflammatory activity of essential oil, after establishing an air pouch model, 48 male mice of Balb/c were treated, infected, and euthanized at 4 and 8 h. Thus, the total and differential white blood cells were counted in the animal's blood, and cytokines IL-1β, IL-6, and TNF-α were titrated using ELISA in the air pouch lavage. Moreover, TNF-α, IL-1β, and IL-6 gene expression was analyzed through an RT-qPCR array, and S. aureus was quantified using qPCR. Our results, p < 0.05, showed that EOC reduced the quantity of microorganisms. The group of mice treated with essential oil citral showed a significant decrease in TNF-α levels in tests demonstrating anti-inflammatory activity. There is no data about the mutual influence of the air pouch model, essential oil citral, and S. aureus. Thus, considering the interaction of these variables and the anti-inflammatory activity of the essential oil citral, we demonstrated, by alternative local treatment, a new antimicrobial agent that is not an antibiotic.

Endotoxin Effects on Cardiac and Renal Functions and Cardiorenal Syndromes

Gram-negative sepsis is a major cause of morbidity and mortality in critical ill patients. Recent findings in molecular biology and in signaling pathways have enhanced our understanding of its pathogenesis and opened up opportunities of innovative therapeutic approaches. Endotoxin plays a pivotal role in the pathogenesis of multi-organ dysfunction in the setting of gram-negative sepsis. Indeed, heart and kidney impairments seem to be induced by the release of circulating pro-inflammatory and pro-apoptotic mediators triggered by endotoxin interaction with immune cells. These molecules are responsible for cellular apoptosis, autophagy, cell cycle arrest, and microRNAs activation. Therefore, the early identification of sepsis-associated acute kidney injury and heart dysfunction may improve the patient clinical outcome. In this report, we will consider the role of endotoxin in the pathogenesis of sepsis, its effects on both cardiac and renal functions, and the interactions between these 2 systems in the setting of cardiorenal syndromes (CRS), particularly in CRS type 5. Finally, we will discuss the possible role of extracorporeal therapies in reducing endotoxin levels.

Cardiac Electrical and Structural Changes During Bacterial Infection: An Instructive Model to Study Cardiac Dysfunction in Sepsis

BACKGROUND

Sepsis patients with cardiac dysfunction have significantly higher mortality. Although several pathways are associated with myocardial damage in sepsis, the precise cause(s) remains unclear and treatment options are limited. This study was designed to develop a new model to investigate the early events of cardiac damage during sepsis progression.

METHODS AND RESULTS

Francisella tularensis subspecies novicida (Ft.n) is a Gram-negative intracellular pathogen causing severe sepsis syndrome in mice. BALB/c mice (N=12) were sham treated or infected with Ft.n through the intranasal route. Serial electrocardiograms were recorded at multiple time points until 96 hours. Hearts were then harvested for histology and gene expression studies. Similar to septic patients, we illustrate both cardiac electrical and structural phenotypes in our murine Ft.n infection model, including prominent R' wave formation, prolonged QRS intervals, and significant left ventricular dysfunction. Notably, in infected animals, we detected numerous microlesions in the myocardium, previously observed following nosocomial Streptococcus infection and in sepsis patients. We show that Ft.n-mediated microlesions are attributed to cardiomyocyte apoptosis, increased immune cell infiltration, and expression of inflammatory mediators (tumor necrosis factor, interleukin [IL]-1β, IL-8, and superoxide dismutase 2). Finally, we identify increased expression of microRNA-155 and rapid degradation of heat shock factor 1 following cardiac Ft.n infection as a primary cause of myocardial inflammation and apoptosis.

CONCLUSIONS

We have developed and characterized an Ft.n infection model to understand the pathogenesis of cardiac dysregulation in sepsis. Our findings illustrate novel in vivo phenotypes underlying cardiac dysfunction during Ft.n infection with significant translational impact on our understanding of sepsis pathophysiology.

Sepsis in Pediatric Cardiac Intensive Care

OBJECTIVES

In this review, we will discuss risk factors for developing sepsis; the role of biomarkers in establishing an early diagnosis, in monitoring therapeutic efficacy, in stratification, and for the identification of sepsis endotypes; and the pathophysiology and management of severe sepsis and septic shock, with an emphasis on the impact of sepsis on cardiovascular function.

DATA SOURCE

MEDLINE and PubMed.

CONCLUSIONS

There is a lot of excitement in the field of sepsis research today. Scientific advances in the diagnosis and clinical staging of sepsis, as well as a personalized approach to the treatment of sepsis, offer tremendous promise for the future. However, at the same time, it is also evident that sepsis mortality has not improved enough, even with progress in our understanding of the molecular pathophysiology of sepsis.

Endotoxemia Engages the RhoA Kinase Pathway to Impair Cardiac Function By Altering Cytoskeleton, Mitochondrial Fission, and Autophagy

AIMS

The RhoA/ROCK pathway controls crucial biological processes involved in cardiovascular pathophysiology, such as cytoskeleton dynamics, vascular smooth muscle contraction, and inflammation. In this work, we tested whether Rho kinase inhibition would beneficially impact cardiac cytoskeleton organization, bioenergetics, and autophagy in experimental endotoxemia induced by lipopolysaccharides (LPSs) in mice.

RESULTS

Fasudil, a potent ROCK inhibitor, prevented LPS-induced cardiac inflammation, oxidative stress, cytoskeleton disarray, and mitochondrial injury. ROCK inhibition prevented phosphorylation of cofilin and dynamin-related protein-1, which promotes stabilization-polymerization of F-actin and mediates mitochondrial fission, respectively. Pyr1, which exclusively alters actin dynamics, prevented LPS-induced myocardial dysfunction, suggesting that beneficial impact of ROCK inhibition was not mainly related to pleiotropic effects of fasudil on cardiac inflammation and oxidative stress. Fasudil reduced mitochondrial fragmentation, stimulated initiation of autophagy, and elicited cardioprotection in LPS heart. Mdivi-1, a potent mitochondria fission inhibitor, converted cardioprotective autophagy to an inefficient form due to cargo loading failure in which autophagic vacuoles fail to trap cytosolic cargo, despite their formation at enhanced rates and lysosomal elimination.

INNOVATION

In experimental endotoxemia, cardioprotection by RhoA/ROCK inhibition may be related to changes in actin cytoskeleton reorganization and mitochondrial homeostasis. Improvement of LPS-induced mitochondrial dysfunction by fasudil was attributed to inhibition of ROCK-dependent Drp1 phosphorylation and activation of autophagic processes that can limit mitochondrial fragmentation and enhance degradation of damaged mitochondria, respectively.

CONCLUSION

Fasudil prevented LPS-induced heart oxidative stress, abnormal F-actin distribution, and oxidative phosphorylation, which concur to improve cardiac contractile and bioenergetic function. We suggest that fasudil may represent a valuable therapy for patients with sepsis.

Elevation of NT-proBNP and cardiac troponins in sepsis-related deaths: a forensic perspective

In the present study, the levels of NT-proBNP, troponin T, and troponin I were measured in postmortem serum from femoral blood in a series of sepsis-related fatalities that had undergone forensic autopsies. We aimed to assess whether a possible increase in the concentrations of these biomarkers was correlated to macroscopic or microscopic observations that suggest myocardial damage or cardiac dysfunction. Two study groups were retrospectively formed, a sepsis-related fatalities group and a control group. Both groups consisted of 16 forensic autopsy cases. Unenhanced computed tomography scan, autopsy, histological, toxicological, microbiological, and biochemical analyses were performed for all cases in both groups. Levels of procalcitonin, C-reactive protein, NT-proBNP, troponin T, and troponin I were systematically measured in postmortem serum from femoral blood. The preliminary results suggest that the postmortem serum troponin I, troponin T, and NT-proBNP levels are increased in sepsis-related deaths in the absence of any relevant coronary artery disease, myocardial ischemia, or signs of heart failure. These findings corroborate clinical data from previous studies pertaining to the usefulness of troponins and natriuretic peptides as indicators of toxic and inflammatory damage to the heart in cases of severe sepsis and septic shock without concomitant underlying coronary syndromes.

LncRNA-HOTAIR promotes TNF-α production in cardiomyocytes of LPS-induced sepsis mice by activating NF-κB pathway

BACKGROUND

Mounting studies have illustrated an important role of HOTAIR in cancer progress, but few studies have reported its function in cardiac disease, including cardiac-associated sepsis. This study aimed to investigate the function of HOTAIR in sepsis, involving its association with the level of tumor necrosis factor-alpha (TNF-α), an important inducer of myocardial dysfunction during LPS-induced sepsis.

METHODS

Sepsis mice model was established by LPS administration, and myocardial dysfunction was evaluated with hemodynamic parameters. HOTAIR expression in isolated cardiomyocytes and TNF-α production in the circulation were detected, as well as the protein levels of phosphorylated p65. HL-1 cells were subjected to LPS treatment in vitro for functional studies, including luciferase report assays for NF-κB activity.

RESULTS

HOTAIR expression was significantly upregulated in cardiomyocytes from sepsis mice, in line with increased TNF-α production and p65 phosphorylation, while similar results were also observed in LPS treated HL-1 cells, which was then reversed by HOTAIR interference. Functional studies demonstrated that HOTAIR showed positive regulation on p65 phosphorylation and NF-κB activation, while HOTAIR-induced TNF-α production was repressed by NF-κB inhibitor. Further in vivo studies confirmed that HOTAIR silence can improve cardiac function of sepsis mice, and markedly decreased TNF-α production in the circulation.

CONCLUSION

HOTAIR upregulation in cardiomyocytes of LPS-induced sepsis mice promoted TNF-α production in the circulation by activating NF-κB, involving the phosphorylation of NF-κB p65 subunit. Moreover, HOTAIR silence preserved cardiac function of sepsis mice during LPS-induced sepsis.

Pathophysiology of sepsis-induced myocardial dysfunction

Sepsis-induced myocardial dysfunction is a common complication in septic patients and is associated with increased mortality. In the clinical setting, it was once believed that myocardial dysfunction was not a major pathological process in the septic patients, at least in part, due to the unavailability of suitable clinical markers to assess intrinsic myocardial function during sepsis. Although sepsis-induced myocardial dysfunction has been studied in clinical and basic research for more than 30 years, its pathophysiology is not completely understood, and no specific therapies for this disorder exist. The purpose of this review is to summarize our current knowledge of sepsis-induced myocardial dysfunction with a special focus on pathogenesis and clinical characteristics.

Role of extracellular histones in the cardiomyopathy of sepsis

The purpose of this study was to define the relationship in polymicrobial sepsis (in adult male C57BL/6 mice) between heart dysfunction and the appearance in plasma of extracellular histones. Procedures included induction of sepsis by cecal ligation and puncture and measurement of heart function using echocardiogram/Doppler parameters. We assessed the ability of histones to cause disequilibrium in the redox status and intracellular [Ca(2+)]i levels in cardiomyocytes (CMs) (from mice and rats). We also studied the ability of histones to disturb both functional and electrical responses of hearts perfused with histones. Main findings revealed that extracellular histones appearing in septic plasma required C5a receptors, polymorphonuclear leukocytes (PMNs), and the Nacht-, LRR-, and PYD-domains-containing protein 3 (NLRP3) inflammasome. In vitro exposure of CMs to histones caused loss of homeostasis of the redox system and in [Ca(2+)]i, as well as defects in mitochondrial function. Perfusion of hearts with histones caused electrical and functional dysfunction. Finally, in vivo neutralization of histones in septic mice markedly reduced the parameters of heart dysfunction. Histones caused dysfunction in hearts during polymicrobial sepsis. These events could be attenuated by histone neutralization, suggesting that histones may be targets in the setting of sepsis to reduce cardiac dysfunction.

Neonatal sepsis and inflammatory mediators

Neonatal sepsis is a major cause of morbidity and mortality and its signs and symptoms are nonspecific, which makes the diagnosis difficult. The routinely used laboratory tests are not effective methods of analysis, as they are extremely nonspecific and often cause inappropriate use of antibiotics. Sepsis is the result of an infection associated with a systemic inflammatory response with production and release of a wide range of inflammatory mediators. Cytokines are potent inflammatory mediators and their serum levels are increased during infections, so changes from other inflammatory effector molecules may occur. Although proinflammatory and anti-inflammatory cytokines have been identified as probable markers of neonatal infection, in order to characterize the inflammatory response during sepsis, it is necessary to analyze a panel of cytokines and not only the measurement of individual cytokines. Measurements of inflammatory mediators bring new options for diagnosing and following up neonatal sepsis, thus enabling early treatment and, as a result, increased neonatal survival. By taking into account the magnitude of neonatal sepsis, the aim of this review is to address the role of cytokines in the pathogenesis of neonatal sepsis and its value as a diagnostic criterion.

Downregulation of adenine nucleotide translocator 1 exacerbates tumor necrosis factor-α-mediated cardiac inflammatory responses

Inflammation contributes significantly to cardiac dysfunction. Although the initial phase of inflammation is essential for repair and healing, excessive proinflammatory cytokines are detrimental to the heart. We found that adenine nucleotide translocator isoform-1 (ANT1) protein levels were significantly decreased in the inflamed heart of C57BL/6 mice following cecal ligation and puncture. To understand the molecular mechanisms involved, we performed small-interfering RNA-mediated knockdown of ANT1 and studied tumor necrosis factor-α (TNFα)-induced inflammatory responses in myocardium-derived H9c2 cells and cardiomyocytes. ANT1 knockdown significantly increased swollen mitochondria and mitochondrial reactive oxygen species, concomitant with increased TNFα-induced NF-κB reporter gene activity and interleukin-6 and TNFα expression. A mitochondrial-targeted antioxidant mito-TEMPO attenuated TNFα-induced mitochondrial reactive oxygen species, NF-κB reporter gene activity, and cytokine expression in ANT1 knockdown cells. Interestingly, TNFα or lipopolysaccharide (LPS) treatment significantly decreased ANT1 protein levels, suggesting a feed-forward regulation of proinflammatory cytokine expression activated by ANT1 downregulation. These data suggest that ANT1 downregulation contributes to cardiac inflammation post-cecal ligation and puncture. Preventing ANT1 downregulation could provide a novel molecular target to temper cardiac inflammation.

Therapeutic interventions in sepsis: current and anticipated pharmacological agents

Sepsis is a clinical syndrome characterized by a multisystem response to a pathogenic assault due to underlying infection that involves a combination of interconnected biochemical, cellular and organ-organ interactive networks. After the withdrawal of recombinant human-activated protein C (rAPC), researchers and physicians have continued to search for new therapeutic approaches and targets against sepsis, effective in both hypo- and hyperinflammatory states. Currently, statins are being evaluated as a viable option in clinical trials. Many agents that have shown favourable results in experimental sepsis are not clinically effective or have not been clinically evaluated. Apart from developing new therapeutic molecules, there is great scope for for developing a variety of drug delivery strategies, such as nanoparticulate carriers and phospholipid-based systems. These nanoparticulate carriers neutralize intracorporeal LPS as well as deliver therapeutic agents to targeted tissues and subcellular locations. Here, we review and critically discuss the present status and new experimental and clinical approaches for therapeutic intervention in sepsis.

Outcome prediction in sepsis: speckle tracking echocardiography based assessment of myocardial function

Introduction

Speckle tracking echocardiography (STE) is a relatively novel and sensitive method for assessing ventricular function and may unmask myocardial dysfunction not appreciated with conventional echocardiography. The association of ventricular dysfunction and prognosis in sepsis is unclear. We sought to evaluate frequency and prognostic value of biventricular function, assessed by STE in patients with severe sepsis or septic shock.

Methods

Over an eighteen-month period, sixty patients were prospectively imaged by transthoracic echocardiography within 24 hours of meeting severe sepsis criteria. Myocardial function assessment included conventional measures and STE. Association with mortality was assessed over 12 months.

Results

Mortality was 33% at 30 days (n = 20) and 48% at 6 months (n = 29). 32% of patients had right ventricle (RV) dysfunction based on conventional assessment compared to 72% assessed with STE. 33% of patients had left ventricle (LV) dysfunction based on ejection fraction compared to 69% assessed with STE. RV free wall longitudinal strain was moderately associated with six-month mortality (OR 1.1, 95% confidence interval, CI, 1.02-1.26, p = 0.02, area under the curve, AUC, 0.68). No other conventional echocardiography or STE method was associated with survival. After adjustment (for example, for mechanical ventilation) severe RV free wall longitudinal strain impairment remained associated with six-month mortality.

Conclusion

STE may unmask systolic dysfunction not seen with conventional echocardiography. RV dysfunction unmasked by STE, especially when severe, was associated with high mortality in patients with severe sepsis or septic shock. LV dysfunction was not associated with survival outcomes.