Sepsis-induced Cardiac Dysfunction Research Articles

Estradiol contributes to sex differences in resilience to sepsis-induced metabolic dysregulation and dysfunction in the heart via GPER-1-mediated PPARδ/NLRP3 signaling

Background and aimClinically, septic males tend to have higher mortality rates, but it is unclear if this is due to sex differences in cardiac dysfunction, possibly influenced by hormonal variations. Cardiac dysfunction significantly contributes to sepsis-related mortality, primarily influenced by metabolic imbalances. Peroxisome proliferator-activated receptor delta (PPARδ) is a key player in cardiac metabolism and its activation has been demonstrated to favor sepsis outcomes. While estradiol (E2) is abundant and beneficial in females, its impact on PPARδ-mediated metabolism in the heart with regards to sex during sepsis remains unknown. Methods and resultsHere, we unveil that while sepsis diminishes PPARδ nuclear translocation and induces metabolic dysregulation, oxidative stress, apoptosis and dysfunction in the heart thereby enhancing mortality, these effects are notably more pronounced in males than females. Mechanistic experiments employing ovariectomized(OVX) mice, E2 administration, and G protein-coupled estrogen receptor 1(GPER-1) knockout (KO) mice revealed that under lipopolysaccharide (LPS)-induced sepsis, E2 acting via GPER-1 enhances cardiac electrical activity and function, promotes PPARδ nuclear translocation, and subsequently ameliorates cardiac metabolism while mitigating oxidative stress and apoptosis in females. Furthermore, PPARδ specific activation using GW501516 in female GPER-1−/− mice reduced oxidative stress, ultimately decreasing NLRP3 expression in the heart. Remarkably, targeted GPER-1 activation using G1 in males mirrors these benefits, improving cardiac electrical activity and function, and ultimately enhancing survival rates during LPS challenge. By employing NLRP3 KO mice, we demonstrated that the targeted GPER-1 activation mitigated injury, enhanced metabolism, and reduced apoptosis in the heart of male mice via the downregulation of NLRP3. ConclusionOur findings collectively illuminate the sex-specific cardiac mechanisms influencing sepsis mortality, offering insights into physiological and pathological dimensions. From a pharmacological standpoint, this study introduces specific GPER-1 activation as a promising therapeutic intervention for males under septic conditions. These discoveries advance our understanding of the sex differences in sepsis-induced cardiac dysfunction and also present a novel avenue for targeted interventions with potential translational impact.

TaoHe ChengQi decoction ameliorates sepsis-induced cardiac dysfunction through anti-ferroptosis via the Nrf2 pathway

BackgroundSepsis-induced cardiac dysfunction (SICD) is a serious complication of sepsis that is associated with increased mortality. Ferroptosis has been reported in the SICD. TaoHe ChengQi decoction (THCQD), a classical traditional Chinese medicinal formula, has multiple beneficial pharmacological effects. The potential effects of THCQD on the SICD remain unknown. PurposeTo investigate the effect of THCQD on SICD and explore whether this effect is related to the regulation of myocardial ferroptosis through nuclear factor erythroid 2-related factor 2 (Nrf2) activation. MethodsWe induced sepsis in a mouse model using cecal ligation and puncture (CLP) and administered THCQD (2 and 4 g/kg) and dexamethasone (40 mg/kg). Mice mortality was recorded and survival curves were plotted. Echocardiography, hematoxylin and eosin staining, and analysis of serum myocardial injury markers and inflammatory factors were used to evaluate cardiac pathology. Myocardial ferroptosis was detected by quantifying specific biomarker content and protein levels. Through HPLC-Q-Exactive-MS analysis, we identified the components of the THCQD. Network pharmacology analysis and Cellular Thermal Shift Assay (CETSA) were utilized to predict the targets of THCQD for treating SICD. We detected the expression of Nrf2 using Western blotting or immunofluorescence. An RSL3-induced ferroptosis model was established using neonatal rat cardiomyocytes (NRCMs) to further explore the pharmacological mechanism of THCQD. In addition to measuring cell viability, we observed changes in NRCM mitochondria using electron microscopy and JC-1 staining. NRF2 inhibitor ML385 and Nrf2 knockout mice were used to validate whether THCQD exerted protective effects against SICD through Nrf2-mediated ferroptosis signaling. ResultsTHCQD reduced mortality in septic mice, protected against CLP-induced myocardial injury, decreased systemic inflammatory response, and prevented myocardial ferroptosis. Network pharmacology analysis and CETSA experiments predicted that THCQD may protect against SICD by activating the Nrf2 signaling pathway. Western blotting and immunofluorescence showed that THCQD activated Nrf2 in cardiac tissue. THCQDs consistently mitigated RSL3-induced ferroptosis in NRCM, which is related to Nrf2. Furthermore, the pharmacological inhibition of Nrf2 and genetic Nrf2 knockout partially reversed the protective effects of THCQD on SICD and ferroptosis. ConclusionThe effect of THCQD on SICD was achieved by activating Nrf2 and its downstream pathways.

4-phenylbutyric acid improves sepsis-induced cardiac dysfunction by modulating amino acid metabolism and lipid metabolism via Comt/Ptgs2/Ppara

IntroductionCardiac dysfunction after sepsis the most common and severe sepsis-related organ failure. The severity of cardiac damage in sepsis patients was positively associated to mortality. It is important to look for drugs targeting sepsis-induced cardiac damage. Our previous studies found that 4-phenylbutyric acid (PBA) was beneficial to septic shock by improving cardiovascular function and survival, while the specific mechanism is unclear.ObjectivesWe aimed to explore the specific mechanism and PBA for protecting cardiac function in sepsis.MethodsThe cecal ligation and puncture-induced septic shock models were used to observe the therapeutic effects of PBA on myocardial contractility and the serum levels of cardiac troponin-T. The mechanisms of PBA against sepsis were explored by metabolomics and network pharmacology.ResultsThe results showed that PBA alleviated the sepsis-induced cardiac damage. The metabolomics results showed that there were 28 metabolites involving in the therapeutic effects of PBA against sepsis. According to network pharmacology, 11 hub genes were found that were involved in lipid metabolism and amino acid transport following PBA treatment. The further integrated analysis focused on 7 key targets, including Comt, Slc6a4, Maoa, Ppara, Pparg, Ptgs2 and Trpv1, as well as their core metabolites and pathways. In an in vitro assay, PBA effectively inhibited sepsis-induced reductions in Comt, Ptgs2 and Ppara after sepsis.ConclusionsPBA protects sepsis-induced cardiac injury by targeting Comt/Ptgs2/Ppara, which regulates amino acid metabolism and lipid metabolism. The study reveals the complicated mechanisms of PBA against sepsis.

Curcumin simultaneously improves mitochondrial dynamics and myocardial cell bioenergy after sepsis via the SIRT1-DRP1/PGC-1α pathway

Septic cardiomyopathy (SCM) is associated with an imbalance in mitochondrial quality and high mortality rates, with no effective treatment developed to date. Curcumin provides antioxidant, anti-inflammatory, cardiovascular, and mitochondrial protection. However, curcumin has not been confirmed to improve cardiac dysfunction in sepsis. We hypothesized that curcumin can reduce abnormal inflammatory responses by improving mitochondrial function as a novel mechanism to improve SCM. To explore this hypothesis, we used an in vivo male C57BL/6 mouse sepsis model and an in vitro model of lipopolysaccharide-stimulated HL-1 cells. The effects of curcumin on sepsis-induced cardiac dysfunction, inflammatory responses, and mitochondrial quality of cardiac cells were observed using quantitative polymerase chain reaction, western blotting, echocardiography, and transmission electron microscopy. Curcumin activated sirtuin 1 (SIRT1); increased expression of the mitochondrial biogenesis-related genes Pgc1α, Tfam, and Nrf2; reduced dynamin-related protein 1 translocation from the cytoplasm to mitochondria; and restored the mitochondrial morphology and function in cardiac cells. Accordingly, curcumin protected heart function after septic shock and alleviated the effects of SCM. SIRT1 knockdown reversed the protective effects of curcumin on mitochondria. Therefore, curcumin promotes mitochondrial biogenesis and inhibits mitochondrial fragmentation by activating SIRT1, thereby improving the mitochondrial quality and reducing oxidative stress in cardiomyocytes and sepsis-induced cardiac dysfunction. These findings provide new evidence supporting the use of curcumin to treat SCM.

Phospholipid transfer protein ameliorates sepsis-induced cardiac dysfunction through NLRP3 inflammasome inhibition.

Cardiomyocyte pyroptosis is a primary contributor to sepsis-induced cardiac dysfunction (SICD). Recombinant phospholipid transfer protein (PLTP) have been demonstrated to possess anti-inflammatory and antiseptic properties. However, the effect of PLTP on SICD remains unknown. In this study, we established the in vivo and in vitro sepsis model with the recombinant PLTP treatment. The survival rates of mice, mouse cardiac function, cell viability, the protein level of proinflammatory cytokine, and lactate dehydrogenase level were evaluated. The cardiomyocyte pyroptotic changes were observed. The distribution of PLTP and NOD-like receptor thermal protein domain associated protein 3 (NLRP3) in mouse myocardial tissue and expression of PLTP, apoptosis associated speck like protein containing a CARD (ASC), NLRP3, caspase-1, interleukin (IL)-1β, and Gasdermin D (GSDMD) were detected. PLTP ameliorated the cecal ligation and puncture-induced mouse survival rate decrease and cardiac dysfunction, inhibited the IL-1β, IL-18, and tumor necrosis factor (TNF)-α release, and blocked the NLRP3 inflammasome/GSDMD signaling pathway in septic mice. In vitro, PLTP reversed the lipopolysaccharide-induced cardiomyocyte pyroptosis, expression of IL-1β, IL-6, TNF-α, and activation of the NLRP3 inflammasome/GSDMD signal pathway. Moreover, PLTP could bind to NLRP3 and negatively regulate the activity of the NLRP3 inflammasome/GSDMD signal pathway. This study demonstrated that PLTP can ameliorate SICD by inhibiting inflammatory responses and cardiomyocyte pyroptosis by blocking the activation of the NLRP3 inflammasome/GSDMD signaling pathway.

Esculin targets TLR4 to protect against LPS-induced septic cardiomyopathy

BackgroundEsculin, a main active ingredient from Cortex fraxini, possesses biological activities such as anti-thrombosis, anti-inflammatory, and anti-oxidation effects. However, the effects of Esculin on septic cardiomyopathy remains unclear. This study aimed to explore the protective properties and mechanisms of Esculin in countering sepsis-induced cardiac trauma and dysfunction. Methods and ResultsIn lipopolysaccharide (LPS)-induced mice model, Esculin could obviously improve heart injury and function. Esculin treatment also significantly reduced the production of inflammatory and apoptotic cells, the release of inflammatory cytokines, and the expression of oxidative stress-associated and apoptosis-associated markers in hearts compared to LPS injection alone. These results were consistent with those of in vitro experiments based on neonatal rat cardiomyocytes. Database analysis and molecular docking suggested that TLR4 was targeted by Esculin, as shown by stable hydrogen bonds formed between Esculin with VAL-308, ASN-307, CYS-280, CYS-304 and ASP-281 of TLR4. Esculin reversed LPS-induced upregulation of TLR4 and phosphorylation of NF-κB p65 in cardiomyocytes. The plasmid overexpressing TLR4 abolished the protective properties of Esculin in vitro. ConclusionWe concluded that Esculin could alleviate LPS-induced septic cardiomyopathy via binding to TLR4 to attenuate cardiomyocyte inflammation, oxidative stress and apoptosis.

Xijiao Dihuang Decoction Protects Against Murine Sepsis-Induced Cardiac Inflammation and Apoptosis via Suppressing TLR4/NF-κB and Activating PI3K/AKT Pathway.

Xijiao Dihuang decoction (XJDHT), a traditional Chinese medicine, is widely used to treat patients with sepsis. However, the mechanisms underlying the effects of XJDHT on cardiac dysfunction have yet to be fully elucidated. The present study evaluated the potential utility of XJDHT in protecting against sepsis-induced cardiac dysfunction and myocardial injury. The mice were randomly divided into 3 groups and administered Lipopolysaccharide (LPS,10 mg/kg) or equivalent saline solution (control) and treated with XJDHT (10 g/kg/day) or saline by gavage for 72 hours. XJDHT was dissolved in 0.9% sodium chloride and administered at 200 μL per mouse. Transthoracic echocardiography, RNA-seq, TUNEL assays and hematoxylin and eosin (H&E) staining of cardiac tissues were performed. Treatment with XJDHT significantly enhanced myocardial function and attenuated pathological change, infiltration of inflammatory cells, levels of TNF-α, IL-1β and expression of TLR4 and NF-κB in mice with sepsis. RNA sequencing and Kyoto Encyclopedia of Genes and Genomes pathway analyses identified 531 differentially expressed genes and multiple enriched signaling pathways including the PI3K/AKT pathway. Further, XJDHT attenuated cardiac apoptosis and decreased Bax protein expression while increasing protein levels of Bcl-2, PI3K, and p-AKT in cardiac tissues of mice with sepsis. In summary, XJDHT improves cardiac function in a murine model of sepsis by attenuating cardiac inflammation and apoptosis via suppressing the TLR4/NF-κB pathway and activating the PI3K/AKT pathway.

The DNA-dependent protein kinase catalytic subunit promotes sepsis-induced cardiac dysfunction through disrupting INF-2-dependent mitochondrial dynamics.

Sepsis-induced cardiomyopathy (SIC) represents a severe complication of systemic infection, characterized by significant cardiac dysfunction. This study examines the role of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) and Inverted Formin 2 (INF2) in the pathogenesis of SIC, focusing on their impact on mitochondrial homeostasis and dynamics. Our research demonstrates that silencing DNA-PKcs alleviates lipopolysaccharide (LPS)-induced cardiomyocyte death and dysfunction. Using HL-1 cardiomyocytes treated with LPS, we observed that DNA-PKcs knockdown notably reverses LPS-induced cytotoxicity, indicating a protective role against cellular damage. This effect is further substantiated by the reduction in caspase-3 and caspase-9 activation, key markers of apoptosis, upon DNA-PKcs knockdown. Besides, our data further reveal that DNA-PKcs knockdown attenuates LPS-induced mitochondrial dysfunction, evidenced by improved ATP production, enhanced activities of mitochondrial respiratory complexes, and preserved mitochondrial membrane potential. Moreover, DNA-PKcs deletion counteracts LPS-induced shifts towards mitochondrial fission, indicating its regulatory influence on mitochondrial dynamics. Conclusively, our research elucidates the intricate interplay between DNA-PKcs and INF2 in the modulation of mitochondrial function and dynamics during sepsis-induced cardiomyopathy. These findings offer new insights into the molecular mechanisms underpinning SIC and suggest potential therapeutic targets for mitigating mitochondrial dysfunction in this critical condition.

ACT001 improved cardiovascular function in septic mice by inhibiting the production of proinflammatory cytokines and the expression of JAK-STAT signaling pathway

Sepsis is a life-threatening multiple organ dysfunction syndrome (MODS) caused by a microbial infection that leads to high morbidity and mortality worldwide. Sepsis-induced cardiomyopathy (SIC) and coagulopathy promote the progression of adverse outcomes in sepsis. Here, we reported that ACT001, a modified compound of parthenolide, improved the survival of sepsis mice. In this work, we used cecal ligation and puncture (CLP) model to induce SIC. Transthoracic echocardiography and HE staining assays were adopted to evaluate the influence of ACT001 on sepsis-induced cardiac dysfunction. Our results showed that ACT001 significantly improved heart function and reduced SIC. Coagulation accelerates organ damage in sepsis. We found that ACT001 decreased blood clotting in the FeCl3-induced carotid artery thrombosis experiment. ACT001 also reduced the production of neutrophil extracellular traps (NETs). RNA-sequencing of heart tissues revealed that ACT001 significantly downregulated the expression of pro-inflammatory cytokines and the JAK-STAT signaling pathway. These results were confirmed with real-time PCR and ELISA. In summary, we found ACT001 rescued mice from septic shock by protecting the cardiovascular system. This was partially mediated by inhibiting pro-inflammatory cytokine production and down-regulating the JAK-STAT signaling.

DLK1 overexpression improves sepsis-induced cardiac dysfunction and fibrosis in mice through the TGF-β1/Smad3 signaling pathway and MMPs.

Sepsis is a serious inflammatory disease caused by bacterial infection. Cardiovascular dysfunction and remodeling are serious complications of sepsis, which can significantly affect sepsis patients' mortality. Delta-like homologue 1 (DLK1) has been reported could inhibit cardiac myofibroblast differentiation. However, the function of DLK1 in sepsis is unknown. In the present study, the DLK1 expression was first identified based on the online dataset GSE79962 analysis and cecal ligation and puncture (CLP)-induced sepsis mouse model. DLK1 expression was significantly reduced in septic heart tissues. In septic mouse heart, CLP operation decreased the fractional shortening (EF) (%) and ejection fraction (FS) (%) and caused significant edema, disordered myofilament arrangement, and degradation and necrosis in myocardial cells; CLP operation also increased collagen deposition and elevated the protein levels of fibrotic markers (α-SMA and F-actin). DLK1 overexpression in septic mice could effectively increase EF (%) and FS (%), attenuate CLP-caused ECM degradation and deposition and partially inhibit the CLP-induced TGF-β1/Smad signaling activation. In conclusion, DLK1 expression was poorly expressed in the CLP-induced septic mouse heart. DLK1 overexpression partially alleviated sepsis-induced cardiac dysfunction and fibrosis, with the involvement of the TGF-β1/Smad3 signaling pathway and MMPs.

Golgi Protein 73 Promotes LPS-Induced Cardiac Dysfunction via Mediating Myocardial Apoptosis and Autophagy.

Sepsis-induced cardiac dysfunction represents a major cause of high mortality in intensive care units with limited therapeutic options. Golgi protein 73 (GP73) has been implicated in various diseases. However, the role of GP73 in lipopolysaccharide (LPS)-induced cardiac dysfunction is unclear. In this study, we established a sepsis-induced cardiac dysfunction model by LPS administration in wild-type and GP73 knockout ( GP73-/- ) mice. We found that GP73 was increased in LPS-treated mouse hearts and LPS-cultured neonatal rat cardiomyocytes (NRCMs). Knockout of GP73 alleviated myocardial injury and improved cardiac dysfunction. Moreover, depletion of GP73 in NRCMs relieved LPS-induced cardiomyocyte apoptosis and activated myocardial autophagy. Therefore, GP73 is a negative regulator in LPS-induced cardiac dysfunction by promoting cardiomyocyte apoptosis and inhibiting cardiomyocyte autophagy.

Baricitinib protects mice from sepsis-induced cardiac dysfunction and multiple-organ failure.

Sepsis is one of the major complications of surgery resulting in high morbidity and mortality, but there are no specific therapies for sepsis-induced organ dysfunction. Data obtained under Gene Expression Omnibus accession GSE131761 were re-analyzed and showed an increased gene expression of Janus Kinase 2 (JAK2) and Signal Transducer and Activator of Transcription 3 (STAT3) in the whole blood of post-operative septic patients. Based on these results, we hypothesized that JAK/STAT activation may contribute to the pathophysiology of septic shock and, hence, investigated the effects of baricitinib (JAK1/JAK2 inhibitor) on sepsis-induced cardiac dysfunction and multiple-organ failure (MOF). In a mouse model of post-trauma sepsis induced by midline laparotomy and cecal ligation and puncture (CLP), 10-week-old male (n=32) and female (n=32) C57BL/6 mice received baricitinib (1mg/kg; i.p.) or vehicle at 1h or 3h post-surgery. Cardiac function was assessed at 24h post-CLP by echocardiography in vivo, and the degree of MOF was analyzed by determination of biomarkers in the serum. The potential mechanism underlying both the cardiac dysfunction and the effect of baricitinib was analyzed by western blot analysis in the heart. Trauma and subsequent sepsis significantly depressed the cardiac function and induced multiple-organ failure, associated with an increase in the activation of JAK2/STAT3, NLRP3 inflammasome and NF- κβ pathways in the heart of both male and female animals. These pathways were inhibited by the administration of baricitinib post the onset of sepsis. Moreover, treatment with baricitinib at 1h or 3h post-CLP protected mice from sepsis-induced cardiac injury and multiple-organ failure. Thus, baricitinib may be repurposed for trauma-associated sepsis.

Targeting of cold-inducible RNA-binding protein alleviates sepsis via alleviating inflammation, apoptosis and oxidative stress in heart.

A systemic inflammatory response is observed in patients undergoing shock and sepsis. This study aimed to explore the effects of cold-inducible RNA-binding protein (CIRP) on sepsis-associated cardiac dysfunction and the underlying mechanism. In vivo and in vitro lipopolysaccharide (LPS)-induced sepsis models were established in mice and neonatal rat cardiomyocytes (NRCMs), respectively. CRIP expressions were increased in the mouse heart and NRCMs treated with LPS. CIRP knockdown alleviated LPS-induced decreases of left ventricular ejection fraction and fractional shortening. CIRP downregulation attenuated the increases of inflammatory factors in the LPS-induced septic mouse heart, and NRCMs. The enhanced oxidative stress in the LPS-induced septic mouse heart and NRCMs was suppressed after CIRP knockdown. By contrast, CIRP overexpression yielded the opposite results. Our current study indicates that the knockdown of CIRP protects against sepsis-induced cardiac dysfunction through alleviating inflammation, apoptosis and oxidative stress of cardiomyocytes.

Stattic ameliorates the cecal ligation and puncture-induced cardiac injury in septic mice via IL-6-gp130-STAT3 signaling pathway

AimSepsis-induced cardiac dysfunction is the leading cause of higher morbidity and mortality with poor prognosis in septic patients. Our recent previous investigation provides evidence of the hallmarks of signal transducer and activator of transcription3 (STAT3) activation in sepsis and targeting of STAT3 with Stattic, a small-molecule inhibitor of STAT3, has beneficial effects in various septic tissues. We investigated the possible cardioprotective effects of Stattic on cardiac inflammation and dysfunction in mice with cecal ligation and puncture (CLP)-induced sepsis. Main methodsA polymicrobial sepsis model was induced by CLP in mice and Stattic (25 mg/kg) was intraperitoneally given at one and twelve hours after CLP operation. The cecum was exposed in sham-control mice without CLP. After 18 h of surgery, electrocardiogram (ECG) for anaesthized mice was registered followed by collecting of samples of blood and tissues for bimolecular and histopathological assessments. Myeloperoxidase, a marker of neutrophil infiltration, was assessed immunohistochemically. Key findingsCLP profoundly impaired cardiac functions as evidenced by ECG changes in septic mice as well as elevation of cardiac enzymes, and inflammatory markers with myocardial histopathological and immunohistochemical alterations. While, Stattic markedly reversed the CLP-induced cardiac abnormalities and restored the cardiac function by its anti-inflammatory activities. SignificanceStattic treatment had potential beneficial effects against sepsis-induced cardiac inflammation, dysfunction and damage. Its cardioprotective effects were possibly attributed to its anti-inflammatory activities by targeting STAT3 and downregulation of IL-6 and gp130. Our investigations suggest that Stattic could be a promising target for management of cardiac sepsis and inflammation-related cardiac damage.

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

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

A new path to prevent sepsis-induced cardiac dysfunction

A new path to prevent sepsis-induced cardiac dysfunction

Role of Pellino-1 in Inflammation and Cardioprotection following Severe Sepsis: A Novel Mechanism in a Murine Severe Sepsis Model †.

Intra-abdominal sepsis is commonly diagnosed in the surgical population and remains the second most common cause of sepsis overall. Sepsis-related mortality remains a significant burden in the intensive care unit despite advances in critical care. Nearly a quarter of the deaths in people with heart failure are caused by sepsis. We have observed that overexpression of mammalian Pellino-1 (Peli1), an E3 ubiquitin ligase, causes inhibition of apoptosis, oxidative stress, and preservation of cardiac function in a myocardial infarction model. Given these manifold applications, we investigated the role of Peli1 in sepsis using transgenic and knockout mouse models specific to this protein. Therefore, we aimed to explore further the myocardial dysfunction seen in sepsis through its relation to the Peli 1 protein by using the loss of function and gain-of-function strategy. A series of genetic animals were created to understand the role of Peli1 in sepsis and the preservation of heart function. Wild-type, global Peli1 knock out (Peli1-/-), cardiomyocyte-specific Peli1 deletion (CP1KO), and cardiomyocyte-specific Peli1 overexpressing (alpha MHC (αMHC) Peli1; AMPEL1Tg/+) animals were divided into sham and cecal ligation and puncture (CLP) surgical procedure groups. Cardiac function was determined by two-dimensional echocardiography pre-surgery and at 6- and 24-h post-surgery. Serum IL-6 and TNF-alpha levels (ELISA) (6 h), cardiac apoptosis (TUNEL assay), and Bax expression (24 h) post-surgery were measured. Results are expressed as mean ± S.E.M. AMPEL1Tg/+ prevents sepsis-induced cardiac dysfunction assessed by echocardiographic analysis, whereas global and cardiomyocyte-specific deletion of Peli1 shows significant deterioration of cardiac functions. Cardiac function was similar across the sham groups in all three genetically modified mice. ELISA assay displayed how Peli 1 overexpression decreased cardo-suppressive circulating inflammatory cytokines (TNF-alpha, IL-6) compared to both the knockout groups. The proportion of TUNEL-positive cells varied according to Peli1 expression, with overexpression (AMPEL1Tg/+) leading to a significant reduction and Peli1 gene knockout (Peli1-/- and CP1KO) leading to a significant increase in their presence. A similar trend was also observed with Bax protein expression. The improved cellular survival associated with Peli1 overexpression was again shown with the reduction of oxidative stress marker 4-Hydroxy-2-Nonenal (4-HNE). Our results indicate that overexpression of Peli1 is a novel approach that not only preserved cardiac function but reduced inflammatory markers and apoptosis following severe sepsis in a murine genetic model.

Electroacupuncture at Neiguan (PC6) attenuates cardiac dysfunction caused by cecal ligation and puncture via the vagus nerve

PurposePrevious studies proved the benefits of electroacupuncture (EA) on heart in ischemia reperfusion injury and chronic heart failure. However, the role of EA on sepsis-induced cardiac dysfunction has rarely been elucidated before. In this study, we aimed to investigate the effects of EA on cardiac dysfunction in a rat model of sepsis and to speculate the underlying mechanisms. MethodsSepsis was induced by cecum ligation and puncture in anesthetized rats. EA at the acupoint “Neiguan (PC6)” was applied 0.5 h after the induction of sepsis for 20 min. Heart rate variability was obtained immediately after EA to evaluate autonomic balance. Echocardiography was performed at 6 h and 24 h after sepsis induction in vivo. Measurements of hemodynamics, blood gases, cytokines and biochemistry were collected at 24 h. Cardiac tissue underwent immunofluorescence staining to determine the expression of α7 nicotinic acetylcholine receptor (α7nAChR) on macrophages. ResultsEA increased vagus nerve activity, prevented the development of hyperlactatemia, attenuated the decline of left ventricle ejection fraction, suppressed systemic and cardiac inflammation and alleviated the histopathological manifestations of heart in sepsis rats. Furthermore, the cardiac tissue from EA treated rats showed increased expressions of α7nAChR on macrophages. The cardio-protective and anti-inflammatory effects of EA were partly or completely prevented in rats with vagotomy. ConclusionEA at PC6 attenuates left ventricle dysfunction and decreases inflammation in sepsis-induced cardiac dysfunction. The cardio-protective effects of EA are mediated through vagus nerve mediated cholinergic pathway.

Ginkgolide A targets forkhead box O1 to protect against lipopolysaccharide-induced septic cardiomyopathy.

Ginkgolide A (GA), a main terpenoid extracted from Ginkgo biloba, possesses biological activities such as anti-inflammatory, anti-tumor, and liver protection. However, the inhibitory effects of GA on septic cardiomyopathy remain unclear. This study aimed to explore the effects and mechanisms of GA in countering sepsis-induced cardiac dysfunction and injury. In lipopolysaccharide (LPS)-induced mouse model, GA alleviated mitochondrial injury and cardiac dysfunction. GA also significantly reduced the production of inflammatory and apoptotic cells, the release of inflammatory indicators, and the expression of oxidative stress-associated and apoptosis-associated markers, but increased the expression of pivotal antioxidant enzymes in hearts from LPS group. These results were consistent with those of in vitro experiments based on H9C2 cells. Database analysis and molecular docking suggested that FoxO1 was targeted by GA, as shown by stable hydrogen bonds formed between GA with SER-39 and ASN-29 of FoxO1. GA reversed LPS-induced downregulation of nucleus FoxO1 and upregulation of p-FoxO1 in H9C2 cells. FoxO1 knockdown abolished the protective properties of GA in vitro. KLF15, TXN2, NOTCH1, and XBP1, as the downstream genes of FoxO1, also exerted protective effects. We concluded that GA could alleviate LPS-induced septic cardiomyopathy via binding to FoxO1 to attenuate cardiomyocyte inflammation, oxidative stress, and apoptosis.

Expression of Concern on "IκB Kinase Inhibitor VII Modulates Sepsis-Induced Excessive Inflammation and Cardiac Dysfunction in 5/6 Nephrectomized Mice".

Expression of Concern on "IκB Kinase Inhibitor VII Modulates Sepsis-Induced Excessive Inflammation and Cardiac Dysfunction in 5/6 Nephrectomized Mice".