Cecal Ligation And Puncture Research Articles

Ubiquitin-independent degradation of Bim blocks macrophage pyroptosis in sepsis-related tissue injury

Pyroptosis, a typical inflammatory cell death mode, has been increasingly demonstrated to have therapeutic value in inflammatory diseases such as sepsis. However, the mechanisms and therapeutic targets of sepsis remain elusive. Here, we reported that REGγ inhibition promoted pyroptosis by regulating members of the gasdermin family in macrophages. Mechanistically, REGγ directly degraded Bim, a factor of the Bcl-2 family that can inhibit the cleavage of GSDMD/E, ultimately preventing the occurrence of pyroptosis. Furthermore, cecal ligation and puncture (CLP)-induced sepsis model mice showed downregulation of REGγ at both the RNA and protein levels. Gasdermin-mediated pyroptosis was augmented in REGγ-knockout mice, and these mice exhibited more severe sepsis-related tissue injury. More importantly, we found that REGγ expression was downregulated in clinical sepsis samples, such as those from patients with Pseudomonas aeruginosa (PA) infection. Finally, PA-infected mice showed decreased REGγ levels in the lung. In summary, our study reveals that the REGγ-Bim-GSDMD/E pathway is a novel regulatory mechanism of pyroptosis in sepsis-related tissue injury.

The natural flavonoid pinocembrin shows antithrombotic activity and suppresses septic thrombosis

Sepsis, an extreme host response to systemic infection, remains one of the leading causes of mortality worldwide. Platelets, which are integral to both thrombosis and inflammation, play a crucial role in the pathophysiology of sepsis. Excessive platelet activation and aggregation significantly increase the risk of thrombosis, thereby elevating mortality in septic patients. However, the etiology and treatment of this condition have not been comprehensively studied. This study identifies pinocembrin, a natural flavonoid compound derived from propolis, as a potential therapeutic agent for mitigating platelet activation and treating sepsis. In vivo, pinocembrin effectively inhibited FeCl3-induced carotid arterial occlusive thrombus formation and collagen/epinephrine-induced pulmonary thromboembolism in mouse models. In vitro, pinocembrin treatment suppressed multiple facets of platelet activation, including aggregation, secretion, and αIIbβ3-mediated signaling events. Mechanistically, pinocembrin repressed platelet functions by inhibiting Src/Syk/PLCγ2/MAPK signaling pathway. Using cecal ligation and puncture (CLP) mouse model to simulate human sepsis, pinocembrin reduced inflammatory cytokine release and septic thrombosis, thereby improving the survival rate of septic mice. Lipopolysaccharide (LPS)-induced model further substantiated these results. Overall, the inhibition of platelet activity by pinocembrin demonstrates significant therapeutic potential for managing life-threatening septic thrombosis.

Cardiovascular effects of Roflumilast during sepsis: Risks or benefits?

BackgroundPhosphodiesterase-4 (PDE4) is responsible for terminating cyclic adenosine monophosphate (cAMP) signalling. PDE4 inhibitors, such as roflumilast (RFM), have anti-inflammatory activity and have been studied in inflammation-induced tissue damage in sepsis. However, the role of RFM on cardiovascular derangements induced by sepsis is still unknown. Thus, we aimed to evaluate the potential effects of RFM on cardiovascular collapse and multiorgan damage caused by sepsis. MethodsSepsis was induced by cecal ligation and puncture (CLP) in male rats. Six hours after the CLP or sham procedure, animals were randomly assigned to receive either RFM (0.3 mg/kg) or vehicle subcutaneously, and cardiovascular parameters were assessed 24 h after the surgery and organ/plasma samples were collected for further analyses. ResultsSepsis induced hypotension, tachycardia, reduced renal blood flow (RBF) and hyporeactivity to vasoconstrictors both in vivo and ex vivo. RFM treatment increased systemic cAMP levels and RBF. RFM also attenuated hypoperfusion and liver damage induced by CLP. Furthermore, RFM reduced systemic nitric oxide (NO) levels in septic rats, while there were no changes in hepatic NOS-2 expression. Nevertheless, RFM exacerbated sepsis-induced hypotension and tachycardia without ameliorating vascular hyporeactivity. ConclusionOur data show that PDE-4 inhibition protects septic rats from hepatic injury and improves renal perfusion. However, RFM worsened hemodynamic parameters and showed no protection against sepsis-induced cardiovascular dysfunction and mortality. Thus, despite the anti-inflammatory benefits of RFM, its application in sepsis should be approached cautiously.

Ablation of mitophagy receptor FUNDC1 accentuates septic cardiomyopathy through ACSL4-dependent regulation of ferroptosis and mitochondrial integrity

Sepsis evokes compromised myocardial function prompting heart failure albeit target therapy remains dismal. Our study examined the possible role of mitophagy receptor FUNDC1 in septic cardiomyopathy. A sepsis model was established using cecal ligation and puncture (CLP) in FUNDC1 knockout (FUNDC1−/−) and WT mice prior to the evaluation of cardiac morphology, echocardiographic and cardiomyocyte contractile, oxidative stress, apoptosis, necroptosis, and ferroptosis. RNAseq analysis depicted discrepant patterns in mitophagy, oxidative stress and ferroptosis between CLP-challenged and control murine hearts. Septic patients displayed cardiac injury alongside low plasma FUNDC1 and iron levels. CLP evoked interstitial fibrosis, cardiac dysfunction (lowered ejection fraction, fractional shortening, shortening/relengthening velocity, peak shortening and electrically-stimulated intracellular Ca2+ rise, alongside increased LV end systolic diameter and relengthening duration), O2− buildup, apoptosis, necroptosis, and ferroptosis (downregulated GPX4 and SLC7A11), the responses of which were accentuated by FUNDC1 ablation. In particular, levels of lipid peroxidation enzyme acyl-CoA synthetase long-chain family member 4 (ACSL4) were upregulated following CLP procedure, with a more pronounced response in FUNDC1−/− mice. Co-immunoprecipitation and interaction interface revealed an evident interaction between FUNDC1 and ACSL4. In vitro studies revealed that the endotoxin lipopolysaccharide provoked cardiomyocyte contractile and lipid peroxidation anomalies, the responses were reversed by the mitophagy inducer oleanolic acid, inhibition of ACSL4 and ferroptosis. These findings favor a role for FUNDC1-ACSL4-ferroptosis cascade in septic cardiomyopathy.

Araloside A alleviates sepsis-induced acute lung injury via PHD2/HIF-1α in macrophages

BackgroundAcute lung injury (ALI)-induced acute respiratory syndromes is a critical pathological sequala of sepsis. Araloside A (ARA), extracted from Aralia taibaiensis, possesses anti-oxidative and pro-apoptotic effects, as well as a protective effect against inflammatory diseases such as gastric ulcers. However, its impact on progression of ALI remains unknown. This study seeks to assess the therapeutic effect of ARA in sepsis-induced ALI, and to elucidate the underlying mechanism. MethodsSepsis-induced ALI was induced in C57BL/6 mice using lipopolysaccharide (LPS) or cecal ligation and puncture (CLP) along with simultaneous administration of ARA. In vitro, bone marrow-derived macrophages (BMDMs) and RAW264.7 cells were exposed to LPS to activate proinflammatory macrophages in the presence/absence of ARA. RNA sequencing of BMDMs was then conducted to elucidate the detailed mechanism. ResultsTreatment of mice with ARA led to a significant reduction in serum level of inflammatory cytokines, ameliorated sepsis-induced ALI (i.e., impaired barrier integrity, cell apoptosis), and increased survival of septic mice. In vitro, ARA effectively inhibited activation of proinflammatory BMDMs. In addition, RNA sequencing revealed that the PHD2/HIF-1α signaling played a critical role in the anti-inflammatory effects of ARA. ARA suppressed proinflammatory macrophages to ameliorate lung inflammation in septic mice by restoring PHD2/HIF-1α signaling. ConclusionsARA prevented mice from the fatal effects of sepsis by restoring PHD2/HIF-1α signaling, thereby inhibiting activation of proinflammatory macrophages. These findings suggest that ARA could be a promising therapy for sepsis-induced ALI.

CircMAPK1 induces cell pyroptosis in sepsis-induced lung injury by mediating KDM2B mRNA decay to epigenetically regulate WNK1

BackgroundMacrophage pyroptosis is a pivotal inflammatory mechanism in sepsis-induced lung injury, however, the underlying mechanisms remain inadequately elucidated.MethodsLipopolysaccharides (LPS)/adenosine triphosphate (ATP)-stimulated macrophages and cecal ligation and puncture (CLP)-induced mouse model for sepsis were established. The levels of key molecules were examined by qRT-PCR, Western blotting, immunohistochemistry (IHC) and ELISA assay. The subcellular localization of circMAPK1 was detected by RNA fluorescence in situ hybridization (FISH). Cell viability, LDH release and caspase-1 activity were monitored by CCK-8, LDH assays, and flow cytometry. The bindings between KDM2B/H3K36me2 and WNK1 promoter was detected by chromatin immunoprecipitation (ChIP) assay and luciferase assay, and associations among circMAPK1, UPF1 and KDM2B mRNA were assessed by RNA pull-down or RNA immunoprecipitation (RIP) assays. The pathological injury of lung tissues was evaluated by lung wet/dry weight ratio and hematoxylin and eosin (H&E) staining.ResultsCircMAPK1 was elevated in patients with septic lung injury. Knockdown of circMAPK1 protected against LPS/ATP-impaired cell viability and macrophage pyroptosis via WNK1/NLRP3 axis. Mechanistically, loss of circMAPK1 enhanced the association between KDM2B and WNK1 promoter to promote the demethylation of WNK1 and increase its expression. CircMAPK1 facilitated KDM2B mRNA decay by recruiting UPF1. Functional experiments showed that silencing of KDM2B or WNK1 counteracted circMAPK1 knockdown-suppressed macrophage pyroptosis. In addition, silencing of circMAPK1 alleviated CLP-induced lung injury in mice via KDM2B/WNK1/NLRP3 axis.ConclusionCircMAPK1 exacerbates sepsis-induced lung injury by destabilizing KDM2B mRNA to suppress WNK1 expression, thus facilitating NLRP3-driven macrophage pyroptosis.

Protective Effects of Crotonis Semen Extract against Sepsis through NF-κB Pathway Inhibition.

Sepsis is an inflammatory condition causing organ failure due to an uncontrolled immune response to infection and remains a significant challenge. Crotonis Semen has displayed various pharmacological effects, yet its potential in protecting against sepsis and the mechanisms involved remains largely unclear. Here, we explored the antiseptic properties of Crotons Semen extract (CSE) in both LPS-stimulated J774 macrophages and mice subjected to sepsis through Cecal ligation and Puncture (CLP) or LPS induction. We found that CSE enhanced survival rates in mouse models with acute sepsis induced by CLP operation and LPS injection. Administering CSE also reduced levels of enzymes indicating organ damage, such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), and creatine kinase (CK), in septic mice. Furthermore, CSE lowered the serum levels of inflammatory mediators and cytokines, such as NO, TNF-α, IL-1β, and IL-6, in septic mice. In LPS-stimulated J774 macrophages, CSE reduced the expression of pro-inflammatory proteins, including iNOS and COX-2. Moreover, CSE inhibited the phosphorylation of IκBα and IKK, key components of the NF-κB signaling pathway, thereby reducing inflammatory mediators and cytokines. These results demonstrate CSE's protective effects against sepsis through NF-κB pathway disruption, indicating its potential as a therapeutic option for acute inflammatory conditions.

Natural hydrogen gas and engineered microalgae prevent acute lung injury in sepsis

BackgroundHydrogen gas and microalgae both exist in the natural environment. We aimed to integrate hydrogen gas and biology nano microalgae together to expand the treatment options in sepsis. MethodsPhosphoproteomics, metabolomics and proteomics data were obtained from mice undergoing cecum ligation and puncture (CLP) and inhalation of hydrogen gas. All omics analysis procedure were accordance with standards. Multi R packages were used in single cell and spatial transcriptomics analysis to identify primary cells expressing targeted genes, and the genes’ co-expression relationships in sepsis related lung landscape. Then, network pharmacology method was used to identify candidate drugs. We used hydrophobic-force-driving self-assembly method to construct dihydroquercetin (DQ) nanoparticle. To cooperate with molecular hydrogen, ammonia borane (B) was added to DQ surface. Then, Chlorella vulgaris (C) was used as biological carrier to improve self-assembly nanoparticle. Vivo and vitro experiments were both conducted to evaluate anti-inflammation, anti-ferroptosis, anti-infection and organ protection capability. ResultsAs a result, we identified Esam and Zo-1 were target phosphorylation proteins for molecular hydrogen treatment in lung. Ferroptosis and glutathione metabolism were two target pathways. Chlorella vulgaris improved the dispersion of DQB and reconstructed morphological features of DQB, formed DQB@C nano-system (size = 307.3 nm, zeta potential = −22mv), with well infection-responsive hydrogen release capability and biosafety. In addition, DQB@C was able to decrease oxidative stress and inflammation factors accumulation in lung cells. Through increasing expression level of Slc7a11/xCT and decreasing Cox2 level to participate with the regulation of ferroptosis. Also, DQB@C played lung and multi organ protection and anti-inflammation roles on CLP mice. ConclusionOur research proposed DQB@C as a novel biology nano-system with enormous potential on treatment for sepsis related acute lung injury to solve the limitation of hydrogen gas utilization in clinics.

MiR-155 induces sepsis-associated damage to the intestinal mucosal barrier via sirtuin 1/nuclear factor-κB-mediated intestinal pyroptosis.

Sepsis is a life-threatening state of organ dysfunction caused by systemic inflammation and a dysfunctional response to host infections that can induce severe intestinal mucosal damage. Pyroptosis is mediated by the activated NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome after stimulation by various inflammatory factors during sepsis. The inflammatory response is a major driver of intestinal damage during sepsis. Intestinal mucosal barrier dysfunction in sepsis is associated with pyroptosis, a type of programmed inflammatory cell death. Several studies have confirmed the role of miR-155 in sepsis and other diseases. However, the effect of miR-155 on intestinal pyroptosis in the context of intestinal mucosal barrier dysfunction during sepsis remains unclear. Thus, a model of sepsis in Sprague-Dawley rats is established using cecal ligation and puncture (CLP), and a series of molecular biological methods are used in this study. The results show that the expression of miR-155 is increased and that of sirtuin 1 (SIRT1) is decreased in the intestinal tissues of patients with sepsis. miR-155 expression is negatively correlated with SIRT1 expression. Increased miR-155 expression significantly inhibits SIRT1 activity and upregulates the expressions of NOD-like receptor family pyrin domain-containing 3 (NLRP3), caspase-1, apoptosis-associated speck-like protein containing a CARD (ASC), interleukin-1β (IL-1β) and interleukin-18 (IL-18) to promote pyroptosis. The inhibition of miR-155 expression is associated with increased SIRT1 expression, promotes the deacetylation of p65, and significantly downregulates p65 acetylation. Herein, we propose that miR-155 induces pyroptosis in the intestine partly by regulating SIRT1, thereby reducing the deacetylation of the nuclear factor (NF)-κB subunit p65 and increasing NF-κB signaling activity in sepsis, leading to intestinal barrier damage.

PEI/MMNs@LNA-542 nanoparticles alleviate ICU-acquired weakness through targeted autophagy inhibition and mitochondrial protection.

Intensive care unit-acquired weakness (ICU-AW) is prevalent in critical care, with limited treatment options. Certain microRNAs, like miR-542, are highly expressed in ICU-AW patients. This study investigates the regulatory role and mechanisms of miR-542 in ICU-AW and explores the clinical potential of miR-542 inhibitors. ICU-AW models were established in C57BL/6 mice through cecal ligation and puncture (CLP) and in mouse C2C12 myoblasts through TNF-α treatment. In vivo experiments demonstrated decreased muscle strength, muscle fiber atrophy, widened intercellular spaces, and increased miR-542-3p/5p expression in ICU-AW mice model. In vitro experiments indicated suppressed ATG5, ATG7 and LC3II/I, elevated MDA and ROS levels, decreased SOD levels, and reduced MMP in the model group. Similar to animal experiments, the expression of miR-542-3p/5p was upregulated. Gel electrophoresis explored the binding of polyethyleneimine/mesoporous silica nanoparticles (PEI/MMNs) to locked nucleic acid (LNA) miR-542 inhibitor (LNA-542). PEI/MMNs@LNA-542 with positive charge (3.03 ± 0.363 mV) and narrow size (206.94 ± 6.19 nm) were characterized. Immunofluorescence indicated significant internalization with no apparent cytotoxicity. Biological activity, examined through intraperitoneal injection, showed that PEI/MMNs@LNA-542 alleviated muscle strength decline, restored fiber damage, and recovered mitochondrial injury in mice. In conclusion, PEI/MMNs nanoparticles effectively delivered LNA-542, targeting ATG5 to inhibit autophagy and alleviate mitochondrial damage, thereby improving ICU-AW.

Divergent effects of tumor necrosis factor (TNF) in sepsis: a meta-analysis of experimental studies

IntroductionExperimental studies in animals have yielded conflicting results on the role of Tumor Necrosis Factor (TNF) in sepsis and endotoxemia, with some reporting adaptive and others inappropriate effects. A meta-analysis of the available literature was performed to determine the factors explaining this discrepancy.MethodsThe study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The protocol was registered with PROSPERO (CRD42020167384) prior to data collection. PubMed and Embase were the databases queried. Risk of bias was evaluated using the SYRCLE Risk of Bias Tool. All animal studies investigating sepsis-related mortality and modified TNF signaling were considered eligible. The exclusion criteria were: lack of mortality data, 7-day mortality rates below 10% in both wild type and TNF-altered pathway animals, and absence of an English abstract. To determine the role of TNF according to the experimental protocol, three approaches were used: first an approach based on the statistical significance of each experiment, then the pooled mortality was calculated, and finally the weighted risk ratio for mortality was assessed.ResultsA total of 175 studies were included in the analysis, comprising a total of 760 experiments and involving 19,899 animals. The main species used were mice (77%) and rats (21%). The most common method of TNF pathway modulation was TNF pathway inactivation that was primarily associated with an inappropriate secretion of TNF. At the opposite, TNF injection was associated with an adaptive role of TNF. Lipopolysaccharide (LPS) injection was the most used stimulus to establish an infectious model (42%) and was strongly associated with an inappropriate role of TNF. Conversely, live bacterial models, especially the cecal ligation and puncture (CLP) model, pneumonia, meningitis, and gastrointestinal infection, were associated with an adaptive role. This was particularly evident for Listeria monocytogenes, Streptococcus pneumoniae.ConclusionThe role of TNF during infection varies depending on the experimental model used. Models that mimic clinical conditions, based on virulent bacteria that cause high mortality even at low inocula, demonstrated an adaptive role of TNF. Conversely, models based on LPS or low-pathogenic live bacteria, administered at doses well above physiological thresholds and combined with early antibiotic therapy, were associated with an inappropriate role.Graphical abstract

Impact of sympathetic hyperactivity induced by brain microglial activation on organ damage in sepsis with chronic kidney disease

BackgroundSympathetic nerve activity (SNA) plays a central role in the pathogenesis of several diseases such as sepsis and chronic kidney disease (CKD). Activation of microglia in the paraventricular nucleus of the hypothalamus (PVN) has been implicated in SNA. The mechanisms responsible for the adverse prognosis observed in sepsis associated with CKD remain to be determined. Therefore, we aimed to clarify the impact of increased SNA resulting from microglial activation on hemodynamics and organ damage in sepsis associated with CKD.Methods and resultsIn protocol 1, male Sprague–Dawley rats underwent either nephrectomy (Nx) or sham surgery followed by cecal ligation and puncture (CLP) or sham surgery. After CLP, Nx-CLP rats exhibited decreased blood pressure, increased heart rate, elevated serum creatinine and bilirubin levels, and decreased platelet count compared to Nx-Sham rats. Heart rate variability analysis revealed an increased low to high frequency (LF/HF) ratio in Nx-CLP rats, indicating increased SNA. Nx-CLP rats also had higher creatinine and bilirubin levels and lower platelet counts than sham-CLP rats after CLP. In protocol 2, Nx-CLP rats were divided into two subgroups: one received minocycline, an inhibitor of microglial activation, while the other received artificial cerebrospinal fluid (CSF) intracerebroventricularly via an osmotic minipump. The minocycline-treated group (Nx-mino-CLP) showed attenuated hypotensive and increased heart rate responses compared to the CSF-treated group (Nx-CSF-CLP), and the LF/HF ratio was also decreased. Echocardiography showed larger left ventricular dimensions and inferior vena cava in the Nx-mino-CLP group. In addition, creatinine and bilirubin levels were lower and platelet counts were higher in the Nx-mino-CLP group compared to the Nx-CSF-CLP group.ConclusionsIn septic rats with concomitant CKD, SNA was significantly enhanced and organ dysfunction was increased. It has been suggested that the mechanism of exacerbated organ dysfunction in these models may involve abnormal systemic hemodynamics, possibly triggered by activation of the central sympathetic nervous system through activation of microglia in the PVN.

Rapamycin mitigates organ damage by autophagy-mediated NLRP3 inflammasome inactivation in sepsis.

Autophagy activation can alleviate sepsis-induced organ injuries. Rapamycin (Rap) has emerged as an autophagy regulator in multiple forms of organ injuries. This study aimed to assess whether Rap protects rats from cecal ligation and puncture (CLP)-induced sepsis through autophagy-mediated inactivation of the NLRP3 inflammasome. Rats were allocated to the sham, CLP, Rap (10 mg/kg), or 3-Methyladenine (3-MA) (15 mg/kg) groups. A rat CLP model was established. The survival of rats and lung wet-to-dry weight ratio in each group was assessed. Blood biochemical indexes and oxidative stress-related factors were analyzed with an automatic biochemical analyzer. The bacterial counts of blood and organs were monitored. The degrees of myeloperoxidase of the ileum, inflammation-related indexes, and pathological changes in the tissues were detected by ELISA and hematoxylin-eosin staining. The levels of NLRP3 inflammasome and autophagy-related factors were analyzed by Western blot. Rap increased the survival and SOD activity, and repressed ALT, AST, BUN, SCr, MDA, and inflammation-related marker levels in CLP rats, it also restrained the bacterial counts of blood, lung, liver, and kidney in CLP rats; the effects of 3-MA on CLP rats on the above-mentioned indicators were opposite to those of Rap. Additionally, Rap alleviated the pathological injury of the lung, liver, and kidney, which was the opposite to the effect of 3-MA on CLP rats. Furthermore, Rap mitigated the ASC, Pro-caspase 1, and NLRP3 levels and increased the Beclin-1 levels and the LC3II/LC3I ratio in the organ tissues. Collectively, autophagy activation can mitigate organ damage by suppressing the NLRP3 inflammasome in sepsis rats.

Sepsis induced dysfunction of liver type 1 innate lymphoid cells

BackgroundSepsis is a life-threatening condition triggered by uncontrolled immune responses to infection, leading to widespread inflammation, tissue damage, organ dysfunction, and potentially death. The liver plays a crucial role in the immune response during sepsis, serving as a major site for immune cell activation and cytokine production. Liver type 1 innate lymphoid cells (ILCs) consist of NK cells and ILC1s. They maintain the local immune microenvironment by directly eliminating target cells and secreting cytokines. However, the specific roles and pathological changes of liver-resident NK cells and ILC1s during sepsis remain poorly understood.ResultsThis study aims to investigate the pathological changes of NK cells and ILC1s, which might contribute the dysfunction of liver. Sepsis mouse model was established by cecal ligation and puncture (CLP). Mouse immune cells from liver were isolated, and the surface makers, gene expression profiles, cytokine response and secretion, and mitochondrial function of NK (Natural Killer) cells and ILC1s (Innate Lymphoid Cell 1) were analyzed. A significant decrease in the number of mature NK cells was observed in the liver after CLP. Furthermore, the secretion of interferon-gamma (IFN-γ) was found to be reduced in spleen and liver NK cells when stimulated by IL-18. Mitochondrial activities in both liver NK cells and ILC1 were found to be increased during sepsis, suggesting an enhanced metabolic response in these cells to combat the infection. However, despite this heightened activity, liver NK cells exhibited a decreased level of cytotoxicity, which might impact their ability to target infected cells effectively. RNA sequencing supported and provided the potential mechanisms for the proinflammatory effects and exhaustion like phenotypes of liver NK cells.ConclusionsSepsis induces dysfunction and exhaustion-like phenotypes in liver NK cells and ILC1, which might further impair other immune cells and represent a potential therapeutic target for sepsis.

Erbin alleviates sepsis-induced cardiomyopathy by inhibiting RIPK1-dependent necroptosis through activating PKA/CREB pathway

Sepsis is a systemic inflammatory disease that can cause multiple organ damage. Septic patients with cardiac dysfunction have a significantly higher mortality. Based on the results of bioinformatics analysis, weighted gene co-expression network analysis (WGCNA), we found that Erbin is vital in cardiomyocyte. However, the function of Erbin in sepsis-induced cardiomyopathy (SIC) has not been explicitly studied. We discussed the role of Erbin in SIC by employing the Erbin−/− mice and HL-1 cardiomyocyte. An in vitro model of inflammation in HL-1 was used to confirm stimulation with lipopolysaccharide (LPS) and a mouse model of cecal ligation and puncture (CLP) to study the molecular mechanisms under SIC. Transmission electron microscopy (TEM) was used to characterize the morphological characteristics at the ultrastructural level. The expressions of Erbin, p-RIPK1, RIPK1, p-RIPK3, RIPK3, p-MLKL, MLKL, p-PKA, PKA, p-CREB and CREB were detected by western blot. qPCR analysis was applied to detect TNF-α, IL-1β, IL-6, RIPK1 and MLKL mRNA expression. Cell survival was detected by CCK-8 assay and the levels of c TnI concentration were detected by ELISA kit. Our study revealed that necroptosis and inflammation were activated in cardiomyocytes during sepsis and deficiency of Erbin aggravated them. Furthermore, deficiency of Erbin exacerbated systolic dysfunction including the decline of LVEF and LVFS induced by CLP. Overexpression of Erbin alleviated necroptosis and inflammation by activating PKA/CREB pathway. Our research elucidates a noval mechanism whereby Erbin participates in SIC, providing a promising therapeutic target for myocardial dysfunction during sepsis.

Evaluation of antioxidant prophylactic effects of parsley (Petroselinum crispum) on sepsis following cecal ligation and puncture

Objective: Sepsis causes the release of free oxygen radicals that disrupt membrane integrity, and damage to Mitochondria due to the production of free oxygen radicals and oxidation leads to exacerbation of sepsis, Cecal ligation and puncture (CLP) in rats mimics the characteristics and course of clinical sepsis (Hubbard et al., 2005). Methods: We evaluated the antioxidant effects of Petroselinum crispum (Pc) in a cecal ligation and puncture (CLP)-induced rat sepsis model, in a rat model of sepsis caused by cecal ligation and puncture (CLP). Wistar albino rats were separated into four groups of eight groups: a sham group with incised and sutured abdomens; a Pc extract (PcE) group, which was given 2 g/kg parsley extract for 14 days by gastric gavage; a CLP group, which was subjected to sepsis caused by CLP; and a PcE + CLP group, which was given parsley extract for 14 days. PcE was given for 14 days, after which sepsis was induced via the CLP procedure. The groups were compared in terms of hemogram, biochemical and histological characteristics. Results: The administration of PcE before CLP-induced sepsis increases neutrophil counts, PLTs and TASs, which decrease with sepsis, and decreases biochemical changes (BUN, AST, ALT, LDH, TOS, and OSI), which increase with sepsis, to protect against sepsis. Compared with that in the CLP group, the severity of intestinal infiltration was significantly lower in the PcE + CLP group; however, the degree of epithelial damage in the PcE + CLP group was similar to that in the CLP group. In the PcE + CLP group, the crypt and villus lengths were greater, and the decrease in Paneth cell degranulation intensity was greater than that in the CLP group. Conclusion: Additionally, the morphology of the cells in the PcE + CLP group was similar to that in the sham group. PcE has potential as a prophylactic agent for sepsis.

Snhg14/miR-181a-5p axis-mediated “M1” macrophages aggravate LPS-induced myocardial cell injury

An increasing number of studies have suggested that macrophages participate in sepsis-induced myocardial injury. Our study highlights the function and mechanism of the lncRNA Snhg14 in “M1” polarized macrophage-mediated myocardial cell damage. Lipopolysaccharide (LPS) was used to treat H9c2 cells to construct an in vitro myocardial injury model. M1 and M2 polarization of RAW264.7 cells were induced and the exosomes were obtained from the supernatant through ultracentrifugation. Moreover, cecal ligation and puncture (CLP) surgery was implemented to establish a mouse sepsis-induced myocardial injury model, and Snhg14 was knocked down with sh-Snhg14. The results showed that the conditioned medium (CM) and the exosomes (Exo) of M1 macrophages substantially augmented LPS-induced apoptosis and oxidative stress in myocardial cells. Notably, M1-CM and M1-Exo contributed to nearly 50 % of myocardial cell viability decline. Snhg14 was highly expressed in M1 macrophages and exosomes derived from M1-MΦ (M1-Exo). Snhg14 overexpression aggravated myocardial cell damage and increased 10 to 50 times expression of proinflammatory cytokines in MΦ. Snhg14 knockdown reversed M1-Exo-mediated myocardial cell damage and inhibited the production of proinflammatory cytokines (50 %–75 % decline) of MΦ. Moreover, Snhg14 targeted and inhibited miR-181a-5p expression. miR-181a-5p upregulation partly reversed Snhg4 overexpression-mediated myocardial cell damage and MΦ activation. In vivo, sh-Snhg14 dramatically ameliorated cardiac damage in septic mice by enhancing miR-181a-5p and inhibiting the HMGB1/NF-κB pathway. In conclusion, “M1” macrophage-derived exosomal Snhg14 aggravates myocardial cell damage by modulating the miR-181a-5p/HMGB1/NF-κB pathway.

N-acetyltransferase 10 mediates cognitive dysfunction through the acetylation of GABABR1 mRNA in sepsis-associated encephalopathy

Sepsis-associated encephalopathy (SAE) is a critical neurological complication of sepsis and represents a crucial factor contributing to high mortality and adverse prognosis in septic patients. This study explored the contribution of NAT10-mediated messenger RNA (mRNA) acetylation in cognitive dysfunction associated with SAE, utilizing a cecal ligation and puncture (CLP)-induced SAE mouse model. Our findings demonstrate that CLP significantly upregulates NAT10 expression and mRNA acetylation in the excitatory neurons of the hippocampal dentate gyrus (DG). Notably, neuronal-specific Nat10 knockdown improved cognitive function in septic mice, highlighting its critical role in SAE. Proteomic analysis, RNA immunoprecipitation, and real-time qPCR identified GABABR1 as a key downstream target of NAT10. Nat10 deletion reduced GABABR1 expression, and subsequently weakened inhibitory postsynaptic currents in hippocampal DG neurons. Further analysis revealed that microglia activation and the release of inflammatory mediators lead to the increased NAT10 expression in neurons. Microglia depletion with PLX3397 effectively reduced NAT10 and GABABR1 expression in neurons, and ameliorated cognitive dysfunction induced by SAE. In summary, our findings revealed that after CLP, NAT10 in hippocampal DG neurons promotes GABABR1 expression through mRNA acetylation, leading to cognitive dysfunction.

Proteomic Profiling of Hindlimb Skeletal Muscle Disuse in a Murine Model of Sepsis.

Sepsis leads to multiple organ dysfunction and negatively impacts patient outcomes. Skeletal muscle disuse is a significant comorbidity in septic patients during their ICU stay due to prolonged immobilization. Combination of sepsis and muscle disuse will promote a unique proteomic signature in skeletal muscle in comparison to disuse and sepsis separately. Following cecal ligation and puncture (CLP) or Sham surgeries, mice were subjected to hindlimb suspension (HLS) or maintained normal ambulation (NA). Tibialis anterior muscles from 24 C57BL6/J male mice were harvested for proteomic analysis. Proteomic profiles were assessed using nano-liquid chromatography with tandem mass spectrometry, followed by data analysis including Partial Least Squares Discriminant Analysis (PLS-DA), to compare the differential protein expression across groups. A total of 2876 differentially expressed proteins were identified, with marked differences between groups. In mice subjected to CLP and HLS combined, there was a distinctive proteomic signature characterized by a significant decrease in the expression of proteins involved in mitochondrial function and muscle metabolism, alongside a marked increase in proteins related to muscle degradation pathways. The PLS-DA demonstrated a clear separation among experimental groups, highlighting the unique profile of the CLP/HLS group. This suggests an important interaction between sepsis-induced inflammation and disuse atrophy mechanisms in sepsis-induced myopathy. Our findings reveal a complex proteomic landscape in skeletal muscle exposed to sepsis and disuse, consistent with an exacerbation of muscle protein degradation under these combined stressors. The identified proteins and their roles in cellular stress responses and muscle pathology provide potential targets for intervention to mitigate muscle dysfunction in septic conditions, highlighting the importance of addressing both sepsis and disuse concurrently in clinical and experimental settings.

Combining ulinastatin with TIENAM improves the outcome of sepsis induced by cecal ligation and puncture in mice by reducing inflammation and regulating immune responses

Despite the high mortality associated with sepsis, effective and targeted treatments remain scarce. The use of conventional antibiotics such as TIENAM (imipenem and cilastatin sodium for injection, TIE) is challenging because of the increasing bacterial resistance, which diminishes their efficacy and leads to adverse effects. Our previous studies demonstrated that ulinastatin (UTI) exerts a therapeutic impact on sepsis by reducing systemic inflammation and modulating immune responses. In this study, we examined the possibility of administering UTI and TIE after inducing sepsis in a mouse model using cecal ligation and puncture (CLP). We assessed the rates of survival, levels of inflammatory cytokines, the extent of tissue damage, populations of immune cells, microbiota in ascites, and important signaling pathways. The combination of UTI and TIE significantly improved survival rates and reduced inflammation and bacterial load in septic mice, indicating potent antimicrobial properties. Notably, the survival rates of UTI+TIE-treated mice increased from 10 % to 75 % within 168 h compared to those of mice that were subjected to CLP. The dual treatment successfully regulated the levels of inflammatory indicators (interleukin [IL]-6, IL-1β, and tumor necrosis factor [TNF]-α) and immune cell numbers by reducing B cells, natural killer cells, and TNFR2+ Treg cells and increasing CD8+ T cells. Additionally, the combination of UTI and TIE alleviated tissue damage, reduced bacterial load in the peritoneal cavity, and suppressed the NF-κB signaling pathway. Our findings indicate that UTI and TIE combination therapy can significantly enhance sepsis outcomes by reducing inflammation and boosting the immune system. The results offer a promising therapeutic approach for future sepsis treatment.