Cecal Ligation Puncture Research Articles

Neoastilbin ameliorates sepsis-induced liver and kidney injury by blocking the TLR4/NF-κB pathway.

Sepsis frequently causes systemic inflammatory response syndrome and multiple organ failure in patients. Neoastilbin (NAS) is a flavonoid that plays vital functions in inflammation. This work aims to investigate the protective effects of NAS against sepsis-induced liver and kidney injury and elucidate its underlying mechanisms. The mouse model was established using cecal ligation puncture (CLP) induction. NAS was given to mice by gavage for 7 consecutive days before surgery. Liver and kidney function, oxidative stress, and inflammatory factors in serum or tissues were examined by ELISA or related kits. The expression of relevant proteins was assessed by Western blot. Hematoxylin and eosin and/or periodic acid-Schiff staining revealed that NAS ameliorated the pathological damage in liver and kidney tissues of CLP-induced mice. NAS improved liver and kidney functions, as evidenced by elevated levels of blood urea nitrogen, Creatinine, ALT, and AST in the serum of septic mice. TUNEL assay and the expression of Bcl-2 and Bax showed that NAS dramatically reduced apoptosis in liver and renal tissues. NAS treatment lowered the levels of myeloperoxidase and malondialdehyde, while elevated the superoxide dismutase content in liver and kidney tissues of CLP-induced mice. The levels of inflammatory cytokines (IL-6, TNF-α, and IL-1β) in the serum and both tissues of CLP-injured mice were markedly decreased by NAS. Mechanically, NAS downregulated TLR4 expression and inhibited NF-κB activation, and overexpression of TLR4 reversed the protective effects of NAS against liver and kidney injury. Collectively, NAS attenuated CLP-induced apoptosis, oxidative stress, inflammation, and dysfunction in the liver and kidney by restraining the TLR4/NF-κB pathway.

Curcumin alleviates septic lung injury in mice by inhibiting TXNIP/TRX-1/GPX4-mediated ferroptosis

To investigate whether curcumin alleviates septic lung injury by inhibiting ferroptosis through modulating the TXNIP/TRX-1/GPX4 pathway. Male C57BL/6 mice were randomly divided into Sham group, cecal ligation puncture (CLP)-induced sepsis group, CLP with curcumin treatment (50, 100, and 200 mg/kg) groups, and CLP with both curcumin (200 mg/kg) and TRX-1 inhibitor PX-12 (25 mg/kg) treatment group. Inflammatory factors, MDA, MPO, and GSH levels in the lung tissue of the mice were detected. Beas-2B cells stimulated with lipopolysaccharide (LPS; 1 μg/mL) were treated with 2.5, 5, or 10 μmol/L curcumin or with 10 μmol/L curcumin combined with 5 μmol/L PX-12, and the changes in MDA, Fe2+ and ROS levels were assessed. Western blotting was performed to detect the protein expressions of TXNIP, TRX-1, GPX4 and X-CT in both the mouse lung tissues and Beas-2B cells. The mice with CLP-induced sepsis showed severe lung injury with elevated expressions of IL-6, IL-1β, TNF-α, MDA and MPO and decreased GSH expression. In Beas-2B cells, LPS stimulation significantly increased MDA and Fe2+ levels and ROS release, increased TXNIP protein expression, and lowered the protein expression levels of TRX-1, GPX4 and X-CT, and these changes were also observed in the septic mice. Curcumin treatments at different concentrations obviously alleviated lung injury in the septic mice and reduced LPS-induced injury in Beas-2B cells. Curcumin significantly decreased the release of inflammatory factors, MDA and MPO, increased GSH level, lowered Fe2+, MDA and ROS levels, increased TXNIP protein expression, and lowered the protein expressions of TRX-1, GPX4 and X-CT in both septic mouse lung tissues and LPS-stimulated Beas-2B cells. The protective effect of curcumin was effectively blocked by PX-12 treatment. Curcumin inhibits ferroptosis and alleviates septic lung injury in mice by elevating TRX-1 and GPX4 and decreasing TXNIP in the lung tissue.

Evaluation of the Efficacy of Tofacitinib, a JAK Inhibitor, in Alleviating Sepsis-Induced Multiple Organ Dysfunction Syndrome.

Sepsis, a life-threatening condition triggered by an uncontrolled response to infection, results in a systemic inflammatory response syndrome (SIRS) and the failure of multiple organs leading to multiple organ dysfunction (MODS). In the present study, we investigated the therapeutic potential of tofacitinib (TOFA), an FDA-approved inhibitor of JAK1 and JAK3 against sepsis, using a mouse model induced by cecal ligation puncture (CLP). Swiss albino mice were employed to replicate the CLP-induced sepsis model and were randomly divided into four groups: control, CLP, 150 mg/kg TOFA, and 300 mg/kg TOFA. Six hours after the last TOFA dose, we collected blood and tissue samples from the liver, lungs, kidneys, and spleen for histological analysis. Blood samples were used to assess granulocyte and lymphocyte percentages. Throughout the experiment, we monitored body weight and short-term survival. Our comparative histological analysis revealed that 150 mg/kg TOFA had a protective effect against multiple organ damage. Conversely, the study highlighted the harmful effects of 300 mg/kg TOFA, primarily due to liver and renal toxicity within this group. In summary, our findings demonstrate that tofacitinib at an optimal dose of 150 mg/kg showed promise as a potential therapeutic intervention for sepsis-induced multiple organ failure. However, caution is warranted when considering higher dosages.

Obeticholic acid ameliorates sepsis-induced renal mitochondrial damage by inhibiting the NF-κb signaling pathway

Acute kidney injury (AKI), a common complication of sepsis, might be caused by overactivated inflammation, mitochondrial damage, and oxidative stress. However, the mechanisms underlying sepsis-induced AKI (SAKI) have not been fully elucidated, and there is a lack of effective therapies for AKI. To this end, this study aimed to investigate whether obeticholic acid (OCA) has a renoprotective effect on SAKI and to explore its mechanism of action. Through bioinformatics analysis, our study confirmed that the mitochondria might be a critical target for the treatment of SAKI. Thus, a septic rat model was established by cecal ligation puncture (CLP) surgery. Our results showed an evoked inflammatory response via the NF-κB signaling pathway and NLRP3 inflammasome activation in septic rats, which led to mitochondrial damage and oxidative stress. OCA, an Farnesoid X Receptor (FXR) agonist, has shown anti-inflammatory effects in numerous studies. However, the effects of OCA on SAKI remain unclear. In this study, we revealed that pretreatment with OCA can inhibit the inflammatory response by reducing the synthesis of proinflammatory factors (such as IL-1β and NLRP3) via blocking NF-κB and alleviating mitochondrial damage and oxidative stress in the septic rat model. Overall, this study provides insight into the excessive inflammation-induced SAKI caused by mitochondrial damage and evidence for the potential use of OCA in SAKI treatment.

Anisodamine hydrobromide ameliorates acute lung injury via inhibiting pyroptosis in murine sepsis model

Objective Sepsis can have severe implications on lung function, leading to acute lung injury (ALI), a major contributor to sepsis-related mortality. Anisodamine hydrobromide (Ani HBr), a bioactive constituent derived from the root of Scopolia tangutica Maxim, a plant endemic to China, has demonstrated efficacy in treating septic shock. We aim to explore whether Ani HBr can alleviate sepsis-triggered ALI and elucidate the fundamental mechanisms involved. Materials and method The protective effects of Ani HBr were assessed in two models: in vitro, lipopolysaccharide (LPS)-stimulated RAW264.7 cells, and in vivo, cecal ligation puncture (CLP)-induced sepsis. To measure the cell viability of RAW264.7 cells after Ani HBr treatment, we used the CCK-8 assay. We quantified the levels of pro-inflammatory cytokines expression using ELISA. We also measured the expression of pyrotosis indicators by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR), Western blotting, and immunofluorescence. Results Our study demonstrates that Ani HBr can alleviate pulmonary edema, bleeding, and excessive inflammation induced by CLP. Additionally, it exhibits protective effects against cytotoxicity induced by LPS in RAW264.7 macrophage cells. Furthermore, Ani HBr downregulates the mRNA and protein levels of NLRP3, Caspase-1, GSDMD, IL-18, and IL-1β in both animal models and cell cultures, thereby inhibiting pyroptosis in a similar mechanism to AC-YVAD-CMK (AYC)’s blockade of Caspase-1. Moreover, Ani HBr suppresses the production and release of proinflammatory cytokines. Conclusion These findings suggest that Ani HBr could serve as a protective agent against sepsis-induced ALI by suppressing pyroptosis.

Protective effect and mechanism of methylene blue on myocardial injury in rats with sepsis

To explore the protective effect of methylene blue (MB) on myocardial injury in sepsis and its possible signaling pathway. A total of 32 female Wistar rats were randomly divided into sham operation group, sepsis model group, MB prevention group, and MB treatment group, with 8 rats in each group. The MB prevention group was injected with 15 mg/kg MB in the peritoneal cavity 6 hours before modeling; the other 3 groups were injected with 4 mL/kg saline in the peritoneal cavity. The sepsis model was established by cecal ligation puncture (CLP); the sham operation group was only subjected to an exploratory incision without ligation or puncture of the caecum. The MB treatment group was injected with 15 mg/kg MB in the peritoneal cavity 0.5 hours after modeling; the other 3 groups were injected with 4 mL/kg saline in the peritoneal cavity. Peripheral blood and myocardial tissue were collected from each group at 6 hours and 12 hours after modeling. Histological changes in the myocardial tissue were observed under the microscope; the levels of serum cardiac troponin I (cTnI), MB isoenzyme of creatine kinase (CK-MB), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were detected by enzyme-linked immunosorbent assay (ELISA); and the expressions of inducible nitric oxide synthase (iNOS), light chain 3 (LC3), and p62 in the myocardial tissue were detected by Western blotting. Under light microscopy, no obvious abnormalities were found in the myocardium of the sham operation group; the myocardium of the sepsis model group showed obvious inflammatory changes; the myocardium of the MB prevention group showed mild inflammatory changes at 6 hours after modeling, severe inflammatory changes at 12 hours but less severe than the sepsis model group; the myocardium of the MB treatment group showed more obvious inflammatory changes at 6 hours after modeling but less severe than the MB prevention group at 12 hours after modeling, and the inflammatory changes at 12 hours after modeling were alleviated but more severe than the 6 hours after modeling in MB prevention group. Compared with the sham operation group, the levels of cTnI, CK-MB, TNF-α and IL-6 in the MB prevention group at 6 hours and 12 hours after modeling were not significantly changed; compared with the sepsis model group, the cTnI, CK-MB, TNF-α and IL-6 levels in the MB treatment group at 6 hours and 12 hours after modeling were significantly lower [cTnI (ng/L): 175.03±12.26, 411.24±21.20 vs. 677.79±43.95 at 6 hours of modeling, 159.52±6.44, 412.46±32.94 vs. 687.61±55.09 at 12 hours of modeling; CK-MB (ng/L): 8.38±0.49, 16.87±1.41 vs. 24.87±1.74 at 6 hours of modeling, 7.94±0.30, 16.66±2.03 vs. 25.02±7.29 at 12 hours of modeling; TNF-α (ng/L): 26.98±3.31, 46.95±3.74 vs. 112.60±6.64 at 6 hours of modeling, 31.31±5.83, 90.97±5.14 vs. 149.30±4.67 at 12 hours of modeling; IL-6 (ng/L): 40.86±4.48, 128.90±3.14 vs. 248.90±12.76 at 6 hours of modeling, 80.13±7.94, 190.40±9.56 vs. 288.90±6.01 at 12 hours of modeling; all P < 0.05]. Western blotting showed that compared with the sham operation group, the protein expressions of iNOS, LC3, and p62 in the sepsis model group were significantly higher at 6 hours and 12 hours after modeling; compared with the sepsis model group, the protein expressions of iNOS, LC3, and p62 in the MB treatment group and MB prevention group were significantly lower at 6 hours and 12 hours after modeling (iNOS/GAPDH: 0.38±0.04, 0.60±0.04 vs. 0.77±0.04 at 6 hours of modeling; 0.38±0.02, 0.66±0.04 vs. 0.79±0.05 at 12 hours of modeling; LC3/GAPDH: 0.13±0.07, 0.42±0.07 vs. 1.05±0.16 at 6 hours of modeling; 0.08±0.02, 0.25±0.03 vs. 0.48±0.09 at 12 hours of modeling; p62/GAPDH: 0.17±0.05, 0.44±0.10 vs. 1.19±0.07 at 6 hours of modeling; 0.07±0.00, 0.28±0.08 vs. 0.69±0.02 at 12 hours of modeling; all P < 0.05). MB can reduce myocardial oxidative stress by inhibiting iNOS expression and mitochondrial autophagy in septic rats, thereby alleviating myocardial damage in sepsis, and has protective effect on myocardial damage in sepsis.

#1524 SKLB023 alleviates kidney inflammation and apoptosis via inhibiting TLR4-mediated NF-κB p65 and MAPK signaling pathways in septic AKI mice

Abstract Background and Aims Sepsis is a severe and complex clinical syndrome resulting from the host's inflammatory response to infection. Acute kidney injury (AKI) is one of the major complications of sepsis with high morbidity and mortality, namely sepsis-associated acute kidney injury (S-AKI). Despite current advances, effective drugs for treatment of S-AKI are scarce. SKLB023 is a small molecule compound designed based on 5-benzylidene-thiazolidine-2,4-dione, which has a potent anti-inflammatory effect with favorable efficacy in rheumatoid arthritis. This study aims to evaluate the efficacy of SKLB023 in treating S-AKI and to explore the underlying mechanisms. Method S-AKI was induced by cecal ligation puncture (CLP) and intraperitoneal injection of LPS (10 mg/kg) in male C57BL/6 mice. SKLB023 (25 mg/kg, 50 mg/kg) was administrated by gavage three days in advance and 30 minutes earlier on the day of modeling. Mice death per group was recorded for 100 hours after CLP to evaluate the effect of SKLB023 on the survival rate of S-AKI mice. Other mice were sacrificed 16 hours after model establishment, blood and kidney specimens were collected. Renal function was measured by the detection of serum creatinine (SCr) and blood urea nitrogen (BUN). Kidney pathological injury was evaluated by the expression of kidney injury markers and the assessment of PAS/HE stainings. In vitro experiments were performed with LPS stimulation of TCMK-1 cells and SKLB023 intervention, and the doses were determined by CCK-8 assay. Possible molecular mechanisms involved in SKLB023 against S-AKI were screened by bioinformatics analysis and further validated in vivo and vitro. RT-PCR, western blot, immunofluorescence, and immunohistochemistry were applied to detect renal inflammation and apoptosis. To determine the role of TLR4, TLR4 siRNA and TLR4-KO mice were applied in S-AKI model, and TLR4 expression and the activities of NF-κB p65 and MAPK signaling pathway were assessed. One-way ANOVA was performed for comparison between groups, and logrank analysis was used for comparison of survival curve. P &amp;lt; 0.05 was considered as statistically significant. Results The S-AKI model was successfully established by CLP and LPS injection with obvious renal dysfunction and kidney pathological damage. The mice administrated with SKLB023 had a higher survival rate, lower levels of Scr and BUN, and improved kidney pathological injury than the mice in the CLP group. Transcriptomic analysis identified TLR4-mediated downstream signaling pathways as the potential mechanism of SKLB023 and further experiments in vivo and in vitro proved that SKLB023 regulated the expression of TLR4 and the activities of NF-κB p65 and MAPK signaling pathway in S-AKI mice and LPS-stimulated TCMK-1 cells. Moreover, TLR4 inhibited the expression of inflammatory cytokines including TNF-α, IL-1β, IL-6, iNOS, COX-2, HMGB-1 and alleviated kidney apoptosis in S-AKI mice and LPS-treated TCMK-1 cells. Additionally, knockout of TLR4 remarkably improved inflammation, apotosis, and kidney injury in LPS-treated mice and TCMK-1 cells. Conclusion SKLB023 confers renoprotective effects in S-AKI by modulating inflammation and apoptosis. TLR4 is a key target in S-AKI, and SKLB023 inhibits inflammation and apoptosis by inhibiting the activities of TLR4 mediated NF-κB p65 and MAPK pathways. SKLB023 may be proposed as one of the potential preventive and therapeutic agents for S-AKI.

Disruption of TIGAR-TAK1 alleviates immunopathology in a murine model of sepsis

Macrophage-orchestrated inflammation contributes to multiple diseases including sepsis. However, the underlying mechanisms remain to be defined clearly. Here, we show that macrophage TP53-induced glycolysis and apoptosis regulator (TIGAR) is up-regulated in murine sepsis models. When myeloid Tigar is ablated, sepsis induced by either lipopolysaccharide treatment or cecal ligation puncture in male mice is attenuated via inflammation inhibition. Mechanistic characterizations indicate that TIGAR directly binds to transforming growth factor β-activated kinase (TAK1) and promotes tumor necrosis factor receptor-associated factor 6-mediated ubiquitination and auto-phosphorylation of TAK1, in which residues 152-161 of TIGAR constitute crucial motif independent of its phosphatase activity. Interference with the binding of TIGAR to TAK1 by 5Z-7-oxozeaenol exhibits therapeutic effects in male murine model of sepsis. These findings demonstrate a non-canonical function of macrophage TIGAR in promoting inflammation, and confer a potential therapeutic target for sepsis by disruption of TIGAR-TAK1 interaction.

Modulation of Unregulated Inflammation‐Associated Coagulopathy in Sepsis Using Multifunctional Nanosheets

AbstractExcessive inflammation‐associated unregulated coagulation leads to disseminated intravascular coagulation (DIC) and mortality in patients with sepsis worldwide, and current clinical treatment is unsatisfactory. Recent studies have shown that circulating cell‐free DNA (cfDNA) and neutrophil extracellular traps (NETs), act as potent pro‐inflammation and pro‐coagulation agents, revealing a mechanistic link between innate immunity and coagulation. After establishing a definite correlation between cfDNA and dysfunctional inflammation and coagulation disorders in samples from patients with sepsis, a novel 2D, sheet‐like, cationic cfDNA scavenger using polyamidoamine (P‐G1) and antimicrobial peptides (AMPs) covered with black phosphorus (BP) nanosheets, called BP‐G1AMP, are fabricated. It is found that BP‐G1AMP significantly suppressed bacterial growth and ameliorated the systemic inflammatory response, associated coagulation disorder, and DIC, resulting in improved survival in a cecal ligation puncture (CLP) mouse sepsis model. This study proposes a novel strategy for fabricating multifunctional nanosheets that can ameliorate inflammation‐associated coagulation during sepsis treatment. These findings demonstrate the importance of 2D nanostructures in the construction of multivalent anti‐bacterial and anti‐coagulation nanoplatforms.

Machine learning reveals ferroptosis features and a novel ferroptosis classifier in patients with sepsis.

Sepsis is an organ malfunction disease that may become fatal and is commonly accompanied by severe complications such as multiorgan dysfunction. Patients who are already hospitalized have a high risk of death due to sepsis. Even though early diagnosis is very important, the technology and clinical approaches that are now available are inadequate. Hence, there is an immediate necessity to investigate biological markers that are sensitive, specific, and reliable for the prompt detection of sepsis to reduce mortality and improve patient prognosis. Mounting research data indicate that ferroptosis contributes to the occurrence, development, and prevention of sepsis. However, the specific regulatory mechanism of ferroptosis remains to be elucidated. This research evaluated the expression profiles of ferroptosis-related genes (FRGs) and the diagnostic significance of the ferroptosis-related classifiers in sepsis. We collected three peripheral blood data sets from septic patients, integrated the clinical examination data and mRNA expression profile of these patients, and identified 13 FRGs in sepsis through a co-expression network and differential analysis. Then, an optimal classifier tool for sepsis was constructed by integrating a variety of machine learning algorithms. Two key genes, ATG16L1 and SRC, were shown to be shared between the algorithms, and thus were identified as the FRG signature of classifier. The tool exhibited satisfactory diagnostic efficiency in the training data set (AUC = 0.711) and two external verification data sets (AUC = 0.961; AUC = 0.913). In the rat cecal ligation puncture sepsis model, in vivo experiments verified the involvement of ATG16L1 and SRC in the early sepsis process. These findings confirm that FRGs may participate in the development of sepsis, the ferroptosis related classifiers can provide a basis for the development of new strategies for the early diagnosis of sepsis and the discovery of new potential therapeutic targets for life-threatening infections.

Pretreatment with interleukin-15 attenuates inflammation and apoptosis by inhibiting NF-κB signaling in sepsis-induced myocardial dysfunction.

Sepsis-induced myocardial dysfunction (SIMD) is associated with poor prognosis and increased mortality in patients with sepsis. Cytokines are important regulators of both the initiation and progression of sepsis. Interleukin-15 (IL-15), a pro-inflammatory cytokine, has been linked to protective effects against myocardial infarction and myocarditis. However, the role of IL-15 in SIMD remains unclear. We established a mouse model of SIMD via cecal ligation puncture (CLP) surgery and a cell model of myocardial injury via lipopolysaccharide (LPS) stimulation. IL-15 expression was prominently upregulated in septic hearts as well as cardiomyocytes challenged with LPS. IL-15 pretreatment attenuated cardiac inflammation and cell apoptosis and improved cardiac function in the CLP model. Similar cardioprotective effects of IL-15 pretreatment were observed in vitro. As expected, IL-15 knockdown had the opposite effect on LPS-stimulated cardiomyocytes. Mechanistically, we found that IL-15 pretreatment reduced the expression of the pro-apoptotic proteins cleaved caspase-3 and Bax and upregulated the anti-apoptotic protein Bcl-2. RNA sequencing and Western blotting further confirmed that IL-15 pretreatment suppressed the activation of nuclear factor kappa B (NF-κB) signaling in mice with sepsis. Besides, the addition of NF-κB inhibitor can significantly attenuate cardiomyocyte apoptosis compared to the control findings. Our results suggest that IL-15 pretreatment attenuated the cardiac inflammatory responses and reduced cardiomyocyte apoptosis by partially inhibiting NF-κB signaling in vivo and in vitro, thereby improving cardiac function in mice with sepsis. These findings highlight a promising therapeutic strategy for SIMD.

Serotonergic neurotransmission mediated cognitive dysfunction in two mouse models of sepsis-associated encephalopathy.

Patients with sepsis-associated encephalopathy (SAE) often exhibit cognitive impairments. Despite this, the underlying mechanisms of SAE remain largely unexplored. Here, we explored the role of serotonergic neurotransmission in cognitive dysfunction of two mouse models of SAE. The mouse models of SAE were established by injection of lipopolysaccharide (LPS, 10 mg/kg, intraperitoneal) and cecal ligation puncture (CLP) respectively. Barnes maze, new object recognition test and open field test were used to evaluate the effects of fluoxetine (selective serotonin reuptake inhibitor) and cyproheptadine (nonselective 5-HT2 receptor antagonist) on cognition and motor activity of mice. Additionally, WAY100635 (5-HT1A receptor antagonist) was co-administered with fluoxetine to explore the mechanism underlying effect of fluoxetine on cognitive impairments of SAE. Enzyme-linked immunosorbent assay (ELISA) was performed to determine 5-HT levels in hippocampus, brainstem and frontal lobe of experimental groups. Both LPS-induced sepsis and CLP induced sepsis resulted in a notable learning deficit. Fluoxetine ameliorated, while cyproheptadine aggravated, cognitive impairment in two classic mouse models of SAE. The cognition-enhancing effect of fluoxetine is reversed by WAY100635. Decreased 5-HT levels in hippocampus, brainstem and frontal lobe were observed in LPS septic model and CLP septic model. Notably, both fluoxetine and cyproheptadine significantly increased 5-HT levels in those brain regions in LPS septic model. Additionally, fluoxetine significantly increased 5-HT levels in frontal lobe of CLP septic model. Our study demonstrated that serotonergic neurotransmission plays a significant role in mechanisms underlying cognitive impairment in SAE. These findings contribute to identification of novel targets to prevent and arrest cognitive impairment in SAE.

Inhibiting apoptosis and GSDME-mediated pyroptosis attenuates hepatic injury in septic mice

BackgroundSepsis is characterized by severe inflammation and organ dysfunction resulting from a dysregulated organismal response to infection. Although pyroptosis has been presumably shown to be a major cause of multiple organ failure and septic death, whether gasdermin E (GSDME)-mediated pyroptosis occurs in septic liver injury and whether inhibiting apoptosis and GSDME-mediated pyroptosis can attenuate septic liver injury remain unclear. This study investigated the role of apoptosis and GSDME-mediated pyroptosis in septic liver injury. MethodsAdult male C57BL/6 mice were randomly divided into four groups: sham, cecal ligation puncture (CLP), CLP + Z-DEVD-FMK (a caspase-3 inhibitor, 5 mg/kg), and CLP + Ac-DMLD-CMK (a GSDME inhibitor, 5 mg/kg). Sepsis severity was assessed using the murine sepsis score (MSS). Hepatic tissue damage was observed by the hematoxylin-eosin staining method, the activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), the levels of malondialdehyde (MDA), the concentrations of interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) were measured according to the related kits, and the changes in the hepatic tissue reactive oxygen species (ROS) levels were detected by immunofluorescence (IF). The protein expression levels of cleaved caspase-3, GSDME-N, IL-1β, B-cell lymphoma-2 (Bcl-2), cytochrome C (Cyt-c), and acetaldehyde dehydrogenase 2 (ALDH2) were detected using western blotting. GSDME expression was detected by immunohistochemistry. ResultsCompared with the Sham group, CLP mice showed high sepsis scores and obvious liver damage. However, in the CLP + Z-DEVD-FMK and CLP + Ac-DMLD-CMK groups, the sepsis scores were reduced and liver injury was alleviated. Compared with the Sham group, the serum ALT and AST activities, MDA and ROS levels, and IL-1β and TNF-α concentrations were increased in the CLP group, as well as the protein expression of cleaved caspase-3, GSDME-N, IL-1β, Cyt-c, and GSDME positive cells (P < 0.05). However, the expression levels of Bcl-2 and ALDH2 protein were decreased (P < 0.05). Compared with the CLP group, the CLP + Z-DEVD-FMK and CLP + Ac-DMLD-CMK groups showed low sepsis scores, ALT and AST activities, MDA and ROS levels, decreased IL-1β and TNF-α concentrations, and decreased expression of cleaved caspase-3, GSDME-N, IL-1β protein expression, and GSDME positive cells (P < 0.05). The expression levels of Bcl-2 and ALDH2 protein were increased (P < 0.05). ConclusionApoptosis and GSDME-mediated pyroptosis are involved in the development of sepsis-induced hepatic injury. Inhibition of apoptosis and GSDME-mediated pyroptosis attenuates injury. ALDH2 plays a protective role by inhibiting apoptosis and pyroptosis.

The role of pomegranate seed oil on kidney and lung tissues in the treatment of sepsis: animal pre-clinical research.

Sepsis is a common disease with a high mortality. Decreasing the speed is possible with early and intensive therapy. However, most medicines have been tested, but none has proven effective. Therefore, the study aimed to discover the protective and therapeutic effects of pomegranate seed oil (PSO). The cecal ligation puncture (CLP) method was used to induce sepsis. The experimental procedure was started with the animals divided haphazardly into four groups: control (C), sepsis (CLP), CLP + low dose PSO (CLP + LD), and CLP + high dose PSO (CLP + HD). First, the cecum was filled with feces. The full cecum was tied under the ileocecal valve for ligation and punctured. At 1 hour after CLP, 0.32 mg/kg and 0.64 mg/kg of PSO were administered. 24 hours after, lung and kidney specimens were collected. Neutrophil infiltration/aggregation and alveolar wall thickness decreased in lung with PSO groups compared with the CLP. The findings for overall lung injury were similar. In renal, all parameters were increased in the CLP compared with C, except for vascular vacuolization and hypertrophy. According to the CLP, all parameters were significantly lower in CLP + HD. Furthermore, glomerular vacuolization, degeneration, and necrosis of tubular cell, dilatation of bowman space, and tubular hyaline cylinders reduced CLP + LD versus CLP. Thiobarbituric acid-reactive substances decreased in lung, with the PSO groups. In addition, superoxide dismutase increased in PSO groups versus CLP. We conclude that the high-dose PSO is especially effective in treating sepsis.

Lactobacillus rhamnosus (LR) ameliorates pulmonary and extrapulmonary acute respiratory distress syndrome (ARDS) via targeting neutrophils

Pulmonary and extrapulmonary acute respiratory distress syndrome (ARDS) is a life-threatening respiratory failure associated with high mortality. Despite progress in our understanding of the pathological mechanism causing the crippling illness, there are currently no targeted pharmaceutical treatments available for it. Recent discoveries have emphasized the existence of a potential nexus between gut and lung health fueling novel approaches including probiotics for the treatment of ARDS. We thus investigated the prophylactic-potential of Lactobacillus rhamnosus-(LR) in lipopolysaccharide (LPS)-induced pulmonary and cecal ligation puncture (CLP) induced extrapulmonary ARDS mice. Our in-vivo findings revealed that pretreatment with LR significantly ameliorated vascular-permeability (edema) of the lungs via modulating the neutrophils along with significantly reducing the expression of inflammatory-cytokines in the BALF, lungs and serum in both pulmonary and extrapulmonary mice-models. Interestingly, our ex-vivo immunofluorescence and flow cytometric data suggested that mechanistically LR via short chain fatty acids (butyrate being the most potent and efficient in ameliorating the pathophysiology of both pulmonary and extra-pulmonary ARDS) targets the phagocytic and neutrophils extracellular traps (NETs) releasing potential of neutrophils. Moreover, our in-vivo data further corroborated our ex-vivo findings and suggested that butyrate exhibits enhanced potential in ameliorating the pathophysiology of ARDS via reducing the infiltration of neutrophils into the lungs. Altogether, our study establishes the prophylactic role of LR and its associated metabolites in the prevention and management of both pulmonary and extrapulmonary ARDS via targeting neutrophils.

ACE2 activation alleviates sepsis-induced cardiomyopathy by promoting MasR-Sirt1-mediated mitochondrial biogenesis

Sepsis-induced cardiomyopathy (SIC), caused by a dysregulated host response to infection, is a major contributor to high mortality. Angiotensin-converting enzyme 2 (ACE2), a crucial component of the renin-angiotensin system (RAS), has protective effects against several cardiovascular diseases, such as myocardial infarction and heart failure. However, the role of ACE2 in the pathogenesis of SIC and underlying mechanisms remain unknown. The present study was designed to examine the effects of ACE2 activation or inhibition on SIC in C57BL/6 mice. The ACE2 activator diminazene aceturate (DIZE) and ACE2 inhibitor MLN-4760 were applied for treatment. Myocardial function, inflammatory response, oxidative stress, apoptosis and mitochondrial biogenesis were investigated. Major assays were echocardiography, H&E staining, immunofluorescence staining, DHE staining, TUNEL staining, Western blot, qPCR analysis, ELISA and corresponding kits. We confirmed that ACE2 was markedly downregulated in septic heart tissues. Pharmacological activation of ACE2 by DIZE ameliorated cecal ligation puncture (CLP)-induced mortality, cardiac dysfunction, inflammatory response, oxidative stress and the cardiomyocyte apoptosis by promoting MasR-Sirt1-mediated mitochondrial biogenesis. In contrast, SIC was aggravated via inhibiting MasR-Sirt1-mediated mitochondrial biogenesis by the use of ACE2 inhibitor MLN-4760. Consequently, activation of ACE2 may protect against SIC by promoting MasR-Sirt1-mediated mitochondrial biogenesis.

Zn-Shik-PEG nanoparticles alleviate inflammation and multi-organ damage in sepsis

Sepsis is defined as a life-threatening organ dysfunction caused by excessive formation of reactive oxygen species (ROS) and dysregulated inflammatory response. Previous studies have reported that shikonin (Shik) possess prominent anti-inflammatory and antioxidant effects and holds promise as a potential therapeutic drug for sepsis. However, the poor water solubility and the relatively high toxicity of shikonin hamper its clinical application. To address this challenge, we constructed Zn2+-shikonin nanoparticles, hereafter Zn-Shik-PEG NPs, based on an organic-inorganic hybridization strategy of metal-polyphenol coordination to improve the aqueous solubility and biosafety of shikonin. Mechanistic studies suggest that Zn-Shik-PEG NPs could effectively clear intracellular ROS via regulating the Nrf2/HO-1 pathway, meanwhile Zn-Shik-PEG NPs could inhibit NLRP3 inflammasome-mediated activation of inflammation and apoptosis by regulating the AMPK/SIRT1 pathway. As a result, the Zn-Shik-PEG NPs demonstrated excellent therapeutic efficacies in lipopolysaccharide (LPS) as well as cecal ligation puncture (CLP) induced sepsis model. These findings suggest that Zn-Shik-PEG NPs may have therapeutic potential for the treatment of other ROS-associated and inflammatory diseases.

Potential roles of HSYA in attenuating sepsis-induced liver injury through multi-omics analysis

Liver injury is a strong independent predictor of mortality in patients with sepsis, in which gut dysbiosis plays a crucial role. Hydroxyl safflower yellow A (HSYA), an important component of safflower, has been used to treat liver injury in animal models. However, its role in sepsis-induced liver dysfunction and the specific molecular mechanisms remain unclear. In the current study, we first discussed the discrepancy in the gut microbiota between the cecal ligation puncture (CLP) and HSYA groups using 16 S RNA sequencing. Our data demonstrated that HSYA supplementation significantly decreased the relative abundance of Proteobacteria, Firmicutes, and Campylobacterota, and further decreased the abundance of Bacteroidota, suggesting that the protective effects of HSYA against sepsis-induced liver injury may be partially attributed to the alteration of these bacteria. In addition, the metabolomic data identified 823 differentially expressed metabolites associated with sepsis-induced liver injury. After HSYA supplementation, the levels of 56 metabolites were restored to sham-like levels. Transcriptomic analysis revealed 4990 differentially expressed genes (DEGs) between the sham and CLP groups, and after HSYA injection, 1613 genes were modulated. Comprehensive analysis demonstrated that the enrichment pathways of the 903 DEGs mainly focused on inflammatory responses, amino acid metabolism, and Lipid reactions. In conclusion, our study revealed the potential mechanism of action of HSYA in sepsis-induced liver injury through a comprehensive analysis of 16 S RNA sequencing, metabolomics, and transcriptomics, thus providing a theoretical basis for further clinical applications of HSYA.

Enhancing Nix-dependent mitophagy relieves AKI by restricting TREM-1-mediated hyperactivation of inflammasome in platelets.

Platelets are highly involved in inflammation and organ injury under pathological conditions. The mitophagy in platelets may restrict hyperactivation of the inflammasome and relieve acute kidney injury (AKI). Cecal ligation puncture (CLP)/LPS-induced AKI Triggering receptor expressed on myeloid cells (TREM-1)-knockout mice models were established. Additionally, septic patients with AKI were also included. TREM-1 expression in platelets and inflammasome activation were examined. Platelet transfer assays were performed to investigate the contribution of platelet TREM-1 to renal injury. Mitophagy was evaluated in the context of inflammation. BNIP3L/Nix knockout mice were used to examine the relationship between platelet mitophagy and inflammatory activation. The results showed that the level of TREM-1 was increased and the platelet inflammasome was hyperactivated in CLP mice and septic patients, and TREM-1 activated platelet inflammasomes. TREM-1 deletion significantly abrogated hyperactivation of the platelet inflammasome and dramatically reduced AKI, whereas ablation of the mitophagy receptor BNIP3L/Nix induced the accumulation of damaged mitochondria and hyperactivation of platelet inflammasomes in CLP mice. BNIP3L/Nix controlled platelet inflammasome activation, and an amplification loop of platelet inflammasome activation and dysfunctional mitochondria controlled sepsis-related AKI. Therefore, targeting TREM-1 and NLRP3/BNIP3L in platelets may represent a novel therapeutic strategy for treating septic AKI.

Exploring the potential mechanism of Xuebijing injection against sepsis based on metabolomics and network pharmacology

Sepsis is a major contributor to the death of critically ill patients globally, in which metabolic disturbance is observed. Xuebijing injection (XBJ), a well-known traditional Chinese medicine, has received approval by the State Food and Drug Administration (SFDA) of China owing to its satisfactory clinical therapeutic effect. Nowadays, it has been applied clinically to the treatment of sepsis, but its effect on metabolic disorders remains unclear. In the present study, we sought to explore its underlying mechanism by employing a combination of network pharmacology and metabolomics. Initially, its protective effects were validated using a sepsis rat model created through cecal ligation puncture (CLP). Subsequently, the metabonomic strategy was utilized to discriminate the differential metabolic markers. Meanwhile, a comprehensive view of the potential ingredient-target-disease network was constructed based on a network pharmacology analysis. Next, the network diagram was constructed by integrating the results of network pharmacology and metabonomics. Finally, qRT-PCR together with Western blot was used to validate the expression levels of the associated genes. Based on our findings, we identified 34 differential metabolites in the sepsis group and 26 distinct metabolites in the XBJ group, with 8 common biological metabolites predominantly associated with arginine and proline metabolism. Through comprehensive analysis, we identified 21 genes that regulate metabolites, and qRT-PCR validation was conducted on six of these genes in both liver and kidney tissues. Additionally, XBJ demonstrated the capability to inhibit the activation of the NF-kB signaling pathway in both liver and kidney tissues, leading to a reduction in the occurrence of inflammatory responses. In summary, our study has validated the complexity of the natural compounds within XBJ and elucidated their potential mechanisms for addressing CLP-induced metabolic disturbances. This work contributes to our understanding of the bioactive compounds and their associated targets, providing insights into the potential molecular mechanisms involved.