Cecal Ligation And Puncture Group Research Articles

Potential therapeutic effect of Carica papaya leaves extract on immune response, biochemical and hematological mechanisms on cecal ligation and puncture model of sepsis in rats: an in vivo study.

Antibiotics and immunotherapies possess unavoidable adverse effects that hinder sepsis management. Herbal drugs have demonstrated potential immunomodulatory properties vital for sepsis treatment. We hypothesized in the present study that the use of Carica papaya leaves extract had the potential to improve survival and modulate immune cytokine release during sepsis. Animals were subjected to cecal ligation and puncture (CLP) to induce sepsis. Septic rats divided into 10 groups received ethanol extract of C. papaya leaves (50 and 100mg/kg), imipenem (120mg/kg) and cyclophosphamide (CP, 10mg/kg). To investigate the immunomodulatory potentials of EE, cytokine levels like interleukin (IL-6), tumor necrosis factor (TNF-α), and IL-10 along with hematological and biochemical parameters were analyzed. Our results exhibited improved survival rates concerning ethanol extract treatment alone and in combination with imipenem and CP (100%) as compared to the CLP group (33.3%) on day 7 post-surgery. The combination treatment of ethanol extract with imipenem and CP significantly (P < 0.001) ameliorated cytokine levels and hematological and biochemical parameters in septic rats. A histopathological examination suggested improved liver and kidney tissue condition after combination treatment as compared to the CLP group. Therefore, it was concluded that combination therapy of extract with imipenem and CP improved survival rates and marked immunomodulatory potential in septic rats compared to monotherapy. The findings suggested the use of a mixture of these drugs in clinical settings to treat sepsis.

Early markers of Sepsis Cardiomyopathy in Murine Models by Echocardiography.

Strain echocardiography (SE) is a procedure for analyzing myocardial dysfunction that is known to be less dependent on preload and afterload of heart function. Unlike dimension-based parameters, like ejection fraction (EF) and fractional shortening (FS), SE measures cardiac function by tracking cardiac tissue deformation and anomalies throughout the cardiac cycle. Although SE is proven to locate myocardial ailments in various heart diseases, few studies exist regarding using SE relevant to sepsis pathophysiology. The study aimed to calculate the myocardial strain and strain rates, like longitudianl strain (LS), global radial strain (GRS), and global longitudinal strain (GLS), and to show these to be reduced earlier in cecal ligation and puncture (CLP) and lipopolysaccharide (LPS)-induced sepsis in coordination with an elevation of pro-inflammatory cytokines Methodology: Wild-type mice C57BL/6J (WT) were taken in this study and classified as CLP, LPS, and control groups. CLP surgery and LPS injection were given to induce sepsis. Endotoxemic septic shock was induced by intraperitoneal (IP) injection of LPS Escherichia coli. Echocardiography short axis views (SAX), longitudinal strain (LS), global circumferential strain (GCS), and global radial strain (GRS) were measured from the anterior and posterior positions of the septal and lateral walls of the heart. Real-time polymerase chain reaction (RT-PCR) was performed to evaluate post-CLP and LPS to analyze cardiac pro-inflammatory cytokines expressions. Inter- and intra-observer variables were tested by Bland-Altman analyses (BA). All data analysis was performed by GraphPad Prism 6 software. p<0.05 was taken as statistically significant. After 48 hours following CLP and LPS-induced sepsis, a significant declination in both longitudinal strain and strain rate (LS and LSR) was identified in the CLP and LPS groups compared to the control group. Strain depression in sepsis was linked with the up-regulation of pro-inflammatory cytokines in RT-PCR analysis. In the present study, we found myocardial strain and strain rate parameters, like LS, GRS, and GLS, to be reduced after CLP and LPS-induced sepsis in coordination with the elevation of pro-inflammatory cytokines.

Effect of SIRT1 regulating Nrf2/HO-1 signaling pathway on sepsis-induced acute lung injury

To investigate whether silence information regulator 1 (SIRT1) could regulate nuclear factor E2-related factor 2/heme oxygenase 1 (Nrf2/HO-1) signaling pathway and its role in acute lung injury (ALI) in sepsis rats. Twenty-four male Sprague-Dawley (SD) rats were randomly divided into sham operation group (Sham group), cecal ligation and puncture (CLP) induced sepsis group (CLP group), sepsis+SIRT1 specific agonist group (CLP+SRT1720 group,10 mg/kg SRT1720 was intraperitoneally injected 2 hours before CLP), sepsis+SIRT1 specific inhibitor group (CLP+EX527 group, 10 mg/kg EX527 was intraperitoneally injected 2 hours before CLP), with 6 rats in each group. The rats were killed 24 hours after modeling and their lung tissues were taken for pathological score (Smith score), superoxide dismutase (SOD), glutathione (GSH), malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), tumor necrosis factor-α (TNF-α), interleukins (IL-6, IL-1β), and SIRT1, Nrf2 and HO-1 mRNA and protein expression were detected. The lung tissue of the CLP group mice was severely damaged, the alveolar interval was widened and a large number of inflammatory cells infiltrated, and there was visible pulmonary capillary hyperemia. The Smith score, the levels of TNF-α, IL-6, IL-1β, MDA and 8-OHdG were significantly increased, the levels of SOD, GSH, SIRT1, Nrf2 and HO-1 were significantly decreased in CLP group. After using SIRT1 specific agonist, the lung injury in CLP+SRT1720 group was significantly alleviated compared with that in CLP group, Smith score and lung tissue TNF-α, IL-6, and IL-1β levels were significantly decreased [Smith score: 2.83±0.75 vs. 5.67±0.52, TNF-α (ng/L): 36.78±5.36 vs. 66.99±5.44, IL-6 (ng/L): 23.97±3.76 vs. 45.70±4.16, IL-1β (ng/L): 16.76±1.39 vs. 39.64±2.59, all P < 0.05], SOD activity and GSH content increased [SOD (kU/g): 115.88±3.31 vs. 101.65±1.09, GSH (μmol/g): 8.42±0.81 vs. 5.74±0.46, both P < 0.05], MDA and 8-OHdG contents decreased [MDA (μmol/g): 5.24±0.33 vs. 9.86±0.66, 8-OHdG (ng/L): 405.76±8.54 vs. 647.12±10.64, both P < 0.05], the mRNA and protein expressions of SIRT1, Nrf2 and HO-1 were increased [SIRT1 mRNA (2-ΔΔCT): 1.49±0.15 vs. 0.64±0.03, Nrf2 mRNA (2-ΔΔCT): 1.19±0.08 vs. 0.84±0.02, HO-1 mRNA (2-ΔΔCT): 1.80±0.41 vs. 0.64±0.11, SIRT1 protein (SIRT1/β-actin): 1.03±0.06 vs. 0.52±0.05, Nrf2 protein (Nrf2/β-actin): 1.14±0.10 vs. 0.63±0.05, HO-1 protein (HO-1/β-actin): 1.01±0.11 vs. 0.73±0.03, all P < 0.05]. The lung injury in CLP+EX527 group was more severe than that in CLP group, Smith score and lung tissue TNF-α, IL-6, IL-1β levels were significantly increased [Smith score: 8.00±0.89 vs. 5.67±0.52, TNF-α (ng/L): 87.15±4.23 vs. 66.99±5.44, IL-6 (ng/L): 66.79±2.93 vs. 45.70±4.16, IL-1β (ng/L): 58.99±2.12 vs. 39.64±2.59, all P < 0.05], SOD activity and GSH content decreased [SOD (kU/g): 72.84±3.85 vs. 101.65±1.09, GSH (μmol/g): 3.30±0.67 vs. 5.74±0.46, both P < 0.05], the contents of MDA and 8-OHdG were increased [MDA (μmol/g): 14.14±0.70 vs. 9.86±0.66, 8-OHdG (ng/L): 927.66±11.47 vs. 647.12±10.64, both P < 0.05], the mRNA and protein expressions of SIRT1, Nrf2 and HO-1 were decreased [SIRT1 mRNA (2-ΔΔCT): 0.40±0.07 vs. 0.64±0.03, Nrf2 mRNA (2-ΔΔCT): 0.48±0.07 vs. 0.84±0.02, HO-1 mRNA (2-ΔΔCT): 0.27±0.14 vs. 0.64±0.11, SIRT1 protein (SIRT1/β-actin): 0.20±0.05 vs. 0.52±0.05, Nrf2 protein (Nrf2/β-actin): 0.45±0.01 vs. 0.63±0.05, HO-1 protein (HO-1/β-actin): 0.36±0.08 vs. 0.73±0.03, all P < 0.05]. In the rat model of ALI induced by sepsis, SIRT1 can regulate the activation of Nrf2/HO-1 signaling pathway, upregulate the expression of downstream antioxidant enzymes, reduce oxidative stress injury, and then alleviate the ALI induced by sepsis in rats.

Pretreatment with Eupatilin Attenuates Inflammation and Coagulation in Sepsis by Suppressing JAK2/STAT3 Signaling Pathway.

Sepsis is an aggressive and life-threatening organ dysfunction induced by infection. Excessive inflammation and coagulation contribute to the negative outcomes for sepsis, resulting in high morbidity and mortality. In this study, we explored whether Eupatilin could alleviate lung injury, reduce inflammation and coagulation during sepsis. We constructed an in vitro sepsis model by stimulating RAW264.7 cells with 1 μg/mL lipopolysaccharide (LPS) for 6 hours. The cells were divided into control group, LPS group, LPS+ Eupatilin (Eup) group, and Eup group to detect their cell activity and inflammatory cytokines and coagulation factor levels. Cells in LPS+Eup and Eup group were pretreated with Eupatilin (10μM) for 2 hours. In vivo, mice were divided into sham operation group, cecal ligation and puncture (CLP) group and Eup group. Mice in the CLP and Eup groups were pretreated with Eupatilin (10mg/kg) for 2 hours by gavage. Lung tissue and plasma were collected and inflammatory cytokines, coagulation factors and signaling were measured. In vitro, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and tissue factor (TF) expression in LPS-stimulated RAW264.7 cells was downregulated by Eupatilin (10μM). Furthermore, Eupatilin inhibited phosphorylation of the JAK2/STAT3 signaling pathway and suppressed p-STAT3 nuclear translocation. In vivo, Eupatilin increased the survival rate of the mice. In septic mice, plasma concentrations of TNF-α, IL-1β and IL-6, as well as TF, plasminogen activator inhibitor 1 (PAI-1), D-dimer, thrombin-antithrombin complex (TAT) and fibrinogen were improved by Eupatilin. Moreover, Eupatilin alleviated lung injury by improving the expression of inflammatory cytokines and TF, fibrin deposition and macrophage infiltration in lung tissue. Our results revealed that Eupatilin may modulate inflammation and coagulation indicators as well as improve lung injury in sepsis via the JAK2/STAT3 signaling pathway.

The effects of etomidate on expression of high mobility group box 1 via the nuclear factor kappa B pathway in rat model of sepsis

ABSTRACT Etomidate is an anesthetic agent used in hemodynamically unstable patients, but its use has been controversial in septic patients. The response of high-mobility group box 1 (HMGB1), a late-phase lethal cytokine in sepsis, to etomidate has not been reported. This study investigated the effects of etomidate on the expression and release of HMGB1 and the underlying mechanism using a cecal ligation and puncture (CLP) model. Thirty-six male Sprague–Dawley rats were divided into sham, CLP, and Etomi groups. Sepsis was induced in the CLP and Etomi groups, and intravenous etomidate (4 mg/kg) was infused for 40 min immediately after operation in the Etomi group. Serum creatinine, alanine aminotransferase (ALT), tumor necrosis factor (TNF)-α, interleukin (IL)-6, and HMGB1 levels were measured 6 and 24 hours after surgery. Activation of nuclear factor (NF)-ĸB and HMGB1 mRNA expression in the liver, lung, kidney, and ileum tissues were measured, and immunohistochemical staining of HMGB1 was implemented. Increases of the TNF-α level 6 h after CLP and ALT and IL-6 levels 24 h after CLP were significantly inhibited by etomidate treatment. Etomidate treatment also significantly attenuated the increase in serum HMGB1 level at 6 and 24 h after CLP and suppressed the NF-ĸB and HMGB1 mRNA in multiple organs 24 h after CLP. Immunohistochemical staining also revealed that etomidate treatment inhibited HMGB1 expression. Etomidate inhibited the systemic release of HMGB1 and its expression in various organs. The mechanism may be associated with the inhibitory effects of etomidate on pro-inflammatory cytokine release and NF-ĸB activity.

Endoplasmic reticulum stress promotes sepsis-induced muscle atrophy via activation of STAT3 and Smad3.

Endoplasmic reticulum (ER) stress is involved in skeletal muscle atrophy in various conditions, but the role of ER stress in sepsis-induced muscle atrophy is not well understood. In this study, we conducted experiments in wild-type (WT) mice and C/EBP homologous protein knockout (CHOP KO) mice to explore the role and mechanism of ER stress in sepsis-induced muscle atrophy. Cecal ligation and puncture (CLP) was used to establish a mouse model of sepsis. In WT mice, the body weight, muscle mass, and cross-sectional area of muscle fibers in CLP group both decreased significantly compared with sham group, which revealed that sepsis-induced dramatic muscle atrophy. Additionally, sepsis activated the ubiquitin-proteasome system (UPS), accompanied by the activation of ER stress. In vitro, inhibition of ER stress suppressed the activity of E3 ubiquitin ligases and alleviated the myotube atrophy. In vivo, CHOP KO also reduced the expression of E3 ubiquitin ligases and UPS-mediated protein degradation, and significantly attenuated sepsis-induced muscle atrophy. Deletion of CHOP also decreased the phosphorylation of signal transducer and activator of transcription 3(STAT3) and Smad3, and inhibition of STAT3 and Smad3 partly reduced proteolysis caused by ER stress in vitro. These findings confirm that ER stress activates UPS-mediated proteolysis and promotes sepsis-induced muscle atrophy, which is partly achieved by activating STAT3 and Smad3.

CTSB promotes sepsis-induced acute kidney injury through activating mitochondrial apoptosis pathway.

Acute kidney injury is a common and severe complication of sepsis. Sepsis -induced acute kidney injury(S-AKI) is an independent risk factor for mortality among sepsis patients. However, the mechanisms of S-AKI are complex and poorly understand. Therefore, exploring the underlying mechanisms of S-AKI may lead to the development of therapeutic targets. A model of S-AKI was established in male C57BL/6 mice using cecal ligation and puncture (CLP). The data-independent acquisition (DIA)-mass spectrometry-based proteomics was used to explore the protein expression changes and analyze the key proteomics profile in control and CLP group. The methodology was also used to identify the key proteins and pathways. S-AKI in vitro was established by treating the HK-2 cells with lipopolysaccharide (LPS). Subsequently, the effect and mechanism of Cathepsin B (CTSB) in inducing apoptosis in HK-2 cells were observed and verified. The renal injury scores, serum creatinine, blood urea nitrogen, and kidney injury molecule 1 were higher in septic mice than in non-septic mice. The proteomic analysis identified a total of 449 differentially expressed proteins (DEPs). GO and KEGG analysis showed that DEPs were mostly enriched in lysosomal-related cell structures and pathways. CTSB and MAPK were identified as key proteins in S-AKI. Electron microscopy observed enlarged lysosomes, swelled and ruptured mitochondria, and cytoplasmic vacuolization in CLP group. TUNEL staining and CTSB activity test showed that the apoptosis and CTSB activity were higher in CLP group than in control group. In HK-2 cell injury model, the CTSB activity and mRNA expression were increased in LPS-treated cells. Acridine orange staining showed that LPS caused lysosomal membrane permeabilization (LMP). CA074 as an inhibitor of CTSB could effectively inhibit CTSB activity. CCK8 and Annexin V/PI staining results indicated that CA074 reversed LPS-induced apoptosis of HK-2 cells. The JC-1 and western blot results showed that LPS inhibited mitochondrial membrane potential and activated mitochondrial apoptosis pathway, which could be reversed by CA074. LMP and CTSB contribute to pathogenesis of S-AKI. LPS treatment induced HK-2 cell injury by activating mitochondrial apoptosis pathway. Inhibition of CTSB might be a new therapeutic strategy to alleviate sepsis-induced acute kidney injury.

Regulatory effects of umbilical cord mesenchymal stem cells and their conditioned medium on gut microbiota of septic mice

To investigate and compare the regulatory effects of umbilical cord mesenchymal stem cells (MSC) and their conditioned medium (MSC-CM) on gut microbiota of septic mice. Twenty-eight six-to-eight-week-old female C57BL/6J mice were randomly divided into sham operation group (Sham group), sepsis model group (CLP group), sepsis+MSC treatment group (CLP+MSC group) and sepsis+MSC-CM treatment group (CLP+MSC-CM group), with seven mice in each group. The septic mouse model was established by cecal ligation and puncture (CLP). In Sham group, CLP were not performed, and other operations were the same as CLP group. Mice in the CLP+MSC group and CLP+MSC-CM group received 0.2 mL 1×106 MSC or 0.2 mL concentrated MSC-CM via intraperitoneal injection 6 hours after CLP, respectively. Sham group and CLP group were given 0.2 mL sterile phosphate buffer saline (PBS) via intraperitoneal injection. Histopathological changes were evaluated by hematoxylin-eosin (HE) staining and colon length. Levels of inflammatory factors in serum were detected by enzyme-linked immunosorbent assay (ELISA). Phenotype of peritoneal macrophages was analyzed by flow cytometry, and the gut microbiota was analyzed via 16S rRNA sequencing. Compared with Sham group, significant inflammatory injury in lung and colon was observed, and shorter colon was detected in CLP group (cm: 6.00±0.26 vs. 7.11±0.09), the level of inflammatory cytokine interleukin-1β (IL-1β) in serum was significantly increased (ng/L: 432.70±17.68 vs. 353.70±17.01), the proportion of F4/80+ peritoneal macrophages was increased [(68.25±3.41)% vs. (50.84±4.98)%], while the ratio of F4/80+CD206+ anti-inflammatory peritoneal macrophages was decreased [(45.25±6.75)% vs. (66.66±3.36)%]. The α diversity sobs index of gut microbiota was downregulated significantly (118.50±23.25 vs. 255.70±6.87), the structure of species composition was altered, and the relative abundance of functional gut microbiota related to transcription, secondary metabolites biosynthesis, transport and catabolism, carbohydrate transport and metabolism, and signal transduction were decreased significantly in CLP group (all P < 0.05). Compared with CLP group, upon MSC or MSC-CM treatment, the pathological injury in lung and colon was alleviated to varying extent, the length of colon was increased (cm: 6.53±0.27, 6.87±0.18 vs. 6.00±0.26), the level of IL-1β in serum was downregulated (ng/L: 382.10±16.93, 343.20±23.61 vs. 432.70±17.68), the ratio of F4/80+ peritoneal macrophages was decreased [(47.65±3.93)%, (48.68±2.51)% vs. (68.25±3.41)%], the ratio of F4/80+CD206+ anti-inflammatory peritoneal macrophages was increased [(52.73±5.02)%, (66.38±4.73)% vs. (45.25±6.75)%], and the α diversity sobs index of gut microbiota was increased (182.50±16.35, 214.00±31.18 vs. 118.50±23.25), and the effects of MSC-CM were more significant (all P < 0.05). At the same time, species composition of gut microbiota was rebuilt, and a tendency of increase in relative abundance of functional gut microbiota was observed upon MSC and MSC-CM treatment. Both MSC and MSC-CM could alleviate inflammatory injury in tissues, and showed regulatory effects on gut microbiota in septic mouse model, moreover, MSC-CM exhibited superior advantages over MSC.

The determination of the protective role of sildenafil administration in rats with sepsis-induced liver injury.

Sepsis is a complex syndrome which comes out after infection, characterized by activation of inflammation and infection and has a high morbidity and mortality. Sildenafil (SLD) is a selective phosphodiesterase Type 5 enzyme inhibitor and is used in the treatment of erectile dysfunction effectively all over the world. In this study, we investigated whether SLD had protective effect or not by studying the effect of SLD on reactive oxygen species and antioxidants in cecal ligation and puncture (CLP) polymicrobial sepsis model in rat liver histopathologically and biochemically. Rats were divided into four groups: (1) 10 mg/kg SLD given CLP group; (2) 20 mg/kg SLD given CLP group; (3) CLP group; and (4) SHAM operated group. CLP polymicrobial sepsis model was applied to the rats. All rats in our study were sacrificed by overdose general anesthetic after 16 h (thiopental sodium, 50 mg/kg). Specimens of rat liver were analyzed histopathologically and biochemically. In the study, superoxide dismutase (SOD) and glutathione (GSH) parameters were measured to indicate the antioxidant activity in liver during sepsis. To evaluate the oxidant activity, myeloperoxidase (MPO) and lipid peroxidation (LPO) parameters were measured in liver tissue. SOD and MPO activities and GSH and LPO levels were high in CLP polymicrobial sepsis model when compared to SHAM group (p<0.05). In all SLD groups, GSH levels were high when compared to CLP group. In 20 mg/kg SLD given sepsis group, high GSH levels were observed according to SHAM group. In addition, while all SLD dose groups had a significant decrease versus CLP group in LPO levels (p<0.05), they had a significant increase in MPO activities. In 20 mg/kg SLD administrated rats, an improvement observed in biochemical parameters. In this study, SOD and MPO activities which were low in SHAM group increased in CLP polymicrobial sepsis model. When SLD administrated, MPO activity increased in both SHAM and CLP groups. In this study, GSH and LPO levels also increase in septic liver tissue. When SLD administrated to SHAM group, it increased VI protective GSH level and decreased detrimental LPO level. In histopathological examination, it was observed that 10 mg/kg SLD administration had a curative effect in liver tissue partly. It was shown that acute SLD administration decreased liver damage in septic rats dose-dependently in this study. In addition, it was observed that it corrected the broken oxidant-antioxidant balance. This might mediate the protective effect of SLD in liver. However, we believe that new experimental and clinical studies should be in the future to understand the protective effect of SLD in liver.

Semaglutide Pretreatment Induces Cardiac Autophagy to Reduce Myocardial Injury in Septic Mice.

Sepsis-induced myocardial dysfunction (SIMD) confers substantial morbidity and mortality. Semaglutide treatment has demonstrated efficacy in ameliorating sepsis-related organ damage via attenuation of inflammation, oxidative stress, and apoptotic cell death. In this study, we constructed a mouse SIMD model using cecal ligation and puncture (CLP) to explore whether semaglutide preconditioning can modulate autophagy levels and attenuate myocardial injury. C57BL/6 mice were randomly divided into six groups: sham, CLP (including CLP-6 h, CLP-12 h and CLP-24 h subgroups), semaglutide, and semaglutide+Compound-C, with five mice in each group. The latter two groups were given daily intraperitoneal injections of semaglutide for 14 days. The semaglutide+Compound-C group was given the autophagy inhibitor Compound-C intraperitoneally 1-hour before CLP surgery. After the last injection of semaglutide, SIMD mouse models were constructed by CLP surgery, while the sham group underwent a sham operation. All mice were sacrificed after surgery, and blood and myocardial specimens were collected. Enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of inflammatory factors and myocardial injury markers in the serum, while quantitative real-time polymerase chain reaction (qRT-PCR) and western blot was used to detect the expression of autophagic markers [microtubule-associated protein 1A/1B-light chain 3B (LC3B), Beclin-1, p62] and AMP-activated protein kinase (AMPK) in myocardial tissue. Hematoxylin and eosin (H&E) staining was used to observe pathological changes in myocardial tissue. The myocardial fibers in the sham group were normal, while those in the CLP group showed disordered arrangement, interstitial edema, and a large number of infiltrating inflammatory cells. A few vacuolar changes were observed locally in the semaglutide group, and more vacuolar changes were observed in the semaglutide+Compound-C group. Autophagy was inhibited in the CLP group mice. Compared with the CLP group, the semaglutide group showed a decreased levels of inflammatory factors (tumor necrosis factor-α, interleukin-1β) and myocardial injury markers (creatine kinase isoenzyme, cardiac troponin T) in the serum, a reduced expression of autophgic substrate p62, and an increased expression of LC3II (the lipidated form of LC3I)/LC3I (microtubule-associated protein 1A/1B-light chain 3), Beclin-1, and p-AMPK (phosphorylated AMP-activated protein kinase)/AMPK in the injured myocardial tissues of mice (p < 0.05). And the protective effects of semaglutide against SIMD were partially reversed by the treatment of AMPK inhibitor Compound-C (p < 0.05). Taken together, these data indicate that semaglutide provides protection against CLP-triggered myocardial inflammation and injury, potentially by reactivating myocardial autophagy pathways via activation of AMPK signaling. Further mechanistic studies are needed to definitively elucidate the functional significance of AMPK signaling in mediating the beneficial cardiac effects of semaglutide during sepsis.

Comparison of Pulmonary and Extrapulmonary Models of Sepsis-Associated Acute Lung Injury

To compare different rat models of sepsis at different time points, based on pulmonary or extrapulmonary injury mechanisms, to identify a model which is more stable and reproducible to cause sepsis-associated acute lung injury (ALI). Adult male Sprague-Dawley rats were subjected to (1) cecal ligation and puncture (CLP) with single (CLP1 group) or two repeated through-and-through punctures (CLP2 group); (2) tail vein injection with lipopolysaccharide (LPS) of 10mg/kg (IV-LPS10 group) or 20mg/kg (IV-LPS20 group); (3) intratracheal instillation with LPS of 10mg/kg (IT-LPS10 group) or 20mg/kg (IT-LPS20 group). Each of the model groups had a sham group. 7-day survival rates of each group were observed (n=15 for each group). Moreover, three time points were set for additional experimental studying in each model group: 4 hours, 24 hours and 48 hours after modeling (every time point, n=8 for each group). Rats were sacrificed to collect BALF and lung tissue samples at different time points for detection of IL-6, TNF-α, total protein concentration in BALF and MPO activity, HMGB1 protein expression in lung tissues, as well as the histopathological changes of lung tissues. More than 50 % of the rats died within 7 days in each model group, except for the IT-LPS10 group. In contrast, the mortality rates in the two IV-LPS groups as well as the IT-LPS20 group were significantly higher than that in IT-LPS10 group. Rats received LPS by intratracheal instillation exhibited evident histopathological changes and inflammatory exudation in the lung, but there was no evidence of lung injury in CLP and IV-LPS groups. Rat model of intratracheal instillation with LPS proved to be a more stable and reproducible animal model to cause sepsis-associated ALI than the extrapulmonary models of sepsis.

Effect and mechanism of Rho kinase inhibitor on intestinal injury in septic rats

To explore the effect of Rho kinase inhibitor on intestinal injury in septic rats and its possible mechanism. Thirty-two male Sprague-Dawley (SD) rats were randomly divided into sham operation group (Sham group), Rho kinase inhibitor Y-27632 control group (Y+Sham group), sepsis model group [cecal ligation and puncture (CLP) group] and Y-27632 pretreatment group (Y+CLP group), with 8 rats in each group. Rat sepsis model was reproduced by CLP. The rats in the Sham group and Y+Sham group were only separated and moved the cecum without ligation and perforation. The rats in the Y+Sham group and Y+CLP group were pretreated with intraperitoneal injection of Y-27632 solution 5 mg/kg 15 minutes before operation; the rats in the Sham group and CLP group were intraperitoneally injected with the same amount of phosphate buffered saline (PBS). Twenty-four hours after operation, the heart blood was collected and the serum diamine oxidase (DAO) content was determined by enzyme-linked immunosorbent assay (ELISA). Then the small intestine tissue was collected, the pathological changes of the intestinal tissue were observed under the light microscope after hematoxylin-eosin (HE) staining, and Chiu's score was performed. The positive expressions of Rho-related coiled-coil kinase 1 (ROCK1) and nuclear factor-κB (NF-κB) in intestinal tissue were detected by immunohistochemistry. ELISA was used to detect the levels of tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) in intestinal tissue homogenate. The intestinal tissue structure of the Sham group and Y+Sham group was intact and the mucosa was arranged neatly. Compared with the Sham group, the intestinal mucosa of the CLP group was arranged disorderly, with a large number of inflammatory cells infiltration, and the Chiu's score was significantly increased (3.83±0.27 vs. 0.12±0.11, P < 0.05), indicating that those rats suffered from septic intestinal injury. Compared with the CLP group, the degree of necrosis of intestinal epithelial cells in the Y+CLP group was reduced, a small amount of inflammatory cells infiltration was seen, and the Chiu's score was significantly decreased (2.85±0.21 vs. 3.83±0.27, P < 0.05), indicating that Y-27632 pretreatment could alleviate intestinal injury in septic rats. Compared with the Sham group, the positive expressions of intestinal tissue ROCK1 and NF-κB, the contents of serum DAO and intestinal homogenate TNF-α in the CLP group were significantly increased [ROCK1 expression (A value): 0.19 (0.18, 0.22) vs. 0.10 (0.09, 0.11), NF-κB expression (A value): 0.40±0.02 vs. 0.15±0.01, DAO (ng/L): 287.81±23.31 vs. 144.92±17.72, TNF-α (ng/L): 101.08±5.62 vs. 74.81±5.56, all P < 0.05], the level of intestinal homogenate IL-10 was significantly decreased (μg/L: 55.16±5.20 vs. 95.95±7.53, P < 0.05). Compared with the CLP group, the positive expressions of intestinal tissue ROCK1, NF-κB, the contents of serum DAO and intestinal homogenate TNF-α in the Y+CLP group were significantly decreased [ROCK1 expression (A value): 0.15 (0.13, 0.18) vs. 0.19 (0.18, 0.22), NF-κB expression (A value): 0.28±0.01 vs. 0.40±0.02, DAO (ng/L): 243.34±19.76 vs. 287.81±23.31, TNF-α (ng/L): 90.41±8.79 vs. 101.08±5.62, all P < 0.05], while the level of intestinal homogenate IL-10 was significantly increased (μg/L: 66.15±5.74 vs. 55.16±5.20, P < 0.05), indicating that the protective effect of Y-27632 pretreatment on sepsis intestinal injury rats might be related to the regulation of RhoA/ROCK1/NF-κB signaling pathway. Rho kinase inhibitors can reduce intestinal injury in septic rats, and the mechanism may be related to inhibiting RhoA/ROCK1/NF-κB signaling pathway and reducing intestinal inflammation in septic rats.

Effects of Gabexate Mesylate on the Gut Microbiota and Metabolomics in Rats with Sepsis.

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. However, there is still no single drug that could reduce septic mortality. Previous studies have reported gabexate mesylate (GM) significantly reduced serum inflammatory factors, alleviated sepsis-induced lung injury and improved clinical outcomes. This study aimed tocombine with microbiome sequencing and metabolomics analysis to explore the effects of GM administration in septic rats. Sixty SD rats were randomly divided into the sham control (SC), cecal ligation and puncture (CLP), and GM injection (GM) groups. The mortality was measured and colonic feces were collected to examine the gut microbiota and metabolism 24 h after the procedure. The lung tissues were collected for hematoxylin-eosin staining. We observed the relative abundance of Pygmaiobacter, which contributed to short-chain fatty acids (SCFAs) promotion, Lactobacillus and Erysipelotrichaceae UCG-003 increased in the GM-treated rats, while Escherichia-Shigella and Akkermansia decreased compared to the sepsis-induced lung injury group. Furthermore, these 3 metabolites including Palmitoylethanolamide, Deoxycholic acid and Chenodeoxycholic acid correlated significantly to CLP- and GM-rich genus (P < 0.05). Besides, the lung tissues of CLP group showed more severe inflammatory infiltration and edema, and the mortality rate in the CLP group (10/20) was significantly higher than in the SC group (0/20) (P < 0.001) and GM group (4/20) (P < 0.05). Our findings showed that GM attenuated sepsis-induced lung injury rats and regulated metabolites related to gut microbiota, which may provide an effective treatment for sepsis patients.

Suberosin Alleviates Sepsis-Induced Lung Injury in A Rat Model of Cecal Ligation and Puncture

Background/aims Sepsis is one of the major problems encountered in intensive care units, causing organ damage and increasing mortality. Suberosin (SBR) is a type of coumarin with antioxidant and anti-inflammatory activities. The goal of this study is to explore the protective effects of SBR on the lungs in a rat model of sepsis. Methods Male Wistar rats were utilized in this study. A cecal ligation and puncture (CLP) model was applied to induce sepsis. Rats were separated into six groups with nine animals in each group, including healthy control, SBR, CLP, and CLP + SBR (5, 10, and 20 mg/kg) groups. Superoxide dismutase (SOD), glutathione (GSH) enzyme activities, and malondialdehyde (MDA) level were measured via enzyme-linked immunosorbent assay (ELISA). The messenger RNA (mRNA) expressions of tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) were evaluated by real-time polymerase chain reaction (RT-PCR). Histopathological changes in the lungs were investigated with hematoxylin and eosin (H&E). Results MDA levels and GSH and SOD enzyme activities were negatively affected in the CLP group, but SBR treatment ameliorated these oxidative stress parameters in the SBR1-3 groups (p< 0.05). The mRNA expressions of TNF-α and IL-1β were increased in the CLP group, and SBR treatment decreased those expression levels in a dose-dependent manner (p < 0.05). Organ damage and necrosis were seen in the CLP group and were alleviated in the SBR3 group. Immunohistochemical (IHC) analysis of lung tissues demonstrated decreased TNF-α and IL-1β immunopositivity in the SBR1-3 groups (p< 0.05). Conclusions SBR ameliorated sepsis-related lung injury in a dose-dependent manner. This compound has significant potential as a future agent in the treatment of sepsis.

Abstract 10402: Activated Protein C Rescues Sepsis-Associated Cardiac Dysfunction and Renal Injury in Aging

Introduction: Sepsis is a progressive life-threatening condition in which mortality has been consistently linked to increasing organ dysfunction. We have found that activated protein C (APC) has cytoprotective and anti-inflammatory properties in cardiovascular disease. Whether APC is critical for maintaining systemic homeostasis under sepsis in aging remains unknown. Hypothesis: Administration of recombinant APC ameliorates sepsis-associated renal injury and cardiac dysfunction in aging via EPCR (endothelial cell protein C receptor). Methods: Young (3-6 months) and aged (18-21 months) C57BL/6J wild type (WT), and EPCR point mutation (EPCR R84A/R84A ) knock in C57BL/6J mice were subjected to cecal ligation and puncture (CLP) surgery. APC (0.2 μg/g) was injected (i.p.) 1 hour after CLP surgery and every 24 hours to determine the therapeutic effects of APC on CLP-induced sepsis. Cardiac function was assessed daily via echocardiogram. Results: The Kaplan-Meier survival curve showed that the survival rate of young mice is 90% and of aged mice is 0% on day 7 of post-CLP. Moreover, the spleens were significantly enlarged in both young and aged CLP WT mice. Intriguingly, administration of recombinant APC can keep all young animals' survival and increased survival rate of aged animals to 65% on day 7 of post-CLP. The spleen size of young/aged CLP groups were significantly reduced by APC treatment. However, the beneficial effects of APC on the survival rate and spleen enlargement caused by CLP were abolished in EPCR R84A/R84A mice versus EPCR WT/WT littermates. The renal tubules necrosis score and cardiac dysfunctions caused by CLP were worse in aged versus young mice, but APC treatment significantly rescued CLP-caused renal pathology and cardiac dysfunctions of young/aged mice and the rescuing capacity of APC for both renal pathology and cardiac dysfunctions in aged versus young mice was stronger. In addition, APC treatment reduced circulating inflammatory monocytes and neutrophils during CLP-induced sepsis in young/aged WT but not EPCR R84A/R84A mice Conclusions: Sepsis associated mortality is increased in aging. APC treatment can ameliorate age-related sepsis renal injury and cardiac dysfunctions through receptor EPCR to reduce sepsis related mortality.

Secukinumab alleviates cognitive impairment by attenuating oxidative stress and neuronal apoptosis via the IL-17RA/AKT/ERK1/2 pathway in a rat model of sepsis

BackgroundSeptic-associated encephalopathy (SAE) is a critical manifestation of sepsis that leads to long-term cognitive impairment. Interleukin (IL)-17A has been shown to mediate neuronal apoptosis in central nervous system diseases, while oxidative stress has been found to have a detrimental effect in SAE. However, the relationship between IL-17A and oxidative stress in SAE remains unclear. This study aimed to investigate the effects of secukinumab on alleviating cognitive impairment in a rat model of sepsis, as well as examine its underlying molecular mechanism of action. MethodsA total of 282 male 8-week-old Sprague-Dawley rats were randomly subjected to cecal ligation and puncture (CLP) or sham treatment followed by volume resuscitation immediately after surgery. Secukinumab was administered intranasally 1 h post-CLP. Rats were given the p-ERK activator ceramide C6 intracerebroventricularly (i.c.v) 24 h before CLP surgery. Recombinant rIL-17A was administered i.c.v. at 0 h in naive rats, followed by intraperitoneal injection of the AKT inhibitor GDC0068 1 h post-rIL-17A injection. Clinical scores, body weight, and survival rate were assessed. In addition, immunofluorescence staining, neurobehavioral tests, Nissl staining, and western blotting were performed. Cognitive function was assessed 15–20 days post-CLP using the Morris water maze test. ResultsIL-17A and IL-17RA protein expression levels in the rat hippocampus increased and peaked 24 h post-CLP. Furthermore, IL-17RA was found to be expressed in neurons. The survival rate after CLP was 50%. Following CLP, an increased clinical score and significant decrease in body weight were observed. However, treatment with secukinumab led to a decrease in the clinical score of rats 24 h post-CLP. CLP resulted in spatial and memory impairment and anxiety-like behaviors in rats, while secukinumab treatment significantly alleviated cognitive impairment compared to the CLP group (p < 0.05). In addition, oxidative stress and neuronal apoptosis were found to be increased in the CLP group, while secukinumab significantly reduced oxidative stress and neuronal apoptosis in the hippocampus following CLP. Furthermore, secukinumab treatment led to a significant decrease in the protein expression levels of p-AKT, p-ERK1/2, Romo1, and Bax, together with increased Bcl-2 protein expression. Finally, treatment with ceramide C6 and GDC0068 abolished the neuroprotective effects of secukinumab post-CLP. ConclusionOur results demonstrated that secukinumab attenuated oxidative stress and neuronal apoptosis and partially ameliorated cognitive impairment via the IL-17RA/AKT/ERK1/2 pathway in a rat model of sepsis. Thus, secukinumab may be a potential therapeutic strategy for septic patients.

Acquisition and Analysis of Microcirculation Image in Septic Model Rats.

Background: Microcirculation is a vital sign that supplies oxygen and nutrients to maintain normal life activities. Sepsis typically influences the operation of microcirculation, which is recovered by the administration of medicine injection. Objective: Sepsis-induced variation and recovery of microcirculation are quantitatively detected using microcirculation images acquired by a non-contact imaging setup, which might assist the clinical diagnosis and therapy of sepsis. Methods: In this study, a non-contact imaging setup was first used to record images of microcirculation on the back of model rats. Specifically, the model rats were divided into three groups: (i) the sham group as a control group; (ii) the cecum ligation and puncture (CLP) group with sepsis; and (iii) the CLP+thrombomodulin (TM) group with sepsis and the application of TM alfa therapy. Furthermore, considering the sparsity of red blood cells (RBCs), the blood velocity is estimated by robust principal component analysis (RPCA) and U-net, and the blood vessel diameter is estimated by the contrast difference between the blood vessel and tissue. Results and Effectiveness: In the experiments, the continuous degradation of the estimated blood velocity and blood vessel diameter in the CLP group and the recovery after degradation of those in the CLP+TM group were quantitatively observed. The variation tendencies of the estimated blood velocity and blood vessel diameter in each group suggested the effects of sepsis and its corresponding therapy.

FGF15 Protects Septic Mice by Inhibiting Inflammation and Modulating Treg Responses.

Fibroblast growth factor 15 (FGF15) through its FGF-receptor (FGFR)-4 inhibits hepatic inflammation. The current study aimed at investigating whether FGF15 could inhibit septic inflammation and its compensative regulatory T cell (Treg) responses in a mouse sepsis model of cecal ligation and puncture (CLP) and in vitro transwell co-culture. Following the sham or CLP procedure, male CLP C57BL/6 mice were intravenously injected with vehicle saline or FGF15 beginning at 2 h post the procedure every 12 h for three days. Some mice were euthanized and their serum and liver samples were collected for examination of cytokines and Tregs by enzyme-linked immunosorbent assay (ELISA), Western blot and flow cytometry. The remaining mice were monitored for their survival up to 14 days post procedure. Moreover, the purified hepatic CD4+ T cells were co-cultured in transwell plates with unmanipulated NCTC 1469 cells or the cells that had been transfected with the control or FGFR4-specific siRNA and treated with, or without, Lipopolysaccharides (LPS) for 24 h, followed by treatment with vehicle PBS or FGF15 for 48 h. Compared with the CLP group of mice, treatment with FGF15 significantly prolonged the mean survival days of mice (12 vs 1.17 in the CLP group, P = 0.022), mitigated hepatic inflammation and reduced the frequency of apoptotic cells in the liver of mice. FGF15 treatment decreased the percentages of hepatic Tregs, hepatic IL-2, TGF-β and FOXP3 expression in septic mice, accompanied by decreasing serum IL-1β, TNF-α, IL-6 and IL-10 levels. Similarly, FGF15 treatment also attenuated the LPS-increased frequency of Tregs, FOXP3 and IL-2 expression and IL-1β, TNF-α, IL-6 and IL-10 secretion in vitro after co-culture with NCTC 1469 cells, but not co-cultured FGFR4-silenced NCTC 1649 cells. FGF15 treatment through FGFR4 ameliorated hepatic inflammation and its compensative Treg responses, which were associated with protecting from septic death in mice.

Electroacupuncture alleviates cognitive dysfunction and neuronal pyroptosis in septic mice.

Sepsis is defined as organ dysfunction caused by an uncontrolled response to infection and is followed by a high incidence of cognitive dysfunction, which can severely affect patients' quality of life. Previous studies have suggested that electroacupuncture (EA) is protective against sepsis-associated cognitive dysfunction and that pyroptosis plays a vital role in cognitive function. The aim of this study was to investigate the effect of EA on cognition and neuronal pyroptosis in a mouse model of sepsis. Sepsis was induced by cecal ligation and puncture (CLP) surgery. Mice were randomly divided into three groups (control, CLP and CLP + EA). EA was performed at bilateral ST36 for three consecutive days after the surgery. The 7-day survival rate of each group was observed on the seventh day after the surgery. The Morris water maze (MWM) was used to test cognitive function from the 8th to 12th day after the surgery. We used transmission electron microscopy (TEM) and transferase dUTP nick-end labeling (TUNEL) staining to determine the structural integrity of hippocampal neuronal membranes and the number of surviving neurons in the hippocampal tissues, respectively. Expression of nucleotide-binding domain-like receptor protein 1 (NLRP1), caspase-1 and gasdermin-D (GSDM D) in hippocampal CA1 neurons was detected by Western blotting and real-time fluorescence quantitative polymerase chain reaction (RT-qPCR), and caspase-1 concentrations were measured by enzyme-linked immunosorbent assay. Compared with the CLP group, 7-day survival rates and cognitive function were significantly improved in the CLP + EA group. After EA treatment, the integrity of the hippocampal CA1 neuronal membrane and mortality of hippocampal neurons were significantly decreased, and expression of NLRP1, caspase-1 and GSDM D was downregulated. EA can alleviate cognitive dysfunction and neuronal pyroptosis in septic mice.

Regulation of RhoA/ROCK1 signaling pathway by miR 26b in sepsis induced acute lung injury

Purpose: To investigate the role of miR-26b in the regulation of RhoA/ ROCK1 signaling pathway in acute lung injury (ALI) caused by sepsis.&#x0D; Methods: Thirty male rats were randomized into sham group (SG), cecal ligation and puncture (CLP) group (CG) and miR-26b mimic group (MG). Hematoxylin and eosin (H &amp; E) staining assay was performed to determine the pathological characteristics of rat lung tissues in each group, while enzyme-linked immunosorbent assay (ELISA) was conducted to determine TNF-α and IL-1β levels. The miR-26b expression was evaluated by quantitative reverse transcription polymerase chain reaction (qRT-PCR), while RhoA and Rock1 protein levels were assessed using western blotting.&#x0D; Results: The CG had significant lung injury in comparison with the SG. There were significant elevation in TNF-α and IL-1β levels (p &lt; 0.05). RhoA and ROCK1 levels in lung tissue were noticeably elevated in CG (p &lt; 0.05). After treatment, lung injury in MG was reduced in contrast to CG. The MG showed statistically significant decrease (p &lt; 0.05) in the levels of TNF-α and IL-1β, while the lung tissue mRNA expression and the RhoA and ROCK1 expression levels were significantly reduced in MG (p &lt; 0.05).&#x0D; Conclusion: The MiR-26b mimics plays an important role in the treatment of ALI induced by sepsis in rats by regulating RhoA/ROCK1 signaling pathway. Thus, the findings of this study provide a theoretical basis for clinical studies on the use of miR-26b in the therapy of sepsis.