Cecal Ligation And Puncture Model Research Articles

Resveratrol ameliorates sepsis-induced acute kidney injury in a pediatric rat model via Nrf2 signaling pathway.

Acute kidney injury (AKI) is a hyper-inflammation-induced abrupt loss of kidney function and has become a major public health problem. The cecal ligation and puncture (CLP) model of peritonitis in rat pups mimics the development of sepsis-induced pediatric AKI is pre-renal without morphological changes of the kidneys and high lethality. Resveratrol, a natural polyphenolic compound with low toxicity, has obvious anti-oxidant and anti-inflammatory properties. The present study aimed to determine whether resveratrol alleviates pediatric AKI and investigated the potential mechanism. Thus, a CLP model of 17-18 day-old rat pups was used to mimic the development of sepsis-induced AKI in children. In the group treated with resveratrol, renal injury induced by CLP was alleviated with downregulation of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and kidney injury molecule (KIM)-1 expression. Nuclear factor-erythroid-2-related factor 2 (Nrf2) signaling is known to effectively inhibit inflammation, the present study found that resveratrol reduced the lipopolysaccharide-induced inflammatory response in kidney cells in vitro and induced the activation of Nrf2 signaling, including accumulation of nuclear Nrf2 and increase of the expression of Nrf2 target genes heme oxygenase (HO)-1 and NAD(P)H dehydrogenase (quinone) 1 (NQO1); this was confirmed by the induction of the expression of HO-1 and NQO1 by treatment of resveratrol in vitro and in vivo. Of note, knockdown of Nrf2 effectively abrogated the downregulation of TNF-α, IL-1β and KIM-1 expression induced by resveratrol in vitro. These results suggested that resveratrol ameliorates sepsis-induced acute kidney injury in a pediatric model of AKI via the Nrf2 signaling pathway.

Resolvin D1 Promotes SIRT1 Expression to Counteract the Activation of STAT3 and NF-κB in Mice with Septic-Associated Lung Injury.

Resolvin D1 (RvD1) is a novel endogenous docosahexaenoic acid (DHA)-derived lipid mediators, which possesses a dual role of anti-inflammation and promotes inflammation resolution. The aim of the present study was to assess the effects of RvD1 on cecal ligation and puncture (CLP) model of sepsis and explore the underlying mechanism. Six-to-eight-week-old male C57BL/6 mice were randomly divided into following three groups: sham-operated group (SO), CLP model group (CLP), and CLP+RvD1 group (RvD1). The SO group underwent the sham operation. The RvD1 groups were administered RvD1 (10-ng/g body weight) by penile vein injection, but the CLP groups were administered the same volume of vehicle (PBS) after CLP. We assessed the survival benefit of RvD1 in CLP-induced septic mice for 7days. After 24h, mice were sacrificed, bronchoalveolar lavage fluids (BALF) was collected for proinflammatory cytokines assay, and albumin assay and the lung tissues were harvested for histologic analysis, myeloperoxidase (MPO) activity and the expression of Sirtuin 1 (SIRT1), signal transducers, and activators of transcription 3 (STAT3), nuclear factor-κB (NF-κB), and mitogen-activated protein kinases (MAPKs). RvD1 treatment increased the survival time in mice with sepsis induced by CLP, reducing the MPO activity and albumin level at 24h. The levels of inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-6 (IL-6) in BALF were significantly decreased by RvD1. RvD1 promoted SIRT1 expression and suppressed the activation of NF-κB, STAT3, ERK, and p38 in lung tissues of septic mice. These results suggest that RvD1 may improve survival and attenuate the degree of lung inflammation reaction in mice with CLP by suppressing STAT3, NF-κB, ERK, and p38 expressions through a mechanism partly dependent on SIRT1.

6% Hydroxyethyl starch (HES 130/0.4) diminishes glycocalyx degradation and decreases vascular permeability during systemic and pulmonary inflammation in mice

BackgroundIncreased vascular permeability is a pathophysiological hallmark of sepsis and results in increased transcapillary leakage of plasma fluid, hypovolemia, and interstitial edema formation. 6% hydroxyethyl starch (HES 130/0.4) is commonly used to treat hypovolemia to maintain adequate organ perfusion and oxygen delivery. The present study was designed to investigate the effects of 6% HES 130/0.4 on glycocalyx integrity and vascular permeability in lipopolysaccharide (LPS)-induced pulmonary inflammation and systemic inflammation in mice.Methods6% HES 130/0.4 or a balanced electrolyte solution (20 ml/kg) was administered intravenously 1 h after cecal ligation and puncture (CLP) or LPS inhalation. Sham-treated animals receiving 6% HES 130/0.4 or the electrolyte solution served as controls. The thickness of the endovascular glycocalyx was visualized by intravital microscopy in lung (LPS inhalation model) or cremaster muscle (CLP model). Syndecan-1, hyaluronic acid, and heparanase levels were measured in blood samples. Vascular permeability in the lungs, liver, kidney, and brain was measured by Evans blue extravasation.ResultsBoth CLP induction and LPS inhalation resulted in increased vascular permeability in the lung, liver, kidney, and brain. 6% HES 130/0.4 infusion led to significantly reduced plasma levels of syndecan-1, heparanase, and hyaluronic acid, which was accompanied by a preservation of the glycocalyx thickness in postcapillary venules of the cremaster (0.78 ± 0.09 μm vs. 1.39 ± 0.10 μm) and lung capillaries (0.81 ± 0.09 μm vs. 1.49 ± 0.12 μm).ConclusionsThese data suggest that 6% HES 130/0.4 exerts protective effects on glycocalyx integrity and attenuates the increase of vascular permeability during systemic inflammation.

Dimethyl Fumarate Limits Neuroinflammation and Oxidative Stress and Improves Cognitive Impairment After Polymicrobial Sepsis.

Sepsis is caused by a dysregulated host response to infection, often associated with acute central nervous system (CNS) dysfunction, which results in long-term cognitive impairment. Dimethyl fumarate (DMF) is an important agent against inflammatory response and reactive species in CNS disorders. Evaluate the effect of DMF on acute and long-term brain dysfunction after experimental sepsis in rats. Male Wistar rats were submitted to the cecal ligation and puncture (CLP) model. The groups were divided into sham (control) + vehicle, sham + NAC, sham + DMF, CLP + vehicle, CLP + NAC, and CLP + DMF. The animals were treated with DMF (15mg/kg at 0 and 12h after CLP, per gavage) and the administration of n-acetylcysteine (NAC) (20mg/kg; 3, 6, and 12h after CLP, subcutaneously) was used as positive control. Twenty-four hours after CLP, cytokines, myeloperoxidase (MPO), nitrite/nitrate (N/N), oxidative damage to lipids and proteins, and antioxidant enzymes were evaluated in the hippocampus, total cortex, and prefrontal cortex. At 10days after sepsis induction, behavioral tests were performed to assess cognitive damage. We observed an increase in cytokine levels, MPO activity, N/N concentration, and oxidative damage, a reduction in SOD and GPx activity in the brain structures, and cognitive damage in CLP rats. DMF treatment was effective in reversing these parameters. DMF reduces sepsis-induced neuroinflammation, oxidative stress, and cognitive impairment in rats subjected to the CLP model.

Assessment of clinical sepsis-associated biomarkers in a septic mouse model.

ObjectiveClinical sepsis-associated biomarkers were utilized in a cecal ligation and puncture (CLP) septic mouse model to provide a reference for investigating pathophysiological mechanisms and evaluating novel therapeutic interventions for sepsis.MethodsSepsis in mice was induced by CLP, and clinical biomarkers were evaluated (survival rate, blood physiological and biochemical indices, cytokines, hepatorenal function parameters, and blood coagulation).ResultsThe mortality rate was >70%. The body temperature, blood pressure, and heart rate decreased within 48 h. Low lactic acid was found at 8 h. The CLP mice showed typical inflammatory symptoms with decreased white blood cells and procalcitonin and increased levels of soluble triggering receptor expressed on myeloid cells-1, interleukin (IL)-6, IL-10, tumor necrosis factor-α, macrophage inflammatory protein (MIP)-1α, MIP-1β, and MIP-2. The platelet count and activated partial thromboplastin time significantly decreased, and the prothrombin time and prothrombin time–international normalized ratio markedly increased. Phenotypes of multiple organ dysfunction were found in the CLP model, including increased liver alanine aminotransferase and aspartate transaminase; significantly reduced total protein, globulin, and serum albumin; increased blood urea nitrogen and creatinine; and decreased blood glucose.ConclusionThe clinical features of the CLP mouse model were similar to those of human patients with sepsis.

Lactate as a Potential Biomarker of Sepsis in a Rat Cecal Ligation and Puncture Model.

We attempted to investigate whether blood lactate is a useful biomarker for sepsis in a rat cecal ligation and puncture (CLP) model. Male Sprague-Dawley rats underwent approximately 75% cecum ligation and two punctures to induce high-grade sepsis. A lactate of 1.64 mmol/L (Youden score of 0.722) was selected as the best cutoff value to predict the onset of sepsis after CLP exposure; 46 of 50 rats who survived 24 hours after the CLP were divided into the L group (lactate < 1.64 mmol/L) and M group (lactate ≥ 1.64 mmol/L). In the M group, the animals had significantly higher murine sepsis scores and none survived 5 days post-CLP, and the rate of validated septic animals, serum procalcitonin, high mobility group box 1, blood urea nitrogen, alanine transaminase, cardiac troponin I, and the wet-to-dry weight ratio were significantly higher compared to the L group. Worsen PaO2/FiO2, microcirculations, and mean arterial pressure were observed in the M group. More severe damage in major organs was confirmed by histopathological scores in the M group compared with the L group. In conclusion, lactate ≥ 1.64 mmol/L might serve as a potential biomarker to identify the onset of sepsis in a rat CLP model.

Role of immune-related GTPase M1 in cortical neurons autophagy of mice with sepsis-induced brain injury

To investigate the role of immune-related GTPase M1 (IRGM1) in cortical neurons autophagy in mice with sepsis induced brain injury (SIBI). Methods: Sixty wild-type C57BL/6 mice and sixty IRGM1 gene knockout C57BL/6 mice were randomly divided into 4 groups: a sham-operated wild-type (SWT) group, a cecal ligation and puncture (CLP) model wild-type (MWT) group, a sham-operated knockout (SKO) group, and a CLP model knockout (MKO) group. Models of mice with sepsis were established by CLP. Six hours of after CLP, the neurobehavioral scores for mice were recorded. The mice were diagnosed with SIBI and enrolled for the studies in next step if the neurobehavioral score was less than 6 in the MWT and MKO groups. The sham operation group only opened the abdominal cavity without CLP. Pathological changes in mouse cerebral cortex were observed by HE staining. Electron microscope was used to observe the ultrastructure of autophagy in cortical neurons. The expression of IRGM1 and INF-γ mRNA in the cerebral cortex of mice were detected by Real time quantitative PCR. The protein expression of microtubule-associated protein 1 light chain 3 (LC3)-II, LC3-I, sequestosome-1 (SQSTM1) and IRGM1 were measured by Western blot. Immunofluorescence staining was used to examine the expression of IRGM1 in mouse cortical neurons. Results: In the MWT group, the cortical neurons showed dilated endoplasmic reticulum, swelling mitochondria, and increased number of autophagosomes after 6 or 24 h of CLP in contrast to the SWT group. At 6 h after CLP, the expression of LC3-II in the cerebral cortex began to up-regulate, and the up-regulation was maintained till 96 h after CLP; on the contrary, SQSTM1 began to decline after 6 h of CLP. Compared with SWT group, IRGM1 was strongly up-regulated in the cerebral cortex of mice at both mRNA and protein levels in the MWT group after 12 h of CLP, and the mRNA expression of IFN-γ was also increased significantly (P<0.05). At 24 h after CLP, the IRGM1 expression of cortical neurons in the MWT group was significantly higher than that in the SWT group. The baseline of autophagy activity was quite low in the cerebral cortex cells in the SWT and the SKO groups. There was almost no detected expression of LC3-II; conversely, the expression of SQSTM1 was very high after 12 h of CLP. However, the expression of LC3-II was significantly up-regulated and the expression of SQSTM1 was down-regulated in the MWT group (P<0.05). On the other hand, there was almost no detected LC3-II expression in cerebral cortex in the MKO group, and the expression of SQSTM1 was up-regulated. At 6 h after CLP, the incidence of SIBI was 90% (27/30) in the MWT group, and 96.67% (29/30) in the MKO group. At 12 h of CLP, the neurobehavioral scores in the MKO group was significantly lower than that in the MWT group (4.97±0.71 vs 5.43±0.86; t=2.284, P=0.026). HE staining showed that mice in the MKO group suffered severe cerebral cortex injury, and the number of nerve cells was significantly reduced compared with that in the MWT group. Conclusion: The IRGM1 exerts a protective effect on the brain of the mice with SIBI, and its mechanism might be related to the regulation of autophagy in mouse cortical neurons.

Comprehensive comparison of three different animal models for systemic inflammation

BackgroundTo mimic systemic inflammation in humans, different animal models have been developed. Since these models are still discussed controversially, we aimed to comparatively evaluate the most widely used models with respect to the systemic effects, the influence on organ functions and to the underlying pathophysiological processes.MethodsSystemic inflammation was induced in C57BL/6N mice with lipopolysaccharide (LPS) treatment, peritoneal contamination and infection (PCI), or cecal ligation and puncture (CLP). Blood glucose and circulating cytokine levels were evaluated at 0, 2, 4, 6, 12, 24, 48, and 72 h after induction of inflammation. Additionally, oxidative stress in various organs and liver biotransformation capacity were determined. Markers for oxidative stress, apoptosis, infiltrating immune cells, as well as cytokine expression patterns, were assessed in liver and spleen tissue by immunohistochemistry.ResultsTreating mice with LPS and PCI induced a very similar course of inflammation; however, LPS treatment elicited a stronger response. In both models, serum pro-inflammatory cytokine levels rapidly increased whereas blood glucose decreased. Organs showed early signs of oxidative stress, and apoptosis was increased in splenic cells. In addition, liver biotransformation capacity was reduced and there was pronounced immune cell infiltration in both the liver and spleen. Mice exposed to either LPS or PCI recovered after 72 h. In contrast, CLP treatment induced comparatively fewer effects, but a more protracted course of inflammation.ConclusionsThe LPS model of systemic inflammation revealed to be most suitable when being interested in the impact of new therapies for acute inflammation. When using the CLP model to mimic human sepsis more closely, a longer time course should be employed, as the treatment induces delayed development of systemic inflammation.

Antimicrobial cathelicidin peptide LL‑37 induces NET formation and suppresses the inflammatory response in a mouse septic model.

LL‑37 is the only known member of the cathelicidin family of antimicrobial peptides in humans. In addition to its broad spectrum of antimicrobial activities, LL‑37 may modulate various inflammatory reactions. The authors previously revealed that LL‑37 improves the survival of a murine cecal ligation and puncture (CLP) sepsis model. In the present study, the mechanism for the protective action of LL‑37 was elucidated using the CLP model, focusing on the effect of LL‑37 on the release of neutrophil extracellular traps (NETs). The results indicated that the intravenous administration of LL‑37 suppressed the increase of damage-associated molecular patterns (DAMPs), including histone‑DNA complex and high‑mobility group protein 1, in addition to interleukin‑1β, tumor necrosis‑α and soluble triggering receptor expressed on myeloid cells (TREM)‑1 in plasma and peritoneal fluids. Notably, LL‑37 significantly suppressed the decrease of mononuclear cell number in blood, and the increase of polymorphonuclear cell (neutrophil) number in the peritoneal cavity during sepsis. Furthermore, LL‑37 reduced the bacterial burden in blood and peritoneal fluids. Notably, LL‑37 increased the level of NETs (myeloperoxidase‑DNA complex) in plasma and peritoneal fluids. In addition, it was verified that LL‑37 induces the release of NETs from neutrophils, and NETs possess the bactericidal activity. Overall, these observations suggest that LL‑37 improves the survival of CLP septic mice by possibly suppressing the inflammatory responses as evidenced by the inhibition of the increase of cytokines, soluble TREM‑1 and DAMPs (host cell death) and the alteration of inflammatory cell numbers, and bacterial growth via the release of NETs with bactericidal activity.

Glutamine reduces myocardial cell apoptosis in a rat model of sepsis by promoting expression of heat shock protein 90

BackgroundMyocardial cell injury and cardiac myocyte apoptosis are associated with sepsis. Glutamine (Gln) has been reported to repair myocardial cell injury. The aim of this study was to explore the role of Gln on cardiac myocytes in a cecal ligation and puncture (CLP) model of sepsis in Wistar rats. Materials and methodsFollowing induction of sepsis in a CLP rat model, viral encoding heat shock protein 90 (Hsp90) gene and Hsp90dsDNA were designed to express and knockdown Hsp90, respectively. Rat cardiac tissues were examined histologically, and apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling staining. The expression of B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein, Hsp90, p53 upregulated modulator of apoptosis, and p53 was measured by western blotting and real-time polymerase chain reaction. Caspase-3, caspase-8, and caspase-9 were detected by enzyme-linked immunosorbent assay. ResultsRat cardiac myocyte damage induced by CLP was reduced by Gln treatment and Hsp90 overexpression, and these changes were reversed by Hsp90 knockdown. Bcl-2 expression, Bcl-2-associated X protein, p53, p53 upregulated modulator of apoptosis, caspase-8, caspase-9, and caspase-3 activities were significantly upregulated in the CLP model, which were reduced by Gln treatment and Hsp90 overexpression. ConclusionsGln reduced apoptosis of cardiac myocytes in a rat model of sepsis, by promoting Hsp90 expression. Further studies are needed to determine the possible therapeutic action of Gln in sepsis in human tissue.

A comparative study of changes of autophagy in rat models of CLP versus LPS induced sepsis.

In the present study, two different rat models of sepsis, cecal ligation and puncture (CLP), and lipopolysaccharide (LPS), were established. Changes in autophagy in both models were compared using transmission electron microscopy (TEM), immunohistochemistry, western blotting, and quantitative polymerase chain reaction techniques. Consequently, TEM analysis revealed autophagic bodies in the CLP and LPS sepsis models. In addition, autophagy-related protein LC3 A-specific staining was detected in the cytoplasm. However, analysis of protein and gene expression levels revealed a statistically significant increase in autophagic activity 12 and 24 h following induction of the CLP group, and 2 h following induction of the LPS group. Thus, it was concluded that both models of sepsis exhibited increased autophagic activity of the cardiomyocytes over time. The LPS model was superior to the CLP model in perturbation of molecular biological mechanisms, while the latter would be more likely suited for the study of physiological functions.

STING and TRIF Contribute to Mouse Sepsis, Depending on Severity of the Disease Model.

IFN regulatory factor (IRF)3 plays a detrimental role in the cecal ligation and puncture (CLP) mouse model of sepsis. However, it is unclear which pathway activates IRF3 in this context. In this report, we investigate two pathways that activate IRF3: the Stimulator of Interferon Genes (STING) pathway (that senses cytosolic DNA) and the TIR-domain-containing adapter-inducing interferon-β (TRIF) pathway (that senses dsRNA and LPS via Toll-like receptor 3 and 4). Initially, we examine the impact of these pathways using a severe CLP model (∼90% mortality). Both STING-KO and TRIF-KO mice are protected from severe sepsis, exhibiting reduced mortality, disease score, hypothermia, and inflammatory cytokines relative to WT counterparts. STING/TRIF-DKO mice exhibit a similar phenotype to each of the single KO strains, suggesting that these pathways have an interrelated function. Subsequently, we examine the impact of these pathways using a moderate CLP model incorporating clinical treatments (Lactated Ringer Solution and antibiotics, ∼36% mortality). In this case, STING-KO mice show a similar phenotype to WT counterparts, while TRIF-KO mice show improved disease score and hypothermia. During sepsis, innate immune receptors recognize bacterial ligands and host-derived danger signals, including cell-free DNA released into the circulation. We show that IRF3 is activated in cultured macrophages treated with bacteria derived from the mouse cecum, dependent on TRIF, and in macrophages treated with mouse genomic DNA/Lipofectamine 2000, dependent on STING. Together, our data demonstrate that both the STING and TRIF pathways can promote sepsis pathogenesis; however, their contribution depends on the severity of the disease model. We show that bacteria are abundant in the peritoneum following both severe and moderate CLP, while cell-free DNA is more highly elevated in the serum following severe CLP compared with sham and moderate CLP. Hence, the presence of bacteria and cell-free DNA may explain the variable phenotypes in our severe CLP model (dependent on TRIF and STING) versus our moderate CLP model (dependent on TRIF only).

Deciphering the mechanism of Huang-Lian-Jie-Du-Decoction on the treatment of sepsis by formula decomposition and metabolomics: Enhancement of cholinergic pathways and inhibition of HMGB-1/TLR4/NF-κB signaling

Sepsis is the major cause of morbidity and mortality in surgical patients. Huang-Lian-Jie-Du-Decoction (HLJDD), a well-known Chinese herb formula, has long been used for the treatment of sepsis. In this investigation, by leaving one herb out each time, the four component herbs of HLJDD were reformulated to four HLJDD variants Form1-4, corresponding to the removal of Phellodendri Chinensis Cortex, Scutellariae Radix, Gardeniae Fructu and Coptidis Rhizoma, respectively. Metabolomics approach combined with histological inspection, biochemical measurement and molecular biology was used to investigate the treatment effects of HLJDD and its four variants on cecal ligation and puncture (CLP) model of sepsis, which were compared to decipher the formulating principles of HLJDD. Our results showed that HLJDD exhibit the strongest therapeutic effects in the CLP models as compared with the four variants, which could be ascribed to its most significant enhancement of cholinergic anti-inflammatory pathway and inhibition of HMGB-1/TLR4/NF-κB signaling pathway. Most of all, metabolites changed specifically between groups of HLJDD and its four variants were related with the exceptional treatment effects of HLJDD.

The Effects of Remifentanil on Expression of High Mobility Group Box 1 in Septic Rats.

High mobility group box 1 (HMGB1) is a pivotal mediator of sepsis progression. Remifentanil, an opioid agonist, has demonstrated anti-inflammatory effects in septic mice. However, it is not yet known whether remifentanil affects the expression of HMGB1. We investigated the effects of remifentanil on HMGB1 expression and the underlying mechanism in septic rats. Forty-eight male Sprague-Dawley rats were randomly divided into 3 groups; a sham group, a cecal ligation and puncture (CLP) group, and a CLP with remifentanil treatment (Remi) group. The rat model of CLP was used to examine plasma concentrations of proinflammatory cytokines, tissue HMGB1 mRNA and the activity of nuclear factor (NF)-κB in the liver, lungs, kidneys, and ileum. Pathologic changes and immunohistochemical staining of NF-κB in the liver, lungs, and kidneys tissue were observed. We found that remifentanil treatment suppressed the level of serum interleukin (IL)-6 and tumor necrosis factor (TNF)-α 6 hours after CLP, and serum HMGB1 24 hours after CLP. HMGB1 mRNA levels and the activity of NF-κB in multiple organs decreased by remifentanil treatment 24 hours after CLP. Remifentanil treatment also attenuated nuclear expression of NF-κB in immunohistochemical staining and mitigated pathologic changes in multiple organs. Altogether, these results suggested that remifentanil inhibited expression of HMGB1 in vital organs and release of HMGB1 into plasma. The mechanism was related to the inhibitory effect of remifentanil on the release of proinflammatory cytokines and activation of NF-κB.

Baicalin Inhibits Renal Cell Apoptosis and Protects Against Acute Kidney Injury in Pediatric Sepsis.

BackgroundPediatric sepsis has high morbidity in children, may lead to acute kidney injury (AKI), and further aggravate the disease. Baicalin is a kind of flavonoid in Scutellaria baicalensis Georgi and has been reported to protect against several diseases, but its roles in septic AKI remain unclear. This study aimed to uncover the effects of baicalin in AKI during pediatric sepsis.Material/MethodsBlood urea nitrogen (BUN) and serum creatinine (Cr) levels were detected in 50 pediatric patients, who underwent basic therapy with or without baicalin adjunctive therapy. Mouse sepsis models were constructed by cecal ligation and puncture (CLP) and treated with baicalin intragastrically, after which BUN and Cr examination, TUNEL apoptosis assay, and expression analyses of BAX and BCL2 were performed.ResultsBaicalin adjunctive therapy significantly decreased BUN and Cr levels in pediatric sepsis patients (P<0.05). CLP led to elevated BUN and Cr levels in the mouse model (P<0.01), indicating kidney injury accompanied by sepsis. Baicalin decreased BUN and Cr levels (P<0.05), and reduced the apoptotic cell percent in the renal tissue (P<0.05) of the CLP model. It inhibited BAX and promoted BCL2 in the renal tissue, which was consistent with cell apoptosis changes.ConclusionsBaicalin is capable of suppressing renal cell apoptosis and protecting against AKI in pediatric sepsis. This study provides a potential adjunctive therapy for treating AKI in pediatric sepsis, and further research is necessary to reveal its deeper mechanisms.

Sepsis modeling in mice: ligation length is a major severity factor in cecal ligation and puncture

BackgroundThe cecal ligation and puncture (CLP) model, a gold standard in sepsis research, is associated with an important variability in mortality. While the number of punctures and needle size is well described in CLP animal studies, the length of cecal ligation is often not. The relationship between cecal ligation and survival in mice is briefly reported in the literature; therefore, we devised an investigation in mice of the consequences of three standardized cecal ligation lengths on mortality and the severity of the ensued sepsis.MethodsMale C57BL/6J mice underwent standardized CLP. The cecum was ligated at 5, 20, or 100 % of its total length and further perforated by a single 20-G puncture. Mortality was analyzed. We assessed blood lactate, serum creatinine levels, and serum cytokines (TNF-α, IL-1β, IL-6, and IL-10) after procedure in a control group and in ligated mice.ResultsMortality was directly related to ligation length: median survival was 24 h for the “100 %” group and 44 h for the “20 %” group. Blood lactate increased proportionally with the ligation length. At 6 h post-procedure, pro-inflammatory cytokines significantly increased in the ligated group with significantly higher serum levels of IL-6 in the 100 % group compared to the other ligated groups. The 20 % group exhibited the characteristics of septic shock with hypotension below 65 mmHg, pro-inflammatory balance, organ dysfunction, and hyperlactatemia.ConclusionsCecal ligation length appears to be a major limiting factor in the mouse CLP model. Thus, this experimental model should be performed with high consistency in future protocol designs.

Xuebijing injection alleviates cytokine-induced inflammatory liver injury in CLP-induced septic rats through induction of suppressor of cytokine signaling 1.

Dysregulation of inflammatory cytokines and liver injury are associated with the pathogenesis of sepsis. Xuebijing injection, a Chinese herbal medicine, has been used in the treatment of sepsis and can contribute to the improvement of patients' health. However, the underlying molecular mechanisms are not yet clearly illuminated. In the present study, a septic rat model with liver injury was established by the cecal ligation and puncture (CLP) method. Histological alterations to the liver, activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), levels of inflammatory cytokine secretion and the expression of suppressors of cytokine signaling 1 (SOCS-1) in the CLP model rats with and without Xuebijing treatment were determined. The results showed that Xuebijing injection ameliorated the pathological changes in liver tissues caused by sepsis, and reduced the sepsis-induced elevation in serum ALT and AST levels. Furthermore, Xuebijing injection markedly downregulated the expression of tumor necrosis factor α and interleukin (IL)-6, and upregulated the expression of IL-10. More importantly, SOCS1 expression levels at the protein and mRNA levels were further increased by Xuebijing. These findings demonstrate that Xuebijing injection can significantly alleviate liver injury in CLP-induced septic rats via the regulation of inflammatory cytokine secretion and the promotion of SOCS1 expression. The protective effects of Xuebijing injection suggest its therapeutic potential in the treatment of CLP-induced liver injury.

Defining the optimal animal model for translational research using gene set enrichment analysis.

The mouse is the main model organism used to study the functions of human genes because most biological processes in the mouse are highly conserved in humans. Recent reports that compared identical transcriptomic datasets of human inflammatory diseases with datasets from mouse models using traditional gene‐to‐gene comparison techniques resulted in contradictory conclusions regarding the relevance of animal models for translational research. To reduce susceptibility to biased interpretation, all genes of interest for the biological question under investigation should be considered. Thus, standardized approaches for systematic data analysis are needed. We analyzed the same datasets using gene set enrichment analysis focusing on pathways assigned to inflammatory processes in either humans or mice. The analyses revealed a moderate overlap between all human and mouse datasets, with average positive and negative predictive values of 48 and 57% significant correlations. Subgroups of the septic mouse models (i.e., Staphylococcus aureus injection) correlated very well with most human studies. These findings support the applicability of targeted strategies to identify the optimal animal model and protocol to improve the success of translational research.

Protective effect of recombinant Trichinella 53-kDa protein in sepsis and the effect on macrophages.

The survival rate of the recombinant Trichinella 53-kDa protein infected by the cecal ligation and puncture (CLP) model of sepsis in rats and the expression difference of macrophages were analyzed. Eighteen clean SD rats were selected for the present study. The rats were divided into the sham operation (n=5), control (n=5) and experimental (n=8) groups. The rats in the sham operation group underwent cecum division and suture with routine therapy for cure. The rats in the control and experimental groups were placed in the CLP model of sepsis in rats. The experimental group was administered recombinant Trichinella 53-kDa protein in advance, and the control group was administered the same dose of placebo. The survival rate of the rats within 6 and 12 h, the macrophage expression ratio, and the differences of the expression levels Th1-type cytokines IFN-γ and tumor necrosis factor (TNF)-α, and the Th2 type cytokines interleukin-4 (IL-4) and IL-13 were analyzed. The survival rate of rats in the experimental group was higher than that of the control group with a statistically significant difference (P<0.05). The expression ratio of the macrophages received from the different handling methods of the rats in the experimental group was higher than that of the control group. The difference was statistically significant (P<0.05). The expression levels of the Th1-type cytokines IFN-γ and TNF-α of the rats in the experimental group was higher than that of the control group, while the expression level of the Th2-type cytokines IL-4 and IL-13 was higher than that of the control group. The difference was statistically significant (P<0.05). In conclusion, recombinant Trichinella 53-kDa protein can increase the survival rate following infection with CLP sepsis, which may be associated with the improvement of the macrophages and the adjustment of the expression of Th2 cytokines.

Oxymatrine protects against sepsis-induced myocardial injury via inhibition of the TNF-α/p38-MAPK/caspase-3 signaling pathway.

Oxymatrine (OMT), which is a quinolizidine alkaloid extracted from the traditional Chinese herb Sophoraflavescens Aiton, is often used to treat various inflammatory diseases. The present study aimed to investigate the protective effects of OMT against septic shock‑induced myocardial injury in rats, and to determine the underlying mechanisms. In the present study, cecal ligation and puncture (CLP) was applied to generate a rat model of sepsis. The rats were randomly divided into six groups (n=8/group): Sham operation (CON) group, OMT control group, CLP model group, and CLP+OMT (high dose, 52mg/kg; medium dose, 26mg/kg; low dose, 13mg/kg) groups. Cardiac function and histological alterations were analyzed by light microscopy and electron microscopy. Myocardial cell apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling assay. The mRNA and protein expression levels were examined by reverse transcription-polymerase chain reaction and western blotting, respectively. Furthermore, the levels of tumor necrosis factor (TNF)‑α in the myocardial tissue were determined by radioimmunoassay. The results demonstrated that OMT exhibited anti‑inflammatory properties, improved myocardial contractility and compliance, and significantly decreased pathological injury to rat myocardial ultrastructure. In addition, OMT significantly decreased heart rate and left ventricular end diastolic pressure, and increased mean arterial pressure, left intraventricular pressure change rate, and left ventricular end systolic pressure in rats following septic shock. Treatment with OMT attenuated the mRNA expression of lipopolysaccharide binding protein, cluster of differentiation14, nuclear factor (NF)‑κB (p65), TNF‑α, p38‑mitogen‑activated protein kinase (MAPK) and caspase‑3, and decreased the protein expression of NF‑κB (p65), phosphorylated (p)NF‑κB inhibitor‑α, p‑p38‑MAPK caspase‑3 and TNF‑α in septic myocardial tissue. The present study concluded that OMT may offer substantial therapeutic potential for the treatment of septic shock‑induced myocardial injury by inhibiting the TNF-α/p38-MAPK/caspase-3 signaling pathway.