Penehyclidine hydrochloride regulates angiopoietin 2/vascular endothelial cadherin (Ang2/VE-cadherin) pathway to alleviate LPS induced lung injury in rats / 细胞与分子免疫学杂志

Objective To explore the effect and mechanism of penehyclidine hydrochloride (PHCD) on vascular endothelial injury in septic rats. Methods Fifty male SD rats were randomly divided into control group, lipopolysaccharide (LPS) induced sepsis group (model group), low dose PHCD (0.3 mg/kg) group, medium dose PHCD (1.0 mg/kg) group and high dose PHCD (3.0 mg/kg) groups, ten mice for each group. Normal saline was injected into the tail vein of the control group, and 10 mg/kg lipopolysaccharide (LPS) was injected into the tail vein of the rats in other groups to prepare the sepsis rat models. After the models were successfully established, low, medium and high doses (0.3, 1.0, 3.0 mg/kg) of PHCD solution were injected into the tail vein of the rats of corresponding groups. Wet/dry mass ratio (W/D) of lung tissue of rats in each group was measured, and ELISA was used to assay interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), IL-6 content and rat plasma angiopoietin 2 (Ang2) content in bronchoalveolar lavage fluid (BALF). HE staining was used to observe the pathological changes of lung tissues. Immunohistochemical staining was used to observe the expression of Ang2 in the right lung tissues. Western blot analysis was performed to detect Ang2 and vascular endothelial cadherin (VE-cadherin) protein in lung tissues. Results Compared with the control group, the W/D ratio of the lung tissues of rats in the model group and the contents of IL-1β, IL-6 and TNF-α in BALF were significantly increased; the lung tissues showed obvious pathological damage, with up-regulation of Ang2 expression and down-regulation of VE-Cadherin expression. Compared with the model group, the W/D ratio of the lung tissues of rats in three PHCD treatment groups and the contents of IL-1β, IL-6 and TNF-α in BALF were significantly reduced; the pathological damage of lung tissue was significantly reduced, with down-regulation of Ang2 expression and up-regulation of VE-cadherin expression. Conclusion PHCD can reduce LPS-induced lung inflammation in rats with sepsis by regulating the Ang2/VE-Cadherin pathway, thereby improving vascular endothelial injury.

Enhanced endoplasmic reticulum RyR1 receptor phosphorylation leads to diaphragmatic dysfunction in septic rats / 南方医科大学学报

OBJECTIVE@#To explore the role of endoplasmic reticulum ryanodine receptor 1 (RyR1) expression and phosphorylation in sepsis- induced diaphragm dysfunction.@*METHODS@#Thirty SPF male SD rats were randomized equally into 5 groups, including a sham-operated group, 3 sepsis model groups observed at 6, 12, or 24 h following cecal ligation and perforation (CLP; CLP-6h, CLP-12h, and CLP-24h groups, respectively), and a CLP-24h group with a single intraperitoneal injection of KN- 93 immediately after the operation (CLP-24h+KN-93 group). At the indicated time points, diaphragm samples were collected for measurement of compound muscle action potential (CMAP), fatigue index of the isolated diaphragm and fitted frequencycontraction curves. The protein expression levels of CaMK Ⅱ, RyR1 and P-RyR1 in the diaphragm were detected using Western blotting.@*RESULTS@#In the rat models of sepsis, the amplitude of diaphragm CMAP decreased and its duration increased with time following CLP, and the changes were the most obvious at 24 h and significantly attenuated by KN-93 treatment (P < 0.05). The diaphragm fatigue index increased progressively following CLP (P < 0.05) irrespective of KN- 93 treatment (P>0.05). The frequency-contraction curve of the diaphragm muscle decreased progressively following CLP, and was significantly lower in CLP-24 h group than in CLP-24 h+KN-93 group (P < 0.05). Compared with that in the sham-operated group, RyR1 expression level in the diaphragm was significantly lowered at 24 h (P < 0.05) but not at 6 or 12 following CLP, irrespective of KN-93 treatment; The expression level of P-RyR1 increased gradually with time after CLP, and was significantly lowered by KN-93 treatment at 24 h following CLP (P < 0.05). The expression level of CaMKⅡ increased significantly at 24 h following CLP, and was obviously lowered by KN-93 treatment (P < 0.05).@*CONCLUSION@#Sepsis causes diaphragmatic dysfunction by enhancing CaMK Ⅱ expression and RyR1 receptor phosphorylation in the endoplasmic reticulum of the diaphragm.

Inertial label-free sorting and chemotaxis of polymorphonuclear neutrophil in sepsis patients based on microfluidic technology / 生物医学工程学杂志

Reduced chemotactic migration of polymorphonuclear neutrophil (PMN) in sepsis patients leads to decreased bacterial clearance and accelerates the progression of sepsis disease. Quantification of PMN chemotaxis in sepsis patients can help characterize the immune health of sepsis patients. Microfluidic microarrays have been widely used for cell chemotaxis analysis because of the advantages of low reagent consumption, near-physiological environment, and visualization of the migration process. Currently, the study of PMN chemotaxis using microfluidic chips is mainly limited by the cumbersome cell separation operation and low throughput of microfluidic chips. In this paper, we first designed an inertial cell sorting chip to achieve label-free separation of the two major cell types by using the basic principle that leukocytes (mainly granulocytes, lymphocytes and monocytes) and erythrocytes move to different positions of the spiral microchannel when they move in the spiral microchannel under different strength of inertial force and Dean's resistance. Subsequently, in this paper, we designed a multi-channel cell migration chip and constructed a microfluidic PMN inertial label-free sorting and chemotaxis analysis platform. The inertial cell sorting chip separates leukocyte populations and then injects them into the multi-channel cell migration chip, which can complete the chemotaxis test of PMN to chemotactic peptide (fMLP) within 15 min. The remaining cells, such as monocytes with slow motility and lymphocytes that require pre-activation with proliferative culture, do not undergo significant chemotactic migration. The test results of sepsis patients ( n=6) and healthy volunteers ( n=3) recruited in this study showed that the chemotaxis index (CI) and migration velocity ( v) of PMN from sepsis patients were significantly weaker than those from healthy volunteers. In conclusion, the microfluidic PMN inertial label-free sorting and chemotaxis analysis platform constructed in this paper can be used as a new tool for cell label-free sorting and migration studies.

Research progress on the role of histone modification in sepsis / 中华危重病急救医学

Sepsis is a life-threatening organ dysfunction caused by dysregulated body response to infection. It is also one of the major causes of death in critically ill patients. Over the past few years, despite the continuous improvement in the treatment of sepsis, there is no specific treatment, clinical morbidity and mortality are still rising. Therefore, finding effective methods to treat sepsis and reduce mortality is an urgent clinical problem. Histone modification is an epigenetic modification that produces heritable phenotypic changes without altering the DNA sequence. In recent years, many studies have shown that histone modification is closely related to sepsis. This review discusses the mechanism of histone modification in the pathogenesis of sepsis from the aspects of inflammatory factors, signaling pathways, and macrophage polarization, in aimed to provide reference for the clinical treatment of sepsis.

Role of Nrf2/GPX4 mediated ferroptosis in intestinal injury in sepsis / 中华危重病急救医学

OBJECTIVE@#To investigate whether ferroptosis exists in sepsis induced intestinal injury, and to verify the association between ferroptosis in sepsis induced intestinal injury and intestinal inflammation and barrier function by stimulating and inhibiting the nuclear factor E2-related factor 2/glutathione peroxidase 4 (Nrf2/GPX4) pathway.@*METHODS@#Forty-eight SPF grade male Sprague-Darvley (SD) rats with a body weight of 220-250 g were divided into sham operation group (Sham group), sepsis group (CLP group), sepsis+iron chelating agent deferoxamine (DFO) group (CLP+DFO group) and sepsis+ferroptosis inducer Erastin group (CLP+Erastin group) using a random number table method, with 12 rats in each group. The sepsis model was established by cecal ligation and puncture (CLP). The Sham group was only performed with abdominal opening and closing operations. After modeling, the CLP+DFO group received subcutaneous injection of 20 mg/kg of DFO, the CLP+Erastin group was intraperitoneally injected with 20 mg/kg of Erastin. Each group received subcutaneous injection of 50 mg/kg physiological saline for fluid resuscitation after surgery, and the survival status of the rats was observed 24 hours after surgery. At 24 hours after model establishment, 6 rats in each group were selected. First, live small intestine tissue was taken for observation of mitochondrial morphology in smooth muscle cells under transmission electron microscopy and determination of reactive oxygen species (ROS). Then, blood was collected from the abdominal aorta and euthanized. The remaining 6 rats were sacrificed after completing blood collection from the abdominal aorta, and then small intestine tissue was taken. Western blotting was used to detect the expression of intestinal injury markers such as Claudin-1 and ferroptosis related proteins GPX4 and Nrf2. Observe the pathological changes of small intestine tissue using hematoxylin-eosin (HE) staining and complete Chiu score; Detection of tumor necrosis factor-α (TNF-α), interleukins (IL-1β, IL-6) levels in serum using enzyme-linked immunosorbent assay (ELISA). The levels of serum iron ions (Fe3+), malondialdehyde (MDA), and D-lactate dehydrogenase (D-LDH) were measured.@*RESULTS@#(1) Compared with the Sham group, the 24-hour survival rate of rats in the CLP group and CLP+Erastin group significantly decreased (66.7%, 50.0% vs. 100%, both P < 0.05), while there was no significant difference in the CLP+DFO group (83.3% vs. 100%, P = 0.25). (2) Western blotting results showed that compared with the Sham group, the expressions of GPX4 and Claudin-1 in the small intestine tissue of the CLP group, CLP+DFO group, and CLP+Erastin group decreased significantly, while the expression of Nrf2 increased significantly (GPX4/β-actin: 0.56±0.02, 1.03±0.01, 0.32±0.01 vs. 1.57±0.01, Claudin-1/β-actin: 0.60±0.04, 0.96±0.07, 0.41±0.01 vs. 1.40±0.01, Nrf2/β-actin: 0.88±0.02, 0.72±0.01, 1.14±0.01 vs. 0.43±0.02, all P < 0.05). Compared with the CLP group, the expressions of GPX4 and Claudin-1 were significantly increased in the CLP+DFO group, while the expression of Nrf2 was significantly reduced. In the CLP+Erastin group, the expressions of GPX4 and Claudin-1 further decreased, while the expression of Nrf2 further increased (all P < 0.05). (3) Under the light microscope, compared with the Sham group, the CLP group, CLP+DFO group, and CLP+Erastin group showed structural disorder in the small intestinal mucosa and submucosal tissue, significant infiltration of inflammatory cells, and destruction of glandular and villous structures. The Chui score was significantly higher (3.25±0.46, 2.00±0.82, 4.50±0.55 vs. 1.25±0.45, all P < 0.05). (4) Under transmission electron microscopy, compared with the Sham group, the mitochondria in the other three groups of small intestinal smooth muscle cells showed varying degrees of volume reduction, increased membrane density, and reduced or disappeared cristae. The CLP+Erastin group showed the most significant changes, while the CLP+DFO group showed only slight changes in mitochondrial morphology. (5) Compared to the Sham group, the CLP group, CLP+DFO group, and CLP+Erastin group had serum levels of TNF-α, IL-1β, IL-6, MDA, D-LDH, and ROS in small intestine tissue were significantly increased, while the serum Fe3+ content was significantly reduced [TNF-α (ng/L): 21.49±1.41, 17.24±1.00, 28.66±2.72 vs. 14.17±1.24; IL-1β (ng/L): 108.40±3.09, 43.19±8.75, 145.70±11.00 vs. 24.50±5.55; IL-6 (ng/L): 112.50±9.76, 45.90±6.52, 151.80±9.38 vs. 12.89±6.11; MDA (μmol/L): 5.61±0.49, 3.89±0.28, 8.56±1.17 vs. 1.86±0.41; D-LDH (kU/L): 39.39±3.22, 25.38±2.34, 53.29±10.53 vs. 10.79±0.52; ROS (fluorescence intensity): 90 712±6 436, 73 278±4 775, 110 913±9 287 vs. 54 318±2 226; Fe3+ (μmol/L): 22.19±1.34, 34.05±1.94, 12.99±1.08 vs. 51.74±11.07; all P < 0.05]. Compared with CLP group, the levels of TNF-α, IL-1β, IL-6, MDA, D-LDH and ROS in CLP+Erastin group were further increased, and the content of Fe3+ was further decreased, the CLP+DFO group was the opposite (all P < 0.05).@*CONCLUSIONS@#Ferroptosis exists in the intestinal injury of septic rats, and stimulating or inhibiting ferroptosis through the Nrf2/GPX4 pathway can effectively intervene in the inflammatory state and intestinal mechanical barrier of the body.

Prognosis analysis of multi-indicator combined with sequential organ failure assessment in patients with sepsis / 中华危重病急救医学

OBJECTIVE@#To explore the prognostic value of early multiple detection indicators in combination with sequential organ failure assessment (SOFA) in sepsis patients.@*METHODS@#A retrospective analysis was conducted. Patients with sepsis admitted to the department of critical care medicine of Huanggang Central Hospital of Yangtze University from May 2020 to May 2022 were selected as the research subjects. Coagulation indicators, inflammatory factors, blood routine, liver and kidney function, and blood gas analysis were collected at admission. Organ dysfunction was assessed based on the SOFA score within 24 hours after admission. Patients were divided into a survival group and a death group according to the outcome of 28 days in ICU. Differences in the above indicators between the two groups were compared. Multifactorial Logistic regression analysis was used to analyze prognostic factors of 28-day mortality in sepsis patients. Receiver operator characteristic curve (ROC curve) was drawn to analyze the predictive performance of various indicators, the SOFA score, and the combine model for the 28-day outcome in patients with sepsis.@*RESULTS@#A total of 101 patients with sepsis were enrolled, 56 patients survived and 45 patients died. Compared to the survival group, patients in the death group were older, the proportion of patients with septic shock was larger, the SOFA score, and the proportion of pulmonary infection were higher, the prothrombin time (PT) and activated partial thromboplastin time (APTT) were significantly prolonged, the prothrombin activity (PTA) was significantly shortened, and antithrombin (AT) was significantly decreased, the levels of hypersensitivity C-reactive protein (hs-CRP), blood urea nitrogen (BUN), total bilirubin (TBil), and lactic acid (Lac) were significantly increased, while the platelet count (PLT) was significantly decreased. Multifactorial Logistic regression analysis showed that pulmonary infection [odds ratio (OR) = 0.010, 95% confidence interval (95%CI) was 0.001-0.164, P = 0.001], AT (OR = 0.944, 95%CI was 0.910-0.978, P = 0.002), hs-CRP (OR = 1.008, 95%CI was 1.001-1.015, P = 0.017), Lac (OR = 1.619, 95%CI was 1.195-2.193, P = 0.002), and SOFA score (OR = 1.363, 95%CI was 1.076-1.727, P = 0.010) were independent prognostic factors for 28-day mortality in patients. A combined model was constructed using pulmonary infection, AT, hs-CRP, Lac, and SOFA score. ROC curve analysis showed that the area under the ROC curve (AUC) for the combine model in predicting sepsis prognosis was 0.936 (95%CI was 0.869-0.975, P < 0.001), which was higher in value compared to single indicators (AUC of AT, hs-CRP, Lac, and SOFA score were 0.775, 0.666, 0.802, 0.796, respectively, all P < 0.05).@*CONCLUSIONS@#The predictive ability of the SOFA score for sepsis patient outcomes is limited. The combine model combining infection site, AT, hs-CRP, and Lac shows better predictive ability.

Effect of circulating exosomes in patients with sepsis on T cell function / 中华危重病急救医学

OBJECTIVE@#To investigate the effect of circulating exosomes (EXO) on T cell function in patients with sepsis.@*METHODS@#Plasma EXO were obtained by ultracentrifugation from 10 patients with sepsis admitted to the emergency intensive care unit of Guangdong Provincial People's Hospital Affiliated to Southern Medical University. Transmission electron microscopy observation, nanoparticle tracking analysis (NTA), and Western blotting were used to detect EXO markers to identify their characteristics. Furthermore, peripheral blood mononuclear cells (PBMC) were isolated from the peripheral blood of 5 healthy volunteers, primary T cells were sorted by magnetic beads and expanded in vitro. After 24 hours of intervention with different doses (0, 1, 2.5, 5, 10 mg/L) of circulating EXO in patients with sepsis, T-cell activity was assessed using a cell counting kit-8 (CCK-8). The expression of T cell activation indicators CD69 and CD25 were observed using flow cytometry. Additional evaluations were performed on immunosuppressive indicators including the expression of programmed cell death 1 (PD-1) in CD4+ T cells and the proportion of regulatory T cell (Treg).@*RESULTS@#The identification results confirmed that the successful isolation of EXO from the plasma of sepsis patients. The expression level of circulating EXO in sepsis patients was higher than that in healthy control group (mg/L: 48.78±5.14 vs. 22.18±2.25, P < 0.01). After 24 hours of intervention with 5 mg/L of plasma EXO from sepsis patients, T cells activity began to show suppression [(85.84±0.56)% vs. (100.00±0.00)%, P < 0.05]. As the dosage increased, after 24 hours of intervention with 10 mg/L of EXO, T cells activity was significantly suppressed [(72.44±2.36)% vs. (100.00±0.00)%, P < 0.01]. Compared with the healthy control group, after T cells intervention with plasma EXO from sepsis patients, the expression of early activation marker CD69 was significantly reduced [(52.87±1.29)% vs. (67.13±3.56)%, P < 0.05]. Meanwhile, there was an upregulation of PD-1 expression in T cells [(57.73±3.06)% vs. (32.07±0.22)%, P < 0.01] and an increase in the proportion of Treg [(54.67±1.19)% vs. (24.60±3.51)%, P < 0.01]. However, the expression of the late activation marker CD25 remained stable [(84.77±3.44)% vs. (85.93±2.32)%, P > 0.05].@*CONCLUSIONS@#Circulating EXO in sepsis patients induce T cell dysfunction, which may be a novel mechanism lead to immunosuppression in sepsis.

Role and mechanism of SIRT1 in regulating Nrf2/HO-1 signaling pathway in septic liver injury / 中华危重病急救医学

OBJECTIVE@#To investigate the role and mechanism of silent information regulator 1 (SIRT1) in regulating nuclear factor E2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway in oxidative stress and inflammatory response to sepsis-induced liver injury.@*METHODS@#A total of 24 male Sprague-Dawley (SD) rats were randomly divided into sham operation (Sham) group, cecal ligation and puncture (CLP) group, SIRT1 agonist SRT1720 pretreatment (CLP+SRT1720) group and SIRT1 inhibitor EX527 pretreatment (CLP+EX527) group, with 6 rats in each group. Two hours before operation, SRT1720 (10 mg/kg) or EX527 (10 mg/kg) were intraperitoneally injected into the CLP+SRT1720 group and CLP+EX527 group, respectively. Blood was collected from the abdominal aorta at 24 hours after modeling and the rats were sacrificed for liver tissue. The serum levels of interleukins (IL-6, IL-1β) and tumor necrosis factor-α (TNF-α) were detected by enzyme-linked immunosorbent assay (ELISA). The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were detected by microplate method. Hematoxylin-eosin (HE) staining was used to observe the pathological injury of rats in each group. The levels of malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), glutathione (GSH) and superoxide dismutase (SOD) in liver tissue were detected by corresponding kits. The mRNA and protein expressions of SIRT1, Nrf2 and HO-1 in liver tissues were detected by real-time quantitative polymerase chain reaction (RT-qPCR) and Western blotting.@*RESULTS@#Compared with the Sham group, the serum levels of IL-6, IL-1β, TNF-α, ALT and AST in the CLP group were significantly increased; histopathological results showed that liver cords were disordered, hepatocytes were swollen and necrotic, and a large number of inflammatory cells infiltrated; the contents of MDA and 8-OHdG in liver tissue increased, while the contents of GSH and SOD decreased; and the mRNA and protein expressions of SIRT1, Nrf2 and HO-1 in liver tissues were significantly decreased. These results suggest that sepsis rats have liver dysfunction, and the levels of SIRT1, Nrf2, HO-1 and antioxidant protein in liver tissues were decreased, while the levels of oxidative stress and inflammation were increased. Compared with the CLP group, the levels of inflammatory factors and oxidative stress were significantly decreased in the CLP+SRT1720 group, the mRNA and protein expressions of SIRT1, Nrf2 and HO-1 were significantly increased [IL-6 (ng/L): 34.59±4.21 vs. 61.84±3.78, IL-1β (ng/L): 41.37±2.70 vs. 72.06±3.14, TNF-α (ng/L): 76.43±5.23 vs. 130.85±5.30, ALT (U/L): 30.71±3.63 vs. 64.23±4.59, AST (U/L): 94.57±6.08 vs. 145.15±6.86, MDA (μmol/g): 6.11±0.28 vs. 9.23±0.29, 8-OHdG (ng/L): 117.43±10.38 vs. 242.37±11.71, GSH (μmol/g): 11.93±0.88 vs. 7.66±0.47, SOD (kU/g): 121.58±5.05 vs. 83.57±4.84, SIRT1 mRNA (2-ΔΔCt): 1.20±0.13 vs. 0.46±0.02, Nrf2 mRNA (2-ΔΔCt): 1.21±0.12 vs. 0.58±0.03, HO-1 mRNA (2-ΔΔCt): 1.71±0.06 vs. 0.48±0.07, SIRT1 protein (SIRT1/β-actin): 0.89±0.04 vs. 0.58±0.03, Nrf2 protein (Nrf2/β-actin): 0.87±0.08 vs. 0.51±0.09, HO-1 protein (HO-1/β-actin): 0.93±0.14 vs. 0.54±0.12, all P < 0.05], these results indicated that SIRT1 agonist SRT1720 pretreatment could improve liver injury in sepsis rats. However, pretreatment with SIRT1 inhibitor EX527 showed the opposite effect [IL-6 (ng/L): 81.05±6.47 vs. 61.84±3.78, IL-1β (ng/L): 93.89±5.83 vs. 72.06±3.14, TNF-α (ng/L): 177.67±5.12 vs. 130.85±5.30, ALT (U/L): 89.33±9.52 vs. 64.23±4.59, AST (U/L): 179.59±6.44 vs. 145.15±6.86, MDA (μmol/g): 11.39±0.51 vs. 9.23±0.29, 8-OHdG (ng/L): 328.83±11.26 vs. 242.37±11.71, GSH (μmol/g): 5.07±0.34 vs. 7.66±0.47, SOD (kU/g): 59.37±4.28 vs. 83.57±4.84, SIRT1 mRNA (2-ΔΔCt): 0.34±0.03 vs. 0.46±0.02, Nrf2 mRNA (2-ΔΔCt): 0.46±0.04 vs. 0.58±0.03, HO-1 mRNA (2-ΔΔCt): 0.21±0.03 vs. 0.48±0.07, SIRT1 protein (SIRT1/β-actin): 0.47±0.04 vs. 0.58±0.03, Nrf2 protein (Nrf2/β-actin): 0.32±0.07 vs. 0.51±0.09, HO-1 protein (HO-1/β-actin): 0.19±0.09 vs. 0.54±0.12, all P < 0.05].@*CONCLUSIONS@#SIRT1 can inhibit the release of proinflammatory factors and alleviate the oxidative damage of hepatocytes by activating Nrf2/HO-1 signaling pathway, thus playing a protective role against CLP-induced liver injury.

Positive effects of Xuebijing injection on intestinal microbiota and metabolite spectrum in septic rats / 中华危重病急救医学

OBJECTIVE@#To explore the effect of Xuebijing injection on inflammation in sepsis by regulating intestinal microbiota and its metabolites.@*METHODS@#A total of 45 male Sprague-Dawley (SD) rats were randomly divided into Sham operation group (Sham group), cecal ligation and perforation (CLP) induced sepsis group (CLP group), and Xuebijing intervention group (XBJ group, 4 mL/kg Xuebijing injection was injected intraperitoneally at 1 hour after CLP), with 15 rats in each group. The survival of rats was observed at 24 hours after operation and sacrificed. Feces were collected for 16S rRNA gene sequencing and liquid chromatography-mass spectrometry (LC-MS) analysis.@*RESULTS@#At 24 hours after operation, all rats in the Sham group survived, the mortality of rats in the XBJ group was lower than that in the CLP group [47% (7/15) vs. 60% (9/15), P > 0.05]. Compared with the Sham group, the diversity of gut microbiota in the CLP group decreased, the dominant flora changed, and the abundance of inflammation-related flora increased. Xuebijing improved the changes in gut microbiota caused by sepsis, and α diversity showed an increasing trend (Ace index: 406.0±22.5 vs. 363.2±38.2, Chao1 index: 409.7±21.8 vs. 362.4±42.5, both P > 0.05). Restrictive constrained principal coordinate analysis (cPCoA) showed a high similarity in gut microbiota among the same group of rats. The CLP group was dominated by Bacteroidetes, while the Sham and XBJ groups were dominated by Firmicutes. In addition, compared with the CLP group, Xuebijing treatment increased the abundance of beneficial bacteria in septic rats, such as Verrucomicrobia, Akkermansia and Lactobacillus. LC-MS and orthogonal partial least squares discriminant analysis (OPLS-DA) showed that there were 12 main differential metabolites among the three groups, and there were certain correlations between these metabolites, which were related to amino acid and lipid metabolism. Correlation analysis showed a significant correlation between changes in metabolites and microbial communities.@*CONCLUSIONS@#Xuebijing can improve the survival rate of septic rats, regulate the composition of intestinal flora and related metabolites, which provides a new pathophysiological mechanism for Xuebijing in the treatment of sepsis.

Inhibiting ferroptosis attenuates myocardial injury in septic mice: the role of lipocalin-2 / 南方医科大学学报

OBJECTIVE@#To explore the contribution of ferroptosis to myocardial injury in mouse models of sepsis and the role lipocalin-2 (Lcn2) in ferroptosis.@*METHODS@#Adult male C57BL/6 mice were randomized equally into sham-operated group, cecal ligation and puncture (CLP)-induced sepsis group, and CLP + Fer-1 group where the mice received intraperitoneal injection of 5 mg/mL Fer-1 (5 mg/kg) 1 h before CLP. The left ventricular functions (including LVEF%, LVFS%, LVIDd and LVIDs) of the mice were assessed by echocardiography at 24 h after CLP. Myocardial injury in the mice was observed with HE staining, and the changes of myocardial ultrastructure and mitochondria were observed using transmission electron microscopy (TEM). Serum TNF-α level was measured with ELISA, and the changes of myocardial iron content were detected using tissue iron kit. The protein expressions of myocardial Lcn2, glutathione peroxidase 4 (GPX4) and ferroptosis suppressor protein 1 (FSP1) were determined with Western blotting.@*RESULTS@#The septic mice showed significantly decreased LVEF%, LVFS% and LVIDd and increased LVIDs at 24 h after CLP (P < 0.05), and these changes were significantly improved by Fer-1 treatment. Sepsis caused obvious myocardial pathologies and changes in myocardial ultrastructure and mitochondria, which were significantly improved by Fer-1 treatment. Fer-1 treatment also significantly ameliorated sepsis-induced elevations of serum TNF-α level, myocardial tissue iron content, and Lcn2 protein expression and the reduction of GPX4 and FSP1 protein expression levels (P < 0.05).@*CONCLUSION@#GPX4- and FSP1-mediated ferroptosis are involved in myocardial injury in mice with CLP-induced sepsis, and inhibition of ferroptosis can attenuate septic myocardial injury, in which Lcn2 may play a role.

MiR-106a aggravates sepsis-induced acute kidney injury by targeting THBS2 in mice model

Abstract Purpose To investigate the role and related mechanisms of miR-106a in sepsis-induced AKI. Methods Serum from sepsis and healthy patients was collected, sepsis mouse model was established by cecal ligation and puncture (CLP). TCMK-1 cells were treated with lipopolysaccharide (LPS) and transfected with THBS2-small interfering RNA (siTHBS2), miR-106a inhibitor, miR-106a mimics and their negative controls (NCs). The expression of miR-106a, thrombospondin 2 (THBS2), Bax, cleaved caspase-3 and Bcl-2, cell viability, relative caspase-3 activity and TNF-α, IL-1β, IL-6 content were respectively detected by quantitative real-time polymerase chain reaction (qRT-PCR), western blotting, Cell Counting Kit-8 (CCK-8) and enzyme linked immunosorbent assay (ELISA). The relationship between miR-106a and THBS2 was confirmed by dual luciferase reporter assay. Results MiR-106a was up-regulated in serum of sepsis patients, CLP-induced mice models and LPS-induced TCMK-1 cells. LPS reduced cell viability and Bcl-2 expression, and increased caspase-3 activity, Bax expression, the content of TNF-α, IL-1β, IL-6. THBS2 was a target of miR-106a. The decreases of caspase-3 activity, TNF-α, IL-1β, IL-6, Bax expression and the increases of cell viability, Bcl-2 expression caused by miR-106a knockdown were reversed when THBS2 silencing in LPS-stimulated TCMK-1 cells. Conclusion MiR-106a aggravated LPS-induced inflammation and apoptosis of TCMK-1 cells via regulating THBS2 expression.

Sepsis: evolving concepts and challenges

Sepsis remains a major cause of morbidity and mortality worldwide, with increased burden in low- and middle-resource settings. The role of the inflammatory response in the pathogenesis of the syndrome has supported the modern concept of sepsis. Nevertheless, a definition of sepsis and the criteria for its recognition is a continuous process, which reflects the growing knowledge of its mechanisms and the success and failure of diagnostic and therapeutic interventions. Here we review the evolving concepts of sepsis, from the "systemic inflammatory response syndrome triggered by infection" (Sepsis-1) to "a severe, potentially fatal, organic dysfunction caused by an inadequate or dysregulated host response to infection" (Sepsis-3). We focused in the pathophysiology behind the concept and the criteria for recognition and diagnosis of sepsis. A major challenge in evaluating the host response in sepsis is to characterize what is protective and what is harmful, and we discuss that, at least in part, the apparent dysregulated host response may be an effort to adapt to a hostile environment. The new criteria for recognition and diagnosis of sepsis were derived from robust databases, restricted, however, to developed countries. Since then, the criteria have been supported in different clinical settings and in different economic and epidemiological contexts, but still raise discussion regarding their use for the identification versus the prognostication of the septic patient. Clinicians should not be restricted to definition criteria when evaluating patients with infection and should wisely use the broad array of information obtained by rigorous clinical observation.

Protein from Hevea brasiliensis "Hev b 13" latex attenuates systemic inflammatory response and lung lesions in rats with sepsis / Proteína do latex de Hevea brasiliensis "Hev b 13" atenua resposta inflamatória sistêmica e lesão pulmonar de ratos com sepse

Abstract Sepsis induces a severe systemic inflammatory response that may result in multiple organ dysfunction and death. Studies using a protein derived from natural Hevea brasiliensis (rubber tree) latex, denominated Hev b 13, have demonstrated important anti-inflammatory effects, but no data have been published regarding its effects on sepsis. The aim of this study was to investigate the effects of Hev b 13 on the inflammatory response and lung lesions of septal rats. Male Wistar rats were submitted to cecal ligation and puncture (CLP), randomized into groups and treated with subcutaneously administered doses of 0.5/2.0/3.0 mg/Kg of Hev b 13. Next, animals were subdivided into three different points in time (1, 6 and 24 hours after treatments) for collection of blood samples and euthanasia accompanied by organ removal. Total and differential leukocyte counts, cytokine dosage and histological assessment were analyzed. Treatment with Hev b 13 resulted in a significant decline in total and differential leukocytes as well as suppression of TNF-α and IL-6 production, associated with the increase in IL-10 and IL-4 in plasma and lung tissue. Moreover, it reduced morphological and pathological changes found in the lungs, including neutrophil infiltration, edema and alveolar thickening. The present study concluded that Hev b 13 exerts anti-inflammatory effects and attenuates lung lesions in septal rats, showing potential for clinical application.

Resumo Sepse induz uma resposta inflamatória sistêmica grave podendo resultar em disfunção de múltiplos órgãos e morte. Pesquisas utilizando uma proteína derivada do látex natural de Hevea brasiliensis (seringueira), denominada Hev b 13 tem demonstrado importantes efeitos anti-inflamatórios, mas nenhum dado foi publicado dos seus efeitos na sepse. O objetivo deste estudo foi investigar os efeitos da Hev b 13 na resposta inflamatória e na lesão pulmonar de ratos com sepse. Ratos machos da linhagem Wistar foram submetidos a ligação e perfuração do ceco (LPC), randomizados em grupos e tratados com as doses 0,5/2,0/3,0 mg/Kg de Hev b 13 subcutâneo. Após subdividiu-se os animais em três pontos diferentes de tempo (1, 6 e 24 horas após os tratamentos) para coleta de amostras sanguíneas e eutanásia com remoção dos órgãos. Contagem total e diferencial de leucócitos, dosagem de citocinas e avaliação histológica foram analisadas. O tratamento com a Hev b 13 resultou em diminuição significativa de leucócitos totais e diferenciais bem como suprimiu a produção de TNF-α e IL-6, associado ao aumento de IL-10 e IL-4 no plasma e tecido pulmonar. Além disso, reduziu as alterações morfológicas e patológicas encontradas nos pulmões, incluindo infiltrado de neutrófilos, edema e espessamento alveolar. Este estudo concluiu que a Hev b 13 tem efeitos anti-inflamatórios e atenua lesões pulmonares em ratos com sepse, apresentando potencialidades para aplicabilidade clínica.

Hiperglicemia por sepsis: del mecanismo a la clínica / Sepsis hyperglycemia in the ICU: from the mechanism to the clinic

Stress hyperglycemia is frequently diagnosed in septic patients in critical care units (ICU) and it is associated with greater illness severity and higher morbimortality rates. In response to an acute injury, high levels of counterregulatory hormones such as glucocorticoids and catecholamines are released causing increased hepatic gluconeogenesis and insulin resistance. Furthermore, during sepsis, proinflammatory cytokines also participate in the pathogenesis of this phenomenon. Septic patients represent a subtype of the critical ill patients in the ICU: this metabolic disarrangement management strategies and insulin therapy recommendations had been inconsistent. In this article, we describe the pathophysiological mechanisms of stress hyperglycemia in critical patients including the action of hormones, inflammatory cytokines and tissue resistance to insulin. In addition, we analyzed the main published studies for the treatment of acute hyperglycemia in critical patients.

Propofol attenuates sepsis-induced acute kidney injury by regulating miR-290-5p/CCL-2 signaling pathway

Previous studies have indicated that propofol has immunomodulatory and antioxidative properties. However, the renoprotection effect and the precise mechanisms of propofol in sepsis-induced renal injury remain unclear. The purpose of the present study was to investigate the role of miR-290-5p/CCL-2 signaling in septic mice treatment with propofol. Mice were treated with propofol (50 mg/kg) twice within 24 h. Survival outcome was monitored within 48 h. The mRNA and protein levels were assayed by qRT-PCR and western blotting, respectively. Mouse podocytes (MPC5) were treated with lipopolysaccharide (LPS) to establish the cell model in vitro. The proliferation of MPC5 was monitored using the MTS assay. Cell apoptosis was analyzed by flow cytometry. Propofol improved survival outcome and alleviated acute kidney injury in cecal ligation and puncture-operated mice. Propofol increased miR-290-5p expression and decreased CCL-2 and inflammatory cytokines levels in the kidney for septic mice. We found that miR-290-5p was a direct regulator of CCL-2 in MPC5. Propofol could abrogate LPS-induced growth inhibition and apoptosis in MPC5. Meanwhile, propofol inhibited CCL-2 expression in LPS-treated MPC5, however, knockdown of miR-290-5p abrogated the inhibitory effect propofol on the mRNA and protein expressions of CCL-2. Propofol could serve as an effective therapeutic medication to suppress sepsis-induced renal injury in vivo and in vitro by regulating the miR-290-5p/CCL-2 signaling pathway.

Evaluation of energy metabolism in septic patients with and without AKI

BACKGROUND: The determination of resting energy expenditure (REE) in critically ill patients could prevent complications such as hypo- and hyper alimentation. This study aims to describe the REE in septic patients with and without acute kidney injury (AKI) and compare the REE estimated by the Harris-Benedict equation (HB) with the REE measured by indirect calorimetry (IC). METHODS: Prospective and observational study was performed. Septic patients older than 18 years, undergoing mechanical ventilation, with or without AKI defined by KDIGO criteria, and admitted to the Intensive Care Unit of University Hospital from Brazil were included. The REE was estimated by HB equation and measured by the IC within72 h after the diagnosis of sepsis and 7 days after the initial measure. RESULTS:Sixty-eight patients were evaluated, age was 62.5 ± 16.6 years, 64.7% were male, 63.2% had AKI, and SOFA was9.8 ± 2.35. The measured REE was 1857.5 ± 685.32 kcal, while the estimated REE was 1514.8 ± 356.72 kcal, with adequacy of 123.5 ± 43%. Septic patients without AKI (n= 25) and with AKI (n= 43) had measured REE statistically higher than the estimated one (1855.0 (1631.75­2052.75) vs. 1551.0 kcal (1349.0­1719.25),p= 0.007 and 1868.0(1219.5­2364.75) vs. 1388.0 kcal (1254.0­1665.5),p= 0.026, respectively). There was no significant difference between the two groups (with and without AKI) in measured and estimated REE (p= 0.63 and 0.64, respectively). There was no significant difference in evolutional REE (1845.95 ± 658.27 kcal vs. 1809.54 ± 755.08 kcal, p=0.86).CONCLUSIONS: The REE measured by IC was significantly higher than that estimated by HB equation in both septic with and without AKI. There was no significant difference in REE between the septic patients with and without AKI, suggesting that AKI does not influence the energy metabolism of septic patients.

Valor prognóstico da disfunção ventricular diastólica em pacientes com sepse grave e choque séptico / Prognostic value of ventricular diastolic dysfunction in patients with severe sepsis and septic shock

RESUMO Objetivo: Avaliar a prevalência de disfunção miocárdica e seu valor prognóstico em pacientes com sepse grave e choque séptico. Métodos: Pacientes sépticos adultos, admitidos em uma unidade de terapia intensiva, foram estudados de forma prospectiva por meio de ecocardiografia transtorácica dentro das primeiras 48 horas após sua admissão e, então, entre o sétimo e o décimo dias. As variáveis ecográficas de função biventricular, inclusive a relação E/e', foram comparadas entre sobreviventes e não sobreviventes. Resultados: Foi realizado um total de 99 ecocardiogramas (53 na admissão e 46 entre os dias 7 e 10) em 53 pacientes com média de idade de 74 anos (desvio padrão de 13 anos). Estava presente disfunção sistólica em 14 (26%); disfunção diastólica foi observada em 42 (83%) pacientes; e ambos os tipos de disfunção estavam presentes em 12 (23%) pacientes. A relação E/e', ou índice de disfunção diastólica, foi o melhor preditor de mortalidade hospitalar segundo a área sob a curva ROC (0,71) e se constituiu em um preditor independente do desfecho, conforme determinado pela análise multivariada (odds ratio - OR = 1,36 [1,05 - 1,76]; p = 0,02). Conclusão: Em pacientes sépticos admitidos em uma unidade de terapia intensiva, a disfunção sistólica determinada ecograficamente não se associa com aumento da mortalidade. Em contraste, a disfunção diastólica foi um preditor independente do desfecho.

ABSTRACT Objectives: To evaluate the prevalence of myocardial dysfunction and its prognostic value in patients with severe sepsis and septic shock. Methods: Adult septic patients admitted to an intensive care unit were prospectively studied using transthoracic echocardiography within the first 48 hours after admission and thereafter on the 7th-10th days. Echocardiographic variables of biventricular function, including the E/e' ratio, were compared between survivors and non-survivors. Results: A total of 99 echocardiograms (53 at admission and 46 between days 7 - 10) were performed on 53 patients with a mean age of 74 (SD 13) years. Systolic and diastolic dysfunction was present in 14 (26%) and 42 (83%) patients, respectively, and both types of dysfunction were present in 12 (23%) patients. The E/e' ratio, an index of diastolic dysfunction, was the best predictor of hospital mortality according to the area under the ROC curve (0.71) and was an independent predictor of outcome, as determined by multivariate analysis (OR = 1.36 [1.05 - 1.76], p = 0.02). Conclusion: In septic patients admitted to an intensive care unit, echocardiographic systolic dysfunction is not associated with increased mortality. In contrast, diastolic dysfunction is an independent predictor of outcome.

Septic encephalopathy: does inflammation drive the brain crazy?

Sepsis and the multiorgan dysfunction syndrome are among the most common reasons for admission to an intensive care unit, and are a leading cause of death. During sepsis, the central nervous system (CNS) is one of the first organs affected, and this is clinically manifested as sepsis-associated encephalopathy (SAE). It is postulated that the common final pathway that leads to SAE symptoms is the deregulation of neurotransmitters, mainly acetylcholine. Thus, it is supposed that inflammation can affect neurotransmitters, which is associated with SAE development. In this review, we will cover the current evidence (or lack thereof) for the mechanisms by which systemic inflammation interferes with the metabolism of major CNS neurotransmitters, trying to explain how systemic inflammation drives the brain crazy.

El corazón endocrino y el proceso inflamatorio / [The endocrine heart and inflammation].

The endocrine heart produces the polypeptide hormones Atrial Natriuretic Factor (ANF or ANP) and Brain Natriuretic Peptide (BNP). Through the peripheral actions of these hormones the heart contributes to the regulation of the cardiac preload and afterload. More recently, new functions for these hormones have been described including the modulation of the immune response. Plasma levels of BNP but not those of ANF, increase following an acute rejection episode of a cardiac allotransplant but return to levels pre-rejection with successful treatment. This observation constitutes the first observation leading to characterizing the interactions of BNP with the immune response. Several other pathologies with an inflammatory component are now known to be associated with an increase in the production of BNP. Such an increase is due to an increase in the transcriptional activity of the BNP gene induced by cytokines and related substances. In vitro investigations have shown that an increase in BNP directly modulates immunological activity. Inflammation and hemodynamic changes co-exist in several cardiovascular diseases and therefore it may be beneficial to measure circulating levels of both ANF and BNP as biomarkers of changes in intravascular volume and of changes in intravascular volume plus inflammation, respectively. Changes in plasma ANF, that are relatively larger than those of BNP, might be an indication of hemodynamic deterioration while important changes in circulating BNP could indicate a worsening of the inflammatory process.