Objective:To study the protective effect and mechanism of paeoniflorin (pae) on myocardial injury in septic rats.Methods:Sprague-Dawley (SD) rats were randomly divided into 4 groups with 10 rats in each group. Rats were intraperitoneally injected with 1.4 ml normal saline and 1.4 ml 5% dimethyl sulfoxide (DMSO)solution independently in control group and DMSO group. Rats were intraperitoneally injected with 1.4 ml normal saline and 1.4 ml pae independently, then with 0.1 ml lipopolysaccharide (LPS) 1 hour later in sepsis group and pae group. Enzyme linked immunosorbent assay (ELISA) was used to detect serum cardiac troponin I (cTnI) levels and myocardial tissue tumor necrosis factor alpha (TNFα), interleukin(IL)-6, IL-1β, chemokine (C-X-C motif) ligand 1 (CXCL1), chemokine (C-X-C motif) ligand 2 (CXCL2), vascular cell adhesion molecule 1 (VCAM-1) levels. Evans blue (EB) method was used to detect the EB content of myocardial tissue. HE staining method was used to observe the pathological changes, real-time quantitative polymerase chain reaction (RT-qPCR) to detect mRNA expression levels of the above molecules, and Western-blot to detect vascular endothelium-cadherin (VE-cadherin), phosphorylated p38 mitogen-activated protein kinase (P-p38MAPK), phosphorylated Src protein (P-Src), Ras-Related C3 Botulinum Toxin Substrate 1 (Rac1) levels.Results:Compared with control group, cTnI level and the EB content in sepsis group increased significantly, and the myocardial inflammatory cell infiltration was obvious. The cTnI level and EB content in pae group were significantly reduced, and myocardial inflammatory cell infiltration was reduced [cTnI: (227.7±15.9)pg/ml vs. (312.9±17.9)pg/ml;EB: (13.2±2.3)μg/g vs. (23.8±2.9)μg/g; P<0.05]. Compared with control group, the levels of TNFα, IL-6, IL-1β, CXCL1, CXCL2, and VCAM-1 in sepsis group were increased. Compared with sepsis group, the above-mentioned molecular levels of pae group were significantly decreased [TNFα: (63.39±9.55)pg/ml vs. (126.54±19.17)pg/ml ;IL-6: (64.03±8.82)pg/ml vs. (85.60±9.52)pg/ml;IL-1β: (69.52±9.23)pg/ml vs. (130.45±15.10)pg/ml;CXCL1: (2 600.19±379.54)pg/ml vs. (4 903.89±533.42)pg/ml;CXCL2: (93.71±10.83)pg/ml vs. (127.24±13.92)pg/ml;VCAM-1: (112.22±13.49)pg/ml vs. (149.32±15.65)pg/ml, both P<0.05]. RT-qPCR results showed that the mRNA expressions of TNFα, IL-6, IL-1β, CXCL1, CXCL2 and VCAM-1 in the sepsis group were increased compared with the control group; Compared with sepsis group, the IL-6 mRNA (1.271±0.139 vs. 1.920±0.191, P<0.05), IL-1βmRNA (1.180±0.130 vs. 1.817±0.191, P<0.05), VCAM-1 mRNA (1.088±0.144 vs. 1.460±0.166, P<0.05) expression decreased significantly in the pae group. Compared with control group, the levels of P-p38MAPK and P-Src in sepsis group increased, and the level of VE-cadherin decreased. Compared with sepsis group, the levels of p38MAPK and P-p38MAPK in pae group were significantly decreased, and the level of VE-cadherin was increased (p38MAPK/β-actin: 1.125±0.078 vs. 1.520±0.164; P-p38MAPK protein: 1.639±0.133 vs. 2.112±0.222; both P<0.05). Conclusion:Paeoniflorin could improve the permeability of cardiac microvascular endothelium in sepsis rats and inhibit the secretion and expression of inflammation-related proteins and genes, which might be related to the inhibition of Src/VE-cadherin pathway by paeoniflorin.

Objective:To investigate the effect of interleukin-33 (IL-33) on lipopolysaccharide (LPS)-induced permeability of rat cardiac microvascular endothelial cells (RCMECs).Methods:RCMECs were cultured in vitro to be divided into control group, LPS group, IL-33 group and LPS+IL-33 group. The effect of IL-33 on the proliferation of RCMECs was detected by cell counting reagent (CCK8). Fluorescein isothiocyanate (FITC)-dextran assay was used to evaluate the permeability of RCMECs. The expression of vascular endothelial calmodulin, ras homologous gene family (Rho) member A (RhoA) and phosphorylated Rho-associated coiled-coil-containing protein kinase (p-ROCK2) proteins were tested by western blot. High-throughput sequencing and gene ontology (GO) were performed for gene expression in LPS and LPS+IL-33 groups.Results:No significant effect of IL-33 at 10-50 ng/ml on the proliferation of RCMECs was observed ( P>0.05). Compared with the control group, the permeability of RCMECs (permeability coefficient ratio 1.404±0.029 vs. 1.000±0.200, P<0.05) was significantly increased in LPS group and the expression of vascular endothelial calmodulin (relative gray value 0.429 5±0.012 9 vs. 0.594 9±0.014 2, P<0.05) was down-regulated, while the permeability of monolayers (permeability coefficient ratio, 0.948±0.013, P<0.01) was decreased in LPS+IL-33 group and the expression of vascular endothelial calmodulin (relative grayscale value 0.549 1±0.012 0, P<0.005) was up-regulated compared with the LPS group. High-throughput sequencing data revealed that the differential genes downregulated in the LPS and LPS+IL-33 groups were associated with cytoskeleton and Rho signaling pathway. Compared with the control group, RhoA (relative gray value 0.211 4±0.009 9 vs. 0.135 0±0.007 6, P<0.000 1) and p-ROCK (relative gray value 0.656 3±0.013 2 vs. 0.503 6±0.036 2, P<0.000 1) protein expression was upregulated in the LPS group. When compared with LPS group, RhoA (relative gray value 0.157 7±0.010 7, P=0.000 2), p-ROCK (relative gray value 0.427 7±0.003 8, P<0.000 1) protein expression was decreased in LPS+IL-33 group. Conclusion:IL-33 may improve LPS-induced hyperpermeability of RCMECs by inhibiting RhoA and p-ROCK protein expression in Rho/Rho-associated coiled-coil-containing protein kinase signaling pathway.

Objective:To investigate the effect and mechanism of paeoniflorin on the permeability of cardiac microvascular endothelial cells (CMECs) in sepsis.Methods:Primary rat CMECs were isolated and cultured in vitro, and the cells in the logarithmic growth phase were used for experiments. Tetramethylazozolium colorimetry (MTT) was used to screen the safe and effective concentrations of paeoniflorin at 10, 20, and 40 μmol/L. The cells were divided into blank control group, lipopolysaccharide (LPS) group and low, medium and high concentration paeoniflorin pretreatment group. The cells in the blank control group were cultured in complete medium; the cells in the LPS group were challenged with LPS (1 mg/L) in complete medium; and the cells in the paeoniflorin pretreatment groups were pretreated with 10, 20, and 40 μmol/L paeoniflorin at 4 hours before LPS stimulation. The cells in each group were further cultured for 24 hours after LPS stimulation. The horseradish peroxidase (HRP) method was used to detect the permeability of rat CMECs. The enzyme-linked immunosorbent assay (ELISA) was used to detect the CXC chemokine ligand (CXCL1, CXCL2) levels in the cell supernatant. The real-time fluorescence quantitative reverse transcription-polymerase chain reaction (RT-qPCR) was used to detect the mRNA expressions of CXCL1 and CXCL2 in the cells. Western Blot was used to detect phosphorylated Src (p-Src), vascular endothelial-cadherin (VE-cadherin) and phosphorylated mitogen activated protein kinase (p-MAPK). Results:Compared with the blank control group, the permeability of rat CMECs in the LPS group was significantly increased. The cell permeability was improved to some extent after paeoniflorin pretreatment at different concentrations, and the improvement was most obvious in the 40 μmol/L paeoniflorin group, with statistically significant difference as compared with the LPS group ( A value: 1.61±0.07 vs. 2.13±0.06, P < 0.01). ELISA results showed that there were moderate amounts of CXCL1 and CXCL2 in the cell supernatant of rat CMECs in the blank control group. However, the secretion of CXCL1 and CXCL2 in the cell supernatant was increased significantly under the induction of LPS. After pretreatment with paeoniflorin at different concentrations, the secretion of CXCL1 and CXCL2 in the cell supernatant was significantly reduced. The most obvious inhibitory effect on CXCL1 was 40 μmol/L paeoniflorin, and the most obvious inhibition on CXCL2 was 20 μmol/L paeoniflorin, the differences were statistically significant as compared with the LPS group [CXCL1 (ng/L): 337.51±68.04 vs. 829.86±65.06, CXCL2 (ng/L): 4.48±0.11 vs. 9.41±0.70, both P < 0.01]. RT-qPCR results showed that the mRNA expressions of CXCL1 and CXCL2 in the rat CMECs were consistent with the ELISA results. LPS could increase mRNA expressions of CXCL1 and CXCL2 in the rat CMECs, and pretreatment with different concentrations of paeoniflorin could significantly reduce the mRNA expressions of CXCL1 and CXCL2. The 40 μmol/L paeoniflorin had the best inhibitory effect on CXCL1 mRNA expression, and the 20 μmol/L paeoniflorin had the best inhibitory effect on CXCL2 mRNA expression, the differences were statistically significant as compared with the LPS group [CXCL1 mRNA (2 -ΔΔCt): 0.543±0.004 vs. 0.812±0.089, CXCL2 mRNA (2 -ΔΔCt): 10.52±0.71 vs. 17.68±1.09, both P < 0.01]. Western Blot results showed that moderate amounts of p-Src, VE-cadherin and p-MAPK proteins were expressed in the rat CMECs in the blank control group. After LPS stimulation, the expressions of p-Src and p-MAPK proteins were increased significantly, while the expression of VE-cadherin protein was decreased significantly. After pretreatment with different concentrations of paeoniflorin, the expressions of p-Src and p-MAPK proteins in the cells were decreased to varying degrees, while the expression of VE-cadherin protein was increased, and 40 μmol/L paeoniflorin had the most obvious effect, the differences were statistically significant as compared with the LPS group [p-Src protein (p-Src/GAPDH): 1.02±0.09 vs. 1.29±0.05, p-MAPK proteins (p-MAPK/GAPDH): 0.24±0.02 vs. 0.62±0.02, VE-cadherin protein (VE-cadherin/GAPDH): 0.64±0.03 vs. 0.31±0.02, all P < 0.01]. Conclusion:Paeoniflorin can regulate the Src/VE-cadherin pathway in CMECs, inhibit the expression and secretion of inflammation-related proteins and chemokines, and improve the cell permeability of CMECs induced by LPS.

Objective: To evaluate the application of heparin-binding protein (HBP) in diagnosis of sepsis in adult patients. Methods: An extensive search for the Chinese and English literatures from the PubMed, Embase, the Cochrane Library, Wanfang data, CNKI and VIP up to July 2019 was performed. The articles regarding HBP for the diagnosing of sepsis in adult patients were enrolled. Two researchers independently extracted related literature. The quality of the studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Meta-Disc 1.4 and STATA 12.0 were used for Meta-analysis. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) were calculated. Summary receiver operating characteristic (SROC) curves and area under the curve (AUC) were used to evaluate the diagnostic performance of HBP for sepsis. Deek funnel plot was used to detect publication bias. Results: A total of 10 studies with 1 884 patients were included in this Meta-analysis. The quality of the literature was relatively moderate. HBP in plasma were detected by enzyme linked immunosorbent assay (ELISA) in all studies. The studies showed substantial heterogeneity, and random effect model was used for Meta-analysis. The pooled sensitivity, specificity, PLR, NLR, and DOR were 0.80 [95% confidence interval (95%CI) was 0.77-0.83], 0.80 (95%CI was 0.78-0.82), 3.96 (95%CI was 2.45-6.41), 0.28 (95%CI was 0.20-0.39) and 14.63 (95%CI was 6.83-31.30) respectively. The pooled AUC was 0.86 and the Cochran-Q was 0.79. To explore the potential sources of heterogeneity, subgroup analyses were performed based on the severity of the disease, diagnostic criteria and region. However, the results indicated that no methodological covariates affected the diagnostic accuracy of HBP, indicating that there was still unexplained heterogeneity. In addition, the sensitivity analysis by removing individual studies were performed. No outlier study was identified and the results were relatively stable and reliable. Deek funnel plot showed little publication bias. Conclusions There is preferable value of HBP for diagnosis of sepsis in adult patients. However, it needs to be further confirmed by large multicenter studies.