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Objective RY-15, a specific agonist of Sphingosine 1-phosphate Receptor 3, was synthesized for investigating the function and mechanism of S1PR3 in bacterial clearance. Methods Measure the ability of RY-15 with FITC to enter the THP-1 cell after coculture for 5 min, 10 min, 20 min, 30 min through confocal microscopy. The function of GY-5 and RY-15 in bacterial clearance was observed by gentamicin protection test. The phosphorylation level of ERK and p-ERK in THP-1 cell was detected by Western Blot after GY-5 and RY-15 stimulation for different times. Results According to confocal microscopy, RY-15 started to enter the THP-1 cell after stimulating for 10 min and the effect of entering cell was very obvious after stimulating for 30 min. Compared to GY-5 group, live bacteria in the macrophage were largely decreased in the RY-15 group( P<0.05). Conmpared to GY-5 group, the p-ERK level raised largely at different poins. Conclusions RY-15, a specific agonist of Sphingosine 1-phosphate Receptor 3, can promote bacterial clearance through entering cell and the phosphorylation level of ERK is a possible mechanism.
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Objective To study the role of KRX-725,a specific agonist of Sphingosin-1 phosphate receptor 3,S1PR3),in the function and mechanism of S1PR3 in respect of bacterial clearance.Methods Twenty healthy male C57BL/6 mice were randomly (random number) divided into two groups:KRX-725 group and control group.Septic mice model were established by intraperitoneal injection of E.coli (3 × 106),then KRX-725 (10 mg/kg) or the vehicle was administered intratracheally.Forty-eight-hour survival rate (n =12),bacterial colony numbers in peritoneal cavity and blood (n =5),and lung injury (n =3)were compared between two groups.In vitro,the peritoneal macrophages were stimulated by E.coli (cell∶E.coli=1∶10) with KRX-725 or the vehicle treatment.The reactive oxygen species (ROS) levels were detected by CM-H2DCFDA in macrophages.The bacteria clearance function of KRX-725 was observed by gentamicin protection test.Survival rates were analyzed with the Log-rank test.A 2-tailed student's t test was used to compare difference between two independent groups.Results Compared with the control group,the 48-hour survival rate of KRX-725 group was significantly higher (P ＜ 0.05).Bacterialload in the blood and the peritoneal lavage fluid (PLF) was greatly decreased in the KRX-725 group (blood:t =3.17,P ＜0.05;PLF:t =4.07,P ＜0.01).The lung tissues injury was also obviously reduced in the KRX-725 group of 24 hours after the injection of E.coli (lung injury score:KRX-725 group 1.4 ± 0.25;control group 2.4 ± 0.25) (t =2.89,P ＜ 0.05).In vitro,KRX-725 could up-regulate the ROS levels in macrophage at 20 min and 30 min after E.coli injected intra-peritoneally (20 min fluorescent intensity:KRX-725 group 522.9 ± 38.76,control group 385.9 ± 15.90,P ＜ 0.05;30 min fluorescent intensity:KRX-725 group 519.7 ±25.02,control group 384.5 ± 15.28,P ＜0.01).The bacterial load in the KRX-725 treated macrophage were significantly decreased at 3 h and 6 h after E.coli injected intra-peritoneally (3 h:KRX-725 group 286.5 ±98.35,control group 710.8 ± 107.8,P ＜0.05;6 h:KRX-725 group 72.5 ±6.45,control group 205.8 ±66.76,P ＜0.01).Conclusion In vivo,KRX-725 could improve the survival rate of septic mice,decrease the bacterial lioad in the blood and PLF,and reduce the lung injury.In vitro,KRX-725 could up-regulate the ROS level in macrophages and accelerate the bacterial clearance.
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Objective To observe the clinical efficacy of Tanreqing Injection combined with levofloxacin injection in treatment of acute episode of chronic bronchitis and its effect on bacterial clearance rate. Methods Totally 66 patients were randomly divided into treatment group and control group (33 cases for each). Both groups were given expectorant and antispasmodic treatment. The treatment group was given Tanreqing Injection combined with levofloxacin injection, while the control group was given levofloxacin injection only. The treatment course was 12 days. The clinical symptoms, signs, and sputum culture before and after treatment were observed. The clinical efficacy and the bacterial clearance rate of the two groups were compared. Results The markedly effective cases and the effective cases in the treatment group were 15 and 29 respectively, and those in the control group were 7 and 21 respectively, with statistical significance (P<0.05). The bacterial clearance rate was 89.5% (17/19) in the treatment group, while 55.6%(10/18) in the control group, with significant difference (P<0.05). Conclusion Acute episode of chronic bronchitis treated by Tanreqing Injection combined with levofloxacin injectcion is more effective than levofloxacin injection only.