S1PR3 agonist RY-15 promotes bacterial clearance / 中华急诊医学杂志

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.

Lentiviral vectors carrying siRNA inhibit S1PR3 gene expression in the corpus cavernosum smooth muscle cells of rats with spontaneous hypertension / 中华男科学杂志

Objective@#To screen lentiviral vectors carrying siRNA which can specifically down-regulate the gene expression of the sphingosine-1-phosphate receptor 3 (S1PR3) in the corpus cavernosum smooth muscle (CCSM) cells of rats with spontaneous hypertension (SHT) and investigate the influence of the vectors on the signaling pathways of ROCK1, ROCK2 and eNOS in the CCSM cells of SHT rats.@*METHODS@#Using the S1PR3 mRNA sequence of the rat as an interfering target, we designed and synthesized three pairs of siRNA sequences (siRNA1, 2 and 3) targeting S1PR3 and one pair of negative control, and then constructed and packaged them into lentiviral vectors. We cultured the CCSM cells of SHT and Wistar-Kyoto (WKY) rats in vitro and randomly divided them into groups A (SHT untransfected control), B (SHT transfected and carrying negative control virus), C (SHT transfected and carrying siRNA1 targeting S1PR3), D (SHT transfected and carrying siRNA2 targeting S1PR3), E (SHT transfected and carrying siRNA3 targeting S1PR3), and F (WKY untransfected control). With the multiplicity of infection (MOI) = 60, we transfected the CCSM cells of the SHT rats with the lentiviral vector and then determined the expression of the green fluorescent protein (GFP) as well as the mRNA and protein expressions of S1PR3, ROCK1, ROCK2 and eNOS in the CCSM cells of the SHT and WKY rats by RT-PCR and Western blot.@*RESULTS@#Gene sequencing proved the successful construction of the lentiviral vector. The transfection efficiency of the CCSM cells of the rats was >80% in groups B, C, D and E. Compared with group A, the mRNA and protein expressions of S1PR3, ROCK1 and ROCK2 exhibited no significant difference in group B but were remarkably decreased in groups C, D, E and F (P0.05) but remarkably lower than those in group F (P0.05) but markedly increased in groups A, B, C and D (P< 0.05), while those of eNOS remarkably decreased in groups A, B, C, D and E (P< 0.05).@*CONCLUSIONS@#The three constructed lentiviral vectors carrying siRNA targeting different loci of the S1PR3 gene could significantly inhibit the expression of S1P3 as well as RhoA/Rho kinase signaling pathways in the CCSM cells of SHT rats, and the vector carrying siRNA3 exhibited the highest inhibitory effect.

S1PR3 agonist KRX-725 promotes bacterial clearance and affects the outcome of sepsis / 中华急诊医学杂志

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.