OBJECTIVETo investigate the effect of triggering receptor expressed on myeloid cells 1 (TREM-1) vshRNA vector on expression of inflammatory cytokines and survival rate in septic mice infected by Bacteroides fragilis.

METHODS(1) TREM-1 vshRNA vector was constructed. Bacteroides fragilis (2.5 x 10(9) CFU/mL, 0.5 mL) was intraperitoneally injected in each mouse, and septic model was reproduced after 12 hours. (2) One hundred and fifteen mice were divided into healthy control group (n = 3, HC), sepsis group (n = 28, S), TREM-1 vshRNA group (n = 28, T), TREM-1 vshRNA hd group (n = 28, Th), GFP group (n = 28, G) according to random number table. Mice in S, T, Th, G groups were firstly injected with isotonic saline, TREM-1 vshRNA 2 x 10(8) TU, TREM-1 vshRNA 1 x 10(8) TU, GFP siRNA through tail vein, and then sepsis was induced after 1 hour. Mice in HC group were injected with equal volume of isotonic saline through tail vein. Three mice in each group were sacrificed after 12 hours for determination of plasma level of TNF-alpha, IL-1 beta and IL-6, and level of TREM-1mRNA and its protein in hepatic tissue. The survival rate of other mice in each group was monitored for 72 hours. (3) In 125 mice sepsis was reproduced, among them 100 mice were injected with TREM-1 vshRNA 2 x 10(8) TU after 1, 2, 4, 6 hours through tail vein (25 mice at each time point), other 25 mice were injected with equal volume of isotonic saline as control. The survival rate of mice in each group was recorded 72 hours after injection.

RESULTS(1) Compared with those in S group, the plasma level of TNF-alpha, IL-1 beta and IL-6 lowered in T and Th groups (P < 0.05), especially in T group, while those in G group showed no obvious difference (P > 0.05). (2) Compared with those in G group, the level of TREM-1mRNA and its protein in hepatic tissue in T and Th groups decreased (P < 0.01), especially in T group. (3) The survival rate of mice in S and G group was 16%, which was obviously lower than that in T and Th groups (76%, 44%, respectively, P < 0.05 or P < 0.01). (4) The survival rate of mice at 1, 2, 4, 6 hours after injection was 72%, 56%, 40%, 16%, respectively, while all that except at 6 hour after injection were higher significantly than that of control (P < 0.05 or P < 0.01).

CONCLUSIONSThe intervention with TREM-1 vshRNA can effectively decrease hepatic level of TREM-1 in septic mice induced by Bacteroides fragilis, inhibit inflammatory response, and improve the survival rate.

Animals ; Bacteroides fragilis ; Disease Models, Animal ; Genetic Vectors ; Lentivirus ; Male ; Mice ; Mice, Inbred BALB C ; RNA, Messenger ; metabolism ; Receptors, Immunologic ; genetics ; Sepsis ; metabolism ; microbiology ; therapy ; Virosomes

BACKGROUND/AIMS: Several clinical trials have revealed various advantages for probiotics in inflammatory bowel disease (IBD). The aim of this study was to further investigate the effects of probiotic yogurt consumption on gut microbiota in patients with this disease. METHODS: A total of 305 participants were divided into three groups; group A (IBD patients receiving probiotic yogurt; n=105), group B (IBD patients receiving placebo; n=105), and control group (healthy individuals receiving probiotic yogurt; n=95). Stool samples were collected both before and after 8 weeks of intervention; and population of Lactobacillus, Bifidobacterium and Bacteroides in the stool specimens was measured by Taqman real-time PCR method. ': By the end of the intervention, no significant variations in the mean weight and body mass index were observed between three groups (p>0.05). However, the mean numbers of Lactobacillus, Bifidobacterium, and Bacteroides in group A were significantly increased compared to group B (p<0.001, p<0.001, and p<0.01, respectively). There were also significant differences in the mean numbers of either of three bacteria between group A and the healthy control group; however, these differences between two groups were observed both at baseline and the end of the intervention. CONCLUSIONS: Consumption of probiotic yogurt by patients with IBD may help to improve intestinal function by increasing the number of probiotic bacteria in the intestine and colon. However, many more studies are required in order to prove the concept.
Adult ; Bacteroides/genetics ; Bifidobacterium/genetics ; DNA, Bacterial/analysis ; Double-Blind Method ; Feces/microbiology ; Female ; Gastrointestinal Microbiome ; Humans ; Inflammatory Bowel Diseases/*drug therapy ; Intestines/microbiology ; Lactobacillus/genetics ; Male ; Middle Aged ; Placebo Effect ; Probiotics/*therapeutic use ; Real-Time Polymerase Chain Reaction