Role and pathogenic mechanism of TcpC in uropathogenic Escherichia coli-induced mouse model of cystitis / 中华微生物学和免疫学杂志

Objective:To investigate the role of TcpC in uropathogenic Escherichia coli (UPEC)-induced cystitis in mice and to preliminarily analyze the pathogenic mechanism. Methods:C57BL/6 mice were injected with 10 9 CFU wild-type UPEC CFT073 (CFT073 wt) or tcpc gene-deleted mutant (CFT073 Δ tcpc) from urethra into bladder to construct the mouse model of cystitis. The mice were sacrificed 3 d after infection and the bladders were taken to observe the gross pathological changes. Histopathological changes in bladder tissues were observed after HE staining. Immunohistochemistry was used to detect TcpC in bladder tissues. Bacterial loads in urine samples of UPEC-infected mice were counted by tenfold dilution method, and the presence of tcpc gene in the genomic DNA of bacteria from the bladder and urine samples of CFT073 wt-infected mice was measured by PCR. Real-time quantitative RT-PCR (qRT-PCR) and Western blot were performed to detect the expression of TcpC at mRNA and protein levels in macrophages after CFT073 wt infection. The influence of UPEC strains on the activation of NF-κB signaling pathway in macrophages were determined by Western blot. The levels of proinflammatory factors and the bacterial and cell activity after infecting macrophages with UPEC strains were detected by ELISA, laser confocal microscope and fluorescence microscope, respectively. Results:Compared with the mice with CFT073 Δ tcpc infection, CFT073 wt-infected mice had significantly enlarged bladder and severe neutrophil infiltration and abundant TcpC in bladder tissues. The number of bacteria in the urine of CFT073 wt-infected mice was significantly greater than that of the CFT073 Δ tcpc group. PCR results showed that the bacteria in bladder or urine were CFT073 wt. The expression of TcpC at both mRNA and protein levels in macrophages increased significantly after CFT073 wt infection. Moreover, in CFT073 wt-infected macrophages, the expression of IκBα was promoted and the phosphorylation of p65 and the production of proinflammatory factors were suppressed. TcpC was instrumental in the survival and invasion of CFT073 wt in macrophages. Conclusions:TcpC expression increased significantly in mice with CFT073 wt-induced cystitis. TcpC inhibited the activation of NF-κB signaling pathway and the production of proinflammatory factors in macrophages to improve the survival rate of CFT073 wt, which was closely related to the pathogenesis and immune evasion of UPEC.

Hypervirulent Klebsiella pneumoniae serotype K1 induces liver abscess through activating NLRP3 inflammasome / 中华微生物学和免疫学杂志

Objective:To investigate whether the hypervirulent Klebsiella pneumoniae (hvKP) induces liver abscess through activating NLRP3 inflammasome. Methods:K1-hvKP and K35-non-hvKP bacterial suspensions were intraperitoneally injected into C57BL/6 mice to establish the models of liver abscess. Human peripheral blood neutrophils were sorted by immunomagnetic beads with CD45 + and Gr-1 + , and the purity was detected by flow cytometry. The concentrations of capsular polysaccharide of K1-hvKP and K35-non-hvKP were detected by total carbohydrate assay kit. The expression of IL-18 and IL-33 by neutrophils at mRNA and protein levels was detected by real-time fluorescence quantitative PCR and ELISA, respectively. The activation of NLRP3 inflammasome in neutrophils was detected by Western blot. Neutrophil extracellular trap formation (NETosis) was observed under confocal laser scanning microscope. Results:The C57BL/6 mice with K1-hvKP infection had significantly serious liver abscess as compared with the K35-non-hvKP-infected mice. The purity of human neutrophils was more than 95%. The concentration of capsular polysaccharide in K1-hvKP was significantly higher than that in K35-non-hvKP. Compared with K35-non-hvKP, K1-hvKP significantly promoted the neutrophils to express IL-18 and IL-33 at both mRNA and protein levels, enhanced the activation of NLRP3 and induced NETosis.Conclusions:This study suggested that hvKP could promote NETosis by activating NLRP3 inflammasome to cause liver abscess.

Signaling pathways involved in inhibition of macrophage phagocytosis by TcpC of uropathogenic Escherichia coli / 中华微生物学和免疫学杂志

Objective:To investigate the signaling pathway of inhibiting macrophage phagocytosis of TIR domain-containing protein encoded by Escherichia coli (TcpC) N-terminal ubiquitin ligase active fragments of uropathogenic Escherichia coli. Methods:Bioinformatics software was used to analyze the amino acid sequences and the function of TcpC N-terminal ubiquitin ligase active fragments as well as the functional sites. PCR was performed to amplify tcpc-330, tcpc-450 and tcpc-510 genes and a prokaryotic expression system was constructed to express the target proteins. The recombinant proteins rTcpC-N110, rTcpC-N150 and rTcpC-N170 were purified by Ni-NTA affinity chromatography. LPS in the recombinant proteins was removed by Detoxi-gel chromatography. The expression of MyD88 at protein and mRNA levels in macrophages incubated with rTcpC-N110, rTcpC-N150, rTcpC-N170 or rTcpC-TIR was detected by Western blot and qRT-PCR. The activation of NF-κB signal pathway and the levels of proinflammatory factors in macrophages incubated with the above TcpC protein fragments were measured by Western blot and ELISA, respectively. Results:Cys12, Trp104 and Trp106 in the N-terminal fragment of TcpC were crucial amino acids in maintaining its ubiquitin ligase activity. The target recombinant proteins rTcpC-N110, rTcpC-N150 and rTcpC-N170 were successfully expressed and purified. After Detoxi-gel chromatography, rTcpC-N110, rTcpC-N150 and rTcpC-N170 extracts were undetectable for LPS. TcpC ubiquitin ligase fragments inhibited the expression of MyD88 at protein level, but not affect its expression at mRNA level in macrophages. LPS-induced phosphorylation of NF-κB signaling pathway-related proteins p50 and p65 was significantly inhibited in macrophages treated with TcpC ubiquitin ligase fragments. Moreover, LPS-induced production of pro-inflammatory factors was also significantly inhibited.Conclusions:The recombinant proteins rTcpC-N110, rTcpC-N150 and rTcpC-N170 could inhibit the expression of MyD88 at protein level and suppress the activation of NF-κB signaling pathway, suggesting that they were closely related to the inhibition of innate immune activity of macrophages.

Depression and associated factors among migrant women of reproductive age in some areas of Wuhan / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand factors as social support, situation of depression and related risk factors among migrant women of reproductive age in some areas of Wuhan.</p><p><b>METHODS</b>Cluster sampling method and face-to-face interview with structured questionnaire were used to investigate 316 migrant women in Wuhan.</p><p><b>RESULTS</b>The overall prevalence rate of depression was 32.3%.</p><p><b>RESULTS</b>from binary logistic regression analysis showed that factors as: under pressure (OR = 4.010, 95%CI: 1.672 - 9.617), having had negative life events (OR = 2.050, 95%CI: 1.170 - 3.591) or tight relations with neighbors (OR = 2.537, 95%CI: 1.053 - 6.113), not quite satisfied (OR = 4.247, 95%CI: 1.521 - 11.855) or satisfied (OR = 2.411, 95%CI: 1.111 - 5.233), on his/her own health status etc., might serve as the possible risk factors for depression. In scores related to social support, and the utilization of such support, there were statistically significant differences seen between the groups with depression and the one without.</p><p><b>CONCLUSION</b>The prevalence of depression among migrant women of reproductive age appeared to be high in some areas on Wuhan. Factors as: under pressure, having had negative life events, tight relations with neighbors, status on satisfaction of one's own health situation as well as related social support, seemed to be the main risk factors for depression in this population.</p>

Clinical analysis of 942 cases of Kawasaki disease / 中华儿科杂志

<p><b>OBJECTIVE</b>The study was designed to investigate the clinical characteristics and the effects of therapeutic proposal on Kawasaki disease (KD).</p><p><b>METHODS</b>Clinical features, diagnosis and treatment for totally 942 patients with KD hospitalized during Jan, 2000 to Dec, 2004 were reviewed. Clinical features of typical and incomplete KD were compared. Also, influential factors for KD resistant to intravenous immune globulin (IVIG) therapy were analyzed. Five hundred and ten cases were followed up for analyzing the prognosis of coronary artery lesion (CAL).</p><p><b>RESULTS</b>(1) 774 cases were diagnosed as typical KD, and 168 cases as incomplete KD. The incidence of infants with incomplete KD was higher than that of infants with typical KD (18.5% vs. 10.1%, P < 0.01). As compared with typical KD, the cases of incomplete KD had a long duration of fever before final diagnosis [(7.7 +/- 2.9) d vs. (7.0 +/- 2.4) d, P < 0.01], high hemoglobin level [Hb, (106.6 +/- 13.4) g/L vs. (103.5 +/- 12.3) g/L, P < 0.01], high hematocrit [Hct, (32.0 +/- 4.3)% vs. (31.0 +/- 4.0)%, P < 0.01], and high prevalence of CAL (23.8% vs. 16.8%, P < 0.05), respectively. The occurrence rate and emerging time of clinical manifestations in incomplete KD and in typical KD were presented, respectively: non-exudative conjunctivitis [occurrence rate, 64.9% vs. 93.5%; emerging time, (4.4 +/- 1.4) d vs. (4.0 +/- 1.6) d, respectively (P < 0.05 or P < 0.01)], erythema and cracking of lips [occurrence rate, 50.6% vs. 94.8%; emerging time, (4.9 +/- 1.4) d vs. (4.5 +/- 1.6) d, respectively (P < 0.05 or P < 0.01)], rash [occurrence rate, 35.1% vs. 87.7%; emerging time, (3.9 +/- 1.9) d vs. (3.4 +/- 1.7) d, respectively (P < 0.05 or P < 0.01)], erythema and edema of extremity [occurrence rate, 26.8% vs. 71.4%; emerging time, (6.7 +/- 1.5) d vs. (5.3 +/- 1.7) d, respectively (P < 0.01)], cervical lymphadenopathy [occurrence rate, 34.5% vs. 68.0%; emerging time, (4.3 +/- 2.5) d vs. (3.6 +/- 2.2) d, respectively (P < 0.05 or P < 0.01)], strawberry tongue [occurrence rate, 31.0% vs. 59.8%; emerging time, (5.6 +/- 2.2) d vs. (4.9 +/- 1.8) d, respectively (P < 0.05 or P < 0.01)], membranous desquamation of fingertips [occurrence rate, 34.5% vs. 56.3%; emerging time, (11.7 +/- 3.3) d vs. (10.3 +/- 2.7) d, respectively (P < 0.01)], and desquamation peri-anus [occurrence rate, 42.9% vs. 50.0%; emerging time, (6.7 +/- 2.7) d vs. (6.9 +/- 2.5) d, respectively (P > 0.05)]. Except for peri-anus desquamation, other clinical manifestations in incomplete KD were sporadical as compared to typical KD. (2) Six per cent (51/857) of cases were resistant to the IVIG therapy. As compared to the group responding to IVIG therapy, high prevalence of CAL (31.4% vs. 17.1%, P < 0.05), long fever duration [(10.6 +/- 3.9) d vs. (7.5 +/- 2.3) d, P < 0.01], low Hb level [(99.9 +/- 14.1) g/L vs. (104.3 +/- 12.4) g/L, P < 0.01], low Hct [(30.1 +/- 4.5)% vs. (31.2 +/- 4.0)%, P < 0.05], low platelet [PLT, (256.9 +/- 142.4) x 10(9)/L vs. (309.7 +/- 131.5) x 10(9)/L, P < 0.05], and low albumin level [ALB, (27.8 +/- 8.4) g/L vs. (33.5 +/- 6.7) g/L, P < 0.01] were found in the group resistant to IVIG therapy, respectively. (3) In patients who received IVIG 1 g/kg and 2 g/kg, the recovery rates from CAL were 83.1% and 89.7% (P > 0.05), respectively. The prevalence of CAL in those without CAL in acute and subacute stages was 0.9% and 3.5% (P > 0.05), respectively, during 2 year-follow-up period.</p><p><b>CONCLUSION</b>(1) Infants appeared to have more chances to suffer from incomplete KD. Incomplete KD had high prevalence of CAL. The peri-anus desquamation might be an important clue for early diagnosis of incomplete KD. (2) In acute stage, the influential factors for KD resistance to IVIG therapy included prolonged fever, non-elevated PLT, and persistent decrease in Hb, Hct and ALB levels. (3) Children receiving IVIG 1 g/kg and 2 g/kg had the similar effects on recovery and prevention from CAL within the first two years after KD onset.</p>