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Meningitis is a life-threatening disease. In order to reduce its threat to public health, the World Health Assembly indorsed a resolution in 2020 for urgent global action to prevent and control meningitis. Defeating Meningitis by 2030: a Global Roadmap was officially launched by the World Health Organization in 2021. We interpreted some key information of the roadmap from the aspects of coverage, objectives and pillar strategies, providing ideas for further strengthening the prevention and control of bacterial meningitis in China.

Objective: To explore the effects of change of activity of vacuolar adenosine triphosphatase (V-ATPase) of myocardial lysosome on myocardial damage in rats after severe burn and its mechanism. Methods: The myocardial lysosomes were extracted from the hearts of 12 SD rats with ultra-high speed gradient density centrifugation, then Western blotting and transmission electron microscope observation were conducted for identification. One hundred and twenty rats were divided into pure burn group, ATP group, normal control group, and bafilomycin group according to the random number table, with 30 rats in each group. Rats in pure burn group and ATP group were inflicted with 40% TBSA full-thickness scald on the back. Immediately after injury, rats in pure burn group were intraperitoneally injected with lactated Ringer's solution in 4 mL·%TBSA(-1)·kg(-1,) and rats in ATP group were intraperitoneally injected with ATP in 0.4 mg/kg at 12 h before burn, immediately after burn, and 12 h after burn. Rats in normal control group did not receive any treatment, and rats in bafilomycin group were intraperitoneally injected with bafilomycin A1 in 0.3 mg/kg at the same time points as those of ATP group. At 24 h after burn, 30 rats from each group were collected for determining activity of V-ATPase of myocardial lysosome with coupled-enzyme assay and the expression of myocardium autophagy-related proteins microtubule-associated protein 1 light chain 3 (LC3) and P62 by Western blotting. Left ventricular arterial blood was collected to detect the content of 5 items of myocardial enzyme spectrum and cardiac troponin T (cTnT). Data were processed with one-way analysis of variance and t test. Results: (1) After identification, both the expression level of lysosome-related membrane protein 1 and purity of lysosome in the sample were high, and the structure of lysosome was intact. (2) At 24 h after burn, the activity values of V-ATPase of myocardial lysosome in rats of pure burn group, ATP group, normal control group, and bafilomycin group were (2.03±0.67), (3.01±0.58), (4.29±0.26), and (1.83±0.52) μmol·mg(-1)·h(-1,) respectively. The activity value of V-ATPase of myocardial lysosome in rats of pure burn group was significantly lower than the values in ATP group and normal control group (with t values respectively 3.14 and 8.87, P values below 0.01). The activity values of V-ATPase of rats in normal control group were significantly higher than those in bafilomycin group ( t =11.87, P <0.01). At 24 h after burn, the expressions of myocardial LC3 and P62 in pure burn group were significantly higher than those in ATP group and normal control group (with t values from 3.73 to 5.88, P values below 0.01). The expressions of myocardial LC3 and P62 in normal control group were significantly lower than those in bafilomycin group (with t values respectively 2.64 and 3.07, P <0.05 or P <0.01). At 24 h after burn, the content of 5 items of myocardial enzyme spectrum and cTnT in pure burn group was significantly higher than that in ATP group and normal control group (with t values from 3.24 to 16.72, P values below 0.01). The content of 5 items of myocardial enzyme spectrum and cTnT in normal control group was significantly lower than that in bafilomycin group (with t values from 2.39 to 10. 70, P values below 0.01). Conclusions: The activity of V-ATPase of myocardial lysosome decreased in rats after severe burn, which can result in myocardial damage by inhibiting myocardial autophagy flux.

Objective: To explore the effects of rapamycin on the migration of human epidermal cell line HaCaT, and to analyze its molecular mechanism., Methods: HaCaT cells were conventionally cultured with RPMI 1640 culture medium containing 10% fetal calf serum (hereinafter referred to as culture medium). (1) According to the random number table, HaCaT cells in logarithmic phase were divided into control group and 1, 5, 50, 100, 200 nmol/L rapamycin groups, with 6 wells in each group. The cells in rapamycin groups were cultured with culture medium containing rapamycin in corresponding mass concentration, and the cells in control group were cultured with culture medium containing dimethyl sulfoxide (DMSO) instead. After being conventionally cultured for 4 hours, proliferative activity of cells was determined with microplate reader (denoted as absorbance value). (2) HaCaT cells in logarithmic phase were grouped and cultured as that in experiment (1), with 1 well in each group. After being conventionally cultured for 4 hours, range of movement of cells in 3 hours was observed under live cell imaging workstation, and their curvilinear movement speeds were calculated. Then the suitable concentration of rapamycin was selected for experiments (3) and (4). (3) HaCaT cells in logarithmic phase were divided into control group and rapamycin group according to the random number table, with 1 well in each group. The cells in rapamycin group were cultured with culture medium containing 50 nmol/L rapamycin, and the cells in control group were cultured with culture medium containing DMSO. After being conventionally cultured for 4 hours, cells were collected for scratch assay. Wound area was observed at post scratching hour (PSH) 0, 5, 10, and 15, and the migration rates of cells at PSH 5, 10, and 15 were calculated respectively. (4) HaCaT cells in logarithmic phase were grouped and cultured as that in experiment (3), with 1 well in each group. Activity of focal adhesion kinase (FAK) was determined with Western blotting (denoted as the ratio of gray value of phosphorylated FAK to that of FAK). Above-mentioned experiments were independently repeated for three or five times. Data were processed with one-way analysis of variance, LSD test, and t test., Results: (1) Proliferative activity of cells in control group and 1, 5, 50, 100, 200 nmol/L rapamycin groups was respectively 1.22±0.28, 1.29±0.38, 1.12±0.27, 1.20±0.29, 1.15±0.30, 1.39±0.40, without statistically significant differences among these groups (F=2.112, P=0.068). (2) The ranges of movement of cells in 1, 5 nmol/L rapamycin groups were similar to the range of movement of cells in control group, while those of cells in 50, 100, 200 nmol/L rapamycin groups were obviously smaller than the range of movement of cells in control group. There were statistically significant differences in cell curvilinear movement speeds among the 6 groups (F=3.525, P=0.004). The curvilinear movement speeds of cells in 1, 5 nmol/L rapamycin groups were respectively (0.8±0.4) and (0.8±0.8) μm/min, and they were similar to the curvilinear movement speed of cells in control group [(0.9±0.5) μm/min, with P values above 0.05]. The curvilinear movement speeds of cells in 50, 100, 200 nmol/L rapamycin groups were respectively (0.7±0.5), (0.7±0.4), (0.7±0.4) μm/min, and they were significantly lower than the curvilinear movement speed of cells in control group (with P values below 0.01). Thus, 50 nmol/L rapamycin was selected for experiments (3) and (4). (3) Compared with those of control group, wound areas of rapamycin group showed no obvious change at PSH 0 and 5, while they were obviously increased at PSH 10 and 15. At PSH 5, migration rate of cells in control group [(17.5±2.6)%] was similar to that in rapamycin group [(15.8±3.5)%, t=1.951, P>0.05]. Migration rates of cells of rapamycin group at PSH 10 and 15 [(42.5±4.0)% and (71.3±9.2)%, respectively] were obviously decreased as compared with those of control group [(46.9±6.7)% and (88.0±7.7)%, with t values respectively 2.732 and 6.746, P values below 0.01]. (4) Compared with that in control group (0.46±0.14), FAK activity of cells in rapamycin group (0.16±0.08) was significantly down-regulated (t=4.967, P<0.01)., Conclusions: FAK signal pathway is sensitive to rapamycin in HaCaT cells. Inhibition effects of rapamycin on migration of HaCaT cells may be mediated by down-regulated activity of FAK.