Phosphorylation of ERK-Dependent NF-κB Triggers NLRP3 Inflammasome Mediated by Vimentin in EV71-Infected Glioblastoma Cells.

Enterovirus 71 (EV71) is a dominant pathogenic agent that may cause severe central nervous system (CNS) diseases among infants and young children in the Asia-pacific. The inflammasome is closely implicated in EV71-induced CNS injuries through a series of signaling pathways. However, the activation pathway of NLRP3 inflammasome involved in EV71-mediated CNS injuries remains poorly defined. In the studies, EV71 infection, ERK1/2 phosphorylation, and activation of NLRP3 are abolished in glioblastoma cells with low vimentin expression by CRISPR/Cas9-mediated knockdown. PD098059, an inhibitor of p-ERK, remarkably blocks the vimentin-mediated ERK1/2 phosphorylation in EV71-infected cells. Nuclear translocation of NF-κB p65 is dependent on p-ERK in a time-dependent manner. Moreover, NLRP3 activation and caspase-1 production are limited in EV71-infected cells upon the caffeic acid phenethyl ester (CAPE) administration, an inhibitor of NF-κB, which contributes to the inflammasome regulation. In conclusion, these results suggest that EV71-mediated NLRP3 inflammasome could be activated via the VIM-ERK-NF-κB pathway, and the treatment of the dephosphorylation of ERK and NF-κB inhibitors is beneficial to host defense in EV71-infected CNS.

Spatiotemporal analysis of imported and local dengue virus and cases in a metropolis in Southwestern China, 2013-2022.

Dengue fever is a viral illness, mainly transmitted by Aedes aegypti and Aedes albopictus. With climate change and urbanisation, more urbanised areas are becoming suitable for the survival and reproduction of dengue vector, consequently are becoming suitable for dengue transmission in China. Chongqing, a metropolis in southwestern China, has recently been hit by imported and local dengue fever, experiencing its first local outbreak in 2019. However, the genetic evolution dynamics of dengue viruses and the spatiotemporal patterns of imported and local dengue cases have not yet been elucidated. Hence, this study implemented phylogenetic analyses using genomic data of dengue viruses in 2019 and 2023 and a spatiotemporal analysis of dengue cases collected from 2013 to 2022. We sequenced a total of 15 nucleotide sequences of E genes. The dengue viruses formed separate clusters and were genetically related to those from Guangdong Province, China, and countries in Southeast Asia, including Laos, Thailand, Myanmar and Cambodia. Chongqing experienced a dengue outbreak in 2019 when 168 imported and 1,243 local cases were reported, mainly in September and October. Few cases were reported in 2013-2018, and only six were imported from 2020 to 2022 due to the COVID-19 lockdowns. Our findings suggest that dengue prevention in Chongqing should focus on domestic and overseas population mobility, especially in the Yubei and Wanzhou districts, where airports and railway stations are located, and the period between August and October when dengue outbreaks occur in endemic regions. Moreover, continuous vector monitoring should be implemented, especially during August-October, which would be useful for controlling the Aedes mosquitoes. This study is significant for defining Chongqing's appropriate dengue prevention and control strategies.

Comparison of Curative Effect between PFNA and PCCP in the Treatment of Femoral Intertrochanteric Fractures.

Objective: To compare and analyze the clinical efficacy of proximal femoral nail anti-rotation (PFNA) and percutaneous compression plate (PCCP) for minimally invasive treatment of femoral intertrochanteric fractures. Methods: A retrospective analysis of 98 patients with femoral intertrochanteric fractures admitted to our hospital from January 2019 to December 2020 was used as the research object, and they were divided into PFNA group and PCCP group according to different treatment methods, with 51 cases and 47 cases. The intraoperative and postoperative indicators were compared between the two groups of patients. Results: There was no significant difference in the operative time, postoperative fracture healing time, and Harris score of hip joint function between the two groups (t = -1.43, 1.86, 1.63; P > 0.05). Compared with the PFNA group, the intraoperative blood loss and postoperative drainage volume in the PCCP group were lower than those in the PFNA group (t = 11.38, 9.66; P < 0.05). Compared with the PFNA group, the time of weight-bearing in the PCCP group was longer than that in the PFNA group (t = -2.23, P < 0.05). The total incidence of postoperative complications was 7.84% in the PFNA group and 10.64% in the PCCP group, and there was no significant difference between the two groups (P > 0.05). Conclusion: The PFNA and PCCP are both effective measures for the clinical treatment of intertrochanteric fractures, and internal fixation should be reasonably selected according to the specific conditions of the patients.

[Establishment of a vimentin knockout and HIV-1 gp120 transgenic mouse model].

OBJECTIVE: To construct a HIV-1 gp120 transgenic mice (gp120 Tg) with vimentin (VIM) gene knockout. METHODS: Female HIV-1 gp120 Tg mice were mated to VIM heterozygote mice (F0). All the offspring mice were derived from these original founders so that both genotypes had the same mixed genetic background. The F1 mice were bred to generate of VIM+/+, VIM-/-, VIM+/+/gp120 Tg and VIM-/-/gp120 Tg mice. PCR was performed for genotyping of the mice, and the expressions of VIM and gp120 in the brain tissues were examined using immunoblotting. RESULTS: The results of PCR showed the presence of the target bands in VIM+/+, VIM-/-, VIM+/+/gp120 Tg and VIM-/-/gp120 Tg mice. In VIM-/-/gp120 Tg mice, gp120 expression was detected throughout the brain regions while no VIM expression was detected. CONCLUSIONS: We generated gp120 transgenic mouse models with VIM gene knockout, which facilitate the exploration of the role of VIM in gp120-induced neurotoxicity.

[Effect of vimentin on activation of NLRP3 inflammasome in the brain of mice with EV71 infection].

OBJECTIVE: To explore whether vimentin (VIM) mediates the activation of inflammasome in mice with EV71 infection in the central nervous system. METHODS: Forty VIM knockout mice (VIM-/-, 3 to 5 days old) were randomly divided into control group and infection group. The infection group was intraperitoneally injected with EV71 (108 TCID50), while the control group was injected with PBS (10 µL); another 40 wild-type mice (WT, 3 to 5 days old) were grouped in the same manner. The general conditions of mice were observed each day. Western blotting, ELISA, and RT-PCR were used to measure the levels of IL-1ß and casepase-1 in the brain or cerebrospinal fluid. The pathological changes in the cerebella and brain were observed using immunohistochemistry. RESULTS: Compared with the control group, the VIM-/- mice infected with EV71 showed no significant changes in NLRP3, IL-1ß or caspase-1 expression. The WT mice infected with EV71 showed obviously increased NLRP3, IL-1ß, and caspase-1 expressions in the central nervous system. The neurons of infected VIM-/- mice exhibited milder cell damage than the those in WT mice. CONCLUSION: VIM mediates the activation of inflammasome and promotes brain inflammation and neuronal damage in mice with EV71 infection in the central nervous system.

Probiotic Mixture Golden Bifido Prevents Neonatal Escherichia coli K1 Translocation via Enhancing Intestinal Defense.

Escherichia coli (E. coli) K1 sepsis and meningitis is a severe infection characterized by high mortality in neonates. Successful colonization and translocation across the intestinal mucosa have been regarded as the critical steps for E. coli K1 sepsis and meningitis. We recently reported that the probiotic mixture, Golden Bifido (containing live Lactobacillus bulgaricus, Bifidobacterium, and Streptococcus thermophilus, LBS) has a preventive role against neonatal E. coli K1 bacteremia and meningitis. However, the interaction between the neonatal gut barrier, probiotics and E. coli K1 is still not elucidated. The present study aims to investigate how LBS exerts its protective effects on neonatal gut barrier during E. coli K1 infection. The beneficial effects of LBS were explored in vitro and in vivo using human colon carcinoma cell lines HT-29 and rat model of neonatal E. coli K1 infection, respectively. Our results showed that stimulation with E. coli K1 was able to cause intestinal barrier dysfunction, which were reflected by E. coli K1-induced intestinal damage and apoptosis of intestinal epithelial cells, reduction of mucin, immunoglobulin A (IgA) and tight junction proteins expression, as well as increase in intestinal permeability, all these changes facilitate E. coli K1 intestinal translocation. However, these changes were alleviated when HT-29 cells were treated with LBS before E. coli K1 infection. Furthermore, we found that LBS-treated neonatal rats (without E. coli K1 infection) have showed higher production of mucin, ZO-1, IgA, Ki67 in intestinal mucosa as well as lower intestinal permeability than that of non-treated rats, indicating that LBS could accelerate the development of neonatal intestinal defense. Taken together, our results suggest that enhancement of the neonatal intestinal defense to fight against E. coli K1 translocation could be the potential mechanism to elucidate how LBS confers a protective effect against neonatal E. coli K1 bacteremia and meningitis. This indirect mechanism makes LBS exert preventive effect on most of gut-derived pathogenic infections rather than only E. coli.