PI3K-dependent host cell actin rearrangements are required for Cronobacter sakazakii invasion of human brain microvascular endothelial cells

2010 ◽  
Vol 199 (4) ◽  
pp. 333-340 ◽  
Author(s):  
Qiang Li ◽  
Wei-Dong Zhao ◽  
Ke Zhang ◽  
Wen-Gang Fang ◽  
Ying Hu ◽  
...  
2021 ◽  
Vol 12 ◽  
Author(s):  
Tong Jin ◽  
Ning Guan ◽  
Yuhang Du ◽  
Xinpeng Zhang ◽  
Jiahui Li ◽  
...  

Cronobacter sakazakii (C. sakazakii) is an emerging opportunistic foodborne pathogen that can cause neonatal necrotizing enterocolitis, meningitis, sepsis in neonates and infants with a relatively high mortality rate. Bacterial transcytosis across the human brain microvascular endothelial cells (HBMEC) is vital for C. sakazakii to induce neonatal meningitis. However, few studies focus on the mechanisms by which C. sakazakii translocates HBMEC. In this study, the translocation processes of C. sakazakii on HBMEC were explored. C. sakazakii strains could effectively adhere to, invade and intracellularly survive in HBMEC. The strain ATCC 29544 exhibited the highest translocation efficiency across HBMEC monolayer among four tested strains. Bacteria-contained intracellular endosomes were detected in C. sakazakii-infected HBMEC by a transmission electron microscope. Endocytosis-related proteins CD44, Rab5, Rab7, and LAMP2 were increased after infection, while the level of Cathepsin L did not change. C. sakazakii induced TLR4/NF-κB inflammatory signal pathway activation in HBMEC, with increased NO production and elevated mRNA levels of IL-8, IL-6, TNF-α, IL-1β, iNOS, and COX-2. C. sakazakii infection also caused LDH release, caspase-3 activation, and HBMEC apoptosis. Meanwhile, increased Dextran-FITC permeability and decreased trans epithelial electric resistance indicated that C. sakazakii disrupted tight junction of HBMEC monolayers, which was confirmed by the decreased levels of tight junction-related proteins ZO-1 and Occludin. These findings suggest that C. sakazakii induced intracellular bacterial endocytosis, stimulated inflammation and apoptosis, disrupted monolayer tight junction in HBMEC, which all together contribute to bacterial translocation.


2021 ◽  
Vol 22 (10) ◽  
pp. 5065
Author(s):  
Tatjana Vujić ◽  
Domitille Schvartz ◽  
Anton Iliuk ◽  
Jean-Charles Sanchez

Over the last decade, the knowledge in extracellular vesicles (EVs) biogenesis and modulation has increasingly grown. As their content reflects the physiological state of their donor cells, these “intercellular messengers” progressively became a potential source of biomarker reflecting the host cell state. However, little is known about EVs released from the human brain microvascular endothelial cells (HBMECs). The current study aimed to isolate and characterize EVs from HBMECs and to analyze their EVs proteome modulation after paraquat (PQ) stimulation, a widely used herbicide known for its neurotoxic effect. Size distribution, concentration and presence of well-known EV markers were assessed. Identification and quantification of PQ-exposed EV proteins was conducted by data-independent acquisition mass spectrometry (DIA-MS). Signature pathways of PQ-treated EVs were analyzed by gene ontology terms and pathway enrichment. Results highlighted that EVs exposed to PQ have modulated pathways, namely the ubiquinone metabolism and the transcription HIF-1 targets. These pathways may be potential molecular signatures of the PQ-induced toxicity carried by EVs that are reflecting their cell of origin by transporting with them irreversible functional changes.


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