Differential Transcriptional Responses in Corneal and Lung Epithelial Cells to Seasonal Influenza With Potential Function of LGALS9

Seasonal flu,primarily caused by influenza A H1N1 and H3N2 subtype viruses or influenza B viruses,is the most prevalent respiratory tract infection globally and leads to substantial morbidity andmortality annually.Despite the influenza virus being initially recognized as a respiratory pathogenwithwell-characterized transmission through respiratory droplets,its impact on the ocular epithelium and associated gene expression remains relatively unexplored.In this study,we investigated the transcriptional profiles of immortalized human corneal epithelial cells(HCE-S)and A549 human lung epithelial cells infected with H1N1 and H3N2 influenza virus.In comparison with A549 cells,a reduced number of differentially expressed geneswas observed in HCE-S upon influenza virus infection.Specifically,there was a significant upregulation of the genes IFI44L and OAS1,along with lower release of the CCL5/RANTES protein.Notably,our findings revealed uniquely upregulated LGALS9(encoding galectin-9)in HCE-S following infection with the 2009 pandemic H1N1 virus.Furthermore,targeted knockdown of LGALS9 in these cells resulted in a measurable decrease in viral infection,highlighting its role in the cellular responses to influenza virus and suggesting a novel avenue for antiviral therapy.Overall,our findings provide insight into the distinct mechanisms of influenza virus interactions with different epithelial cells and underscore the importance of studying the ocular surface in understanding influenza pathogenesis.

ROLE OF TOLL-LIKE RECEPTOR 4 IN AIRWAY INFLAMMATION OF CHRONIC OBSTRUCTIVE PULMONARY DISEASES

Objective To confirm if pulmonary epithelial cells express Toll-like receptor 4 （TLR4） and investigate the role of TLR4 in airway inflammation of chronic obstructive pulmonary diseases （COPD）. Methods The expressions of TLR4, IL-8 mRNA and NF-KB activation stimulated by differen factors E lipopolysacharides （LPS）, interleukin-lβ, cigarette smoking extract （CSE）] in pulmonary epithelial cells were investigated. Results LPS, CSE and IL-lβ induced the production of IL-8 and activation of NF-KB. The levels of 1L-8 mRNA and NF-KB protein in E1A ＋ cell were markedly higher than E1A- cell and A549 cell （ P 〈0. 05）. The TLR4 mRNA of all the cells increased along with the increase of LPS＇ stimulated time. There was significant difference among different LPS＇ doses （ 12 h： P = O. 039 ; 24 h ： P = O. 013 ）. The TLR4 mRNA of E1A ＋ cell was higher than the other two groups （ P 〈0. 05）. IL-lβ induced all the cells expressing TLR4 mRNA. CSE had no effect on the expression of TLR4 mRNA. Conclusion Pulmonary epithelial cells express TLR4. LPS and IL-lβ up-regulate IL-8 mediated via the activation of NF-KB induced by TLR4. But CSE up-regulates IL-8 mediated via the activation of NF-KB, which has no relation to TLR4 and may have another signal transduction pathway.

Ginsenoside Rg_1 reduced the invasion of S.aureus into respiratory epithelial cells involving pro-inflammatory cytokines and glucocorticoid receptor

The invasion of Staphylococcus aureus into respiratory epithelial cells and the followed inflammatory responses cause serious tissue damage.The aim of this study was to investigate the effects of ginsenoside Rg_1（Rg_1）on S.aureus infection in vitro and its action mechanism.An internalization model was constructed to determine the effect of Rg_1 on S.aureus invasion. The changes of expression of integrinβ1,NF-κB and glucocorticoid receptor were analyzed by Western blot.Expression of pro-inflammatory genes was validated using RT-PCR.The results demonstrated that Rg_1 treatment could reduce the invasion of S.aureus into rat pulmonary epithelial cells by down-regulating integrinβ1.Its anti-inflammatory action was exerted through reducing NF-κB and expressions of intercellular adhesion molecule-1（ICAM-1）,tumor necrosis factor-α（TNF-α）,interleukin-2 （IL-2）and interleukin-6（IL-6）.The increased expression of glucocorticoid receptor was involved in this regulation.The results suggested that Rg_1 could play a positive role in reducing S.aureus infections.Rg_1 could be used for the treatment of S.aureus infection,potentially.