Lipopolysaccharide downregulates the expression of ZO-1 protein through the Akt pathway
Abstract Background Neonatal bacterial meningitis is a common neonatal disease with high morbidity, and can cause serious sequelae when left untreated. Escherichia coli is the common pathogen, and its endotoxin, lipopolysaccharide (LPS) can damage the endothelial cells, increasing the permeability o...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
BMC
2022-10-01
|
| Series: | BMC Infectious Diseases |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s12879-022-07752-1 |
| _version_ | 1811226692808605696 |
|---|---|
| author | Peicen Zou Fan Yang Yijun Ding Di Zhang Ying Liu Jinjing Zhang Dan Wu Yajuan Wang |
| author_facet | Peicen Zou Fan Yang Yijun Ding Di Zhang Ying Liu Jinjing Zhang Dan Wu Yajuan Wang |
| author_sort | Peicen Zou |
| collection | DOAJ |
| description | Abstract Background Neonatal bacterial meningitis is a common neonatal disease with high morbidity, and can cause serious sequelae when left untreated. Escherichia coli is the common pathogen, and its endotoxin, lipopolysaccharide (LPS) can damage the endothelial cells, increasing the permeability of the blood-brain barrier (BBB), leading to intracranial inflammation. However, the specific mechanism of bacterial meningitis induced by LPS damaging BBB remains unclear. In this study, the mouse brain microvascular endothelial (bEND.3) cells were used as a research object to investigate whether LPS damage BBB through the PI3K/Akt pathway. Methods The bEND.3 cells were stimulated with different concentrations of LPS for 12 h, and the expression of tight junction proteins (ZO-1, claudin-5, occludin) was detected using western blotting. The cells were challenged with the same concentration of LPS (1ug/ml) across different timepoints (0, 2 h, 4 h, 6 h, 12 h, 24 h). Expression of TJ proteins and signal pathway molecules (PI3K, p-PI3K, Akt, p-Akt) were detected. The distribution of ZO-1 in bEND.3 cells were detected by immunofluorescence staining. Results A negative correlation is observed between ZO-1 and LPS concentration. Moreover, a reduced expression of ZO-1 was most significant under 1 ug/ml of LPS, and the difference was statistically significant (P < 0.05). Additionally, there is a negative correlation between ZO-1 and LPS stimulation time. Meanwhile, the expression of claudin-5 and occludin did not change significantly with the stimulation of LPS concentration and time. The immunofluorescence assay showed that the amount of ZO-1 on the surface of bEND.3 cells stimulated with LPS was significantly lower than that of the control group. After LPS stimulation, p-Akt protein increased at 2 h and peaked at 4 h. The titer of p-PI3K did not change significantly with time. Conclusion LPS can downregulate the expression of ZO-1; however, its effect on claudin-5 and occludin is minimal. Akt signal pathway may be involved in the regulation of ZO-1 expression induced by LPS in bEND.3 cells. |
| first_indexed | 2024-04-12T09:29:37Z |
| format | Article |
| id | doaj.art-b38ea3d0f781428b95e169b424bfa9c1 |
| institution | Directory Open Access Journal |
| issn | 1471-2334 |
| language | English |
| last_indexed | 2024-04-12T09:29:37Z |
| publishDate | 2022-10-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Infectious Diseases |
| spelling | doaj.art-b38ea3d0f781428b95e169b424bfa9c12022-12-22T03:38:24ZengBMCBMC Infectious Diseases1471-23342022-10-012211710.1186/s12879-022-07752-1Lipopolysaccharide downregulates the expression of ZO-1 protein through the Akt pathwayPeicen Zou0Fan Yang1Yijun Ding2Di Zhang3Ying Liu4Jinjing Zhang5Dan Wu6Yajuan Wang7Capital Institute of PediatricsDepartment of Neonatology, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s HealthDepartment of Neonatology, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s HealthDepartment of Neonatology, Children’s Hospital, Capital Institute of PediatricsDepartment of Neonatology, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s HealthDepartment of Neonatology, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s HealthDepartment of Neonatology, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s HealthDepartment of Neonatology, Children’s Hospital, Capital Institute of PediatricsAbstract Background Neonatal bacterial meningitis is a common neonatal disease with high morbidity, and can cause serious sequelae when left untreated. Escherichia coli is the common pathogen, and its endotoxin, lipopolysaccharide (LPS) can damage the endothelial cells, increasing the permeability of the blood-brain barrier (BBB), leading to intracranial inflammation. However, the specific mechanism of bacterial meningitis induced by LPS damaging BBB remains unclear. In this study, the mouse brain microvascular endothelial (bEND.3) cells were used as a research object to investigate whether LPS damage BBB through the PI3K/Akt pathway. Methods The bEND.3 cells were stimulated with different concentrations of LPS for 12 h, and the expression of tight junction proteins (ZO-1, claudin-5, occludin) was detected using western blotting. The cells were challenged with the same concentration of LPS (1ug/ml) across different timepoints (0, 2 h, 4 h, 6 h, 12 h, 24 h). Expression of TJ proteins and signal pathway molecules (PI3K, p-PI3K, Akt, p-Akt) were detected. The distribution of ZO-1 in bEND.3 cells were detected by immunofluorescence staining. Results A negative correlation is observed between ZO-1 and LPS concentration. Moreover, a reduced expression of ZO-1 was most significant under 1 ug/ml of LPS, and the difference was statistically significant (P < 0.05). Additionally, there is a negative correlation between ZO-1 and LPS stimulation time. Meanwhile, the expression of claudin-5 and occludin did not change significantly with the stimulation of LPS concentration and time. The immunofluorescence assay showed that the amount of ZO-1 on the surface of bEND.3 cells stimulated with LPS was significantly lower than that of the control group. After LPS stimulation, p-Akt protein increased at 2 h and peaked at 4 h. The titer of p-PI3K did not change significantly with time. Conclusion LPS can downregulate the expression of ZO-1; however, its effect on claudin-5 and occludin is minimal. Akt signal pathway may be involved in the regulation of ZO-1 expression induced by LPS in bEND.3 cells.https://doi.org/10.1186/s12879-022-07752-1LPSBlood-brain barrierTight junction proteinPI3K/Akt signal pathway |
| spellingShingle | Peicen Zou Fan Yang Yijun Ding Di Zhang Ying Liu Jinjing Zhang Dan Wu Yajuan Wang Lipopolysaccharide downregulates the expression of ZO-1 protein through the Akt pathway BMC Infectious Diseases LPS Blood-brain barrier Tight junction protein PI3K/Akt signal pathway |
| title | Lipopolysaccharide downregulates the expression of ZO-1 protein through the Akt pathway |
| title_full | Lipopolysaccharide downregulates the expression of ZO-1 protein through the Akt pathway |
| title_fullStr | Lipopolysaccharide downregulates the expression of ZO-1 protein through the Akt pathway |
| title_full_unstemmed | Lipopolysaccharide downregulates the expression of ZO-1 protein through the Akt pathway |
| title_short | Lipopolysaccharide downregulates the expression of ZO-1 protein through the Akt pathway |
| title_sort | lipopolysaccharide downregulates the expression of zo 1 protein through the akt pathway |
| topic | LPS Blood-brain barrier Tight junction protein PI3K/Akt signal pathway |
| url | https://doi.org/10.1186/s12879-022-07752-1 |
| work_keys_str_mv | AT peicenzou lipopolysaccharidedownregulatestheexpressionofzo1proteinthroughtheaktpathway AT fanyang lipopolysaccharidedownregulatestheexpressionofzo1proteinthroughtheaktpathway AT yijunding lipopolysaccharidedownregulatestheexpressionofzo1proteinthroughtheaktpathway AT dizhang lipopolysaccharidedownregulatestheexpressionofzo1proteinthroughtheaktpathway AT yingliu lipopolysaccharidedownregulatestheexpressionofzo1proteinthroughtheaktpathway AT jinjingzhang lipopolysaccharidedownregulatestheexpressionofzo1proteinthroughtheaktpathway AT danwu lipopolysaccharidedownregulatestheexpressionofzo1proteinthroughtheaktpathway AT yajuanwang lipopolysaccharidedownregulatestheexpressionofzo1proteinthroughtheaktpathway |