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Vanadium pentoxide increased PTEN and decreased SHP1 expression in NK-92MI cells, affecting PI3K-AKT-mTOR and Ras-MAPK pathways.
- Source :
- Journal of Immunotoxicology; Dec2018, Vol. 15 Issue 1, p1-11, 11p
- Publication Year :
- 2018
-
Abstract
- Vanadium is an air pollutant that imparts immunosuppressive effects on NK cell immune responses, in part, by dysregulating interleukin (IL)-2/IL-2R-mediated JAK signaling pathways and inducing apoptosis. The aim of the present study was to evaluate effects of vanadium pentoxide (V<subscript>2</subscript>O<subscript>5</subscript>) on other IL-2 receptor-mediated signaling pathways, i.e. PI3K-AKT-mTOR and Ras-MAPK. Here, IL-2-independent NK-92MI cells were exposed to different V<subscript>2</subscript>O<subscript>5</subscript> doses for 24 h periods. Expression of PI3K, Akt, mTOR, ERK1/2, MEK1, PTEN, SHP1, BAD and phosphorylated forms, as well as caspases-3, -8, -9, BAX and BAK in/on the cells were then determined by flow cytometry. The results show that V<subscript>2</subscript>O<subscript>5</subscript> was cytotoxic to NK cells in a dose-related manner. Exposure increased BAD and pBAD expression and decreased that of BAK and BAX, but cell death was not related to caspase activation. At 400 µM V<subscript>2</subscript>O<subscript>5</subscript>, expression of PI3K-p85 regulatory subunit increased 20% and pPI3K 50%, while that of the non-pPI3K 110α catalytic subunit decreased by 20%. At 200 μM, V<subscript>2</subscript>O<subscript>5</subscript> showed significant decrease in non-pAkt expression (p < 0.05); the decrease in pAkt expression was significant at 100 μM. Non-pmTOR expression displayed a significant downward trend beginning at 100 μM. Expressions of pMEK-1/2 and pERK-1/2 increased substantially at 200 μM V<subscript>2</subscript>O<subscript>5</subscript>. No differences were found with non-phosphorylated ERK-1/2. PTEN expression increased significantly at 100 μM V<subscript>2</subscript>O<subscript>5</subscript> exposure whereas pPTEN decreased by 18% at 25 μM V<subscript>2</subscript>O<subscript>5</subscript> concentrations, but remained unchanged thereafter. Lastly, V<subscript>2</subscript>O<subscript>5</subscript> at all doses decreased SHP1 expression and increased expression of its phosphorylated form. These results indicated a toxic effect of V<subscript>2</subscript>O<subscript>5</subscript> on NK cells that was due in part to dysregulation of signaling pathways mediated by IL-2 via increased PTEN and decreased SHP1 expression. These results can help to explain some of the known deleterious effects of this particular form of vanadium on innate immune responses<subscript>.</subscript> [ABSTRACT FROM AUTHOR]
- Subjects :
- VANADIUM pentoxide
POLLUTANTS
IMMUNE response
INTERLEUKINS
APOPTOSIS
Subjects
Details
- Language :
- English
- ISSN :
- 1547691X
- Volume :
- 15
- Issue :
- 1
- Database :
- Complementary Index
- Journal :
- Journal of Immunotoxicology
- Publication Type :
- Academic Journal
- Accession number :
- 134609647
- Full Text :
- https://doi.org/10.1080/1547691X.2017.1404662