Dexamethasone promotes the expression of PTEN by stimulating PTEN transcription To further confirm the part of dexamethasone in PTEN expression, human A549 lung epithelial cells were handled with dexamethasone on the concentration 10 five M 10 8 M for 24 h, or in the concentration 10 five M and harvested at 24, 48, 72, 96 h. The expression of PTEN mRNA was analyzed by real time PCR. As proven in Figure 3A and 3B, dexamethasone therapy enhanced PTEN mRNA expression in a dose and time dependent manner, indicating the results of dexamethasone on PTEN expression could possibly have occurred in the transcriptional level. To confirm this hypothesis, the PTEN promoter was cloned and constructed into the pGL3 luciferase plasmid, as described within the Systems part. We noticed that dexamethasone remedy significantly greater the PTEN promoter activity , indicating that dexamethasone promoted the expression of PTEN by stimulating PTEN transcription. The effect of acetylation of histone around the regulation of PTEN expression As histone acetylation is one of the significant mechanisms for the result of glucocorticoids , we hypothesized that the regulation of PTEN expression by dexamethasone may well involve histone acetylation.
We treated A549 cells initially with TSA, and confirmed that histone deacetylase inhibition was related with the up regulation of PTEN transcription , an observation that was constant by using a prior report . We then STAT inhibitors selleck treated A549 cells with dexamethasone plus the histone acetylase inhibitor anacardic acid for 24 h. We extracted the total RNA and analyzed it by realtime PCR. We uncovered that dexamethasone alone elevated PTEN mRNA expression, whereas remedy with anacardic acid attenuated the dexamethasoneinduced up regulation of PTEN mRNA , indicating that histone acetylation inhibition is involved with the dexamethasone induced PTEN expression. Discussion OVA induced asthma mice model is widely implemented for study of human asthma as a consequence of resemblance pathology and pathophysiology. Based on this model, we confirmed that PTEN proteins had been below expressed in mice with OVAinduced asthma.
We also discovered that treatment of these mice with dexamethasone resulted inside the restoration of PTEN expression. PI3K Inhibitor In vitro scientific studies making use of human lung epithelial cell A549 uncovered that dexamethasone was ready to improve both PTEN promoter activity and gene expression. Data from every one of these assays collectively propose that the effect of glucocorticoids on asthma may perhaps partly pass with the PTEN signaling pathway, and that PTEN is actually a new target gene involved with the response to dexamethasone. Although PTEN may be a really conserved gene with greater than 80% identity while in the promoter area among Homo sapiens and Mus musculus, additional beneficial data could be derived fromhumans. So, further studies in asthma individuals is critical.