![]() ![]() The slides were rinsed gently with distilled water, then washed with PBS twice for five minutes each. Endogenous peroxidase activity was destroyed in 0.03% hydrogen peroxide in methanol for 30 minutes at room temperature. ![]() Slides were heated to 4☌ for five minutes, then to room temperature before washing in phosphate buffered saline (PBS) twice for five minutes each. ![]() Nasal polyps from steroid treated and steroid naive subjects were examined by immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR).Ĭryostat sections (4 μm) were cut onto silanated glass slides and stored at –20☌. It was hypothesised that c-fos-irm would be expressed as a marker of cellular activation in polyps, but that glucocorticoid treatment would reduce the levels of expression. Since Emery et al 1 noted the presence of c-fos, c-jun, and c-myc mRNA in human nasal polyps it has been of interest to determine the distribution of c-fos immunoreactive material ( c-fos-irm) in nasal polyps and the effects of glucocorticoids on c-fos-irm and mRNA expression in vivo. 9, 10Ī human model would be useful for studying this postulated interaction between glucocorticoid and c-fos and to learn its relevance to the actions of glucocorticoids in vivo. 3-5, 7, 8 Hence, synthesis of mRNAs for many proinflammatory products may become reduced. This reduction in the amount of free activated AP-1 may lead to a “default” reduction in the expression of genes that require AP-1 for activation. These activated receptors are thought to bind to activated AP-1, leading to mutual inactivation of both protein factors. 3-6 Glucocorticoids enter cells and bind to glucocorticoid receptors. One mechanism of glucocorticoid action is postulated to be an interaction with c-fos or AP-1. AP-1 helps initiate transcription of many proinflammatory genes, including those for cytokines. AP-1moves from the cytoplasm into the nucleus where it binds to AP-1 promoter sites on a wide variety of genes. 2 c-Fos combines with members of the c-jun family to form the transcription factor activation protein 1 ( AP-1). 1 The c-fos oncogene participates in transduction cascades that are initiated by many proinflammatory mediators. Nasal polyps are known to express high levels of proinflammatory transcription factors such as c-fos. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |