Up-regulation of stomatin expression by hypoxia and glucocorticoid stabilizes membrane-associated actin in alveolar epithelial cells.
Bottom Line: Stomatin is an important lipid raft-associated protein which interacts with membrane proteins and plays a role in the membrane organization.In this study we found that hypoxia and dexamethasone (dex), a synthetic GC not only up-regulated the expression of stomatin alone, but also imposed additive effect on the expression of stomatin in A549 cells, primary AEC and lung of rats.Moreover, we found that hypoxia exposure did not affect membrane-associated actin, but decreased actin in cytoplasm in A549 cells.
Affiliation: Department of Pathophysiology, The Second Military Medical University, Shanghai, China.Show MeSH
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Mentions: As actin cytoskeleton plays an important role in alveolar epithelial barrier and in many cellular functions, we examined the relationship between stomatin and actin cytoskeleton. We first studied the cellular localization of actin and stomatin in A549 cells transiently transfected with blank vector (pEGFP-N3) or EGFP-tagged stomatin expression vector (pEGFP-N3-stom). The results showed that EGFP-tagged stomatin protein was clustered in the membrane and around the perinucleus. Stomatin proteins in the membrane were co-localized with membrane-associated actin filaments labelled by rhodamine-phalloidine in A549 cells (Fig. 6A).
Affiliation: Department of Pathophysiology, The Second Military Medical University, Shanghai, China.