Albumin is a major serum protein and is frequently used as a cell culture supplement. It is
crucially involved in the regulation of osmotic pressure and distribution of fluid between different
compartments. Alveolar epithelial Na+
transport drives alveolar fluid clearance (AFC), enabling air
breathing. Whether or not albumin affects AFC and Na+
transport is yet unknown. We therefore
determined the acute and chronic effects of albumin on Na+
transport in fetal distal lung epithelial
(FDLE) cells and the involved kinase pathways. Chronic BSA treatment strongly increased epithelial
Na+
transport and barrier integrity in Ussing chambers. BSA did not elevate mRNA expression of
Na+
transporters in FDLE cells after 24 h. Moreover, acute BSA treatment for 45 min mimicked the
chronic effects. The elevated Na+
transport was caused by an increased maximal ENaC activity, while
Na,K-ATPase activity remained unchanged. Acute and chronic BSA treatment lowered membrane
permeability, confirming the increased barrier integrity observed in Ussing chambers. Western blots
demonstrated an increased phosphorylation of AKT and SGK1, and PI3K inhibition abolished the
stimulating effect of BSA. BSA therefore enhanced epithelial Na+
transport and barrier integrity by
activating the PI3K/AKT/SGK1 pathway
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:88457 |
| Date | 05 December 2023 |
| Creators | Laube, Mandy, H. Thome, Ulrich |
| Publisher | MDPI |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, doc-type:article, info:eu-repo/semantics/article, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | 1422-0067, 10.3390/ijms23158823 |
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