Comparison of Albumin Uptake in Rat Alveolar Type II and Type I-like Epithelial Cells in Primary Culture
Overview
Affiliations
Purpose: To elucidate and compare the activity and mechanism of albumin uptake in primary cultured alveolar type II and type I-like epithelial cells.
Materials And Methods: Type II epithelial cells isolated from rat lungs were cultured for 2 days at 5 x 10(6) cells/35-mm dish or for 6 days at 2 x 10(6) cells/35-mm dish. The mRNA expression of marker genes and FITC-albumin uptake were examined.
Results: The cells cultured for 2 days exhibited cuboidal type II epithelial morphology with lamellar bodies inside the cells, while the cells cultured for 6 days exhibited squamous type I epithelial morphology. These morphological characteristics were consistent with the changes in mRNA expression pattern of marker genes. FITC-albumin uptake in both cells was temperature-dependent and was inhibited by metabolic inhibitors and bafilomycin A1. The rate of uptake was much higher in type II cells than type I-like cells. In both cells, FITC-albumin uptake was inhibited by clathrin mediated-endocytosis inhibitors, but not by caveolae mediated-endocytosis inhibitors.
Conclusions: These findings indicate that albumin in alveolar lining fluid is internalized into type II and type I epithelial cells via clathrin-mediated endocytosis, and the rate of albumin uptake is higher in type II cells than type I cells.
Kryvenko V, Vadasz I Front Immunol. 2024; 15:1360370.
PMID: 38533500 PMC: 10963603. DOI: 10.3389/fimmu.2024.1360370.
Kryvenko V, Alberro-Brage A, Fysikopoulos A, Wessendorf M, Tello K, Morty R Int J Mol Sci. 2023; 24(3).
PMID: 36768968 PMC: 9916738. DOI: 10.3390/ijms24032644.
Challenges and Strategies to Enhance the Systemic Absorption of Inhaled Peptides and Proteins.
Qin L, Cui Z, Wu Y, Wang H, Zhang X, Guan J Pharm Res. 2022; 40(5):1037-1055.
PMID: 36385216 PMC: 9668393. DOI: 10.1007/s11095-022-03435-3.
Laube M, Thome U Int J Mol Sci. 2022; 23(15).
PMID: 35955955 PMC: 9368928. DOI: 10.3390/ijms23158823.
Maity N, Jaswal A, Gautam A, Sahai V, Mishra S Bioprocess Biosyst Eng. 2022; 45(2):409-424.
PMID: 34999948 DOI: 10.1007/s00449-021-02670-z.