Effects of the cationic protein poly-L-arginine on airway epithelial cells in vitro.
BACKGROUND
Allergic asthma is associated with an increased number of eosinophils in the airway wall. Eosinophils secrete cationic proteins, particularly major basic protein (MBP).


OBJECTIVE
To investigate the effect of synthetic cationic polypeptides such as poly-L-arginine, which can mimic the effect of MBP, on airway epithelial cells.


METHODS
Cultured airway epithelial cells were exposed to poly-L-arginine, and effects were determined by light and electron microscopy.


RESULTS
Poly-L-arginine induced apoptosis and necrosis. Transmission electron microscopy showed mitochondrial damage and changes in the nucleus. The tight junctions were damaged, as evidenced by penetration of lanthanum. Scanning electron microscopy showed a damaged cell membrane with many pores. Microanalysis showed a significant decrease in the cellular content of magnesium, phosphorus, sodium, potassium and chlorine, and an increase in calcium. Plakoglobin immunoreactivity in the cell membrane was decreased, indicating a decrease in the number of desmosomes


CONCLUSIONS
The results point to poly-L-arginine induced membrane damage, resulting in increased permeability, loss of cell-cell contacts and generalized cell damage.
Shahana
Shahida
S
Department of Medical Cell Biology, University of Uppsala, Sweden. shahida.shahana@medcellbiol.uu.se
Kampf
Caroline
C
Roomans
Godfried M
GM
D017209:Apoptosis / Q000502:physiology; D001249:Asthma / Q000276:immunology / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000648:ultrastructure; D002467:Cell Nucleus / Q000187:drug effects / Q000648:ultrastructure; D002470:Cell Survival; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins / Q000032:analysis; D051180:Desmoplakins; D003896:Desmosomes / Q000187:drug effects / Q000648:ultrastructure; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D006801:Humans; D007150:Immunohistochemistry; D008928:Mitochondria / Q000187:drug effects / Q000648:ultrastructure; D009336:Necrosis; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D020545:Respiratory Mucosa / Q000187:drug effects* / Q000648:ultrastructure; D051185:gamma Catenin
D003598:Cytoskeletal Proteins; D051180:Desmoplakins; D010455:Peptides; D051185:gamma Catenin; C015462:polyarginine