Maintenance of paracellular barrier function by insulin-like growth factor-I in submandibular gland cells.
Insulin-like growth factor-I (IGF-I) is expressed in salivary glands. We examined the effects of IGF-I on cell number, the expression and distribution of tight junction proteins and the paracellular barrier function in cells derived from rat submandibular glands. When those cells were cultured in medium containing 10% foetal bovine serum (FBS) or IGF-I, the number of cells was comparable at 10 days. However, in the presence of inhibitor of IGF-I receptors, the number of cells cultured with FBS only was clearly reduced. The tight junction proteins occludin and claudin-3 were similarly detected by Western blotting in cells cultured with IGF-I or FBS. Immunostaining revealed that occludin and another tight junction protein (ZO-1) were similarly localized at intracellular junctions of cells cultured with IGF-I or FBS. The barrier functions were evaluated by transepithelial resistance (TER) and by FITC-dextran permeability. The TER values and FITC-dextran permeability of cells cultured with IGF-I or FBS were comparable. These observations suggest that IGF-I contributes to the maintenance not only of the cell number of salivary gland cells but also of their paracellular barrier function via the expression and distribution of tight junction proteins.
Mitsui
Retsu
R
Department of Physiology, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba 271-8587, Japan.
Fujita-Yoshigaki
Junko
J
Narita
Takanori
T
Matsuki-Fukushima
Miwako
M
Satoh
Keitaro
K
Qi
Bing
B
Guo
Ming-Yu
MY
Katsumata-Kato
Osamu
O
Sugiya
Hiroshi
H
D000818:Animals; D001769:Blood; D002452:Cell Count; D018929:Cell Culture Techniques; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D062465:Claudin-3; D003470:Culture Media; D016895:Culture Media, Serum-Free; D003911:Dextrans; D017097:Electric Impedance; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives; D005456:Fluorescent Dyes; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D008565:Membrane Proteins / Q000032:analysis / Q000187:drug effects; D062793:Occludin; D010539:Permeability; D010750:Phosphoproteins / Q000032:analysis; D051381:Rats; D017526:Receptor, IGF Type 1 / Q000037:antagonists & inhibitors; D018987:Salivary Ducts / Q000166:cytology / Q000187:drug effects; D013363:Submandibular Gland / Q000166:cytology / Q000187:drug effects*; D019108:Tight Junctions / Q000187:drug effects*; D062826:Zonula Occludens-1 Protein
D062465:Claudin-3; C568124:Cldn3 protein, rat; D003470:Culture Media; D016895:Culture Media, Serum-Free; D003911:Dextrans; D005456:Fluorescent Dyes; D008565:Membrane Proteins; D062793:Occludin; C568987:Ocln protein, rat; D010750:Phosphoproteins; C569044:Tjp1 protein, rat; D062826:Zonula Occludens-1 Protein; C015219:fluorescein isothiocyanate dextran; D007334:Insulin-Like Growth Factor I; D017526:Receptor, IGF Type 1; D016650:Fluorescein-5-isothiocyanate