Comparative characterization of mouse rectum CMT93-I and -II cells by expression of claudin isoforms and tight junction morphology and function.
Recent studies suggest that the morphological and physiological properties of tight junctions (TJs) are determined by the combination and mixing ratios of claudin isoforms. In this study, we tried to characterize mouse cell lines by expression of claudin isoforms to use for studying epithelial TJs by overexpression or suppression of claudin(s) in the cells and found that claudin-2 was expressed in a few mouse rectum carcinoma cells, CMT93 cells. We have isolated CMT93-I and -II cells from CMT93 cells by immunohistochemical screening for the presence or absence of claudin-2 expression. Immunofluorescence and RT-PCR analyses showed that expression of claudin-4, -6, -7 and -12 was detected in both cell lines, but claudin-2 was only expressed in CMT93-II cells. There were no differences in paracellular permeability between CMT93-I and -II cells examined by 4 kDa FITC-dextran and fluorescein sodium, or in the number of TJ strands examined by freeze-fracture electron microscopy. However, the transepithelial electrical resistance (TER) of CMT93-I cells was approximately 6.5 times higher than that of CMT93-II cells, suggesting that expression of claudin-2 may be related to decreased TER. Comparative examinations of CMT93-I and -II cells provide a clue how the combination and mixing ratios of claudin isoforms regulate the paracellular permeability.
Inai
Tetsuichiro
T
Department of Developmental Molecular Anatomy, Graduate School of Medical Sciences, Kyushu University, Maidashi 3-1-1, Higashi-ku, 812-8582 Fukuoka, Japan. inai@ana2.med.kyushu-u.ac.jp
Sengoku
Akihito
A
Hirose
Eiji
E
Iida
Hiroshi
H
Shibata
Yosaburo
Y
D000818:Animals; D002277:Carcinoma / Q000378:metabolism* / Q000648:ultrastructure*; D002460:Cell Line; D002462:Cell Membrane / Q000502:physiology; D057167:Claudins; D020285:Cryoelectron Microscopy; D017097:Electric Impedance; D005347:Fibroblasts / Q000378:metabolism / Q000648:ultrastructure; D005614:Freeze Fracturing; D015151:Immunoblotting; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D020033:Protein Isoforms / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D012004:Rectal Neoplasms / Q000378:metabolism* / Q000648:ultrastructure*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019108:Tight Junctions / Q000378:metabolism* / Q000648:ultrastructure*
D057167:Claudins; C113371:Cldn2 protein, mouse; D008565:Membrane Proteins; D020033:Protein Isoforms; D012333:RNA, Messenger