TY - JOUR
T1 - Connexin 26 expression prevents down-regulation of barrier and fence functions of tight junctions by Na+/K+-ATPase inhibitor ouabain in human airway epithelial cell line Calu-3
AU - Go, Mitsuru
AU - Kojima, Takashi
AU - Takano, Ken ichi
AU - Murata, Masaki
AU - Koizumi, Junichi
AU - Kurose, Makoto
AU - Kamekura, Ryuta
AU - Osanai, Makoto
AU - Chiba, Hideki
AU - Spray, David C.
AU - Himi, Tetsuo
AU - Sawada, Norimasa
N1 - Funding Information:
We thank Ms. E. Suzuki (Sapporo Medical University) for technical support. This work was supported by Grants-in-Aid from the Ministry of Education, Culture, Sports Science, and Technology, and the Ministry of Health, Labour and Welfare of Japan and the Akiyama Foundation and the Long-Range Research Initiative Project of the Japan Chemical Industry Association.
PY - 2006/11/15
Y1 - 2006/11/15
N2 - Gap junctions are considered to play a crucial role in differentiation of epithelial cells and to be associated with tight junction proteins. In this study, to investigate the role of gap junctions in regulation of the barrier function and fence function on the tight junctions, we introduced the Cx26 gene into human airway epithelial cell line Clau-3 and used a disruption model of tight junctions employing the Na+/K+-ATPase inhibitor ouabain. In parental Calu-3 cells, gap junction proteins Cx32 and Cx43, but not Cx26, and tight junction proteins occludin, JAM-1, ZO-1, claudin-1, -2, -3, -4, -5, -6, -7, -8, -9, and -14 were detected by RT-PCR. The barrier function and fence function of tight junctions were well maintained, whereas the GJIC was low level. Treatment with ouabain caused disruption of the barrier function and fence function of tight junctions together with down-regulation of occludin, JAM-1, claudin-2, and -4 and up-regulation of ZO-1 and claudin-14. In Cx26 transfectants, Cx26 protein was detected by Western blotting and immunocytochemistry, and many gap junction plaques were observed with well-developed tight junction strands. Expression of claudin-14 was significantly increased in Cx26 transfectants compared to parental cells, and in some cells, Cx26 was co-localized with claudin-14. Interestingly, transfection with Cx26 prevented disruption of both functions of tight junctions by treatment with ouabain without changes in the tight junction proteins. Pretreatment with the GJIC blockers 18β-glycyrrhetinic acid and oleamide did not affect the changes induced by Cx26 transfection. These results suggest that Cx26 expression, but not the mediated intercellular communication, may regulate tight junction barrier and fence functions in human airway epithelial cell line Calu-3.
AB - Gap junctions are considered to play a crucial role in differentiation of epithelial cells and to be associated with tight junction proteins. In this study, to investigate the role of gap junctions in regulation of the barrier function and fence function on the tight junctions, we introduced the Cx26 gene into human airway epithelial cell line Clau-3 and used a disruption model of tight junctions employing the Na+/K+-ATPase inhibitor ouabain. In parental Calu-3 cells, gap junction proteins Cx32 and Cx43, but not Cx26, and tight junction proteins occludin, JAM-1, ZO-1, claudin-1, -2, -3, -4, -5, -6, -7, -8, -9, and -14 were detected by RT-PCR. The barrier function and fence function of tight junctions were well maintained, whereas the GJIC was low level. Treatment with ouabain caused disruption of the barrier function and fence function of tight junctions together with down-regulation of occludin, JAM-1, claudin-2, and -4 and up-regulation of ZO-1 and claudin-14. In Cx26 transfectants, Cx26 protein was detected by Western blotting and immunocytochemistry, and many gap junction plaques were observed with well-developed tight junction strands. Expression of claudin-14 was significantly increased in Cx26 transfectants compared to parental cells, and in some cells, Cx26 was co-localized with claudin-14. Interestingly, transfection with Cx26 prevented disruption of both functions of tight junctions by treatment with ouabain without changes in the tight junction proteins. Pretreatment with the GJIC blockers 18β-glycyrrhetinic acid and oleamide did not affect the changes induced by Cx26 transfection. These results suggest that Cx26 expression, but not the mediated intercellular communication, may regulate tight junction barrier and fence functions in human airway epithelial cell line Calu-3.
KW - Barrier function
KW - Cx26
KW - Fence function
KW - Ouabain
KW - Tight junctions
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U2 - 10.1016/j.yexcr.2006.08.014
DO - 10.1016/j.yexcr.2006.08.014
M3 - Article
C2 - 16982053
AN - SCOPUS:33750289407
SN - 0014-4827
VL - 312
SP - 3847
EP - 3856
JO - Experimental Cell Research
JF - Experimental Cell Research
IS - 19
ER -