Abstract
Ca2+ activated Cl- transport is found in airways and other organs and is abnormal in cystic fibrosis, polycystic kidney disease and infectious diarrhea. The molecular identity of Ca2+ activated Cl- channels (CaCC) in the airways is still obscure. Bestrophin proteins were described to form CaCC and to regulate voltage gated Ca2+ channels. The present Ussing chamber recordings on tracheas of bestrophin 1 knockout (vmd2-/-) mice indicate a reduced Cl- secretion when activated by the purinergic agonist ATP (0.1-1 μM). As two paralogs, best1 and best2, are present in mouse tracheal epithelium, we examined the contribution of each paralog to Ca2+ activated Cl- secretion. In whole cell patch-clamp measurements on primary airway epithelial cells from vmd2-/- tracheas, ATP activated Cl- currents were reduced by 50%. Additional knockdown of mbest2 in vmd2-/- cells by short interfering RNA further suppressed ATP-induced Cl- currents down to 20% of that observed in cells from vmd2+/+ animals. Moreover, RNAi-suppression of both mbest1 and mbest2 reduced CaCC in vmd2+/+ cells. Direct activation of CaCC by increase of intracellular Ca2+ was also reduced in whole cell recordings of vmd2-/- cells. These results clearly suggest a role of bestrophin 1 and 2 for Ca2+ dependent Cl- secretion in mouse airways.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1993-2000 |
| Number of pages | 8 |
| Journal | Biochimica et Biophysica Acta - Molecular Cell Research |
| Volume | 1783 |
| Issue number | 10 |
| DOIs | |
| State | Published - Oct 1 2008 |
| Externally published | Yes |
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Keywords
- Airways
- Bestrophin 1
- Bestrophin 2
- Ca activated Cl channel
- Cl conductance
- Epithelium
- Vmd2
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology
Cite this
Bestrophin 1 and 2 are components of the Ca2+ activated Cl- conductance in mouse airways. / Barro, Rene; Schreiber, Rainer; Kunzelmann, Karl.
In: Biochimica et Biophysica Acta - Molecular Cell Research, Vol. 1783, No. 10, 01.10.2008, p. 1993-2000.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Bestrophin 1 and 2 are components of the Ca2+ activated Cl- conductance in mouse airways
AU - Barro, Rene
AU - Schreiber, Rainer
AU - Kunzelmann, Karl
PY - 2008/10/1
Y1 - 2008/10/1
N2 - Ca2+ activated Cl- transport is found in airways and other organs and is abnormal in cystic fibrosis, polycystic kidney disease and infectious diarrhea. The molecular identity of Ca2+ activated Cl- channels (CaCC) in the airways is still obscure. Bestrophin proteins were described to form CaCC and to regulate voltage gated Ca2+ channels. The present Ussing chamber recordings on tracheas of bestrophin 1 knockout (vmd2-/-) mice indicate a reduced Cl- secretion when activated by the purinergic agonist ATP (0.1-1 μM). As two paralogs, best1 and best2, are present in mouse tracheal epithelium, we examined the contribution of each paralog to Ca2+ activated Cl- secretion. In whole cell patch-clamp measurements on primary airway epithelial cells from vmd2-/- tracheas, ATP activated Cl- currents were reduced by 50%. Additional knockdown of mbest2 in vmd2-/- cells by short interfering RNA further suppressed ATP-induced Cl- currents down to 20% of that observed in cells from vmd2+/+ animals. Moreover, RNAi-suppression of both mbest1 and mbest2 reduced CaCC in vmd2+/+ cells. Direct activation of CaCC by increase of intracellular Ca2+ was also reduced in whole cell recordings of vmd2-/- cells. These results clearly suggest a role of bestrophin 1 and 2 for Ca2+ dependent Cl- secretion in mouse airways.
AB - Ca2+ activated Cl- transport is found in airways and other organs and is abnormal in cystic fibrosis, polycystic kidney disease and infectious diarrhea. The molecular identity of Ca2+ activated Cl- channels (CaCC) in the airways is still obscure. Bestrophin proteins were described to form CaCC and to regulate voltage gated Ca2+ channels. The present Ussing chamber recordings on tracheas of bestrophin 1 knockout (vmd2-/-) mice indicate a reduced Cl- secretion when activated by the purinergic agonist ATP (0.1-1 μM). As two paralogs, best1 and best2, are present in mouse tracheal epithelium, we examined the contribution of each paralog to Ca2+ activated Cl- secretion. In whole cell patch-clamp measurements on primary airway epithelial cells from vmd2-/- tracheas, ATP activated Cl- currents were reduced by 50%. Additional knockdown of mbest2 in vmd2-/- cells by short interfering RNA further suppressed ATP-induced Cl- currents down to 20% of that observed in cells from vmd2+/+ animals. Moreover, RNAi-suppression of both mbest1 and mbest2 reduced CaCC in vmd2+/+ cells. Direct activation of CaCC by increase of intracellular Ca2+ was also reduced in whole cell recordings of vmd2-/- cells. These results clearly suggest a role of bestrophin 1 and 2 for Ca2+ dependent Cl- secretion in mouse airways.
KW - Airways
KW - Bestrophin 1
KW - Bestrophin 2
KW - Ca activated Cl channel
KW - Cl conductance
KW - Epithelium
KW - Vmd2
UR - http://www.scopus.com/inward/record.url?scp=50849126787&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=50849126787&partnerID=8YFLogxK
U2 - 10.1016/j.bbamcr.2008.06.016
DO - 10.1016/j.bbamcr.2008.06.016
M3 - Article
C2 - 18652850
AN - SCOPUS:50849126787
VL - 1783
SP - 1993
EP - 2000
JO - Biochimica et Biophysica Acta - Molecular Cell Research
JF - Biochimica et Biophysica Acta - Molecular Cell Research
SN - 0167-4889
IS - 10
ER -