| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 From the Laboratory for Retina and Optic Nerve Research, and 2 Departments of Pharmacology, 3 Physiology and Biophysics, and 4 Ophthalmology, Dalhousie University, Halifax, Nova Scotia, Canada; and the 5 Department of Ophthalmology, Yale Medical School, New Haven, Connecticut.
PURPOSE. To investigate whether signaling pathways that incorporate protein tyrosine kinases and phosphatases regulate PKC-sensitive, volume-sensitive Cl- currents (ICl,vol) in cultured rabbit nonpigmented ciliary epithelial cells.
METHODS. Activation of ICl,vol in response to hyposmotic stimulation was recorded with whole-cell patch-clamp techniques in the presence of pharmacologic agents that activate or block kinases and phosphatases.
RESULTS. ICl,vol in rabbit nonpigmented ciliary epithelial cells was identified as a PKC-sensitive, volume-sensitive Cl- current, because current was downregulated during cell swelling by phorbol-12-dibutyrate, a PKC activator, and the PKC inhibitors, calphostin and chelerythrine, enhanced the current. Activation of c-Src tyrosine kinases, with an Src activator peptide (EPQ(pY)EEIPI), increased ICl,vol after hyposmotic stimulation, whereas the protein tyrosine kinase inhibitor, genistein, but not its inactive analogue daidzein, inhibited the current. The phosphatidylinositol-3-kinase (PI3K) inhibitor, wortmannin, inhibited ICl,vol. Wortmannin did not further inhibit ICl,vol in cells pretreated with the protein tyrosine kinase inhibitor, genistein, but blocked enhancement of ICl,vol by PKC inhibitors. The serine-threonine protein phosphatase (PP) inhibitor, okadaic acid, blocked activation of ICl,vol, whereas insulin, which activates PI3K and PP-1, enhanced the current. The insulin-enhanced current was also blocked by okadaic acid. ICl,vol was not activated under isosmotic conditions by the simultaneous inhibition of PKC with calphostin and activation of PP-1 by insulin.
CONCLUSIONS. These data show that PKC-sensitive Cl- currents activated in response to cell swelling in nonpigmented ciliary epithelial cells are modulated by protein tyrosine kinase, PI3K, and PP signaling pathways. Activation of PP and PKC may involve the upstream intermediaries Src tyrosine kinase and PI3K.
This article has been cited by other articles:
|
|
 |
|
  C. Jeulin, V. Seltzer, D. Bailbe, K. Andreau, and F. Marano EGF mediates calcium-activated chloride channel activation in the human bronchial epithelial cell line 16HBE14o-: involvement of tyrosine kinase p60c-src Am J Physiol Lung Cell Mol Physiol, September 1, 2008; 295(3): L489 - L496. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. Alessandri-Haber, O. A. Dina, E. K. Joseph, D. B. Reichling, and J. D. Levine Interaction of Transient Receptor Potential Vanilloid 4, Integrin, and Src Tyrosine Kinase in Mechanical Hyperalgesia J. Neurosci., January 30, 2008; 28(5): 1046 - 1057. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A M Petrunkina, R A P Harrison, M Tsolova, E Jebe, and E Topfer-Petersen Signalling pathways involved in the control of sperm cell volume Reproduction, January 1, 2007; 133(1): 61 - 73. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. S. Dawson, D. C. Zawieja, M. H. Wu, and H. J. Granger Signaling pathways mediating VEGF165-induced calcium transients and membrane depolarization in human endothelial cells FASEB J, May 1, 2006; 20(7): 991 - 993. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. M. Browe and C. M. Baumgarten EGFR Kinase Regulates Volume-sensitive Chloride Current Elicited by Integrin Stretch via PI-3K and NADPH Oxidase in Ventricular Myocytes J. Gen. Physiol., February 27, 2006; 127(3): 237 - 251. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. B. Walsh and J. Zhang Regulation of cardiac volume-sensitive chloride channel by focal adhesion kinase and Src kinase Am J Physiol Heart Circ Physiol, December 1, 2005; 289(6): H2566 - H2574. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Z. Ren and C. M. Baumgarten Antagonistic regulation of swelling-activated Cl- current in rabbit ventricle by Src and EGFR protein tyrosine kinases Am J Physiol Heart Circ Physiol, June 1, 2005; 288(6): H2628 - H2636. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. W. Do, W. Lu, C. H. Mitchell, and M. M. Civan Inhibition of Swelling-Activated Cl- Currents by Functional Anti-ClC-3 Antibody in Native Bovine Non-Pigmented Ciliary Epithelial Cells Invest. Ophthalmol. Vis. Sci., March 1, 2005; 46(3): 948 - 955. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. M. Browe and C. M. Baumgarten Angiotensin II (AT1) Receptors and NADPH Oxidase Regulate Cl- Current Elicited by {beta}1 Integrin Stretch in Rabbit Ventricular Myocytes J. Gen. Physiol., August 30, 2004; 124(3): 273 - 287. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Alessandri-Haber, O. A. Dina, J. J. Yeh, C. A. Parada, D. B. Reichling, and J. D. Levine Transient Receptor Potential Vanilloid 4 Is Essential in Chemotherapy-Induced Neuropathic Pain in the Rat J. Neurosci., May 5, 2004; 24(18): 4444 - 4452. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
X.-L. Du, Z. Gao, C.-P. Lau, S.-W. Chiu, H.-F. Tse, C. M. Baumgarten, and G.-R. Li Differential Effects of Tyrosine Kinase Inhibitors on Volume-sensitive Chloride Current in Human Atrial Myocytes: Evidence for Dual Regulation by Src and EGFR Kinases J. Gen. Physiol., March 29, 2004; 123(4): 427 - 439. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. E. Bucheimer and J. Linden Purinergic regulation of epithelial transport J. Physiol., March 1, 2004; 555(2): 311 - 321. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. M. Browe and C. M. Baumgarten Stretch of {beta}1 Integrin Activates an Outwardly Rectifying Chloride Current via FAK and Src in Rabbit Ventricular Myocytes J. Gen. Physiol., November 24, 2003; 122(6): 689 - 702. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
