LAMP, a new imaging assay of gap junctional communication unveils that Ca2+ influx inhibits cell coupling

2004 ◽  
Vol 2 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Kenneth Dakin ◽  
YuRui Zhao ◽  
Wen-Hong Li
Keyword(s):  
Cell Coupling ◽  
Gap Junctional Communication ◽  
Junctional Communication ◽  
Gap Junctional

Gap-junctional communication in a communication-defective and in a communication-competent teratocarcinoma cell line

1985 ◽  
Vol 76 (1) ◽  
pp. 85-95
Author(s):  
C.W. Lo ◽  
D. Fang ◽  
M.L. Hooper
Keyword(s):  
Cell Line ◽  
Coupling Coefficient ◽  
Dye Coupling ◽  
Cell Coupling ◽  
Teratocarcinoma Cell ◽  
Gap Junctional Communication ◽  
Junctional Communication ◽  
Gap Junctional ◽  
Ionic Coupling ◽  
Cell Cell

We examined the gap-junctional communication properties of a communication-defective cell line R5/3 and its communication-competent revertant H2T12. For these studies, we carried out microelectrode impalements to monitor ionic coupling and dye coupling. Our dye-injection experiments revealed that the H2T12 cells are much more efficient in dye coupling than the R5/3 cells. This latter observation is in agreement with the previous finding that the H2T12 cells are much better metabolically coupled than the R5/3 cells. With ionic coupling measurements, however, both cell lines exhibited similar levels of cell-cell coupling. The R5/3 cells demonstrated an ionic coupling coefficient of 0.19 +/− 0.011 (S.E.M.) and H2T12 a coupling coefficient of 0.25 +/− 0.009 (S.E.M.). These results in conjunction with observations from other studies indicate that the different experimental approaches for monitoring gap-junctional communication may have different levels of sensitivity for detecting as opposed to measuring the level of cell-cell coupling.

scholarly journals Inhibition of Endothelial Wound Repair by Dominant Negative Connexin Inhibitors

2001 ◽  
Vol 12 (4) ◽  
pp. 831-845 ◽  
Author(s):  
Brenda R. Kwak ◽  
Michael S. Pepper ◽  
Daniel B. Gros ◽  
Paolo Meda
Keyword(s):  
Endothelial Cells ◽  
Wound Repair ◽  
Single Cells ◽  
Dominant Negative ◽  
Cell Coupling ◽  
Mechanical Wounding ◽  
Functional Changes ◽  
Gap Junctional Communication ◽  
Junctional Communication ◽  
Gap Junctional

Wounding of endothelial cells is associated with altered direct intercellular communication. To determine whether gap junctional communication participates to the wound repair process, we have compared connexin (Cx) expression, cell-to-cell coupling and kinetics of wound repair in monolayer cultures of PymT-transformed mouse endothelial cells (clone bEnd.3) and in bEnd.3 cells expressing different dominant negative Cx inhibitors. In parental bEnd.3 cells, mechanical wounding increased expression of Cx43 and decreased expression of Cx37 at the site of injury, whereas Cx40 expression was unaffected. These wound-induced changes in Cx expression were associated with functional changes in cell-to-cell coupling, as assessed with different fluorescent tracers. Stable transfection with cDNAs encoding for the chimeric connexin 3243H7 or the fusion protein Cx43-βGal resulted in perturbed gap junctional communication between bEnd.3 cells under both basal and wounded conditions. The time required for complete repair of a defined wound within a confluent monolayer was increased by ∼50% in cells expressing the dominant negative Cx inhibitors, whereas other cell properties, such as proliferation rate, migration of single cells, cyst formation and extracellular proteolytic activity, were unaltered. These findings demonstrate that proper Cx expression is required for coordinated migration during repair of an endothelial wound.

Gap junctional communication underpins EDHF-type relaxations evoked by ACh in the rat hepatic artery

2001 ◽  
Vol 280 (6) ◽  
pp. H2441-H2450 ◽  
Author(s):  
Andrew T. Chaytor ◽  
Patricia E. M. Martin ◽  
David H. Edwards ◽  
Tudor M. Griffith
Keyword(s):  
Gap Junctions ◽  
Hepatic Artery ◽  
Lucifer Yellow ◽  
Dye Transfer ◽  
Cell Coupling ◽  
Gap Junctional Communication ◽  
Junctional Communication ◽  
A7r5 Cells ◽  
Gap Junctional

Synthetic peptides homologous to the Gap 26 and Gap 27 domains of the first and second extracellular loops of the major vascular connexins (Cx37, Cx40, and Cx43) have been used to investigate the role of gap junctions in endothelium-derived hyperpolarizing factor (EDHF)-type relaxations of the rat hepatic artery. These peptides were designated 37,40Gap 26,43Gap 26, 37,43Gap 27, and 40Gap 27, according to connexin specificity. When administered at 600 μM, none of the peptides individually affected maximal EDHF-type relaxations to ACh. By contrast, at 300 μM each, paired peptide combinations targeting more than one connexin subtype attenuated relaxation by up to 50%, and responses were abolished by the triple peptide combination 43Gap 26 + 40Gap 27 + 37,43Gap 27. In parallel experiments with A7r5 cells expressing Cx40 and Cx43, neither 43Gap 26 nor40Gap 27 affected intercellular diffusion of Lucifer yellow individually but, in combination, significantly attenuated dye transfer. The findings confirm that functional cell-cell coupling may depend on more than one connexin subtype and demonstrate that direct intercellular communication via gap junctions constructed from Cx37, Cx40, and Cx43 underpins EDHF-type responses in the rat hepatic artery.

Manipulation of gap junctional communication during compaction of the mouse early embryo

Development ◽  
1986 ◽  
Vol 91 (1) ◽  
pp. 283-296
Author(s):  
Harry Goodall
Keyword(s):  
Cell Adhesion ◽  
Early Embryo ◽  
Embryonal Carcinoma Cell ◽  
Cell Coupling ◽  
Calcium Dependent ◽  
Gap Junctional Communication ◽  
Embryonal Carcinoma Cell Line ◽  
Junctional Communication ◽  
Junctional Coupling ◽  
Gap Junctional

Three treatments that prevent cell flattening during compaction of the mouse preimplantation embryo were assessed for their effects on the onset of gap junctional communication. Medium low in calcium (LCM) and an antiserum to an embryonal carcinoma cell line (anti-EC; Johnson et al. 1979) both prevented the establishment of coupling between blastomeres of the 8-cell embryo as assessed by transmission of carboxyfluorescein or by ionic coupling. Since neither of these agents prevents the contact-mediated induction of cell polarity that occurs at this stage, it is concluded that the induction of this process is not signalled via gap junctions. A monoclonal antibody (ECCD-1; Yoshida-Noro, Suzuki & Takeichi, 1984), that recognizes more specific components of the calcium-dependent cell adhesion system, failed to prevent the onset of junctional coupling. This suggests that the onset of junctional coupling is not dependent upon extensive cell apposition and that the requirement for extracellular Ca2+ resides at a level other than that of cell adhesion. Moreover, neither LCM nor anti-EC could reverse cell coupling once it had become established despite their complete reversal of cell flattening.

Conduction of vasomotor responses in arterioles: a role for cell-to-cell coupling?

1989 ◽  
Vol 256 (3) ◽  
pp. H838-H845 ◽  
Author(s):  
S. S. Segal ◽  
B. R. Duling
Keyword(s):  
Adrenergic Receptors ◽  
Adrenergic Receptor ◽  
Sucrose Solution ◽  
Cheek Pouch ◽  
Cell Coupling ◽  
Vasomotor Responses ◽  
Gap Junctional Communication ◽  
Alpha Adrenergic Receptors ◽  
Junctional Communication ◽  
Gap Junctional

Vasomotor responses of arterioles triggered by the iontophoretic application of acetylcholine (ACh) or norepinephrine (NE) are conducted along the vessel wall. The present experiments focus on elucidating the mechanism of conduction in arterioles of the superfused cheek pouch preparation in pentobarbital-anesthetized hamsters. Localized muscarinic or adrenergic receptor blockade on an arteriolar segment produced by atropine or phentolamine, respectively, did not affect propagation through the region of blockade but did block vasomotor responses to ACh or NE applied to the segment. Thus muscarinic and alpha-adrenergic receptors can trigger the propagation of vasomotor responses, but these receptors are not involved in their conduction. Tetrodotoxin did not affect either local or propagated responses to ACh or NE. Treatment of arteriolar segments with calcium antagonists (verapamil, diltiazem, nifedipine, or manganese) caused maximal dilation locally but did not affect propagation through the dilated region. The preceding findings argue against a neural pathway for propagation. A depolarizing solution (137 mM KCl) applied by micropipette to arteriolar segments caused both local and propagated vasoconstriction and significantly attenuated propagated vasodilation induced with ACh (P less than 0.05). Putative antagonists of gap-junctional communication (hypertonic sucrose solution, octanol, CO2) reversibly attenuated or abolished propagated responses. We hypothesize that propagation of vasomotor responses along arterioles is initiated via a local change in membrane potential secondary to receptor occupation and that changes in potential spread electrotonically through gap junctions coupling smooth muscle cells, endothelial cells, or both.

scholarly journals Disruption of Gap Junctional Communication by the Platelet-derived Growth Factor Is Mediated via Multiple Signaling Pathways

1999 ◽  
Vol 274 (15) ◽  
pp. 10489-10496 ◽  
Author(s):  
Mohammad Z. Hossain ◽  
Ajit B. Jagdale ◽  
Peng Ao ◽  
Andrius Kazlauskas ◽  
Alton L. Boynton
Keyword(s):  
Growth Factor ◽  
Signaling Pathways ◽  
Platelet Derived Growth Factor ◽  
Gap Junctional Communication ◽  
Junctional Communication ◽  
Gap Junctional ◽  
Multiple Signaling

Role of protein kinase C in the regulation of gap junctional communication

1994 ◽  
Vol 14 (6) ◽  
pp. 259-270 ◽  
Author(s):  
Irina V. Budunova ◽  
Leonid A. Mittelman ◽  
Joanna Miloszewska
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Gap Junctional Communication ◽  
Kinase C ◽  
Junctional Communication ◽  
Gap Junctional
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