Decreased gap-junctional communication associated with segregation of the neuronal phenotype in the RT4 cell-line family

1998 ◽  
Vol 292 (1) ◽  
pp. 27-35 ◽  
Author(s):  
L. M. Donahue ◽  
Daniel R. Webster ◽  
Ivvanee Martinez ◽  
David C. Spray
Keyword(s):  
Cell Line ◽  
Neuronal Phenotype ◽  
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 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

Gap junction-mediated transfer of left-right patterning signals in the early chick blastoderm is upstream of Shh asymmetry in the node

Development ◽  
1999 ◽  
Vol 126 (21) ◽  
pp. 4703-4714 ◽  
Author(s):  
M. Levin ◽  
M. Mercola
Keyword(s):  
Gene Expression ◽  
Gap Junction ◽  
Large Scale ◽  
Chick Blastoderm ◽  
Gap Junction Channels ◽  
Gap Junctional Communication ◽  
Junctional Communication ◽  
Left And Right ◽  
The Right ◽  
Gap Junctional

Invariant patterning of left-right asymmetry during embryogenesis depends upon a cascade of inductive and repressive interactions between asymmetrically expressed genes. Different cascades of asymmetric genes distinguish the left and right sides of the embryo and are maintained by a midline barrier. As such, the left and right sides of an embryo can be viewed as distinct and autonomous fields. Here we describe a series of experiments that indicate that the initiation of these programs requires communication between the two sides of the blastoderm. When deprived of either the left or the right lateral halves of the blastoderm, embryos are incapable of patterning normal left-right gene expression at Hensen's node. Not only are both flanks required, suggesting that there is no single signaling source for LR pattern, but the blastoderm must be intact. These results are consistent with our previously proposed model in which the orientation of LR asymmetry in the frog, Xenopus laevis, depends on large-scale partitioning of LR determinants through intercellular gap junction channels (M. Levin and M. Mercola (1998) Developmental Biology 203, 90–105). Here we evaluate whether gap junctional communication is required for the LR asymmetry in the chick, where it is possible to order early events relative to the well-characterized left and right hierarchies of gene expression. Treatment of cultured chick embryos with lindane, which diminishes gap junctional communication, frequently unbiased normal LR asymmetry of Shh and Nodal gene expression, causing the normally left-sided program to be recapitulated symmetrically on the right side of the embryo. A survey of early expression of connexin mRNAs revealed that Cx43 is present throughout the blastoderm at Hamburger-Hamilton stage 2–3, prior to known asymmetric gene expression. Application of antisense oligodeoxynucleotides or blocking antibody to cultured embryos also resulted in bilateral expression of Shh and Nodal transcripts. Importantly, the node and primitive streak at these stages lack Cx43 mRNA. This result, together with the requirement for an intact blastoderm, suggests that the path of communication through gap junction channels circumvents the node and streak. We propose that left-right information is transferred unidirectionally throughout the epiblast by gap junction channels in order to pattern left-sided Shh expression at Hensen's node.

Syncytial organization of cultured rat mesangial cells

1991 ◽  
Vol 260 (6) ◽  
pp. F848-F855 ◽  
Author(s):  
K. Iijima ◽  
L. C. Moore ◽  
M. S. Goligorsky
Keyword(s):  
Calcium Channels ◽  
Mesangial Cells ◽  
Calcium Waves ◽  
Oxygen Intermediates ◽  
Voltage Gated ◽  
Fura 2 ◽  
Gap Junctional Communication ◽  
Voltage Gated Calcium Channels ◽  
Junctional Communication ◽  
Gap Junctional

To investigate communication competence of cultured rat mesangial cells, Lucifer yellow transfer was studied using microinjection and scrape-loading techniques. Both methods yielded results indicating considerable gap junctional communication between cultured mesangial cells. Gap junctional communication between mesangial cells was upregulated by adenosine 3',5'-cyclic monophosphate (cAMP). Conversely, cell-to-cell communication was attenuated by exposure to the tumor promoter phorbol myristate acetate, the Ca ionophore ionomycin, reduced oxygen intermediates, and cell acidification. Expression of voltage gated calcium channels by mesangial cells was studied microspectrofluorimetrically using fura-2 fluorescence. KCl-induced depolarization, BAY-K 8644, and readdition of calcium to Ca-free depolarizing medium all produced a nifedipine-inhibitable increase in cytosolic calcium concentration. The existence of voltage-gated calcium channels in communication-competent cells suggests the possibility of propagation of depolarizing signals across the syncytium. This was studied by microapplication of KCl to the microenvironment of a single cell and monitoring fura-2 fluorescence in remote cells. This maneuver resulted in propagating calcium waves in communication-competent monolayers; calcium waves could not be evoked in monolayers exposed to an alkanol-type gap junction uncoupler, octanol. It is concluded that cultured rat mesangial cells form a syncytium capable of propagating calcium transients from a single depolarized cell to its coupled neighbors.

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