The acquisition of a migratory/invasive phenotype by tumor cells is characterized by the loss of cell-cell adhesion contacts and the expression of degradative properties. In this study, we examined the effect of the disorganization of occludin/zonula occludens (ZO)-1 tight junction (TJ) complexes on the expression of membrane-type 1 matrix metalloproteinase (MT1-MMP). We first compared the expr...

Brain microvascular endothelial cells (BMECs) are the primary component of the blood-brain barrier (BBB). Tight junction (TJ) proteins, including claudin, occludin and zonula occludens (ZO)-1, ZO-2 and ZO-3, maintain the structural integrity of BMECs. Ethanol activates the assembly and disassembly of TJs, which is a process that is regulated by protein kinase C (PKC). In addition, ethanol treat...

Endothelial cell migration is a fundamental process during angiogenesis and, therefore, a point of intervention for therapeutic strategies aimed at controlling pathologies involving blood vessel growth. We sought to determine the role of the gap junction protein connexin 43 (Cx43) in key features of angiogenesis in the central nervous system. We used an in vitro model to test the hypothesis tha...

Lateralization of the ventricular gap junction protein connexin 43 (Cx43) occurs in epicardial border zone myocytes following myocardial infarction (MI) and is arrhythmogenic. Alterations in Cx43 protein partners have been hypothesized to play a role in lateralization although mechanisms by which this occurs are unknown. To examine potential mechanisms we did nuclear magnetic resonance, yeast 2...

The polarized functions of epithelia require an intact tight junction (TJ) to restrict paracellular movement and to separate membrane proteins into specific domains. TJs contain scaffolding, integral membrane and signaling proteins, but the mechanisms that regulate TJs and their assembly are not well defined. Galpha12 (GNA12) binds the TJ protein ZO-1 (TJP1), and Galpha12 activates Src to incre...

Ma, Thomas Y., Gary K. Iwamoto, Neil T. Hoa, Vimesh Akotia, Ali Pedram, Michel A. Boivin, and Hamid M. Said. TNFinduced increase in intestinal epithelial tight junction permeability requires NFB activation. Am J Physiol Gastrointest Liver Physiol 286: G367–G376, 2004; 10.1152/ajpgi.00173.2003.—Crohn’s disease (CD) patients have an abnormal increase in intestinal epithelial permeability. The def...

The gap junction protein connexin-43 is normally located at the intercalated discs of cardiac myocytes, and it plays a critical role in the synchronization of their contraction. The mechanism by which connexin-43 is localized within cardiac myocytes is unknown. However, localization of connexin-43 likely involves an interaction with the cytoskeleton; immunofluorescence microscopy showed that in...

The intercellular geometry of connexin43 (Cx43) gap junctional coupling is key to coordinated spread of electrical activation through the ventricle of the mammalian heart. A progressive redistribution of electrical and mechanical junctions into intercalated discs occurs during postnatal development. Breakdown of disc-localized pattern in the adult heart, to recapitulate immature distributions, ...

The regulation of intercellular adhesion by hepatocyte growth factor (HGF) was examined on a novel nontumorigenic gastric epithelial cell line (IMGE-5) derived from H-2Kb-tsA58 transgenic mice. IMGE-5 cells constitutively expressed cytokeratin 18 and HGF receptors. Under permissive conditions (33 degrees C + interferon-gamma), IMGE-5 cells proliferated rapidly but did not display membrane expre...