Quantitative analysis of gap-junctional intercellular communication in precision-cut mouse liver slices.
Direct intercellular communication through gap junction channels is involved in the maintenance of tissue homeostasis and suppression of carcinogenesis. Gap-junctional communication is often altered in tumor cells but it can also be modulated in response to tumor promotors or inflammatory signals. In order to evaluate the effect of nongenotoxic compounds, suggested to be involved in tumor promotion, on gap junctional intercellular communication in the liver, we have developed a direct dye transfer method. The fluorescent dye Alexa Fluor 488 was iontophoretically injected into hepatocytes of freshly prepared, precision-cut mouse liver slices (250 microm). The area of dye spreading was monitored and quantified by microscopy. Comparison of dye spreading in connexin-32-deficient versus wild-type liver revealed a 96% decrease in connexin-32-deficient tissue. Induction of an acute phase response in connexin-32-deficient mice by intraperitoneal injection of lipopolysaccharide increased dye coupling by 33%, probably due to upregulation of connexin-26-containing gap junction channels.
Romualdi
Alessandro
A
Institut für Genetik, Römerstrasse 164, 53117 Bonn, Germany.
Niessen
Heiner
H
Dombrowski
Frank
F
Willecke
Klaus
K
Ott
Thomas
T
D000818:Animals; D002450:Cell Communication / Q000502:physiology*; D002470:Cell Survival; D017630:Connexins / Q000235:genetics / Q000378:metabolism; D005260:Female; D005456:Fluorescent Dyes / Q000378:metabolism; D017629:Gap Junctions / Q000378:metabolism*; D022781:Hepatocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D066298:In Vitro Techniques; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D008099:Liver / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008845:Microinjections / Q000379:methods*; D000097002:Gap Junction beta-1 Protein
D017630:Connexins; D005456:Fluorescent Dyes; D007770:L-Lactate Dehydrogenase; D008070:Lipopolysaccharides; D000097002:Gap Junction beta-1 Protein