Models and methods for in vitro testing of hepatic gap junctional communication

Area of Science:

• Hepatocellular biology and toxicology
• Cellular communication and gap junctions

Background:

• Hepatocellular gap junctions, mainly connexin32, regulate liver cell life cycles.
• These junctions are disrupted by impaired homeostatic balance, such as during liver toxicity.
• Tumor promoters and epigenetic carcinogens specifically target hepatic gap junctions.

Purpose of the Study:

• To establish connexin32-based gap junction inhibition assays for routine in vitro testing.
• To identify reliable cellular systems and techniques for probing gap junction activity in liver toxicity assessment.

Main Methods:

• Discussion of cellular models expressing in vivo-like levels of gap junctions.
• Review of appropriate techniques for assessing gap junction activity and inhibition.
• Focus on connexin32-based gap junctions for assay development.

Main Results:

• Inhibition of gap junction functionality serves as a reliable indicator for detecting non-genotoxic hepatocarcinogenicity.
• The study discusses models and methods crucial for developing robust in vitro liver toxicity assays.

Conclusions:

• Connexin32-based gap junction inhibition assays are suitable for in vitro detection of non-genotoxic hepatocarcinogenicity.
• Development of reliable assays requires specific cellular systems and techniques to probe gap junction activity.