Connexin and pannexin (hemi)channels in the liver.
The liver was among the first organs in which connexin proteins have been identified. Hepatocytes harbor connexin32 and connexin26, while non-parenchymal liver cells typically express connexin43. Connexins give rise to hemichannels, which dock with counterparts on adjacent cells to form gap junctions. Both hemichannels and gap junctions provide pathways for communication, via paracrine signaling or direct intercellular coupling, respectively. Over the years, hepatocellular gap junctions have been shown to regulate a number of liver-specific functions and to drive liver cell growth. In the last few years, it has become clear that connexin hemichannels are involved in liver cell death, particularly in hepatocyte apoptosis. This also holds true for hemichannels composed of pannexin1, a connexin-like protein recently identified in the liver. Moreover, pannexin1 hemichannels are key players in the regulation of hepatic inflammatory processes. The current paper provides a concise overview of the features of connexins, pannexins and their channels in the liver.
Department of Toxicology, Center for Pharmaceutical Research, Vrije Universiteit Brussel Brussels, Belgium.
Michaël
M
Maes
Physiology Group, Department of Basic Medical Sciences, Ghent University Ghent, Belgium.
Elke
E
Decrock
Department of Pathology, School of Veterinary Medicine and Animal Science, University of Sao Paulo Sao Paulo, Brazil.
Bruno
B
Cogliati
Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais Belo Horizonte, Brazil.
André G
AG
Oliveira
Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais Belo Horizonte, Brazil.
Pedro E
PE
Marques
Department of Pathology, School of Veterinary Medicine and Animal Science, University of Sao Paulo Sao Paulo, Brazil.
Maria L Z
ML
Dagli
Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais Belo Horizonte, Brazil.
Gustavo B
GB
Menezes
Department of Pathology, School of Veterinary Medicine and Animal Science, University of Sao Paulo Sao Paulo, Brazil.
Gregory
G
Mennecier
Physiology Group, Department of Basic Medical Sciences, Ghent University Ghent, Belgium.
Luc
L
Leybaert
Department of Toxicology, Center for Pharmaceutical Research, Vrije Universiteit Brussel Brussels, Belgium.
Tamara
T
Vanhaecke
Department of Toxicology, Center for Pharmaceutical Research, Vrije Universiteit Brussel Brussels, Belgium.
Vera
V
Rogiers
Department of Toxicology, Center for Pharmaceutical Research, Vrije Universiteit Brussel Brussels, Belgium.
Mathieu
M
Vinken
cell death; connexin; gap junction; hemichannel; hepatocyte; inflammation; pannexin