Connexin36 and pancreatic beta-cell functions.
Most cell types are functionally coupled by connexin (Cx) channels, i.e. exchange cytoplasmic ions and small metabolites through gap junction domains of their membrane. This form of direct cell-to-cell communication occurs in all existing animals, whatever their position in the phylogenetic scale, and up to humans. Pancreatic beta-cells are no exception, and normally cross-talk with their neighbors via channels made of Cx36. These exchanges importantly contribute to coordinate and synchronize the function of individual cells within pancreatic islets, particularly in the context of glucose-induced insulin secretion. Compelling evidence now indicates that Cx36-mediated coupling, and/or the Cx36 protein per se, play significant regulatory roles in various beta-cell functions, ranging from the biosynthesis, storage and release of insulin. Recent preliminary data further suggest that the protein may also be implicated in the balance of beta-cell growth versus necrosis and apoptosis, and in the regulated expression of specific genes. Here, we review this evidence, discuss the possible involvement of Cx36 in the pathophysiology of diabetes, and evaluate the relevance of this connexin in the therapeutic approaches to the disease.
Nlend
Rachel Nlend
RN
Department of Cell Physiology and Metabolism, University of Geneva, Medical School, 1211 Genève 4, Switzerland.
Michon
Laetitia
L
Bavamian
Sabine
S
Boucard
Nathalie
N
Caille
Dorothée
D
Cancela
José
J
Charollais
Anne
A
Charpantier
Eric
E
Klee
Philippe
P
Peyrou
Manon
M
Populaire
Céline
C
Zulianello
Laurence
L
Meda
Paolo
P
D000818:Animals; D017630:Connexins / Q000235:genetics / Q000502:physiology*; D006801:Humans; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D000097004:Gap Junction delta-2 Protein
D017630:Connexins; D000097004:Gap Junction delta-2 Protein