Enhancement of Connexin 43 Expression Increases Proliferation and Differentiation of an Osteoblast-like Cell Line

doi:10.1006/excr.2000.5145

Experimental Cell Research

Volume 264, Issue 2, 1 April 2001, Pages 397-407

https://doi.org/10.1006/excr.2000.5145 Get rights and content

Abstract

Bone cells form a functional syncytium as they are coupled by gap junctions composed mainly of connexin 43 (Cx43). To further understand the role of Cx43 in bone cell growth and differentiation, we stably transfected Cx45-expressing UMR 106-01 cells with Cx43 using an expression vector containing rat Cx43 cDNA. Three stably transfected clones were analyzed, all of which showed altered expression of Cx43 and/or Cx45 as was obvious from immunocytochemistry and Northern blotting. Double whole-cell patch clamping revealed single-channel conductances of 20 (Cx45) and 60 pS (Cx43). The overexpression of Cx43 led to an increase in dye coupling concomitant with elevated gap-junctional conductance. The phenotype of the transfected clones was characterized by an increased proliferation (4- to 7-fold) compared to controls. Moreover, a transfectant clone with 10- to 12-fold enhanced Cx43 expression showed a significantly increased calcium content of the extracellular matrix and enlarged mineralization nodules, while alkaline phosphatase was moderately increased. We conclude that enhanced gap-junctional coupling via Cx43 significantly promotes proliferation and differentiation of UMR cells.

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¹: To whom reprint requests should be addressed at the Institut für Physiologie, Universität Essen, D-45122 Essen, Germany. Fax: +49 201 723-4648. E-mail: [email protected].

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Regular ArticleEnhancement of Connexin 43 Expression Increases Proliferation and Differentiation of an Osteoblast-like Cell Line

Abstract

Trends Cell. Biol.

J. Biol. Chem.

Bone

Bone

Exp. Cell. Res.

Neuron

Mutat. Res.

J. Biol. Chem.

Connections with connexins: The molecular basis of direct intercellular signalling

Eur. J. Biochem.

Mechanisms of coordination of Ca2+ signals in pancreatic islet cells

Diabetes

Signalling in bone: Electrophysiological studies on cultured cells derived from calvarial fragments of rats

Cells Mater.

Biochemical and biophysical analysis of cell-to-cell channels and regulation of gap junctional permeability

Rev. Physiol. Biochem. Pharmacol.

Oxygen consumption of calvarial bone cells in vitro

J. Orthop. Res.

Morphological evidence of gap junctions between bone cells

Calcif. Tissue Int.

Gap junctional intercellular communication contributes to the contraction of rat osteoblast populated collagen lattices

J. Bone Miner. Res.

Gap junctional intercellular communication in bone: A cellular basis for the mechanostat set point

Calcif. Tissue Int.

Mechanotransduction and functional response of bone to mechanical strain

Calcif. Tissue Int.

Osteoblasts are regulated by the cellular adhesion through ICAM-1 and VCAM-1

J. Bone Miner. Res.

Regulation of connexin43 expression and function by prostaglandin E2 (PGE2) and parathyroid hormone (PTH) in osteoblastic cells

J. Cell. Biochem.

Connexin43 mediates direct intercellular communication in human osteoblastic cell networks

J. Clin. Invest.

Cell-to-cell communication in osteoblastic networks: Cell line-dependent hormonal regulation of gap junction function

J. Bone Miner. Res.

Characterization of gap junctions between osteoblast-like cells in culture

Calcif. Tissue Int.

Hormonal regulation of intercellular communication: Parathyroid hormone increases connexin43 gene expression and gap-junctional communication in osteoblastic cells

Mol. Endocrinol.

Regular Article
Enhancement of Connexin 43 Expression Increases Proliferation and Differentiation of an Osteoblast-like Cell Line

Mechanisms of coordination of Ca²⁺ signals in pancreatic islet cells

Regulation of connexin43 expression and function by prostaglandin E₂ (PGE₂) and parathyroid hormone (PTH) in osteoblastic cells