Morphologic and molecular evidence for gap junctions and connexin 43 and 45 expression in annulus fibrosus cells from the human intervertebral disc

Data are presented which provide evidence for gap junction formation and co nnexin (Cx) 43 and 45 gene expression in human intervertebral disc cells in vivo and in vitro. These findings in cells from the annulus are important in conjunction with the well-recognized loss of disc cells during aging and disc degeneration. As a result of this loss of cells, cell-cell communicat ion, which we propose is an important, but as yet poorly understood, mechan ism which links and coordinates cellular function throughout the entire pop ulation of disc cells, is also disrupted. These studies provide additional information on the fundamental cell biology of the disc cell and provide an additional framework for understanding aging, degeneration and potential r epair of the human disc. (C) 2001 Orthopaedic Research Society. Published b y Elsevier Science Ltd. All rights reserved.