Glucose-evoked alterations in connexin43-mediated cell-to-cell communication in human collecting duct: a possible role in diabetic nephropathy

Hills, Claire E. and Bland, Rosemary and Wheelans, Dianne C. and Bennett, Jeanette and Ronco, Pierre M. and Squires, Paul E. (2006) Glucose-evoked alterations in connexin43-mediated cell-to-cell communication in human collecting duct: a possible role in diabetic nephropathy. AJP: Renal Physiology, 291 (5). F1045-F1051. ISSN 1931-857x

Full content URL: http://dx.doi.org/10.1152/ajprenal.00344.2005

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Abstract

Aberrant sodium absorption has been linked to the development of hypertension in both renal disease and diabetes. Efficient absorption depends on coordination of cellular activity across the entire epithelium via cell-to-cell coupling. In the current study we have utilized a model human collecting duct cell line (HCD) to assess the role of connexin43 (Cx43)-mediated gap junctions in the transfer of intracellular Ca2+ transients within coupled cell clusters. HCD cells express Cx43 mRNA and protein, as well as that for the mechanosensitive transient receptor potential receptor (TRPV4). Mechanical stimulation of individual cells within a cluster evoked a transient rise in cytosolic Ca2+ concentration ([Ca2+]i) that propagated between cells via a heptanol-sensitive mechanism. The rise in [Ca2+]i was dependent on both store release and Ca2+-influx pathways. Lucifer yellow dye transfer and Cx43 knockdown experiments confirmed direct cell-to-cell communication. Application of the Ca2+ ionophore ionomycin, or an increase in glucose (5 to 25 mM), produced a time-dependent (48 h) increase in Cx43 protein expression. The transmission rate of touch-evoked Ca2+ transients between coupled cells was accelerated after exposure to high glucose, providing a functional correlate to increased Cx43 expression. These data suggest a pivotal role for Cx43-mediated gap junctions in the synchronization of activity between HCD cells in response to stimuli that mimic osmotic and physical changes. Cx43 expression and cell-to-cell communication increased in response to high glucose and may protect the collecting duct from renal damage associated with more established diabetic nephropathy.

Keywords:Diabetic nephropathy, oaopen
Subjects:C Biological Sciences > C720 Biological Chemistry
Divisions:College of Science > School of Life Sciences
ID Code:14140
Deposited On:29 May 2014 10:10

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