TRANS-EPITHELIAL CHEMOTAXIS OF RAT PERITONEAL-EXUDATE CELLS

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  • 1 January 1983
    • journal article
    • research article
    • Vol. 64  (6) , 644-654
Abstract
The migration of peritoneal exudate (PE) cells into plain Millipore filters mounted in Boyden chambers occurs under random, chemokinetic and chemotactic conditions. Significant migration of such cells in vivo, however, involve both transendothelial and transepithelial penetration and occurs predominantly under pathological conditions where chemotactic agents are presumed to be present in gradient form. When Madin-Darby canine kidney (MDCK) epithelial cells are grown as a confluent monolayer on the Millipore filter of a Boyden chamber, transepithelial migration is seen only under chemotactic conditions thus modeling in vivo behavior more effectively. The MDCK cell line exists as 2 variant strains which model different regions of the mammalian nephron. Strain I MDCK cells share features of the distal and collecting tubules and have relatively high junctional resistance (> 1k.OMEGA.cm2). Strain II MDCK cells model the proximal segment of the nephron and have relatively low junctional resistance (.apprx. 70.OMEGA.cm2). PE cells penetrate the less resistant strain II MDCK monolayer at a faster rate (as assessed by leading front migration) than they penetrate the tighter strain I monolayer. The electrophysiological features of MDCK monolayers were utilized to monitor transepithelial penetration. Electrophysiological data indicate that rat PE cells penetrate MDCK monolayers of either strain by a transjunctional route with consequent reversible dissolution of the junctional complex. This extracellular path of PE cell migration was confirmed by ultrastructural observations. The extent of junctional dissolution and the delay in re-establishment of monolayer integrity (as assessed by electrophysiological means) are related to the concentration of PE cells added to the MDCK monolayer. Brief treatment (10 min) of the MDCK monolayer with the cation chelating agent EDTA also disrupts monolayer integrity, although its re-establishment is significantly faster than when disruption occurs by PE cell transmigration. A clear parallel was shown between PE cell migration across an MDCK monolayer and changes in its electrophysiological parameters and thus suggest that transepithelial chemotaxis may be directly assessed by electrophysiological means. The use of Boyden chambers modified by the incorporation of epithelial monolayers may prove useful in in vitro studies of inflammation and could be adapted for studies of other pathological processes, such as metastasis, where considerable cell invasion is involved.