MIGRATION OF HUMAN AND GUINEA-PIG AIRWAY EPITHELIAL-CELLS IN RESPONSETO CALCITONIN-GENE-RELATED PEPTIDE

Calcitonin gene-related peptide (CGRP) is contained within and secrete d by nerves and neuroepithelial bodies in the airway epithelium. To de termine whether CGRP is a chemoattractant, tracheal epithelial cells i solated from 23 guinea pigs, and bronchial epithelial cells isolated f rom seven human donors were grown in primary culture for 4 to 5 days. Cell migration was assessed in a blindwell chemotaxis chamber. A gelat in-coated polycarbonate filter (8-mu m pore size) separated the upper wells containing 5 x 10(4) cells from the lower wells containing chemo attractant (either CGRP or insulin). Cells were stimulated for 6 h, af ter which migrated cells on the filter were stained and counted. Both insulin and CGRP elicited migration of guinea pig tracheal epithelial (GPTE) cells. Exposure to 30 mu g/ml insulin caused migration of 26.5 +/- 4.0 cells versus 4.3 +/- 0.6 cells per 10 hpf for control (P < 0.0 01). Treatment with 10(-9) M CGRP elicited migration of 39.6 +/- 2.5 c ells versus 2.6 +/- 0.9 cells per 10 hpf for control (P < 0.001). Huma n bronchial epithelial (HBE) cells also migrated after stimulation wit h either insulin or CGRP: after 10(-9) M CGRP, HBE cell migration was 41.0 +/- 6.1 cells versus 3.4 +/- 0.3 cells per 10 hpf (P < 0.002; n = 3). Checkerboard analysis showed that the migration to CGRP was both chemotactic and chemokinetic. Incubation with 10(-8) M hCGRP-(8-37), a receptor antagonist for CGRP, plus 10(-9) M CGRP decreased GPTE cell migration to 9.8 +/- 2.4 cells versus 38.6 +/- 1.2 cells per 10 hpf fo r 10(-9) M CGRP alone (P < 0.0001). These data demonstrate that CGRP c auses migration of both guinea pig and human airway epithelial cells i n primary culture through stimulation of a specific receptor, suggesti ng a role for this neuropeptide in regulating airway epithelial cell m igration and repair.