Changes Produced by Different Concentrations of Inflammatory Cytokines in the Proliferation and Ciliary Movement of Human Respiratory Epithelial Cells

ABSTRACT

The aim of this study was to determine the effects of cytokines IL-1beta, TNF-alpha, and TGF-beta on the proliferation and ciliary beat frequency (CBF) of human nasal epithelial cells (HNECs) in vitro. Subcultured HNECs were incubated in a medium containing recombinant human (rh) cytokines rhIL-1beta rhTNF-alpha and rhTGF-beta at concentrations of 0.01 ng/ml, 0.1 ng/ml, 1 ng/ml, 10 ng/ml, and 100 ng/ml. After a two-day incubation with these cytokines, daily cell proliferation was measured by MTT assay for six days. The CBF was measured at concentrations of 1 ng/ml of rhIL-1beta 10 ng/ml of TNF-alpha and 1 ng/ml of TGF-beta solutions. While rhIL-1beta inhibited proliferation of HNECs in concentration-dependent and time-dependent manners, rhTNF-alpha stimulated HNEC growth at concentrations ranging from 0.01 ng/ml to 10 ng/ml in concentration-dependent and time-dependent manners. In contrast, rhTGF-beta inhibited HNEC growth irrespective of concentration and incubation time. The CBF of the human nasal ciliated epithelial cells increased after the addition of rhIL-1beta and rhTNF-alpha The CBF increased progressively for four hours after the addition of rhIL-1beta and rhTNF-alpha The increased CBF continued for 24 hours and decreased after two days. However, no variation of the CBF was observed after the addition of rhTGF-beta regardless of concentration or incubation time. The results of this study suggest that during acute inflammation, IL-1beta TNF-alpha and TGF-beta may have important roles in the repair and defense mechanism of the human nasal epithelium by regulating the proliferation and CBF of nasal epithelial cells.