The role of calcineurin in the lung fibroblasts proliferation and collagen synthesis induced by basic fibroblast growth factor / 中华医学杂志(英文版)

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the role of calcineurin (CaN) in the lung fibroblast proliferation and collagen synthesis induced by basic fibroblast growth factor (bFGF).</p><p><b>METHODS</b>We used Western blot and immunohistochemical methods for investigating the content and distribution of calcineurin in the lung tissue. Calcineurin activity in different tissues was measured using (32)P-labelled substrate. In the primary culture of lung fibroblasts, (3)H-thymidine ((3)H-TdR) and (3)H-proline incorporation methods were used to study the effect of cyclosporin A (CsA), an inhibitor of calcineurin, on the lung fibroblast DNA and collagen synthesis stimulated by bFGF.</p><p><b>RESULTS</b>We found that calcineurin was expressed in lung tissue and has phosphatase activity (7.1 +/- 2.0 pmol Pi/mg pr/min). CsA (10(-8) - 10(-6) mol/L) inhibited lung fibroblast (3)H-TdR incorporation induced by bFGF in a dose-dependent manner, with the inhibitory rates by 20%, 46% and 66% (P < 0.01). CsA (10(-7) - 10(-6) mol/L) inhibited (3)H-proline incorporation in lung fibroblasts stimulated by bFGF, with the inhibitory rates by 21% and 37% (P < 0.01). In a culture medium, CsA (10(-8) - 10(-6) mol/L) inhibited (3)H-proline secretion induced by bFGF in a dose-dependent manner, with the inhibitory rates by 19%, 29% (P < 0.05) and 56% (P < 0.01). CsA (10(-7) mol/L) could inhibit calcineurin activity by 44% in lung fibroblasts (P < 0.01).</p><p><b>CONCLUSIONS</b>Calcineurin is expressed in lung tissue and has phosphatase activity. It is involved in the bFGF stimulated lung fibroblast DNA and collagen synthesis.</p>