[Study on HSP70, 90 mRNA gene expression in peripheral blood mononuclear cells with steroid-resistant asthmatics]

To investigate the role of heat shock protein(HSP) 70, 90 alpha, 90 beta mRNA on the pathogenesis of steroid-resistant(SR) asthma.

9 SR asthmadics 16 steroid sensitive (SS) asthmatics and 10 normal healthy volunteers were studied. With reverse transcription-polymerase chain reaction(RT-PCR), the expression of hsp70, 90 alpha, 90 beta mRNA were detected in peripheral blood mononuclear cell(PMBC) from normal volunteers and SR. steroid-sensitive(SS) asthmatics. Inhibition of PHA-induced lymphocyte proliferation by dexamethasones (Dex) was investigated using lymphocyte proliferation assay.

There were no expression of hsp70mRNA in PMBC of normal volunteers; the levels of expression of hsp70, 90 alpha, 90 beta mRNA in PBMC of SR asthmatics (70 = 2.95 +/- 1.12, 90 alpha = 2.17 +/- 0.89, 90 beta = 2.22 +/- 0.83) were significantly higher than SS asthmatics (70 = 0.23 +/- 0.09, 90 alpha = 1.07 +/- 0.39, 90 beta = 0.94 +/- 0.32) (P < 0.01) and normal volunteers (70 = 0, 90 alpha = 0.45 +/- 0.19, 90 beta = 0.32 +/- 0.15) (P < 0.01); There were significantly positive correlation between the degree of inhibition by Dex(10(-7) mol/L) of SR, SS asthmatics of proliferation of T lymphocytes and the expression of hsp70, 90 alpha, 90 beta mRNA in PMBC(P < 0.01).

There were expression of hsp70, 90 alpha, 90 beta gene in PMBC from SR asthmatics, but increased with worsening of inflammation and prolonging of the duration of disease. The more hsp 90 gene expression, the less T lymphocytes were inhibited by Dex.