Nuclear HSP90 and HSP70 in COPD patients treated with formoterol or formoterol and corticosteroids

OBJECTIVE: Heat shock proteins assist cellular protein folding and are required for the normal activity of steroid receptors. In this study we assessed nuclear HSP90 and HSP70 proteins and mRNA levels in cells isolated from induced sputum of chronic obstructive pulmonary disease patients treated for 4 weeks with formoterol (F) or formoterol+budesonide (F/ICS). METHODS: Nuclear heat shock protein levels were assessed by Western blot and specific mRNAs were quantified in cell lysates using qRT-PCR. RESULTS: Both HSP90 and HSP70 protein levels were higher in the F/ICS-treated patients in comparison with the F-treated group (by 31%, P < 0.05 and 28%, P < 0.05, respectively), while specific mRNAs were lowered. HSP86/HSP89 and D6S182/HSP90-BETA were repressed by about 40% (P < 0.05)whileHSP70-1/HSP70-1A, HSP70-1B/HSP70-2, and HSP70-HSC54/HSC70 were repressed by 47% (P < 0.01), 57% (P < 0.01) and 65% (P < 0.01), respectively. CONCLUSIONS: It is possible that increased nuclear heat shock proteins may play a role in the attenuation of the response to glucocorticoids in COPD patients.