摘要： Abstract: Background Eosinophils play a pivotal role in asthmatic airway inflammation. We previously found a significantly
high expression of Slingshot-1L (SSH-1L) in peripheral eosinophils in acute exacerbations of asthma. Objective To investigate
the expression and localization patterns of SSH-1L in peripheral blood eosinophils of asthmatic patients and their changes after
treatment with inhaled corticosteroids. Methods We recruited 4 outpatients with acute exacerbations of asthma who received
no previous corticosteroid treatment and 1 healthy volunteer. From all the subjects 30 ml peripheral venous blood samples
were collected before and after a 3-month treatment with inhaled fluticasone. The eosinophils were isolated, purified and
counted, and the expressions of SSH-1L in the eosinophils were examined by RT-PCR and Western blotting. The localization
of SSH-1L phosphatases in the peripheral eosinophils was detected by immunofluorescence assay in one patient. Results
SSH-1L phosphatases distributed diffusely in the cytoplasm, especially dense near the membrane of the peripheral
eosinophils. Glucocorticoids treatment resulted in a significant reduction in both the SSH-1L mRNA expression (0.7403±
0.1124 vs 0.4101 ± 0.0363, P=0.001) and SSH-1L protein expression (0.3410 ± 0.1337 vs 0.1543 ± 0.0551, P=0.039). Conclusions A high expression of SSH-1L in peripheral eosinophils in acute exacerbations of asthma may play a role in the
activation and migration of eosinophils. The efficacy of inhaled corticosteroids in asthma control might be partly attributed to a
down-regulated expression of SSH-1L.