Fig. 2.

α₂-integrin representative Western blots and summary densitometry. A: Western blots performed with antibody 1 (detects cytoplasmic sequences of α₂-integrin) did not demonstrate any difference in protein levels of the 150-kDa protein isoform of α₂-integrin between normal human lung from the canalicular (Can) and alveolar (Alv) stage of lung development and bronchopulmonary sequestration (BPS) and congenital cystic adenomatoid malformation (CCAM) tissue. B: Western blots using antibody 2 (detects extracellular sequences of α₂-integrin) detected a significantly upregulated 130-kDa protein isoform of α₂-integrin in BPS and CCAM compared with normal alveolar or canalicular stage lung tissue, but there were no differences in the 150-kDa α₂-integrin isoform (*P = 0.005, means ± SE; BPS and CCAM vs. Alv or Can). A and B: n = 6, Can; n = 3, Alv; n = 4, BPS; n = 7, CCAM. C: representative Western blot of one CCAM sample in absence (−) or presence (+) of blocking peptide for antibody 2 showed that when antibody 2 activity was blocked with α₂-specific blocking peptide against antibody 2, neither the 150- nor the 130-kDa protein isoform was detected. D: mouse fetal lung fibroblasts treated with Hoxb5-specific siRNA to downregulate Hoxb5 protein had significantly decreased α₂-integrin protein levels compared with scramble-treated cells or control (no treatment) (*P = 0.04, means ± SE, n = 5).