[The expression of capillary hypoxia-induced factor-alpha and pulmonary artery remodeling in chronic obstructive pulmonary disease].

OBJECTIVE

To observe the expression of hypoxia-inducible factor-alpha (HIF-1alpha, HIF-2alpha, HIF-3alpha) and pulmonary vascular remodeling in pulmonary arteries of patients with chronic obstructive pulmonary disease (COPD).

METHODS

Pulmonary specimens were obtained from patients undergoing lobectomy for lung cancer, of whom 12 had concurrent COPD and 10 without COPD. Pulmonary vascular remodeling was observed with optical microscope, and HIF-alpha mRNA and protein were detected by in situ hybridization and immunohistochemistry respectively.

RESULTS

Vascular remodeling parameters (WT%, WA%) of COPD patients [(24 +/- 3)%, (48 +/- 6)%, respectively] were statistically different from those of the control subjects [(15 +/- 2)%, (39 +/- 4)%, respectively]. Relative quantification of mRNA and protein levels (absorbance, A) showed that HIF-1alpha in COPD group (0.172 +/- 0.011, 0.089 +/- 0.013, respectively) were statistically higher than those of the control subjects (0.103 +/- 0.010, 0.042 +/- 0.010, P < 0.01). Furthermore, they correlated positively with the parameters for vascular remodeling. The mRNA and protein levels of HIF-2alpha in COPD group (0.038 +/- 0.010, 0.077 +/- 0.010, respectively) were significantly lower than those of the control subjects (0.133 +/- 0.017, 0.169 +/- 0.010, respectively, P < 0.01), and correlated negatively with the parameters for vascular remodeling. Regarding HIF-3alpha, only the mRNA level in COPD group (0.077 +/- 0.010) was statistically lower than that of the control subjects (0.088 +/- 0.010) (P < 0.05), and no correlation with vascular remodeling parameters was observed.

CONCLUSIONS

Pulmonary vascular remodeling in COPD patients was accompanied by the differential expression of HIF-alpha gene, which may be involved in the process of hypoxic pulmonary vascular remodeling in COPD.