Expression of histone deacetylase 2 in tracheal stenosis models and its relationship with tracheal granulation tissue proliferation.

The current treatments for benign tracheal stenosis are inefficient. The present study examined the expression of histone deacetylase 2 (HDAC2) in different tracheal stenosis models and explored its association with the proliferation of tracheal granulation tissue and its ability to constitute a potential therapy for tracheal stenosis. Animal tracheal stenosis models were established, as indicated by hematoxylin and eosin (H&E) staining. A total of 24 New Zealand White rabbits were randomly divided into control, erythromycin, budesonide and vorinostat groups. Stenotic tracheal tissues were collected on day 11 after drug administration for 10 days. The degree of tracheal stenosis in each group was calculated, and pathological alterations were observed using H&E staining. The mRNA expression of HDAC2, interleukin-8 (IL-8), transforming growth factor-β1 (TGF-β1) and vascular endothelial growth factor (VEGF) was examined via reverse transcription-quantitative PCR. The protein expression of HDAC2 was examined via immunofluorescence, while the expression of type I and type III collagen was assessed using immunohistochemistry. The results of the present study demonstrated that tracheal epithelial hyperplasia in the erythromycin group was improved, the degree of hyperplasia being the lowest among all groups, and tracheal stenosis was reduced compared with the control group. In the vorinostat group, tracheal epithelial tissue hyperplasia was aggravated and stenosis was increased. The HDAC2 mRNA and protein levels were increased and decreased in the erythromycin and vorinostat groups, respectively. In contrast, the IL-8 mRNA expression levels were decreased and increased in the erythromycin and vorinostat groups, respectively. TGF-β1, VEGF, type I and type III collagen expression was decreased in the erythromycin group, while TGF-β1, VEGF and type III collagen expression was increased in the vorinostat group. Compared with the control, the budesonide group did not exhibit any alterations in all of the indicators examined, including TGF-β1, VEGF, IL-8, HDAC2 and collagen. Erythromycin treatment upregulated the expression of HDAC2, inhibited the inflammatory responses and reduced the proliferation of tracheal granulation tissue. In contrast, vorinostat treatment downregulated HDAC2 expression, promoted the inflammatory responses and increased the proliferation of tracheal granulation tissue. These results suggest that regulating HDAC2 may be used as a potential treatment for benign tracheal stenosis.