Rapamycin blocks fibrocyte migration and attenuates bronchiolitis obliterans in a murine model.
Ann Thorac Surg
; 95(5): 1768-75, 2013 May.
Article
em En
| MEDLINE
| ID: mdl-23561805
ABSTRACT
BACKGROUND:
Fibrocytes are integral in the development of fibroproliferative disease. The CXCL12/CXCR4 chemokine axis has been shown to play a central role in fibrocyte migration and the development of bronchiolitis obliterans (BO) after lung transplantation. Inhibition of the mammalian target of rapamycin (mTOR) pathway with rapamycin has been shown to decrease expression of both CXCR4 and its receptor agonist CXCL12. Thus, we hypothesized that rapamycin treatment would decrease fibrocyte trafficking into tracheal allografts and prevent BO.METHODS:
A total alloantigenic mismatch murine heterotopic tracheal transplant (HTT) model of BO was used. Animals were either treated with rapamycin or dimethyl sulfoxide (DMSO) for 14 days after tracheal transplantation. Fibrocyte levels were assessed by flow cytometry, and allograft neutrophil, CD3(+) T-cell, macrophage, and smooth muscle actin (SMA) levels were assessed by immunohistochemistry. Tracheal luminal obliteration was assessed on hematoxylin and eosin (H&E) stains.RESULTS:
Compared with DMSO-treated controls, rapamycin-treated mice showed a significant decrease in fibrocyte levels in tracheal allografts. Fibrocyte levels in recipient blood showed a similar pattern, although it was not statistically significant. Furthermore, animals treated with rapamycin showed a significant decrease in tracheal allograft luminal obliteration compared with controls. Based on immunohistochemical analyses, populations of α-SMA-positive (α-SMA(+)) cells, neutrophils, CD3(+) T cells, and macrophages were all decreased in rapamycin-treated allografts versus DMSO controls.CONCLUSIONS:
Rapamycin effectively reduces recruitment of fibrocytes into tracheal allografts and mitigates development of tracheal luminal fibrosis. Further studies are needed to determine the cellular and molecular mechanisms that mediate the protective effect of rapamycin against BO.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Bronquiolite Obliterante
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Sirolimo
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Serina-Treonina Quinases TOR
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Ann Thorac Surg
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Estados Unidos