RESUMO
Chronic inflammation, a hallmark of obliterative bronchiolitis, is known to induce lymphangiogenesis. We therefore studied the role of lymphangiogenic vascular endothelial growth factor C (VEGF-C), its receptor VEGFR-3, and lymphangiogenesis during development of experimental obliterative bronchiolitis [ie, obliterative airway disease (OAD)] in rat tracheal allografts. The functional importance of VEGF-C was investigated by adenovirus-mediated overexpression of VEGF-C (AdVEGF-C), and by inhibition of VEGF-C activity with VEGFR-3-Ig (AdVEGFR-3-Ig). Analyses included histology, immunohistochemistry, and real-time RT-PCR 10 and 30 days after transplantation. In the course of OAD development, lymphangiogenesis was induced in the airway wall during the alloimmune response, which was reversed by cyclosporine A in a dose-dependent fashion. VEGF-C overexpression in tracheal allografts induced epithelial activation, neutrophil chemotaxis, and a shift toward a Th17 adaptive immune response, followed by enhanced lymphangiogenesis and the development of OAD. In contrast, inhibition of VEGF-C activity with VEGFR-3-Ig inhibited lymphangiogenesis and angiogenesis and reduced infiltration of CD4(+) T cells and the development of OAD. Lymphangiogenesis was linked to T-cell responses during the development of OAD, and VEGF-C/VEGFR-3 signaling modulated innate and adaptive immune responses in the development of OAD in rat tracheal allografts. Our results thus suggest VEGFR-3-signaling as a novel strategy to regulate T-cell responses in the development of obliterative bronchiolitis after lung transplantation.
Assuntos
Imunidade Adaptativa/imunologia , Bronquiolite Obliterante/imunologia , Bronquiolite Obliterante/metabolismo , Imunidade Inata/imunologia , Transdução de Sinais/imunologia , Fator C de Crescimento do Endotélio Vascular/metabolismo , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Imunidade Adaptativa/efeitos dos fármacos , Animais , Bronquiolite Obliterante/patologia , Bronquiolite Obliterante/fisiopatologia , Quimiotaxia/efeitos dos fármacos , Ciclosporina/farmacologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Relação Dose-Resposta a Droga , Regulação para Baixo/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Epitélio/efeitos dos fármacos , Epitélio/metabolismo , Epitélio/patologia , Rejeição de Enxerto/complicações , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/patologia , Rejeição de Enxerto/fisiopatologia , Imunidade Inata/efeitos dos fármacos , Imunoglobulinas/farmacologia , Inflamação/complicações , Inflamação/imunologia , Inflamação/patologia , Linfangiogênese/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Neutrófilos/efeitos dos fármacos , Ratos , Transdução de Sinais/efeitos dos fármacos , Células Th17/efeitos dos fármacos , Células Th17/imunologia , Traqueia/efeitos dos fármacos , Traqueia/patologia , Traqueia/transplante , Transplante Homólogo , Regulação para Cima/efeitos dos fármacos , Fator C de Crescimento do Endotélio Vascular/antagonistas & inibidoresRESUMO
OBJECTIVES: To review our experience with valve-sparing aortic root replacement (VSARR) in adult patients after the previous surgery for congenital heart disease. METHODS: From August 2008 to February 2014, 11 patients (mean age: 30.5 ± 7.7 years), previously operated for various congenital cardiac defects, mostly conotruncal lesions, underwent VSARR for progressive aortic root dilatation. Five patients had also developed moderate, and 1 patient severe aortic valve (AoV) insufficiency. All aortic root procedures were performed by the same operating surgeon in two institutions. The mean interval between the initial procedure and aortic root surgery was 25.7 ± 7.7 years. At the time of reoperation, the mean aortic root diameter was 53.4 ± 6.2 mm. The reimplantation technique (David procedure) was used in all patients. Seven patients underwent concomitant procedures. The median follow-up was 32 months (range 12-78 months). RESULTS: No mortality occurred in hospital or during the follow-up period. Ten patients remain in NYHA functional class I; 1 patient with a single-ventricle circulation is in NYHA functional class II. During the immediate postoperative period, 2 patients underwent drainage of a pericardial collection and 1 patient required renal replacement therapy with eventual full recovery of renal function. No other reoperations or reinterventions were needed during the follow-up period. The most recent echocardiogram in 10 patients have demonstrated no or trivial AoV insufficiency. One patient, however, with severe aortic insufficiency preoperatively, developed mild AoV regurgitation shortly after the operation, which has progressed to moderate regurgitation 1 year following the operation. CONCLUSIONS: Analysis of our experience in a small group of patients confirms that valve-sparing aortic root surgery can be safely performed in adult congenital patients presenting with progressive aortic root dilatation following their previous surgery. Although we have analysed patients with different original congenital cardiac lesions and the follow-up period is not long, we can conclude that the use of the reimplantation technique (David procedure) have resulted in overall satisfactory AoV function at follow-up. Longer follow-up with larger series will be needed, however, before firm conclusions can be drawn.
Assuntos
Doenças da Aorta/cirurgia , Valva Aórtica/cirurgia , Cardiopatias Congênitas/cirurgia , Implante de Prótese de Valva Cardíaca , Tratamentos com Preservação do Órgão , Adolescente , Adulto , Seguimentos , Próteses Valvulares Cardíacas , Implante de Prótese de Valva Cardíaca/métodos , Implante de Prótese de Valva Cardíaca/mortalidade , Humanos , Pessoa de Meia-Idade , Tratamentos com Preservação do Órgão/métodos , Tratamentos com Preservação do Órgão/mortalidade , Adulto JovemRESUMO
BACKGROUND: Obliterative bronchiolitis after lung transplantation is characterized by chronic airway inflammation leading to the obliteration of small airways. Hypoxia-inducible factor-1 (HIF-1) is a master regulator of cellular responses to hypoxia and inflammation. The Von Hippel-Lindau protein (pVHL) drives the degradation of oxygen-sensitive subunit HIF-1α that controls the activity of HIF-1. We investigated the effect of myeloid cell-targeted gene deletion of HIF-1α or its negative regulator pVHL on the development of obliterative airway disease (OAD) in the recipients of tracheal allografts, a mouse model for obliterative bronchiolitis after lung transplantation. METHODS: Tracheal allografts were heterotopically transplanted from BALB/c donor mice to fully major histocompatibility complex-mismatched recipient mice with HIF-1α or VHL gene deletion in myeloid cells. The recipients were left non-immunosuppressed or received tacrolimus daily. Histologic, immunohistochemical, and real-time reverse transcription polymerase chain reaction analyses were performed at 3, 10, and 30 days. RESULTS: In the absence of immunosuppression, myeloid cell-specific VHL deficiency of the recipient mice improved epithelial recovery, decreased inflammatory cell infiltration and expression of pro-inflammatory cytokines, increased regulatory forkhead box P3 messenger RNA expression, and reduced OAD development in tracheal allografts. In the presence of tacrolimus immunosuppression, loss of HIF-1α activity in myeloid cells of the recipient by HIF-1α gene deletion accelerated OAD development in mouse tracheal allografts. CONCLUSIONS: Activity of the HIF-pathway affects the development of allograft rejection, and our results suggest that myeloid cell-specific VHL-deficiency that potentially increases HIF-activity decreases allograft inflammation and the subsequent development of OAD in mouse tracheal allografts.
Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Animais , Bronquiolite Obliterante , Hipóxia Celular , Rejeição de Enxerto , Transplante de Pulmão , Camundongos , Transplante HomólogoRESUMO
BACKGROUND: Obliterative bronchiolitis after lung transplantation is characterized by airway inflammation leading to obliteration of small airways. Statins are known to have lipid-independent immunomodulatory properties. We investigated the effect of simvastatin treatment on innate and adaptive immune responses and the development of obliterative airway disease (OAD). METHODS: In fully MHC-mismatched rat tracheal allograft recipients, we used simvastatin at different doses (0.1 to 20 mg/kg/day orally) to assess its effect on OAD development. No immunosuppressive treatment was administered. Histologic, immunohistochemical and real-time RT-PCR analyses were performed 3, 10 and 30 days after transplantation. RESULTS: Simvastatin treatment with doses ranging from 0.5 to 20 mg/kg/day significantly enhanced early epithelial recovery and reduced the development of OAD. No dose response was observed. Simvastatin treatment markedly reduced IL-23 mRNA and lymphocyte chemokine CCL20 production, and the infiltration of CD4(+) and CD8(+) T cells into allografts already at 3 days. At 10 days, simvastatin significantly attenuated the production of pro-inflammatory cytokines, IL-1ß, TNF-α, MCP-1 and IP-10, and Th17-polarizing cytokines, IL-6 and IL-17e, and inhibited allograft infiltration by inflammatory cells. The protective effects of simvastatin on inflammation and OAD were partially mediated through nitric oxide synthase. CONCLUSIONS: Simvastatin treatment inhibited adaptive T-cell alloimmune activation as depicted by reduced expression of lymphocyte chemokine and pro-inflammatory cytokine mRNA and reduced allograft infiltration by inflammatory cells. Importantly, simvastatin inhibits the development of OAD and this effect is partially mediated by increased nitric oxide activity. These results suggest a role for simvastatin in the prevention of obliterative bronchiolitis.
Assuntos
Bronquiolite Obliterante/prevenção & controle , Imunossupressores/administração & dosagem , Transplante de Pulmão/imunologia , Sinvastatina/administração & dosagem , Animais , Relação Dose-Resposta a Droga , Masculino , Modelos Animais , Ratos , Ratos Endogâmicos WFRESUMO
BACKGROUND: We assessed cellular innate and adaptive immune responses in a rat heterotopic tracheal allograft model during the development of obliterative airway disease. METHODS: Syngeneic tracheal grafts were transplanted heterotopically from DA to DA rats and fully MHC-mismatched allografts from DA to WF rats. The recipients received either no immunosuppression or two different doses of cyclosporine and were euthanized at 3, 10 and 30 days. Non-transplanted DA tracheas served as controls. Histologic, immunohistochemical and real-time RT-PCR analyses were performed. RESULTS: The syngrafts had normal epithelium at 10 days and no tracheal occlusion was seen at 30 days. In non-immunosuppressed allografts, almost total loss of epithelium was observed at 10 days, culminating in tracheal occlusion at 30 days. The activation of innate immune response was observed during the ischemic period at 3 days in both groups. Influx of the infiltrating inflammatory cells was more prominent in the allografts. In syngrafts, mRNA expression of pro-inflammatory, but also tolerogenic, cytokines was significantly upregulated, whereas Th1 and Th17 priming factors were significantly downregulated. In allografts, prominent mRNA expression of pro-inflammatory cytokines was seen and adaptive Th1 and Th17 alloresponses were increased. Cyclosporine treatment reduced tracheal occlusion and inhibited both tolerogenic and pro-inflammatory T-cell responses in allografts. CONCLUSIONS: Ischemia induced a self-limiting, alloantigen-independent innate immune response in syngrafts. In allografts, the predominant pro-inflammatory milieu and alloantigen-dependent Th1 and Th17 responses were linked to the development of obliterative airway disease and were inhibited by cyclosporine treatment.