Murphy Gavin J, Bicknell Gareth R, Nicholson Michael L
Department of Cardiothoracic Surgery, Derriford Hospital, Derriford Road, Plymouth, PL6 8DH, UK.
Transpl Int. 2003 May;16(5):347-53. doi: 10.1007/s00147-003-0547-9. Epub 2003 Mar 19.
Chronic allograft dysfunction, the leading cause of solid-organ transplant failure, is characterised by histological evidence of extracellular matrix (ECM) accumulation (fibrosis). The aim of this study was to compare the effect of combined rapamycin and cyclosporine therapy on fibrosis-associated gene expression and ECM turnover during the development of allograft vasculopathy, compared with either agent alone. Lewis recipients of F344 rat thoracic-to-abdominal aorta transplants were administered rapamycin, cyclosporine, combined rapamycin and cyclosporine or no treatment. F344-to-F344 isografts served as controls. Six grafts in each group were harvested at 16 weeks. Vascular remodelling and ECM accumulation (Sirius red) were measured by computerised histomorphometry of aortic sections. Messenger RNA was extracted from frozen tissue, and expression of fibrosis-associated genes was studied by means of semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). Rapamycin (0.5 mg/kg per day) or cyclosporine (5 mg/kg per day) inhibited intimal hyperplasia, medial ECM accumulation and expansive vascular remodelling (increasing vessel circumference) in rat aortic allografts. This was associated with attenuation of the graft inflammatory infiltrate and a reduction in intra-graft gelatinase, collagen III and tissue inhibitor of metalloproteinase (TIMP)-1 mRNA levels. Combined rapamycin and cyclosporine inhibited intimal hyperplasia; however, there was a lesser effect on vascular remodelling and medial ECM accumulation. Combined-treatment aortic allografts were also seen to have a more-severe inflammatory infiltrate and larger amounts of intra-graft matrix metalloproteinase (MMP)-9, transforming growth factor (TGF)-beta and TIMP-1 mRNA than those treated with monotherapy. Rapamycin and cyclosporine act synergistically to inhibit intimal hyperplasia but not the inflammatory infiltrate, allograft fibrosis or vessel remodelling. In the high-responder F344-to-Lewis rat model, effective immunosuppression is required to reduce graft fibrosis.
慢性移植器官功能障碍是实体器官移植失败的主要原因，其特征是细胞外基质（ECM）积聚（纤维化）的组织学证据。本研究的目的是比较雷帕霉素和环孢素联合治疗与单独使用任一药物相比，在移植血管病变发展过程中对纤维化相关基因表达和ECM周转的影响。将F344大鼠胸主动脉至腹主动脉移植给Lewis受体，分别给予雷帕霉素、环孢素、雷帕霉素与环孢素联合治疗或不治疗。F344到F344的同基因移植作为对照。每组6个移植物在16周时收获。通过主动脉切片的计算机组织形态计量学测量血管重塑和ECM积聚（天狼星红染色）。从冷冻组织中提取信使核糖核酸（mRNA），并通过半定量逆转录聚合酶链反应（RT-PCR）研究纤维化相关基因的表达。雷帕霉素（每天0.5mg/kg）或环孢素（每天5mg/kg）可抑制大鼠主动脉移植中的内膜增生、中膜ECM积聚和扩张性血管重塑（增加血管周长）。这与移植炎症浸润的减轻以及移植内明胶酶、胶原III和金属蛋白酶组织抑制剂（TIMP）-1 mRNA水平的降低有关。雷帕霉素和环孢素联合治疗可抑制内膜增生；然而，对血管重塑和中膜ECM积聚的影响较小。联合治疗的主动脉移植也比单一疗法治疗的移植有更严重的炎症浸润和更多的移植内基质金属蛋白酶（MMP）-9、转化生长因子（TGF）-β和TIMP-1 mRNA。雷帕霉素和环孢素协同作用以抑制内膜增生，但不能抑制炎症浸润、移植器官纤维化或血管重塑。在高反应性F344到Lewis大鼠模型中，需要有效的免疫抑制来减少移植器官纤维化。
