Lung regeneration : implantation of fetal rat lung fragments into adult rat lung with bleomycine induced fibrosis

我们以前曾报道正常的胎儿肺组织可以在正常成人肺内存活并进一步生长和分化(J Thorac心脏ovasc Surg 2006；131；1148-53)。在本研究中，将正常胎肺组织植入博莱霉素诱导的纤维化成年大鼠肺实质。取GFP-LEW胎肺组织(第17天)作为供体。正常成年大鼠经细导管气管内注射博莱霉素造成肺纤维化。每只大鼠在给药前三天置入导管(气管切开管)。博莱霉素以4.5 mg/kg或3 mg/kg的总剂量分4次给药。对照组大鼠注射生理盐水。第17天将GFP阳性的胎鼠肺组织接种于3周或4周前用博莱霉素组的成年大鼠。为了抑制对GFP抗原的免疫反应，受体大鼠注射环孢素A(10 mg/kg)。从第0天开始隔天，环孢素用量逐渐减少)。分别于植入后1、2、4、8、12周处死受体大鼠。移植胎肺组织的受体肺连续切片，荧光显微镜下观察。苏木精-伊红染色，博莱霉素性肺纤维化肺实质内移植物可存活、生长，并随肺泡开放而分化。

We previously reported that normal fetal lung tissues could survive and further grow and differentiate inside normal adult lung (J Thorac Cardiovasc Surg 2006; 131; 1148-53). In the present study, normal fetal lung tissues were implanted to bleomycine induced fibrotic adult rat lung parenchyma. GFP-LEW fetal lung tissues (day 17) were used as a donor. Normal adult rats were treated with intratracheal administration of bleomycine via a fine catheter to cause a situation of pulmonary fibrosis. A catheter (tracheotomy tube) was implanted in each rat three days before dosing. Bleomycine at a total dose of 4.5mg/kg or 3mg/kg was administered in four divided doses. Saline was administered for control rats.Day 17 fetal rat lungs tissues (GFP positive) in culture medium implanted to adult rats treated with bleomycine 3 or 4 weeks ago. To suppress immune responses to GFP antigen, recipient rats were administrated cyclosporine (10mg/kg i.m. on alternate days from day 0, dose of cyclosporine was decrease gradually). Recipient rats were killed 1, 2, 4, 8, 12 weeks after implantation. Recipient lungs implanted with fetal lung tissues were serially cut and examined under fluorescence microscope. The same specimens were stained with hematoxylin and eosin.The grafts implanted into pulmonary parenchyma with bleomycine induced fibrosis could survive and grow and differentiated with opening of the alveolar space.