反义细胞外信号调节激酶对移植物血管的保护作用

目的探讨反义细胞外信号调节激酶（ERK1／2）基因治疗对移植物血管的保护作用及可能的保护机制。方法建立BN至Lewis大鼠的腹主动脉移植模型。反义ERK1／2治疗组移植前取供者动脉血管段给予经脂质体包装的反义ERK1／2基因转染；腹主动脉移植术后1个月内受者每日从尾静脉或阴茎背静脉注入经脂质体包装的反义ERK1／2寡核苷酸100μl。对照组移植未经任何处理的血管段，移植后也无特殊处理。移植术后60d取移植段主动脉进行组织病理学观察内膜和胶原纤维变化；免疫组织化学法观察移植段血管ERK1／2基因的表达和CD4^＋、CD8^＋T淋巴细胞的浸润情况；ELISA法检测血清中细胞间粘附分子（ICAM-1）的变化。结果移植术后60d，对照组的移植动脉呈慢性移植物血管病表现，血管内膜显著增厚，移植血管中ERK1／2基因高表达，CD4^＋、CD8^＋T淋巴细胞大量浸润；反义ERK1／2基因治疗组移植动脉呈血管内膜炎改变，ERK1／2基因表达不明显，内膜有少量CD4^＋、CD8^＋T淋巴细胞；对照组ICAM-1表达显著高于反义ERK1／2治疗组（P〈0．05）。结论反义ERK1／2基因治疗对移植物血管具有保护作用，可以减缓慢性移植物血管病的发生，这种保护机制可能和减少ICAM-1的表达以及减少移植血管T淋巴细胞的浸润有关。     

移植物转染血红素氧合酶-1基因抑制慢性移植物血管病

目的探讨移植物转染血红素氧合酶-1（HO-1）基因对慢性移植物血管病的影响。方法克隆HO-1基因，并构建含有HO-1基因的重组腺病毒载体（Ad-HO-1），实验分为4组：A组为同系移植对照组，供、受者均为Lewis大鼠，无特殊处理；B组为同种移植对照组，Lewis大鼠接受未经处理的BN大鼠胸主动脉移植；C组为同种移植空载体对照组，Lewis大鼠接受以空载体（不含HO-1基因）处理的BN大鼠的胸主动脉移植；D组为同种移植实验组，Lewis大鼠接受转染HO-1基因的BN大鼠的胸主动脉移植。于移植后60d取移植动脉，进行组织形态学观察，测量内膜厚度；免疫组化和逆转录聚合酶链反应检测HO-1在移植动脉中的表达。结果A组移植动脉形态正常；B组、C组移植动脉呈移植物血管病表现，血管内膜显著增厚，D组移植动脉呈内膜炎改变，内膜厚度与B组、C组相比，差异有统计学意义（P〈0．01）。免疫组化及RT-PCR检测显示，与A组、B组和C组相比，D组移植动脉可以检测到HO-1基因及其蛋白表达。结论在移植血管中预先转染HO-1基因，能明显缓解移植动脉的纤维化进程以及内膜的增生，对慢性排斥反应所致的移植物血管病具有抑制作用。     

阻断ERK2信号转导通路对血小板源生长因子-BB诱导血管平滑肌细胞增殖、迁移和表达转化生长因子-β1的影响

目的 观察ERK2信号转导通路在血小板源生长因子(PDGF-BB)诱导血管平滑肌细胞(VSMC)增殖、迁移和表达转化生长因子(TGF)-β1中的作用.方法 将原代培养的大鼠VSMC分为4组:(1)对照组;(2)PDGF刺激组;(3)Ad-LacZ组;(4)Adanti-ERK2组.用Westernblot检测细胞磷酸化ERK2蛋白水平;噻唑蓝(MTT)比色法测定细胞增殖率;流式细胞仪检测细胞细胞周期;Boyden小室测定细胞的跨膜迁移能力;酶联免疫吸附试验(ELISA)法检测细胞培养液上清中TGF-β1的浓度.结果 Adanti-ERK2组和对照组细胞增殖率、S期细胞百分比及跨膜迁移细胞数目明显低于PDGF刺激组和Ad-LacZ组(细胞增殖率:2.75%、0.00%比64.45%、61.88%;s期细胞百分比:14.18%、13.58%比38.14%、32.99%;跨膜迁移细胞数:8.2±3.2、6.3±2.6比24.8±6.1、23.3±5.8,均P<0.05);(2)Adanti-ERK2组和对照组细胞培养上清液中TGF-β1含量明显低于PDGF刺激组和Ad-LacZ组(P<0.05);而Adanti-ERK2组明显高于对照组(P<0.05).结论 ERK2信号转导通路参与调控PDGF-BB诱导的VSMC增殖、迁移和基因表达.反义ERK2基因预先转染阻断ERK信号转导能显著抑制PDGF-BB刺激的VSMC增殖、迁移,阻断细胞周期由G1期进入S期,并且部分下调TGF-β1的合成分泌.     

冬虫夏草提取物抑制大鼠移植物血管病的实验研究

目的 探讨冬虫夏草提取物抑制大鼠移植动脉硬化的效果及其机制.方法 制备大鼠腹主动脉移植模型,分为4组进行实验:同系对照组供、受者均为Lewis大鼠,生理盐水灌胃60d;同种对照组,以Brown-Norway大鼠(BN大鼠)为供者,Lewis大鼠为受者,生理盐水灌胃60d;低剂量实验组,以BN大鼠为供者,Lewis大鼠为受者,以冬虫夏草提取物(1.5 g·kg-1·d-1)灌胃60 d;高剂量实验组,以BN大鼠为供者,Lewis大鼠为受者,以冬虫夏草提取物(3.0g·kg-1·d-1)灌胃60d.于移植后60 d取移植动脉,HE染色,进行病理学观察;免疫组织化学和蛋白质印迹法检测血管内皮生长因子(VEGF)和血小板衍生生长因子BB(PDGF-BB)在移植动脉中的表达.酶联免疫吸附试验检测受鼠血清中VEGF和PDGF- BB含量.结果 同系对照组移植动脉形态正常;同种对照组移植动脉呈移植物血管病表现,血管内膜显著增厚;2个实验组移植动脉呈内膜炎症改变,内膜厚度与同种对照组相比,差异有统计学意义(P＜0.05).同种对照组移植动脉中VEGF和PDGF-BB的表达高于同系对照组(P＜0.05);2个实验组移植动脉中VEGF和PDGF-BB的表达低于同种对照组(P＜0.05).同系对照组受鼠血清中几乎无VEGF和PDGF-BB;同种对照组血清中VEGF和PDGF-BB浓度高于同系对照组(P＜0.05);和同种对照组相比较,2个实验组血清VEGF和PDGF-BB浓度较低(P＜0.05).结论 冬虫夏草提取物能明显抑制动脉内膜的增生,可缓解慢性排斥反应所致的移植动脉硬化,这种保护作用可能与下调VEGF和PDGF-BB表达有关.     

反义寡核苷酸防治移植物动脉硬化的作用

目的　探讨防治移植物动脉硬化的途径。方法　通过大鼠胸腹主动脉移植简化模型 ,用各种增殖细胞核抗原 (PCNA)寡核苷酸在脂质体介导下转染大鼠胸主动脉后 ,移植到大鼠腹主动脉 ,于术后 15、3 0和 60d取移植动脉作病理学检查及PCNA逆转录PCR检测。结果　病理学结果示 ,在 3个时相点 ,反义寡核苷酸组移植动脉再狭窄率 (8.3 %、12 .4%、19.5 % )均显著低于对照组 (P <0 .0 5 )。逆转录PCR结果显示 ,在 3个时相点 ,反义寡核苷酸组PCNAmRNA的表达(5 9.2 4、80 .16、18.5 8)均明显低于对照组 (P >0 .0 5 )。结论　PCNA反义寡核苷酸可明显抑制移植动脉PCNA蛋白的表达 ,抑制动脉内膜增生 ,防治移植物动脉硬化。     

沙利度胺延缓大鼠的慢性移植物血管病

目的 研究沙利度胺对慢性移植物血管病的缓解作用,并探讨其机制.方法 建立大鼠腹主动脉慢性移植物血管病模型.同系对照组的供、受者均为Brown-Norway大鼠(BN大鼠),术后每天以生理盐水灌胃;同种移植组均以BN大鼠为供者,Lewis大鼠为受者,术后每天以生理盐水灌胃,溶剂对照组术后每天以二甲基亚砜灌胃,高剂量组术后每天以沙利度胺200mg/kg灌胃,低剂量组术后每天以沙利度胺100mg/kg灌胃.术后8周,光镜下观察移植血管组织形态学变化;采用免疫组织化学法测定移植血管中白细胞介素9(IL-9)和转化生长因子β(TGF-β)表达情况;采用双抗体夹心酶联免疫吸附试验检测血清血小板衍生生长因子(PDGF)浓度.结果 同种对照组、溶剂对照组、高剂量组和低剂量组均呈现出典型的移植相关血管硬化,内膜明显增生,并呈同心圆增厚,同系对照组、同种对照组、溶剂对照组、高剂量组和低剂量组移植血管内膜厚度分别为(4.12±0.21)、(67.23±6.12)、(53.11±5.71)、(21.28±4.52)和(23.45±3.64)μm,高剂量组和低剂量组移植血管内膜厚度明显小于同种对照组和溶剂对照组(P＜0.05).同系对照组、同种对照组、溶剂对照组、高剂量组和低剂量组IL-9阳性细胞率分别为(12.54±4.56)％、(50.55±6.39)％、(45.26±2.32)％、(27.37±5.29)％和(29.11±3.20)％;TGF-β阳性细胞率分别为(18.12±6.21)％、(49.23±3.23)％、(40.61±4.13)％、(31.71±8.60)％和(29.35±6.85)％,高剂量组和低剂量组IL-9阳性细胞率和TGF-β阳性细胞率均明显低于同种对照组和溶剂对照组(P＜0.05).同系对照组、同种对照组、溶剂对照组、高剂量组和低剂量组血清中PDGF含量分别为0、(998±18)、(745±29)、(287±97)和(299±36)pg/ml,高剂量组和低剂量组血清PDGF含量均明显低于同种对照组和溶剂对照组(P＜0.05).结论 低剂量沙利度胺即可缓解慢性移植物血管病,这种作用可能与组织中TGF-β和IL-9表达下调,以及血清中PDGF浓度下降相关.     

野生型p53基因转染和低能量激光照射防治移植静脉再狭窄的实验研究

目的：探索转基因疗法和激光疗法防治移植静脉远期再狭窄的可行性及作用机制。方法：建立兔颈外静脉颈总动脉移植模型，分为（1）对照组，（2）绿色荧光蛋白（GFP）基因转染组，（3）p53基因转染组，（4）低能量激光照射组，（5）p53基因转染并低能量激光照射组。术后4周，免疫组织化学方法检测外源p53基因的表达及增殖细胞核抗原（PCNA），应用DNA片段末端标记法（TUNEL）标记凋亡细胞。HE、Masson及维多利亚兰染色后，应用计算机图像分析系统检测移植静脉内膜、中膜增生情况。结果：术后4周，与对照组相比，GFP基因转染组移植静脉血管平滑肌细胞（VSMC）增殖率、凋亡率差异无显著性，移植静脉内膜和中膜厚度无明显变化；p53基因转染组VSMC增殖率降低61％，凋亡率增加25％，移植静脉内膜和中膜厚度分别减少60％、33％，内膜厚度/中膜厚度比值(I/M)减少37％；应用低能量激光照射组VSMC增殖率降低41.5％，细胞凋亡率增加40.9％，移植静脉内膜和中膜厚度分别减少了58.5％、18.0％，I/M比值减少47.2％；转染p53基因同时应用低能量激光照射组VSMC增殖率较对照组降低61.7％，细胞凋亡率增高47.0％，移植静脉内膜和中膜厚度分别减少69.7％、44.4％，I/M比值减少44.5％。结论：转染野生型p53基因和低能量激光血管外照射可以抑制静脉VSMC增殖，促进移植静脉VSMC凋亡，使移植静脉内膜和中膜的增生减轻，具有防治移植静脉远期再狭窄的作用。     

反义细胞外信号调节激酶-2基因治疗移植物动脉血管病内膜病变

目的 观察移植物动脉血管病(TA)的内膜病变机制和反义细胞外信号调节激酶2基因腺病毒载体(Adanti-ERK2)基因治疗的效果.方法 建立Brown-Norway(BN)-Lewis移植物动脉血管病模型,分为同系组、Control组、LacZ组和Adanti-ERK2组(给予5×109 pfu Adanti-ERK2基因治疗),每组各6例.术后60 d检测各组内膜病变和血管腔内膜/(内膜+中膜)比,α-肌动蛋白(α-actin)和血小板源性生长因子-BB(PDGF-BB)染色检测移植动脉平滑肌细胞(VSMCs)增殖和分泌功能,评估移植动脉新生毛细血管情况并检测移植动脉中环氧化酶-2(COX-2)的表达.结果　术后60 d同系组内膜无异常,Control组和LacZ组典型内膜增殖改变,Adanti-ERK2组内膜病变较轻;内膜/(内膜+中膜)比各组分别为7.6%、81.4%、85.9%、15.9%;α-actin阳性细胞(内膜平滑肌细胞)每视野计数各组分别为0、71.3±9.2、76.4±11.3、34.8±5.3;PDGF-BB阳性细胞每视野计数各组分别为0.9±0.5、28.4±3.4、29.1±3.2、8.6±1.7;移植动脉中膜和内膜新生毛细血管检测各组分别无、丰富、丰富、少量;COX-2新生血管阳性细胞计数各组分别为0、36.3±8.3、40.9±9.2、10.4±3.9.Adanti-ERK2组与其他组别间比较,差异有统计学意义(P＜0.05).结论　内膜增生,血管腔缩窄,PDGF-BB诱导内膜平滑肌细胞募集分化并激发血管新生是TA重要病理生理环节,AdantiERK2基因治疗可有效干预各发病环节,达到治疗效果.

Abstract：

Objective To explore the mechanisms of intimal injury underlying transplant arteriosclerosis (TA) and to clarify the treatment effect of adenovirus-mediated anti-extracellular signal regulated kinase 2 (Adanti-ERK2) gene therapy on TA. Methods The Brown-Norway (BN)-Lewis TA model was employed. According to different gene therapy, the recipients were divided into isograft group, control group, LacZ group, which were used as control, and Adanti-ERK2 group (5 × 109 pfu Adanti-ERK2 was transferred into the graft before transplant, 6 cases in each group). The grafts were harvested on the day60 post-transplantation to evaluate the intimal injury and calculate the ratio of intima/( intima + media). The staining of α-actin and PDGF-BB was performed to analyze proliferation and secretion of vascular smooth muscle cells (VSMCs). The angingenesis was evaluated and the cyclooxygenase-2 (COX-2) staining was detected. Results The intima was normal in the isograft group but a typical intimal proliferation was observed in the control group and the LacZ group. A mild intima injury was obtained in the Adanti-ERK2 group. The ratio of intima/( intima + media) was 7.6%, 81.4%, 85.9% and 15.9% in isograft, control, LacZ and Adanti-ERK2 groups, respectively. The α-actin staining-positive cells, which indicated VSMCs, were counted per vision-field as 0, 71.3 ± 9.2, 76. 4 ± 11.3 and 34. 8 ± 5.3, respectively. The platelet derived growth factor-BB (PDGF-BB) positive cells were counted as 0. 9 ± 0. 5, 28.4 ± 3.4,29. 1 ± 3.2 and 8.6 ± 1.7, respectively. The angiogenesis was detected as none, abundant, abundant and few, and COX-2 positive cells were counted as 0, 36. 3 ± 8. 3, 40. 9 ± 9. 2 and 10. 4 ± 3.9, respectively (P ＜ 0. 05 between Adanti-ERK2 group and other groups). Conclusion Intimal proliferation, luminal narrow, VSMCs recruitment and differentiation induced by PDGF-BB in intima and the following angiogenesis are the important pathophysiological process of TA. Adanti-ERK2 gene therapy modulates the process and then ameliorates TA.     

联合转染eNOS基因反义ET核酸对自体移植静脉内膜增生的影响

目的;探讨联合转染eNOS基因和反义ET核酸对自体移植静脉内膜增生的影响。方法：制作20只自体颈静脉腹主动脉移植Wistar大鼠模型,实验组,对照组各10只,实验组移植血管行腺病毒介导的eNOS溶液浸泡和反义ET核酸凝胶涂布,对照组仅行空载腺病毒溶液浸泡和凝胶兴布。术后2周取出移植血管,利用病理学,免疫组织化学,RT－PCR方法检测移植血管内膜厚度,管腔狭窄度,内膜VSMC数及PCNA阳性表达,血管ETmRNA,eNOSmRNA表达情况。结果：实验组移植血管内膜厚度,管腔狭窄及VSMC数均较对照组减小或减少,PCNA阳性表达及ETmRNA表达较对照组减少,而eNOSmRNA表达则明显增加。结论;联合转染NOS基因和反义ET核酸可有效地抑制移植静脉内膜的增生,是一种有效地防治移植静脉再狭窄的基因疗法。     

应用吡格列酮抑制大鼠血管移植物慢性病变

目的 研究吡格列酮对血管移植物慢性病变的影响,并探讨其作用机理.方法 制备大鼠腹主动脉移植模型.实验组以Wistar大鼠为供者,SD大鼠为受者,进行腹主动脉移植,术后采用吡格列酮(0.04 g/kg)灌胃8周;同种移植对照组以Wistar大鼠为供者,SD大鼠为受者,进行腹主动脉移植.术后采用牛理盐水灌胃8周;同系移植对照组的供、受者均为SD大鼠,术后采用生理盐水灌胃8周.移植后第8周,取移植腹主动脉段,行HE染色,显微镜F观察组织形态学变化,测量内膜厚度与中膜厚度的比值;采用免疫组织化学法测定移植动脉绀织中细胞问粘附分子-1(ICAM-1)的表达;采用双抗体夹心酶联免疫吸附试验检测血清血小板衍生生长因子(PDGF)浓度.结果 移植后第8周,同系移植对照组的血管内膜无明显变化,同种移植对照组和实验组移植血管组织均呈现出典型的移植相关血管硬化,内膜呈弥漫性向心性显著增生,管腔狭窄,新生内膜见较多血管平滑肌细胞增生,大量成纤维细胞增生,内膜可见少量单核细胞浸润;中膜变薄,内弹力纤维有断裂;外膜见大量单个核细胞,同种移植对照组的病理改变较实验组更加明显.同种移植对照组内膜厚度/中膜厚度比值为1.4140±0.2232,实验组为0.4010±0.0910,二者比较,差异有统计学意义(P＜0.01).同种移植对照组ICAM-1阳性细胞数为(26.114±1.493)个,实验组为(8.943±1.061)个,二者比较,差异有统计学意义(P＜0.01).同种移植对照组的血清PDGF含量为(1023±27)pg/ml,实验组为(265±100)pg/ml,二者比较,差异有统计学意义(P＜0.01).结论 吡格列酮能够延缓移植动脉慢性血管病变的发展,这种作用可能与局部ICAM-1表达下调、血清PDGF浓度下降有关.     

Antisense extracellular signal-regulated kinase-2 gene therapy inhibits platelet-derived growth factor-induced proliferation, migration and transforming growth factor-beta(1) expression in vascular smooth muscle cells and attenuates transplant vasculopathy.

Platelet-derived growth factor-BB (PDGF-BB) enables vascular smooth muscle cells (VSMCs) to proliferate, migrate and secrete connective tissue matrix, which are critical events in transplant vasculopathy. However, little is known about the intracellular pathways that mediate these biologic responses of VSMCs. Extracellular signal-regulated kinase (ERK) pathway plays a major role in cellular responses and vascular diseases. In this study, we observed that the inhibition of ERK2 activity by recombinant adenovirus encoding antisense ERK2 (Adanti-ERK2) significantly suppressed the proliferation, converting of cell cycle from G(1) phase to S phase and directed migration, and partially abrogated transforming growth factor-beta(1) (TGF-beta(1)) expression in VSMCs stimulated with PDGF-BB. Ex vivo gene transfer of Adanti-ERK2 into rat aortic allograft attenuated chronic transplant vasculopathy by the inhibition of VSMC proliferation and migration. In conclusion, ERK2 is involved in PDGF-BB-induced VSMCs proliferation, migration and TGF-beta(1) expression and may be a potential therapeutic target for transplant vasculopathy.     

Adenovirus-mediated antisense-ERK2 gene therapy attenuates chronic allograft nephropathy

BACKGROUND: The aim of this study was to investigate the effects of adenovirus-mediated antisense ERK2 (Adanti-ERK2) gene therapy on chronic allograft nephropathy. METHODS: We employed a rat kidney transplantation mode (F344-->Lewis) and studied four groups: (1) controls (n = 6); (2) vector controls (n = 6); (3) an Adanti-ERK2 group (n = 10); and (4) an isograft group (n = 4). The animals were monitored for proteinuria, graft histology, infiltrating cells, and immune-related gene (interleukin-2 [IL-2] and intracellular adhesion molecule-1 [ICAM-1]) expression for 20 weeks after transplantation. RESULTS: The control group had increasing proteinuria during the 20-week follow-up. All rats showed advanced chronic renal failure associated with strong immune cell infiltration and immune gene expression. Chronic graft injury was accelerated in the vector-control group, but no significant difference was observed compared with the control group. In contrast, the Adanti-ERK2 group showed less inflammation and improved graft histology/function compared with controls. Moreover, ERK2 protein expression in the Adanti-ERK2 group was lower than in the control group (P < .05) and vector-control group (P < .05). Furthermore, serial estimates of genes (IL-2, ICAM-1) related to chronic rejection showed significant downregulation in the Adanti-ERK2 group (P < .01). CONCLUSIONS: Adenovirus-mediated antisense ERK2 gene therapy attenuated chronic allograft nephropathy. The protective effects of antisense ERK2 gene therapy may have derived from a blocked ERK signal transduction pathway, which reduced ERK expression as well as those of immune-related genes.     

低分子肝素对大鼠心脏移植物血管病的抑制作用

目的 观察低分子肝素对大鼠心脏移植物血管病(CAV)的作用及其机制.方法 以SD大鼠为供者,Wistar大鼠为受者,进行异位(腹部)心脏移植.将受者分为3组,每组30只.CsA组自手术当天至术后第9天腹腔注射环孢素A(CsA);实验组腹腔注射CsA(用法同CsA组),并从手术当天开始皮下注射低分子肝素,2 mg·kg-1·d-1,直至处死;L-NAME组在给予低分子肝素的同时皮下注射左旋精氨酸甲酯(L-NAME),10 mg·kg-1·d-1,其他用药同实验组.每组分别于术后30、60和90 d各选取10只大鼠,测定血中NO及内皮素-1(ET-1)的浓度,切取移植心脏,镜下观察并进行CAV评分.结果 随着时间的延长,各组的CAV评分逐渐升高,血NO浓度和ET-1浓度逐渐降低.实验组术后30、60和90 d时的CAV评分分别为1.1±0.6、1.6±0.7和2.1±0.6,血ET-1浓度分别为(133±26)pg/ml、(106±16)pg/ml和(79±16)pg/ml,均明显低于CsA组和L-NAME组(P<0.05);实验组术后30、60和90 d时的血NO浓度分别为(171±22)μmol/L、(122±27)μmol/L和(92±17)μmol/L,均明显高于CsA组和L-NAME组(P<0.05).结论 低分子肝素可以延缓心脏CAV的进展,其作用可能是通过增加NO的浓度和抑制ET-1的合成来实现的.     

重组人肝细胞生长因子对心脏移植后冠状动脉内膜c—Met表达的影响

目的探讨重组人肝细胞生长因子（rh—HGF）对大鼠移植心脏冠状动脉内膜c—Met表达的影响及其意义。方法雄性Wistar大鼠80只，雄性SD大鼠40只，建立腹腔异位心脏移植模型。将60只受体大鼠分为3组，对照组：20只Wistar大鼠，术后当天开始腹腔注射生理盐水1ml／kg·d；环孢菌素A（CsA）组：20只SD大鼠，术后当天开始腹腔注射CsA 5mg／kg·d；rh—HGF组：20只SD大鼠，术后当天开始腹腔注射rh—HGF 500μg／kg·d＋CsA 5mg／kg·d。分别于术后15d、60d观察冠状动脉的病理变化；采用免疫组织化学方法检测冠状动脉内膜c—Met的表达，逆转录聚合酶链反应（RT—PCR）检测冠状动脉内膜c—Met mRNA的表达。结果rh—HGF组移植心脏冠状动脉内皮细胞完整，内膜轻度增厚，管腔轻度狭窄，病理改变明显轻于CsA组。术后15d、60drh—HGF组c—Met和c—Met mRNA在移植心脏冠状动脉内膜的表达均明显高于CsA组和对照组（术后60dc—Met：1．85±0．26 vs．0．96±0．10，t=8．491，P=0．000；1．85±0．26 vs．0．58±0．03，t=13．725，P=0．000；术后60dc—Met mRNA：1．92±0．22VS．0．88±0．07，t=11．940，P=0．000；1．92±0．22 vs．0．42±0．02，t=19．206，P=0．000）。结论rh—HGF通过上调移植心脏冠状动脉内膜c—Met的表达，可促进冠状动脉内皮细胞修复和再生，预防移植心脏血管病的发生。     

The natural killer cell activating receptor,NKG2D,is critical to antibody-dependent chronic rejection in heart transplantation

Chronic rejection is among the most pressing clinical challenges in solid organ transplantation. Interestingly, in a mouse model of heterotopic heart transplantation, antibody-dependent, natural killer (NK) cell-mediated chronic cardiac allograft vasculopathy occurs in some donor–recipient strain combinations, but not others. In this study, we sought to identify the mechanism underlying this unexplained phenomenon. Cardiac allografts from major histocompatibility complex (MHC) mismatched donors were transplanted into immune-deficient C57Bl/6.rag^−/− recipients, followed by administration of a monoclonal antibody against the donor MHC class I antigen. We found marked allograft vasculopathy in hearts from C3H donors, but near-complete protection of BALB/c allografts from injury. We found no difference in recipient NK cell phenotype or intrinsic responsiveness to activating signals between recipients of C3H versus BALB/c allografts. However, cardiac endothelial cells from C3H allografts showed an approximately twofold higher expression of Rae-1, an activating ligand of the NK cell receptor natural killer group 2D (NKG2D). Importantly, the administration of a neutralizing antibody against NKG2D abrogated the development of allograft vasculopathy in recipients of C3H allografts, even in the presence of donor-specific antibodies. Therefore, the activating NK cell receptor NKG2D is necessary in this model of chronic cardiac allograft vasculopathy, and strain-dependent expression of NK activating ligands correlates with the development of this disease.     

Mixed hematopoietic chimerism prevents allograft vasculopathy.

BACKGROUND: Mixed hematopoietic chimerism has been shown to induce long-term acceptance of transplant organs. We determined whether mixed chimerism prevented allograft vasculopathy, using the rat aortic allograft model. METHODS: Mixed chimeras were prepared by reconstituting lethally irradiated (1100 cGy) WF rats with a mixture of T-cell depleted (TCD) syngeneic (WF) plus TCD allogeneic (ACI) bone marrow. Donor-specific (ACI) or third-party (F344) aortic grafts were transplanted into mixed chimeric animals 1 to 2 months after bone marrow reconstitution. No immunosuppressive drugs were administered. At 30 days postoperatively, aortic allografts were harvested for histology and measurement of cytokine mRNA by semiquantitative RT-PCR. Some aortic grafts were harvested at 90 and 180 days after transplantation for histological analysis. The degree of intimal hyperplasia and cytokine gene expression were compared among 4 groups: I (syngeneic; ACI donors to ACI recipients), II (allografts; ACI to WF), III (donor specific; ACI donor to chimeras) and IV (third-party; F344 to chimeras). RESULTS: There was no difference in the degree of intimal hyperplasia (IH) between groups I and III. Groups II and IV had significantly more IH than group I. Compared to group I, levels of mRNA for IFN-y, IL-2, IL-10 and iNOS in groups II and IV were higher, while there was no difference in mRNA levels between group I and III. CONCLUSIONS: These data suggest that mixed chimerism prevents allograft vasculopathy. Mixed chimerism holds great promise in clinical transplantation as a means to prevent allograft vasculopathy.     

Adenovirus-mediated anti-sense ERK2 gene therapy inhibits tubular epithelial-mesenchymal transition and ameliorates renal allograft fibrosis

Purpose

Epithelial-mesenchymal transition (EMT) plays an important role in progress of renal allograft fibrosis. The adenovirus-mediated anti-sense extracellular signal-regulated kinase 2 (Adanti-ERK2) gene therapy was used to block ERK signaling pathway, and its effect on EMT and renal allograft fibrosis both in vivo and in vitro was explored.

Methods

We first generated an in vitro EMT model by connective tissue growth factor (CTGF) stimulation in a HK-2 cell culture system, and then applied Adanti-ERK2 gene therapy on it. The transition of epithelial marker (E-cadherin) to mesenchymal markers (??-SMA, Vimentin) and the cell mobility function alteration were monitored for the observation of EMT progress. In vivo, a rat renal transplant model with Fisher-Lewis combination was employed and the Adanti-ERK2 gene therapy was given. The tubular EMT changes and pathology of allograft fibrosis were examined.

Results

In vitro, Adanti-ERK2 gene therapy inhibited CTGF-induced tubular EMT and attenuated the cell motility function induced by CTGF. In vivo, Adanti-ERK2 gene therapy attenuated tubular EMT, modulated the infiltration of macrophages and CD8⁺, CD4⁺T lymphocytes, and ameliorated fibrosis effectively in the renal allografts 24 weeks after transplantation.

Conclusions

Adanti-ERK2 gene therapy inhibits tubular EMT and attenuates renal allograft fibrosis. It is possible to develop promising molecular drug(s) in the future based on ERK signaling pathway.