CAJ | 학술논문

目的探讨大鼠心脏移植后心肌组织内支链氨基酸(BACC)代谢对移植物血管病变发生、发展的影响.方法实验分为同系移植组和同种移植组,采用改良的Ono模型建立大鼠腹部异位心脏移植模型.移植后2周和8周,取两组受鼠,分别获取其血液和移植心脏标本.观察两组受鼠的血管狭窄程度,使用比较蛋白质组学技术观察移植心肌内蛋白质表达的变化,获得一些影响BACC代谢的差异蛋白质,并采用免疫组织化学法进行验证.用氨基酸自动分析仪测定心脏组织和血浆中BACC浓度.结果移植后2周和8周,同系移植组冠脉血管未出现狭窄,而同种移植组冠脉血管出现明显狭窄(P＜0.01),并且随时间的延长,其血管狭窄程度逐渐加重(P＜0.01).经搜索得到37个差异蛋白质(肽)点,其中3个为支链酮酸脱氢酶(BCKDH)亚单位E1 α、E1 β和E3,BCKDH E1 α、E1β在同种移植心脏组织和血管组织中的表达均显著下调(P＜0.05).同时,移植心脏心肌组织内BACC浓度升高,而血浆内BACC浓度并未明显升高.结论同种移植心脏组织内支链氨基酸氧化代谢的限速酶受到抑制,使心脏组织内支链氨基酸(缬氨酸、亮氨酸和异亮氨酸)的浓度升高,其中亮氨酸作为蛋白质翻译的启动因子,通过哺乳动物雷帕霉素靶蛋白(mTOR)途径和非mTOR途径促进了蛋白质合成,可能在移植心脏心肌肥厚和移植物血管病变的发生、发展中发挥了一定的作用.
목적 탐토대서심장이식후심기조직내지련안기산(BACC)대사대이식물혈관병변발생、발전적영향.방법 실험분위동계이식조화동충이식조,채용개량적Ono모형건립대서복부이위심장이식모형.이식후2주화8주,취량조수서,분별획취기혈액화이식심장표본.관찰량조수서적혈관협착정도,사용비교단백질조학기술관찰이식심기내단백질표체적변화,획득일사영향BACC대사적차이단백질,병채용면역조직화학법진행험증.용안기산자동분석의측정심장조직화혈장중BACC농도.결과 이식후2주화8주,동계이식조관맥혈관미출현협착,이동충이식조관맥혈관출현명현협착(P＜0.01),병차수시간적연장,기혈관협착정도축점가중(P＜0.01).경수색득도37개차이단백질(태)점,기중3개위지련동산탈경매(BCKDH)아단위E1 α、E1 β화E3,BCKDH E1 α、E1β재동충이식심장조직화혈관조직중적표체균현저하조(P＜0.05).동시,이식심장심기조직내BACC농도승고,이혈장내BACC농도병미명현승고.결론 동충이식심장조직내지련안기산양화대사적한속매수도억제,사심장조직내지련안기산(힐안산、량안산화이량안산)적농도승고,기중량안산작위단백질번역적계동인자,통과포유동물뢰파매소파단백(mTOR)도경화비mTOR도경촉진료단백질합성,가능재이식심장심기비후화이식물혈관병변적발생、발전중발휘료일정적작용.
Objective Allograft vasculopathy (AV), feature of chronic rejection, is a major serious long-term post-operation complication in organ transplantation. The accurate mechanisms for AV have not been definitively established, but extensive basic and clinical studies demonstrate AV is triggered by immune reaction and nonimmunologic factors, and also possibly attributed to the metabolism of branched-chain amino acids (BCAA). Methods The transplanted hearts from Lewis to Sprague-Dawely rats served as allografts and those from Lewis to Lewis rats as isografts based on Ono 's model. The differential proteins in transplanted hearts were separated by comparative proteomic technique, and some enzymes which regulated the metabolism of BCAA were identified and validated.Results All transplanted hearts at second week postoperation were characterized by lumen loss (total area-luminal area/total area) in coronary artery, but more predominant at 8th week. All samples from the left ventricles were analyzed by proteomic techniques and the subunits E1 a, E1β and E3 of branched-chain α-ketoacid dehydrogenase (BCKDH) complex were decreased in the heart allografts.Immunohistological detection also showed the expression of BCKDH was reduced not only in the cardiac muscle but also more significantly in blool vessels with cardiac allograft vasculopathy (CAV).BCAA concentrations were increased in the cardiac allografts, but there was no difference in the serum. Conclusion These findings suggest that the catabolic pathways of the BCAA may be inhibited owing to the reduced expression of BCKDH complex, and elevated intracellular concentrations of leucine. The vascular smooth muscle cell and cardiac muscle cell proliferation is stimulated via mTOR-dependent and mTOR-independent pathways, which is associated with the formation of myocardial hypertrophy and AV in the heart allografts.