2016-08-012024-05-13https://scholars.lib.ntu.edu.tw/handle/123456789/645533摘要：缺氧腎臟傷害是急性腎衰竭的重要原因，臨床上，會造成併發症及死亡。缺氧再灌流腎臟傷害的恢復過程中，組織的發炎狀態會消退，腎小管再生，並有血管新生現象。任何因素會影響這些過程，將會抑制腎臟自缺氧再灌流傷害後的組織修復。 Angiopoietin系統，包含內皮生長因子1（angiopoietin1, Angpt1）、內皮生長因子2（angiopoietin 2）及其受體tyrosine kinase with Ig and EGF homologydomains 2是很重要的血管生成系統，這個系統參與血管生成與維持內皮細胞的完整。缺乏Angpt1有可能會影響腎臟缺氧再灌流傷害後之血管新生。我們初步的研究顯示：腎臟缺氧再灌流傷害後的三到十四天，腎臟中的Angpt1會增加，我們利用可引發性全身Angpt1基因剔除鼠實驗，發現這些基因剔除鼠在缺氧再灌流腎臟傷害後的三到七天，腎臟功能及再生的狀況都比正常老鼠差。Ａngpt1也會影響發炎，一些報告顯示：Angpt1可以發揮抗發炎的效果，促進巨噬細胞參與血管生成及傷口修復。此外，Angpt1也可以促進endothelial progenitor cell (EPC)自骨髓啟動釋出，而這些EPC對於血管的修復及新生扮演重要的角色。Angpt1也會促進內皮細胞分泌hepatocyte growthfactor，召集血管平滑肌細胞參與血管的生成。Angpt1有可能也會刺激內皮細胞分泌生長因，促進腎臟缺氧再灌流傷害之腎小管再生。因此，我們假設：Angpt1可以藉由改變巨噬細胞的功能，釋放EPC，並刺激內皮細胞分泌生長因子，從而減少腎臟缺氧再灌流的傷害，加強腎臟組織的修復。在本計劃，我們將探討Angpt1影響腎臟缺氧再灌流傷害的詳細機轉，利用可引發性Angpt1基因剔除及過度表現基因鼠，我們會檢視剔除或過度表現Angpt1基因是否會影響腎臟的缺氧再灌流傷害，或改變腎臟組織的再生及功能恢復。實驗的項目包括檢視腎功能、病理變化、腎小管的再生、發炎現象的改變，以及EPC的啟動及移入。為了評估Angpt1對個別內皮細胞及巨嗜細胞的影響，我們將以流式細胞儀個別分離出內皮細胞及巨噬細胞，詳細分析其基因表現。臨床上，尿毒及感染的存在，有可能會影響Angpt1在腎臟缺氧再灌流傷害後的增加，因而影響腎臟在受到傷害後的組織修復。我們將利用在腎臟缺氧再灌流傷害的動物模式中，額外給予indosylsulfate，以模擬急性腎臟缺氧病變後持續有尿毒的現象，檢視尿毒是否會抑制Angpt1在腎臟缺氧再灌流傷害表現增加的功能。同時，在這樣的動物模式中，我們也會過度表現Angpt1，看看是否可以補充Angpt1，來改善尿毒藉由抑制Angpt1生成對於腎臟缺氧再灌流傷害的不良影響。我們預期：Angpt1可以藉由促進EPC的移入、改變巨噬細胞的功能及促進內皮細胞分泌生長因子，來減少腎臟缺氧再灌流傷害，促進腎臟組織的修復；除此之外，過度表現Angpt1也可以逆轉尿毒藉由抑制Angpt1生成來影響腎臟缺氧再灌流傷害。我們相信這個研究對於發展急性腎臟傷害的治療有相當大的幫助。<br> Abstract: Ischemic renal injury is an important cause of acute renal failure causing significant morbidity andmortality. The recovery from renal IRI involves the resolving of inflammation, renal tubular regenerationand neo-angiogenesis. Any factor influencing the process will delay the recovery from renal IRI anddevelopment of chronic kidney disease from acute kidney injury (AKI).Angiopoietin system, including angiopoietin 1 (Angpt1), angiopoietin 2 (Angpt2), and its receptor,tyrosine kinase with Ig and EGF homology domains 2 (Tie2), is an important angiogenic system involvedin angiogenesis and integrity maintaining of endothelium. The lack of Angpt1 may impair theneo-angiogenesis after ischemic reperfusion renal injury. Our preliminary result revealed that Angpt1 wasup regulated 3~14 days after ischemic reperfusion renal injury. Using inducible whole body Angpt1 knockout mice, we found that the renal function and regeneration score was worse 3 and 7 days after IRI inAngpt1 knock out mice.Angpt1 also influences inflammation. Some reports showed that Angpt1 exerted anti-inflammatoryeffect and facilitated macrophage participating in angiogenesis and would repair. In addition, Angpt1 canhelp mobilizing endothelial progenitor (EPC) cells that are important cells in vessel repair andneo-angiogenesis. Angpt1 also stimulate endothelium to secret HGF and recruit smooth muscle cell toform blood vessel. It is possible Angpt1 could stimulate endothelium to secret growth factor and facilitaterenal tubule to regenerate after IRI. We hypothesize that Angpt1 could influence IRI through changingmacrophage phenotype/function, mobilizing EPC, and stimulating endothelium to secret growth factor.In this project, we will explore the detail mechanisms that Angpt1 influences renal IRI. Using inducibleAngpt1 knock out and over expression mice, we will first examine the influence of knocking out or overexpression of Angpt1 on renal IRI and recovery from renal damage. The renal function, pathology, tubularregeneration, inflammation and endothelial progenitor cell mobilization will be examined. To evaluate theinfluence of Angpt1 on endothelium and macrophage, both cells are isolated individually with flowcytometry and gene expression is analyzed.In clinical condition, the presence of uremia and infection may also impair the generation of Angpt1,therefore inhibits the recovery from acute ischemic renal injury. We will also examine whether uremiawill inhibit Angpt1 expression and impair the recovery from IRI suing indosyl sulfate + IRI mouse model.In addition, we will over express Angpt1 in indosyl sulfate + IRI mouse model to see whether we canreverse the impairment of recovery from renal IRI induced by indosyl sulfate through suppression ofAngpt1.We expect Angpt1 can promote EPC mobilization, shift macrophage from M1 to M2 type, and enhanceendothelium expressing growth factor. Through above mechanisms Angpt1 attenuate IRI renal injury andaccelerate recovery from AKI. Besides, supplement of Angpt1 could also reverse the uremia suppressedAngpt1 expression and therefore promote renal regeneration after IRI. This study will be helpful indeveloping treatment strategy for AKI.