Bassiouny Ahmad R, Zaky Amira Z, Abdulmalek Shaymaa A, Kandeel Kamal M, Ismail Alaa, Moftah Marie
Department of Biochemistry, Alexandria University, Egypt.
Int J Clin Exp Pathol. 2011;4(7):692-707. Epub 2011 Oct 16.
Oxidative stress in liver cells may contribute to the etiology of hepatic diseases, as in liver cirrhosis. AP-Endonuclease1 (APE1/Ref-1) is essential for cell protection toward oxidative stress by acting as a transcriptional regulator of pro-survival genes and as a redox sensitive protein. The aim of this study was to critically analyze the various parameters governing the success of human umbilical cord blood mononuclear stem cell-based (MNCs) therapy without the use of an immunosuppressant and to investigate for the first time the expression of APE1 during thioacetamide (TAA)-induced cirrhosis and MNCs therapy in a rat model. Umbilical cord blood samples from full-term deliveries were collected. Lethal fulminant hepatic cirrhosis in rats was induced by intraperitoneal injection of thio-acetamide. MNCs were then intrahepatically transplanted. We measured APE1 expression at mRNA and protein levels, mRNA expression of TGF-β, α-SMA, STAP, CTGF, MMP-9 and TIMP-1 in a follow up study. Histopathological and immunohistochemical analyses were performed 10 weeks after intrahepatic injection of the cells. Transdifferentiated cells could be efficiently stained with antihuman hepatocytes. Interestingly, human hepatocyte-specific markers, human albumin, cytokeratin-18 and cytokeratin-19 mRNAs were detected in rat liver after 10 days of MNCs infusion. MNC transplanted by intrahepatic route, could engraft recipient liver, differentiated into functional hepatocytes, and rescued liver failure. Moreover up regulation of APE1 expression confirmed by marked immunohistochemical staining may be involved in MNCs-induced hepatocytes regeneration suggesting that maintaining high level of APE1 has protective effect as pro-survival signal.
肝细胞中的氧化应激可能导致肝脏疾病的发生，如肝硬化。脱嘌呤嘧啶核酸内切酶1（APE1/Ref-1）通过作为促生存基因的转录调节因子和氧化还原敏感蛋白，对细胞免受氧化应激至关重要。本研究的目的是严格分析在不使用免疫抑制剂的情况下，基于人脐带血单个核干细胞（MNCs）治疗成功的各种参数，并首次研究硫代乙酰胺（TAA）诱导的肝硬化和MNCs治疗大鼠模型中APE1的表达。收集足月分娩的脐带血样本。通过腹腔注射硫代乙酰胺诱导大鼠发生致死性暴发性肝硬化。然后将MNCs肝内移植。在后续研究中，我们测量了APE1在mRNA和蛋白质水平的表达，以及转化生长因子-β（TGF-β）、α-平滑肌肌动蛋白（α-SMA）、富含半胱氨酸的酸性分泌蛋白（STAP）、结缔组织生长因子（CTGF）、基质金属蛋白酶-9（MMP-9）和基质金属蛋白酶组织抑制因子-1（TIMP-1）的mRNA表达。在细胞肝内注射10周后进行组织病理学和免疫组织化学分析。转分化细胞可以用抗人肝细胞抗体有效染色。有趣的是，在MNCs输注10天后，在大鼠肝脏中检测到了人肝细胞特异性标志物、人白蛋白、细胞角蛋白-18和细胞角蛋白-19的mRNA。通过肝内途径移植的MNCs可以植入受体肝脏，分化为功能性肝细胞，并挽救肝功能衰竭。此外，免疫组织化学染色显著证实的APE1表达上调可能参与了MNCs诱导的肝细胞再生，这表明维持高水平的APE1作为促生存信号具有保护作用。
