Division of Hematology, Oncology and Transplantation, Department of Medicine, University of Minnesota, 420 Delaware St SE, MMC 480, Minneapolis, MN 55455, USA.
J Mol Med (Berl). 2010 Jul;88(7):665-75. doi: 10.1007/s00109-010-0613-6. Epub 2010 Mar 23.
Increases in heme oxygenase-1 (HO-1) and administration of heme degradation products CO and biliverdin inhibit vascular inflammation and vasoocclusion in mouse models of sickle cell disease (SCD). In this study, an albumin (alb) promoter-driven Sleeping Beauty (SB) transposase plasmid with a wild-type rat hmox-1 (wt-HO-1) transposable element was delivered by hydrodynamic tail vein injections to SCD mice. Eight weeks after injection, SCD mice had three- to five-fold increases in HO-1 activity and protein expression in liver, similar to hemin-treated mice. Immunohistochemistry demonstrated increased perinuclear HO-1 staining in hepatocytes. Messenger RNA transcription of the hmox-1 transgene in liver was confirmed by quantitative real-time polymerase chain reaction restriction fragment length polymorphism (qRT-PCR RFLP) with no detectible transgene expression in other organs. The livers of all HO-1 overexpressing mice had activation of nuclear phospho-p38 mitogen-activated protein kinase (MAPK) and phospho-Akt, decreased nuclear expression of nuclear factor-kappa B (NF-kappaB) p65, and decreased soluble vascular cell adhesion molecule-1 (sVCAM-1) in serum. Hypoxia-induced stasis, a characteristic of SCD, but not normal mice, was inhibited in dorsal skin fold chambers in wt-HO-1 SCD mice despite the absence of hmox-1 transgene expression in the skin suggesting distal effects of HO activity on the vasculature. No protective effects were seen in SCD mice injected with nonsense (ns-) rat hmox-1 that encodes carboxy-truncated HO-1 with little or no enzyme activity. We speculate that HO-1 gene delivery to the liver is beneficial in SCD mice by degrading pro-oxidative heme, releasing anti-inflammatory heme degradation products CO and biliverdin/bilirubin into circulation, activating cytoprotective pathways and inhibiting vascular stasis at sites distal to transgene expression.
血红素加氧酶-1（HO-1）的增加和血红素降解产物 CO 和胆红素的给药可抑制镰状细胞病（SCD）小鼠模型中的血管炎症和血管阻塞。在这项研究中，通过尾静脉注射将带有野生型大鼠 hmox-1（wt-HO-1）可转座元件的白蛋白（alb）启动子驱动的 Sleeping Beauty（SB）转座酶质粒递送至 SCD 小鼠。注射后 8 周，SCD 小鼠肝脏中的 HO-1 活性和蛋白表达增加了 3 到 5 倍，与血红素处理的小鼠相似。免疫组织化学显示肝细胞中 HO-1 染色的核周增加。通过定量实时聚合酶链反应限制性片段长度多态性（qRT-PCR RFLP）证实肝脏中 hmox-1 转基因的信使 RNA 转录，并且在其他器官中未检测到转基因表达。所有 HO-1 过表达小鼠的肝脏中均激活了核磷酸化 p38 丝裂原激活蛋白激酶（MAPK）和磷酸化 Akt，核因子-kappaB（NF-kappaB）p65 的核表达减少，血清中可溶性血管细胞黏附分子-1（sVCAM-1）减少。尽管 wt-HO-1 SCD 小鼠的皮肤中未检测到 hmox-1 转基因表达，但 SCD 但不是正常小鼠的缺氧诱导的停滞，即 SCD 的特征，在 wt-HO-1 SCD 小鼠的背部皮肤褶皱室中受到抑制，这表明 HO 活性对血管的远端影响。在注射无意义（ns-）大鼠 hmox-1 的 SCD 小鼠中未观察到保护作用，该大鼠 hmox-1 编码羧基截断的 HO-1，其具有很少或没有酶活性。我们推测，HO-1 基因递送至肝脏通过降解促氧化血红素，将抗炎血红素降解产物 CO 和胆红素/胆绿素释放到循环中，激活细胞保护途径并抑制转基因表达部位以外的血管停滞，从而有益于 SCD 小鼠。
