Permeability Changes in Small Bowel Allograft Rejection

小肠同种异体移植排斥反应的渗透性变化

• 批准号: 7140459
• 负责人: Jonathan P Fryer
• 金额: $ 13.55万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-15 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7140459
• 关键词: biological signal transduction; cell differentiation; cytokine; disease /disorder model; enzyme linked immunosorbent assay; flow cytometry; gastrointestinal epithelium; gastrointestinal transplantation; gel mobility shift assay; genetically modified animals; homologous transplantation; laboratory mouse; membrane permeability; mucosal immunity; nuclear factor kappa beta; phosphorylation; polymerase chain reaction; postoperative complications; protein structure function; small intestines; tight junctions; transplant rejection; western blottings

DESCRIPTION (provided by applicant): SB transplantation is a potential solution for patients with intestinal failure who otherwise will need lifelong parenteral nutrition. However allograft rejection and excessive infectious complications continue to limit its wider application. SB allograft rejection is associated with an increased epithelial permeability that facilitates translocation of bacterial products, that augment rejection and ultimately contribute to systemic sepsis, multiorgan failure and death. The molecular basis for this rejection mediated mucosal barrier defect is not known. We have established a mouse model of SB transplantation to evaluate SB allograft rejection and its consequences. Using this model we have demonstrated that increased permeability occurs early in early SB allograft rejection and is associated with changes in epithelial tight junction associated proteins. Since crypt cells are associated with weaker tight junctions, concurrent decreases in the villus to crypt ratio may also contribute to rejection mediated permeability. We have therefore proposed experiments that will better define the relationship between changes in epithelial tight junction barrier function and epithelial differentiation in early SB allograft rejection. Furthermore, early rejection is associated with the induction of TH1 cytokines and chemokines that perpetuate rejection by inducing an inflammatory response in intestinal epithelial cells. NF-KB mediates inflammatory changes in many cell types, including epithelial cells. In mouse SB allografts, we have demonstrated that epithelial NF-KB activation correlates with rejection mediated permeability changes. To further study the role of NF-KB in rejection mediated permeability changes we have developed a double transgenic mutant mouse with an enterocyte-specific IkB mutation (mIKBalpha) that acts as an NF-KB superrepressor. SB transplants performed using this mouse as a donor are associated with significant downregulation of NF-KB dependent, enterocyte specific proteins and delayed allograft rejection. We propose to exploit the mIKBalpha double transgenic mouse in a mouse SB transplant model to determine if graft enterocyte specific NF-KB signaling plays a role in rejection mediated changes in epithelial permeability and tight junction associated proteins in early SB allograft rejection.

描述（由申请方提供）：SB移植是肠衰竭患者的潜在解决方案，否则这些患者将需要终身肠外营养。然而，同种异体移植排斥反应和过度的感染并发症继续限制其更广泛的应用。SB同种异体移植物排斥与促进细菌产物移位的增加的上皮渗透性相关，这增加了排斥并最终导致全身性脓毒症、多器官衰竭和死亡。这种排斥介导的粘膜屏障缺陷的分子基础尚不清楚。我们建立了小鼠SB移植模型，以评估SB移植排斥反应及其后果。使用这个模型，我们已经证明，增加的渗透性发生在早期SB同种异体移植排斥反应的早期，并与上皮紧密连接相关蛋白的变化。由于隐窝细胞与较弱的紧密连接相关，绒毛与隐窝比率的同时降低也可能有助于排斥介导的渗透性。因此，我们提出的实验，将更好地确定上皮细胞紧密连接屏障功能的变化和上皮细胞分化的早期SB同种异体排斥反应之间的关系。此外，早期排斥与TH 1细胞因子和趋化因子的诱导有关，TH 1细胞因子和趋化因子通过诱导肠上皮细胞中的炎症反应而使排斥持续存在。NF-κ B介导包括上皮细胞在内的许多细胞类型的炎症变化。在小鼠SB同种异体移植物中，我们已经证明上皮NF-κ B活化与排斥介导的渗透性变化相关。为了进一步研究NF-κ B在排斥介导的通透性变化中的作用，我们开发了一种具有肠细胞特异性IkB突变（mIKB α）的双转基因突变小鼠，其充当NF-κ B超阻遏物。使用该小鼠作为供体进行的SB移植与NF-κ B依赖性肠上皮细胞特异性蛋白的显著下调和延迟的同种异体移植物排斥相关。我们建议在小鼠SB移植模型中利用mIKB α双转基因小鼠，以确定移植物肠上皮细胞特异性NF-κ B信号传导是否在早期SB同种异体移植排斥中上皮通透性和紧密连接相关蛋白的排斥介导的变化中起作用。