Study on cell-specific roles of nudear factor KB in the progression of renal diseases with genetically modified animals

首先，利用含cre -重组酶表达载体的水通道蛋白启动子区，制备仅在脂肪细胞和近端小管S3段表达cre -重组酶的小鼠细胞系。我们获得了7株小鼠，尽管在近端小管S1和S2段观察到少量的re-recombinase活性。我们还检测了cre -重组酶mRNA在各器官和组织中的表达。在睾丸和脂肪组织中有强烈表达，在肝脏、肌肉和肠道等组织中也有显著表达。根据这些结果，我们放弃了这些小鼠系进行我们的研究。另一方面，我们之前已经开发了条件转基因小鼠，其中在cre -重组酶存在下表达NFκB抑制因子的显性阴性形式IκBΔN。我们获得了IκBΔN条件转基因小鼠和足细胞特异性表达cre -重组酶小鼠的双转基因小鼠。双转基因小鼠和野生型小鼠均可诱导肾毒性血清肾炎。双转基因小鼠尿蛋白排泄量显著降低，月牙形形成和肾小球改变也不明显。IκBΔN条件转基因小鼠和内皮细胞特异性表达cre -重组酶小鼠的双转基因小鼠未出生，提示内皮细胞NFκB活性是发育过程中生存所必需的。此外，我们还研究了聚簇素在肾小管细胞凋亡中的作用，提示聚簇素可能促进肾小管细胞凋亡。由此提示足细胞NFκB活性在肾毒性血清肾炎发病过程中起重要作用。

At first, to generate mice lines in which Cre-recombinase is expressed only in adipocyte and proximal tubules S3 segment, aquaporin promoter region with Cre-recombinase expression vector was used to. We obtained 7 lines of mouse, although, Cre-recombinase activity was observed in a patchy manner in the proximal tubules S1 and S2 segments. We also examined the expression of Cre-recombinase mRNA expression in various organs and tissues. Strong expression was seen in testis and adipose tissue, while significant expression was also seen in various tissues, such as liver, muscle, and intestine. From these results, we abandoned these lines of mouse for our study.On the other hand, we have previously developed conditional transgenic mouse, in which IκBΔN, a dominant-negative form of inhibitory factor of NFκB, is expressed in the presence of Cre-recombinase. We obtained double transgenic mouse of IκBΔN conditional transgenic mouse and podocyte-specific Cre-recombinase expressing mouse. Nephrotoxic serum nephritis was induced in this double transgenic mouse and wild-type mouse. Urinary excretion of protein was significantly lower in double transgenic mouse and crescent formation and glomerular changes were less prominent in double transgenic mouse, too. Double transgenic mouse of IκBΔN conditional transgenic mouse and endothelial-cell-specific Cre-recombinase expressing mouse was not born suggesting that endothelial NFκB activity is required to survive during development.Furthermore, we examined roles of clusterin in renal tubular cell apoptosis and it was suggested that clusterin might facilitate apoptosis.From these results, it is suggested that NFκB activity in podocytes plays important roles in the pathogenesis of nephrotoxic serum nephritis.