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

首先，为了获得Cre重组酶仅在脂肪细胞和近曲小管S3段表达的小鼠品系，使用带有Cre重组酶表达载体的水通道蛋白启动子区。我们获得了7个品系的小鼠，尽管在近端小管S1和S2段中以斑片状的方式观察到Cre重组酶活性。我们还研究了Cre重组酶mRNA在各种器官和组织中的表达。在睾丸和脂肪组织中观察到强表达，而在各种组织中也观察到显著表达，如肝脏、肌肉和肠。另一方面，我们已经建立了条件性转基因小鼠，其中IκBΔN（一种显性负性形式的NFκB抑制因子）在Cre重组酶存在下表达。获得了IκBΔN条件转基因小鼠和足细胞特异性Cre重组酶表达小鼠的双转基因小鼠。在该双转基因小鼠和野生型小鼠中诱导肾毒性血清肾炎。双转基因小鼠尿蛋白排泄量明显减少，新月体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Cre重组酶表达小鼠的双转基因小鼠没有出生，提示内皮细胞NFκB活性是发育过程中生存所必需的。此外，我们研究了clusterin在肾小管细胞凋亡中的作用，提示clusterin可能促进凋亡。提示足细胞NFκB活性在肾毒血清肾炎的发病机制中起重要作用。

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.