Rao Nikhil S, Putra Marson, Meyer Christina, Parameswaran Sirisha, Thippeswamy Thimmasettappa
Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University of Science and Technology, Ames, IA 50011, USA.
Cells. 2025 May 19;14(10):743. doi: 10.3390/cells14100743.
Previous studies have demonstrated neuronal and microglial Fyn, a Src family kinase (SFK), and how its interactions with tau contribute to epileptogenesis. Saracatinib, a Fyn/SFK inhibitor, modifies disease progression in rat kainate (KA) epilepsy models. In this study, we investigated neuronal-specific knockdown effects on Fyn-tau signaling, neurodegeneration, and gliosis using a calcium/calmodulin-dependent protein kinase II (CaMKII)-promoter-driven adeno-associated viral vector (AAV9)-mediated -shRNA injection in the rat hippocampus. Eight days following AAV administration, rats received repeated low-dose KA injections intraperitoneally to induce (SE). Both -shRNA and control groups showed comparable SE severity, indicating inadequate neuronal knockdown at this timepoint. Two weeks post -shRNA injection, hippocampal Fyn significantly decreased, alongside reductions in NR2B, pNR2B, PSD95, and total tau. There was also a compensatory activation of SFK (pSFK:Fyn) and tau hyperphosphorylation (AT8:total tau), negatively correlating with NeuN expression. Proximity ligation assay indicated unchanged Fyn-tau interactions, suggesting tau interactions with alternative SH3 domain proteins. Persistent neuronal loss, astrogliosis, and microgliosis suggested limited effectiveness of neuronal-specific knockdown at this timepoint. An extended-duration knockdown study, or using broad SFK inhibitors such as saracatinib or tau-SH3 blocking peptides, may effectively prevent SE-induced epileptogenesis.
先前的研究已经证明了神经元和小胶质细胞中的Fyn（一种Src家族激酶，SFK），以及它与tau的相互作用如何导致癫痫发生。Fyn/SFK抑制剂萨拉卡替尼可改变大鼠红藻氨酸（KA）癫痫模型中的疾病进展。在本研究中，我们使用钙/钙调蛋白依赖性蛋白激酶II（CaMKII）启动子驱动的腺相关病毒载体（AAV9）介导的-shRNA注射到大鼠海马体中，研究了神经元特异性敲低对Fyn-tau信号传导、神经变性和胶质增生的影响。在给予AAV八天后，大鼠腹腔内反复接受低剂量KA注射以诱发癫痫持续状态（SE）。-shRNA组和对照组的SE严重程度相当，表明此时神经元敲低不足。在-shRNA注射两周后，海马体中的Fyn显著降低，同时NR2B、pNR2B、PSD95和总tau也减少。还存在SFK的代偿性激活（pSFK:Fyn）和tau的过度磷酸化（AT8:总tau），与NeuN表达呈负相关。邻近连接分析表明Fyn-tau相互作用未改变，提示tau与其他SH3结构域蛋白相互作用。持续的神经元丢失、星形胶质细胞增生和小胶质细胞增生表明此时神经元特异性敲低的效果有限。延长敲低时间的研究，或使用如萨拉卡替尼等广泛的SFK抑制剂或tau-SH3阻断肽，可能有效预防SE诱导的癫痫发生。
