Stranahan Alexis M, Tabet Anthony, Anikeeva Polina
Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, 1120 15th St, Augusta, GA 30912, USA.
Research Laboratory of Electronics and McGovern Institute for Brain Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139-4307, USA.
Brain Behav Immun. 2024 Jan;115:131-142. doi: 10.1016/j.bbi.2023.09.021. Epub 2023 Oct 17.
Region-specific genetic manipulation of glial cells remains challenging due to the lack of anatomically selective transgenic models. Although local transduction is achievable with viral vectors, uniform recombination can be challenging in larger brain regions. We investigated the efficacy of intraparenchymal delivery of the tamoxifen metabolite endoxifen using inducible cre reporter mice. After observing localized reporter induction following stereotaxic injections of endoxifen in CX3CR1creERT2 mice, we carried out chronic delivery via osmotic pumps attached to bilateral cannulas made of stainless steel or microfluidic polymer fibers. Analysis of reporter expression in sections or iDISCO-cleared brains from TMEM119creERT2 mice revealed widespread induction following chronic infusion. Neuronal damage and gliosis were more prevalent around steel cannulas than polymer fibers, and glial reactivity was further attenuated when devices were implanted two months before drug delivery. In summary, region-specific recombination is achievable in glia with minimal tissue damage after endoxifen delivery via microfluidic polymer implants.
由于缺乏解剖学上具有选择性的转基因模型，对神经胶质细胞进行区域特异性基因操作仍然具有挑战性。尽管使用病毒载体可以实现局部转导，但在较大的脑区实现均匀重组可能具有挑战性。我们使用诱导型cre报告基因小鼠研究了他莫昔芬代谢产物4-羟基他莫昔芬实质内递送的效果。在CX3CR1creERT2小鼠中立体定向注射4-羟基他莫昔芬后观察到局部报告基因诱导后，我们通过连接由不锈钢或微流体聚合物纤维制成的双侧套管的渗透泵进行了长期递送。对TMEM119creERT2小鼠切片或经iDISCO清除的大脑中报告基因表达的分析显示，长期输注后有广泛的诱导。与聚合物纤维相比，钢套管周围的神经元损伤和胶质增生更为普遍，并且当在给药前两个月植入装置时，神经胶质反应性进一步减弱。总之，通过微流体聚合物植入物递送4-羟基他莫昔芬后，在神经胶质细胞中可以实现区域特异性重组，且组织损伤最小。
