Li Tianfu, Steinbeck Julius A, Lusardi Theresa, Koch Philipp, Lan Jing Q, Wilz Andrew, Segschneider Michaela, Simon Roger P, Brüstle Oliver, Boison Detlev
R.S. Dow Neurobiology Laboratories, Legacy Research, 1225 NE 2nd Ave, Portland, OR 97232, USA.
Brain. 2007 May;130(Pt 5):1276-88. doi: 10.1093/brain/awm057.
Epilepsy therapy is largely symptomatic and no effective therapy is available to prevent epileptogenesis. We therefore analysed the potential of stem cell-derived brain implants and of paracrine adenosine release to suppress the progressive development of seizures in the rat kindling-model. Embryonic stem (ES) cells, engineered to release the inhibitory neuromodulator adenosine by biallelic genetic disruption of the adenosine kinase gene (Adk-/-), and respective wild-type (wt) cells, were differentiated into neural precursor cells (NPs) and injected into the hippocampus of rats prior to kindling. Therapeutic effects of NP-derived brain implants were compared with those of wt baby hamster kidney cells (BHK) and adenosine releasing BHK cell implants (BHK-AK2), which were previously shown to suppress seizures by paracrine adenosine release. Wild-type NP-graft recipients were characterized by an initial delay of seizure development, while recipients of adenosine releasing NPs displayed sustained protection from developing generalized seizures. In contrast, recipients of wt BHK cells failed to display any effects on kindling development, while recipients of BHK-AK2 cells were only moderately protected from seizure development. The therapeutic effect of Adk(-/-)-NPs was due to graft-mediated adenosine release, since seizures could transiently be provoked after blocking adenosine A1 receptors. Histological analysis of NP-implants at day 26 revealed cell clusters within the infrahippocampal cleft as well as intrahippocampal location of graft-derived cells expressing mature neuronal markers. In contrast, BHK and BHK-AK2 cell implants only formed cell clusters within the infrahippocampal cleft. We conclude that ES cell-derived adenosine releasing brain implants are superior to paracrine adenosine release from BHK-AK2 cell implants in suppressing seizure progression in the rat kindling-model. These findings may indicate a potential antiepileptogenic function of stem cell-mediated adenosine delivery.
癫痫治疗主要是对症治疗，目前尚无有效的疗法来预防癫痫发生。因此，我们分析了干细胞衍生的脑植入物和旁分泌腺苷释放抑制大鼠点燃模型中癫痫发作进行性发展的潜力。通过腺苷激酶基因双等位基因遗传破坏（Adk-/-）设计为释放抑制性神经调节剂腺苷的胚胎干细胞（ES细胞）和相应的野生型（wt）细胞，分化为神经前体细胞（NP），并在点燃前注入大鼠海马体。将NP衍生的脑植入物的治疗效果与wt幼仓鼠肾细胞（BHK）和释放腺苷的BHK细胞植入物（BHK-AK2）的治疗效果进行比较，之前已证明后者通过旁分泌腺苷释放来抑制癫痫发作。野生型NP移植受体的特征是癫痫发作发展初期延迟，而释放腺苷的NP受体则持续受到保护，不会发展为全身性癫痫发作。相比之下，wt BHK细胞受体对点燃发展没有任何影响，而BHK-AK2细胞受体仅受到中度保护，防止癫痫发作发展。Adk(-/-)-NP的治疗效果归因于移植介导的腺苷释放，因为在阻断腺苷A1受体后癫痫发作可被短暂诱发。在第26天对NP植入物进行组织学分析，发现在海马裂内有细胞簇，以及在海马内移植来源的细胞表达成熟神经元标志物的位置。相比之下，BHK和BHK-AK2细胞植入物仅在海马裂内形成细胞簇。我们得出结论，在抑制大鼠点燃模型中的癫痫发作进展方面，ES细胞衍生的释放腺苷的脑植入物优于BHK-AK2细胞植入物的旁分泌腺苷释放。这些发现可能表明干细胞介导的腺苷递送具有潜在的抗癫痫发生功能。
