Neural stem cells may be uniquely suited for combined gene therapy and cell replacement: Evidence from engraftment of Neurotrophin-3-expressing stem cells in hypoxic-ischemic brain injury
Neural stem cells may be uniquely suited for combined gene therapy and cell replacement: Evidence from engraftment of Neurotrophin-3-expressing stem cells in hypoxic-ischemic brain injury
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DOI：
10.1016/j.expneurol.2006.03.016
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发表时间：
2006-05-01
影响因子：
5.3
通讯作者：
Snyder, Evan Y.
中科院分区：
文献类型：
--
作者：
Park, Kook In;Himes, B. Timothy;Snyder, Evan Y.
以前，我们报道，当克隆的神经干细胞（NSC）移植到出生后的小鼠的大脑受到单侧缺氧缺血性（HI）损伤（最佳3-7天后梗死），供体来源的细胞优先归巢（甚至从遥远的位置），并广泛整合在大的缺血区域，跨越半球。一个亚群的神经干细胞和宿主细胞，特别是在半影区，“转移”他们的分化向神经元和少突胶质细胞，细胞类型通常受损后窒息和最不可能自发地再生，并在“后发育”的中枢神经系统足够的数量。在完整的出生后皮层中，没有神经元和少数少突胶质细胞从NSC产生，这表明HI后NSC可能对新的信号进行短暂的阐述。“替代”神经元的比例与5%相似。已知神经营养因子-3（NT-3）在发育期间和可能在损伤后诱导神经元分化中起作用。我们证明了NSC表达功能性TrkC受体。此外，供体细胞继续在受损的脑内稳健地表达外源报告基因转基因。因此，如果供体NSC在移植前被工程化以（过）表达生物活性基因如NT-3，则外源NSC（以及内源祖细胞）的神经元分化可能被增强，这似乎是可行的。将用编码NT-3的逆转录病毒转导的NSC的亚克隆（体外产生> 90%的神经元）植入单侧窒息的出生后第7天小鼠脑（模拟脑瘫的常见原因之一）。该亚克隆在体内有效表达NT-3。NSC衍生的神经元的比例在梗死腔中增加至接近20%，在半暗带中增加至> 80%。神经元进一步分化为适合皮质的胆碱能、GABA能或谷氨酸能亚型。供体来源的神经胶质细胞是罕见的，星形胶质细胞疤痕是钝化。NT-3可能不仅以自分泌/旁分泌方式作用于供体细胞，而且还作用于宿主细胞以增强两者的神经元分化。综上所述，这些观察结果表明：（1）对损伤采取基本生物学反应并增强其用于修复目的的可行性，以及（2）在某些退行性疾病中迁移NSC的潜在用途，用于在相同受体中使用相同细胞的相同程序期间同时组合基因治疗和细胞置换（具有干细胞样属性的细胞的独特性质）。(c)2006年爱思唯尔公司All rights reserved.
Previously, we reported that, when clonal neural stem cells (NSCs) were transplanted into brains of postnatal mice subjected to unilateral hypoxic-ischemic (HI) injury (optimally 3-7 days following infarction), donor-derived cells homed preferentially (from even distant locations) to and integrated extensively within the large ischemic areas that spanned the hemisphere. A subpopulation of NSCs and host cells, particularly in the penumbra, "shifted" their differentiation towards neurons and oligodendrocytes, the cell types typically damaged following asphyxia and least likely to regenerate spontaneously and in sufficient quantity in the "post-developmental" CNS. That no neurons and few oligodendrocytes were generated from the NSCs in intact postnatal cortex suggested that novel signals are transiently elaborated following HI to which NSCs might respond. The proportion of "replacement" neurons was similar to 5%. Neurotrophin-3 (NT-3) is known to play a role in inducing neuronal differentiation during development and perhaps following injury. We demonstrated that NSCs express functional TrkC receptors. Furthermore, the donor cells continued to express a foreign reporter transgene robustly within the damaged brain. Therefore, it appeared feasible that neuronal differentiation of exogenous NSCs (as well as endogenous progenitors) might be enhanced if donor NSCs were engineered prior to transplantation to (over)express a bioactive gene such as NT-3. A subclone of NSCs transduced with a retrovirus encoding NT-3 (yielding > 90% neurons in vitro) was implanted into unilaterally asphyxiated postnatal day 7 mouse brain (emulating one of the common causes of cerebral palsy). The subclone expressed NT-3 efficiently in vivo. The proportion of NSC-derived neurons increased to similar to 20% in the infarction cavity and > 80% in the penumbra. The neurons variously differentiated further into cholinergic, GABAergic, or glutamatergic subtypes, appropriate to the cortex. Donor-derived glia were rare, and astroglial scarring was blunted. NT-3 likely functioned not only on donor cells in an autocrine/paracrine fashion but also on host cells to enhance neuronal differentiation of both. Taken together, these observations suggest (1) the feasibility of taking a fundamental biological response to injury and augmenting it for repair purposes and (2) the potential use of migratory NSCs in some degenerative conditions for simultaneous combined gene therapy and cell replacement during the same procedure in the same recipient using the same cell (a unique property of cells with stem-like attributes). (c) 2006 Elsevier Inc. All rights reserved.