Pivotal Role of Brain-Derived Neurotrophic Factor Secreted by Mesenchymal Stem Cells in Severe Intraventricular Hemorrhage in Newborn Rats
Pivotal Role of Brain-Derived Neurotrophic Factor Secreted by Mesenchymal Stem Cells in Severe Intraventricular Hemorrhage in Newborn Rats
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DOI：
10.3727/096368916x692861
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发表时间：
2017-01-01
影响因子：
3.3
通讯作者：
Park, Won Soon
中科院分区：
文献类型：
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作者：
Ahn, So Yoon;Chang, Yun Sil;Park, Won Soon
间充质干细胞(MSC)移植对新生儿重症脑室出血(IVH)所致脑损伤的保护作用是通过旁分泌而不是再生机制实现的，但其所涉及的旁分泌因素及其作用尚未阐明。本研究旨在确定旁分泌介体(S)，并确定其在骨髓间充质干细胞治疗重症IVH中的作用。我们首次发现，在凝血酶暴露后，与成纤维细胞相比，在DNA和抗体微阵列中，MSCs中脑源性神经营养因子(BDNF)的表达显著上调。然后，我们通过转染针对人BDNF的小干扰(Si)RNA，在MSCs中击倒了BDNF。分别于新生SD大鼠出生后第4天(P4)注射L血200亩，于P6脑室移植MSCs(1×10(5)细胞)，在凝血酶刺激的大鼠神经细胞和新生SD大鼠体内观察BDNF基因敲除前后MSCs的治疗效果。SiRNA诱导的BDNF基因敲除消除了MSCs在凝血酶诱导的神经细胞死亡中的体外益处。BDNF基因敲除也取消了对IVH所致严重脑损伤的体内保护作用，如出血后脑积水减轻，行为测试能力受损，星形胶质细胞增多，TUNEL细胞，ED-1(+)细胞和炎性细胞因子数量增加，髓鞘碱性蛋白表达减少。我们的数据表明，移植的MSCs分泌的BDNF是关键的旁分泌因子之一，在减轻IVH诱导的新生大鼠严重脑损伤方面发挥了重要作用。
Mesenchymal stem cell (MSC) transplantation protects against neonatal severe intraventricular hemorrhage (IVH)-induced brain injury by a paracrine rather than regenerative mechanism; however, the paracrine factors involved and their roles have not yet been delineated. This study aimed to identify the paracrine mediator(s) and to determine their role in mediating the therapeutic effects of MSCs in severe IVH. We first identified significant upregulation of brain-derived neurotrophic factor (BDNF) in MSCs compared with fibroblasts, in both DNA and antibody microarrays, after thrombin exposure. We then knocked down BDNF in MSCs by transfection with small interfering (si)RNA specific for human BDNF. The therapeutic effects of MSCs with or without BDNF knockdown were evaluated in vitro in rat neuronal cells challenged with thrombin, and in vivo in newborn Sprague Dawley rats by injecting 200 mu l of blood on postnatal day 4 (P4), and transplanting MSCs (1 x 10(5) cells) intraventricularly on P6. siRNA-induced BDNF knockdown abolished the in vitro benefits of MSCs on thrombin -induced neuronal cell death. BDNF knockdown also abolished the in vivo protective effects against severe IVH-induced brain injuries such as the attenuation of posthemorrhagic hydrocephalus, impaired behavioral test performance, increased astrogliosis, increased number of TUNEL cells, ED-1(+) cells, and inflammatory cytokines, and reduced myelin basic protein expression. Our data indicate that BDNF secreted by transplanted MSCs is one of the critical paracrine factors that play a seminal role in attenuating severe IVH-induced brain injuries in newborn rats.