BIT/SHPS-1 Promotes Antiapoptotic Effect of BDNF on Low Potassium-Induced Cell Death of Cultured Cerebellar Granule Neurons
BIT/SHPS-1 Promotes Antiapoptotic Effect of BDNF on Low Potassium-Induced Cell Death of Cultured Cerebellar Granule Neurons
复制标题
DOI：
10.1007/s10571-011-9700-7
复制
发表时间：
2011-10-01
影响因子：
4
通讯作者：
Hatanaka, Hiroshi
中科院分区：
文献类型：
--
作者：
Koshimizu, Hisatsugu;Suzuki, Shingo;Hatanaka, Hiroshi
具有酪氨酸激活基序的脑免疫球蛋白样分子/SHP底物1（BIT/SHPS-1）是一种在小脑颗粒神经元（CGN）中高度表达的神经元粘附分子，但其在CGN中的功能尚不清楚。我们的前期研究表明BIT/SHPS-1能够通过细胞类型特异性机制调节脑源性神经营养因子（BDNF）对中枢神经元的抗凋亡作用。在这篇文章中，我们研究了BIT/SHPS-1在BDNF对低钾（LK）诱导的培养CGNs细胞死亡的抗凋亡功能中的作用，CGNs是脑发育过程中神经元凋亡的体外模型系统。用野生型大鼠BIT/SHPS-1（BIT/SHPS-1（WT））、其4F-突变体（BIT/SHPS-1（4F），其中所有细胞质酪氨酸残基被苯丙氨酸取代）或表达核定位信号连接的β-半乳糖苷酶（NLS-LacZ，作为对照）的腺病毒转导培养的大鼠CGN。BIT/SHPS-1（WT）和BIT/SHPS-1（4F）单独表达不影响稳态细胞活力。BIT/SHPS-1的酪氨酸磷酸化仅在存在和不存在BDNF的BIT/SHPS-1（WT）表达培养物中检测到。当在BDNF存在下进行LK时，BIT/SHPS-1（WT）-和BIT/SHPS-1（4F）-表达培养物显示出对细胞死亡的显著抗性，而对照病毒转染培养物则没有。此外，磷脂酰肌醇3-激酶（PI 3-K）抑制剂LY 294002减弱了BDNF对BIT/SHPS-1（WT）和BIT/SHPS-1（4F）表达培养物的抗凋亡作用。这些结果表明，BIT/SHPS-1以酪氨酸磷酸化非依赖和PI 3-K依赖的方式促进BDNF对LK诱导的CGNs细胞死亡的抗凋亡作用。
Brain immunoglobulin-like molecule with tyrosine-based activation motifs/SHP substrate 1 (BIT/SHPS-1) is a neuronal adhesion molecule that is highly expressed in cerebellar granule neurons (CGNs); however its function in CGNs remains unclear. Our previous studies indicated that BIT/SHPS-1 is able to modulate the antiapoptotic effect of brain-derived neurotrophic factor (BDNF) on CNS neurons by cell type-specific mechanisms. In this article, we have studied the role of BIT/SHPS-1 in the antiapoptotic function of BDNF on low potassium (LK)-induced cell death of cultured CGNs which is an in vitro model system of neuronal apoptosis during brain development. Cultured rat CGNs were transduced with wild-type rat BIT/SHPS-1 (BIT/SHPS-1(WT)), its 4F-mutant (BIT/SHPS-1(4F), in which all cytoplasmic tyrosine residues were substituted with phenylalanine), or nuclear localization signal-attached beta-galactosidase (NLS-LacZ, as control)-expressing adenoviruses. Expression of BIT/SHPS-1(WT) and BIT/SHPS-1(4F) alone did not affect steady-state cell viability. Tyrosine phosphorylation of BIT/SHPS-1 was only detected in BIT/SHPS-1(WT)-expressing cultures in the presence and the absence of BDNF. When subjected to LK in the presence of BDNF, BIT/SHPS-1(WT)- and BIT/SHPS-1(4F)-expressing cultures showed a significant resistance to cell death, while the control virus-transfected culture did not. In addition, a phosphatidylinositol 3-kinase (PI3-K) inhibitor, LY294002, attenuated the antiapoptotic effect of BDNF on BIT/SHPS-1(WT)-, and BIT/SHPS-1(4F)-expressing cultures. These results demonstrated that in both tyrosine phosphorylation-independent and PI3-K-dependent manners, BIT/SHPS-1 promotes the antiapoptotic effect of BDNF on the LK-induced cell death of CGNs.