N-myc downstream-regulated gene 2 controls astrocyte morphology via Rho-GTPase signaling
N-myc downstream-regulated gene 2 controls astrocyte morphology via Rho-GTPase signaling
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N-myc 下游调节基因 2 通过 Rho-GTPase 信号传导控制星形胶质细胞形态
DOI：
10.1002/jcp.28689
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发表时间：
2019
影响因子：
5.6
通讯作者：
Ma Yulong
中科院分区：
文献类型：
--
作者：
Zhang Zengli;Ma Zhi;Zou Wangyuan;Zhang Lixia;Li Yan;Zhang Jian;Liu Min;Hou Wugang;Ma Yulong
星形胶质细胞的形态变化与突触的信号传递密切相关。N-myc下游调节基因2(NDRG2)在星形胶质细胞中特异表达，与星形胶质细胞的多种重要功能相关，但其在星形胶质细胞形态变化中的潜在作用(S)尚不清楚。本研究从新生Ndrg2+/+和Ndrg2−/−幼鼠制备原代星形胶质细胞，并用药物Y27632诱导星形胶质细胞。然后，我们使用各种方法检测了Y27632处理的星形胶质细胞以及Ndrg2+/+、Ndrg2−/−或Ndrg2−/−+ 慢病毒(恢复NDRG2表达)星形胶质细胞中NDRG2、Ndrg2-Actinin4和胶质纤维酸性蛋白的水平，以及RhoA、Rac1和CDC42的活性。我们还对培养的星形胶质细胞进行了活体成像和蛋白质组学研究。我们发现，星形胶质细胞的诱导(以胞浆收缩和突起生长为特征)导致NDRG2蛋白表达和RAC1活性增加，α-Actinin4蛋白表达和RhoA活性降低。Ndrg2缺失导致星形胶质细胞扁平化，而NDRG2表达恢复则导致星形胶质细胞分化。Ndrg2缺失还显著增加α-Actinin4蛋白表达和RhoA活性，而降低GFAP蛋白表达和Rac1活性，这些趋势可被NDRG2表达恢复所逆转。总之，我们的结果表明，Ndrg2的缺失促进了细胞的增殖，中断了星座的能力，并广泛地改变了在Rho-GTPase信号转导中起作用的蛋白质的蛋白表达谱。这些发现表明，NDRG2通过改变Rho-GTPase信号通路成分的积累来调节星形胶质细胞的形态，从而支持NDRG2应该被理解为突触可塑性的调节器，从而调节神经元的通讯。
Astrocyte undergoes morphology changes that are closely associated with the signaling communications at synapses. N‐myc downstream‐regulated gene 2 (NDRG2) is specifically expressed in astrocytes and is associated with several important astrocyte functions, but its potential role(s) relating to astrocyte morphological changes remain unknown. Here, primary astrocytes were prepared from neonatal Ndrg2+/+and Ndrg2−/−pups, and the drug Y27632 was used to induce stellation. We then used a variety of methods to measure the levels of NDRG2, α‐Actinin4, and glial fibrillary acidic protein (GFAP), and the activity of RhoA, Rac1, and Cdc42 in Y27632‐treated astrocytes as well as in Ndrg2+/+, Ndrg2−/−, or Ndrg2−/−+ lentivirus (restore NDRG2 expression) astrocytes. We also conducted live‐imaging and proteomics studies of the cultured astrocytes. We found that induction of astrocytes stellation (characterized by cytoplasmic retraction and process outgrowth) resulted in increased NDRG2 protein expression and Rac1 activity and in reduced α‐Actinin4 protein expression and RhoA activity. Ndrg2 deletion induced astrocyte flattening, whereas the restoration of NDRG2 expression induced stellation. Ndrg2 deletion also significantly increased α‐Actinin4 protein expression and RhoA activity yet reduced GFAP protein expression and Rac1 activity, and these trends were reversed by restoration of NDRG2 expression. Collectively, our results showed that Ndrg2 deletion promoted cell proliferation, interrupted stellation capability, and extensively altered the protein expression profiles of proteins that function in Rho‐GTPase signaling. These findings suggest that NDRG2 functions to regulate astrocytes morphology via altering the accumulation of the Rho‐GTPase signaling pathway components, thereby supporting that NDRG2 should be understood as a regulator of synaptic plasticity and thus neuronal communications.