Protein deiminases: New players in the developmentally regulated loss of neural regenerative ability
Protein deiminases: New players in the developmentally regulated loss of neural regenerative ability
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DOI：
10.1016/j.ydbio.2011.04.015
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发表时间：
2011-07-15
影响因子：
2.7
通讯作者：
Ferretti, Patrizia
中科院分区：
文献类型：
--
作者：
Lange, Sigrun;Goegel, Stefanie;Ferretti, Patrizia
脊髓再生能力随着发育而丧失，但这种丧失的机制仍然知之甚少。在鸡胚中，当脊髓损伤诱导广泛的凋亡反应和组织损伤时，在E13后不会发生有效的再生。由于最初的实验表明，脊髓损伤后用钙螯合剂治疗可减少细胞凋亡和空化，我们假设继发性损伤反应中钙依赖过程的发育调节介质可能导致再生能力丧失。为了这个目的，我们在鸡脊髓的发育允许（E11）和非允许（E15）再生阶段筛选这种变化。在发育调节的钙依赖性蛋白中，发现了PAD 3，它是肽基精氨酸脱亚胺酶（PAD）家族的一员，可将蛋白质精氨酸残基转化为瓜氨酸，这一过程称为脱亚胺或瓜氨酸。这种翻译后修饰以前与对损伤的反应无关。损伤后，在E15损伤的脊髓中，PAD 3的上调大于E11。与基因表达的这些差异相一致，脱亚胺化在非再生阶段E15更广泛，无论是在灰色和白色物质。由于脱亚氨基化增加了细胞凋亡的程度，我们研究了阻断PAD活性对细胞死亡和脱亚氨基化组蛋白3的影响，脱亚氨基化组蛋白3是我们通过脊髓脱亚氨基化蛋白质的质谱分析确定的PAD靶点之一。用PAD抑制剂Cl-脒处理降低了脱亚氨基组蛋白3的丰度，与PAD活性的抑制一致，并显著降低了E15损伤后的细胞凋亡和组织损失。总之，我们的研究结果确定了PAD和脱亚胺作为继发性损伤反应的发育调节剂，并表明PAD可能是脊髓损伤有价值的治疗靶点。(C)2011 Elsevier Inc. All rights reserved.
Spinal cord regenerative ability is lost with development, but the mechanisms underlying this loss are still poorly understood. In chick embryos, effective regeneration does not occur after E13, when spinal cord injury induces extensive apoptotic response and tissue damage. As initial experiments showed that treatment with a calcium chelator after spinal cord injury reduced apoptosis and cavitation, we hypothesized that developmentally regulated mediators of calcium-dependent processes in secondary injury response may contribute to loss of regenerative ability. To this purpose we screened for such changes in chick spinal cords at stages of development permissive (E11) and non-permissive (E15) for regeneration. Among the developmentally regulated calcium-dependent proteins identified was PAD3, a member of the peptidylarginine deiminase (PAD) enzyme family that converts protein arginine residues to citrulline, a process known as deimination or citrullination. This post-translational modification has not been previously associated with response to injury. Following injury, PAD3 up-regulation was greater in spinal cords injured at E15 than at E11. Consistent with these differences in gene expression, deimination was more extensive at the non-regenerating stage, E15, both in the gray and white matter. As deimination paralleled the extent of apoptosis, we investigated the effect of blocking PAD activity on cell death and deiminated-histone 3, one of the PAD targets we identified by mass-spectrometry analysis of spinal cord deiminated proteins. Treatment with the PAD inhibitor, Cl-amidine, reduced the abundance of deiminated-histone 3, consistent with inhibition of PAD activity, and significantly reduced apoptosis and tissue loss following injury at E15. Altogether, our findings identify PADs and deimination as developmentally regulated modulators of secondary injury response, and suggest that PADs might be valuable therapeutic targets for spinal cord injury. (C) 2011 Elsevier Inc. All rights reserved.