Identification of regenerative roadblocks via repeat deployment of limb regeneration in axolotls
Identification of regenerative roadblocks via repeat deployment of limb regeneration in axolotls
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DOI：
10.1038/s41536-017-0034-z
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发表时间：
2017-11-06
影响因子：
7.2
通讯作者：
Whited, Jessica L.
中科院分区：
文献类型：
--
作者：
Bryant, Donald M.;Sousounis, Konstantinos;Whited, Jessica L.
蝾螈是了解复杂身体部位再生的强大模型，而哺乳动物在这方面的能力受到严重限制。可以在哺乳动物中检查促进正常蝾螈再生的因素，以确定它们在这种情况下是否表现出改变的活性。此外，阻止蝾螈再生的因素可以提供关键的洞察机制，目前在再生能力差的物种。我们试图确定我们是否可以实验性地损害美西螈再生肢体的能力，如果可以的话，发现可能导致它们无法再生的分子变化。我们发现，反复截肢严重损害了蝾螈启动肢体再生的能力。使用RNA-seq，我们观察到大多数差异表达的转录物在反复截肢受损的肢体中被过度激活，这表明这些基因的错误调节拮抗了再生。为了证实我们的发现，我们还检测了双调蛋白的作用，双调蛋白是一种EGF样配体，在受损动物中异常上调。在正常肢体再生期间，双调蛋白由早期创伤表皮表达，并且错误表达该因子导致增厚的创伤上皮、延迟的再生起始和严重的再生缺陷。总的来说，我们的研究结果表明，反复截肢的肢体可能会经历一个持续的伤口愈合反应，这干扰了他们启动再生程序的能力。这些发现对人类再生医学具有重要意义。
Axolotl salamanders are powerful models for understanding how regeneration of complex body parts can be achieved, whereas mammals are severely limited in this ability. Factors that promote normal axolotl regeneration can be examined in mammals to determine if they exhibit altered activity in this context. Furthermore, factors prohibiting axolotl regeneration can offer key insight into the mechanisms present in regeneration-incompetent species. We sought to determine if we could experimentally compromise the axolotl's ability to regenerate limbs and, if so, discover the molecular changes that might underlie their inability to regenerate. We found that repeated limb amputation severely compromised axolotls' ability to initiate limb regeneration. Using RNA-seq, we observed that a majority of differentially expressed transcripts were hyperactivated in limbs compromised by repeated amputation, suggesting that mis-regulation of these genes antagonizes regeneration. To confirm our findings, we additionally assayed the role of amphiregulin, an EGF-like ligand, which is aberrantly upregulated in compromised animals. During normal limb regeneration, amphiregulin is expressed by the early wound epidermis, and mis-expressing this factor lead to thickened wound epithelium, delayed initiation of regeneration, and severe regenerative defects. Collectively, our results suggest that repeatedly amputated limbs may undergo a persistent wound healing response, which interferes with their ability to initiate the regenerative program. These findings have important implications for human regenerative medicine.