Li Chunyi, Yang Fuhe, Sheppard Allan
AgResearch Invermay Agricultural Centre, Private Bag 50034, Mosgiel, New Zealand.
Curr Stem Cell Res Ther. 2009 Sep;4(3):237-51. doi: 10.2174/157488809789057446.
Mammalian organ regeneration is the "Holy Grail" of modern regenerative biology and medicine. The most dramatic organ replacement is known as epimorphic regeneration. To date our knowledge of epimorphic regeneration has come from studies of amphibians. Notably, these animals have the ability to reprogram phenotypically committed cells at the amputation plane toward an embryonic-like cell phenotype (dedifferentiation). The capability of mammals to initiate analogous regeneration, and whether similar mechanisms would be involved if it were to occur, remain unclear. Deer antlers are the only mammalian appendages capable of full renewal, and therefore offer a unique opportunity to explore how nature has solved the problem of mammalian epimorphic regeneration. Following casting of old hard antlers, new antlers regenerate from permanent bony protuberances, known as pedicles. Studies through morphological and histological examinations, tissue deletion and transplantation, and cellular and molecular techniques have demonstrated that antler renewal is markedly different from that of amphibian limb regeneration (dedifferentiation-based), being a stem cell-based epimorphic process. Antler stem cells reside in the pedicle periosteum. We envisage that epimorphic regeneration of mammalian appendages, other than antler, could be made possible by recreating comparable milieu to that which supports the elaboration of that structure from the pedicle periosteum.
哺乳动物器官再生是现代再生生物学和医学的“圣杯”。最显著的器官替代方式被称为形态再生。迄今为止，我们对形态再生的了解来自于对两栖动物的研究。值得注意的是，这些动物能够在截肢平面将表型定型的细胞重新编程为类似胚胎的细胞表型（去分化）。哺乳动物启动类似再生的能力，以及如果发生这种情况是否会涉及类似机制，仍不清楚。鹿角是唯一能够完全更新的哺乳动物附属器官，因此为探索大自然如何解决哺乳动物形态再生问题提供了独特的机会。旧的硬鹿角脱落后，新的鹿角从永久性的骨质突起（称为角柄）再生。通过形态学和组织学检查、组织缺失和移植以及细胞和分子技术进行的研究表明，鹿角更新与两栖动物肢体再生（基于去分化）明显不同，是一个基于干细胞的形态过程。鹿角干细胞存在于角柄骨膜中。我们设想，除鹿角外，通过创造与支持从角柄骨膜发育出该结构的环境相当的环境，哺乳动物附属器官的形态再生是有可能实现的。
