Department of Biochemistry and Tissue Biology, Universidade Estadual de Campinas, São Paulo, Brazil.
Sci Rep. 2019 Jul 4;9(1):9720. doi: 10.1038/s41598-019-45521-4.
Regeneration is classically demonstrated in mammals using mice digit tip. In this study, we compared different amputation plans and show that distally amputated digits regrow with morphology close to normal but fail to regrow the fat pad. Proximally amputated digits do not regrow the phalangeal bone, but the remaining structures (nail, skin and connective tissue), all with intrinsic regenerative capacity, re-establishing integrity indistinguishably in distally and proximally amputated digits. Thus, we suggest that the bone growth promoted by signals and progenitor cells not removed by distal amputations is responsible for the re-establishment of a drastically different final morphology after distal or proximal digit tip amputations. Despite challenging the use of mouse digit tip as a model system for limb regeneration in mammals, these findings evidence a main role of bone growth in digit tip regeneration and suggest that mechanisms that promote joint structures formation should be the main goal of regenerative medicine for limb and digit regrowth.
再生在哺乳动物中经典地通过小鼠指尖进行演示。在这项研究中，我们比较了不同的截肢方案，并表明远端截肢的指尖再生具有接近正常的形态，但不能再生脂肪垫。近端截肢的指尖不会再生指骨，但剩余的结构（指甲、皮肤和结缔组织），所有这些都具有内在的再生能力，在远端和近端截肢的指尖中重新建立了难以区分的完整性。因此，我们认为，由信号和祖细胞促进的骨生长而不是由远端截肢去除的信号和祖细胞促进的骨生长是导致远端或近端指尖截肢后最终形态明显不同的重新建立的原因。尽管对使用小鼠指尖作为哺乳动物肢体再生模型系统提出了挑战，但这些发现证明了骨生长在指尖再生中的主要作用，并表明促进关节结构形成的机制应该是肢体和指尖再生的再生医学的主要目标。
