Reines Brandon, Cheng Lily I, Matzinger Polly
Ghost Lab, T Cell Tolerance and Memory Section, Laboratory of Cellular and Molecular Immunology, Twinbrook III, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
Rejuvenation Res. 2009 Feb;12(1):45-52. doi: 10.1089/rej.2008.0792.
Complete regeneration of damaged extremities, including both the epithelium and the underlying tissues, is thought to occur mainly in embryos, fetuses, and juvenile mammals, but only very rarely in adult mammals. Surprisingly, we found that common strains of mice are able to regenerate all of the tissues necessary to completely fill experimentally punched ear holes, but only if punched at middle age. Although young postweaning mice regrew the epithelium without typical pre-scar granulation tissue, they showed only minimal regeneration of connective tissues. In contrast, mice punched at 5-11 months of age showed true amphibian-like blastema formation and regrowth of cartilage, fat, and dermis, with blood vessels, sebaceous glands, hair follicles, and, in black mice, melanocytes. These data suggest that at least partial appendage regeneration may be more common in adult mammals than previously thought and call into question the common view that regenerative ability is lost with age. The data suggest that the age at which various inbred mouse strains become capable of epimorphic regeneration may be correlated with adult body weight.
受损肢体的完全再生，包括上皮组织和其下的组织，被认为主要发生在胚胎、胎儿和幼年哺乳动物中，而在成年哺乳动物中则极为罕见。令人惊讶的是，我们发现普通品系的小鼠能够再生出完全填充实验性打孔耳孔所需的所有组织，但前提是在中年时打孔。虽然断奶后的幼鼠能再生上皮组织且无典型的瘢痕前肉芽组织，但它们的结缔组织再生极少。相比之下，5至11个月大的小鼠打孔后会形成真正类似两栖动物的芽基，并再生出软骨、脂肪和真皮，还有血管、皮脂腺、毛囊，对于黑色小鼠而言，还有黑素细胞。这些数据表明，成年哺乳动物中至少部分附肢再生可能比以前认为的更为常见，并质疑了随着年龄增长再生能力会丧失的普遍观点。数据表明，各种近交系小鼠具备形态发生再生能力的年龄可能与成年体重相关。
