Haynes L W
Department of Zoology, University of Bristol, UK.
Mol Neurobiol. 1988 Winter;2(4):263-89. doi: 10.1007/BF02935635.
Nearly thirty growth and trophic factors that have been purified from mammalian tissues in the last 15 yr have been found to share chemical identity. The results of their chemical purification and molecular cloning show that they are two distinct polypeptides (Mr 17,400 and 18,400), each of which gives rise to families of smaller size peptides. These peptides share a common affinity for heparin. In view of this property, a common nomenclature for the two principle peptide growth factors (heparin-binding growth factor classes 1 and 2; HBGF-1 and -2) has been proposed. However, the names acidic and basic Fibroblast Growth Factors (aFGF,bFGF), which were applied to them originally to describe their mitogenic activity, are more commonly in use and will therefore be adopted in this review. Brain tissue is one of the richest sources of FGFs. It has been used as a starting point for their chemical purification and to prepare genomic libraries for molecular cloning of the aFGF and bFGF genes. There is increasing evidence that these growth factors, expressed in neurons and glia throughout the mammalian nervous system, are implicated in neuronal cell proliferation, differentiation, and histogenesis. FGFs have a strong affinity not only for heparin, but also for the related heparan sulphate proteoglycans that are abundant in neural tissues. This fact provides a clue to the importance of tissue-associated proteoglycans in mediating the release, sequestration, and activation of FGFs and the modulation of their receptor binding and bioactivity. The relevance of FGFs to neural development and their mechanisms of action in neurons will be considered in light of the existing literature describing their biological properties and activity in mesodermal cell types. Evidence is reviewed showing that FGFs have in vivo biological activity, ameliorating the degeneration of central and peripheral neurons after axotomy. The presence and implications of high levels of FGFs in adult mammalian brain provides a direction for future research into neural regeneration. The bioactivity of FGFs in neural tissue may not depend on the regulation of their expression per se, but on the subregional modification of their interaction with proteoglycans.
在过去15年中，从哺乳动物组织中纯化出的近30种生长因子和营养因子被发现具有化学同一性。它们的化学纯化和分子克隆结果表明，它们是两种不同的多肽（分子量分别为17400和18400），每种多肽都会产生更小的肽家族。这些肽对肝素具有共同的亲和力。鉴于此特性，有人提出了两种主要肽生长因子（肝素结合生长因子1类和2类；HBGF-1和-2）的通用命名法。然而，最初用于描述它们的促有丝分裂活性的酸性和碱性成纤维细胞生长因子（aFGF、bFGF）这两个名称更为常用，因此本综述将采用这两个名称。脑组织是FGFs最丰富的来源之一。它已被用作化学纯化的起始材料，并用于制备用于aFGF和bFGF基因分子克隆的基因组文库。越来越多的证据表明，这些在整个哺乳动物神经系统的神经元和神经胶质细胞中表达的生长因子与神经元细胞增殖、分化和组织发生有关。FGFs不仅对肝素具有很强的亲和力，而且对神经组织中丰富的相关硫酸乙酰肝素蛋白聚糖也具有很强的亲和力。这一事实为组织相关蛋白聚糖在介导FGFs的释放、隔离和激活以及调节其受体结合和生物活性方面的重要性提供了线索。将根据现有文献中描述的FGFs在中胚层细胞类型中的生物学特性和活性，来探讨FGFs与神经发育的相关性及其在神经元中的作用机制。有证据表明FGFs具有体内生物学活性，可改善轴突切断后中枢和外周神经元的退化。成年哺乳动物脑中高水平FGFs的存在及其意义为未来神经再生研究提供了方向。FGFs在神经组织中的生物活性可能不取决于其表达本身的调节，而取决于其与蛋白聚糖相互作用的亚区域修饰。
