Department of Anatomy, University of Mississippi Medical Center, Jackson, Mississippi 39216-4505.
Mol Cell Neurosci. 1993 Jun;4(3):250-8. doi: 10.1006/mcne.1993.1032.
Platelet-derived growth factor (PDGF) is a potent mitogen and differentiation signal for glial cells in the central nervous system. Several lines of evidence have indicated that neurons are one source of PDGF. We present data suggesting that they may respond to a PDGF signal as well. Immunofluorescence techniques have been used to demonstrate the presence of PDGF and its receptor in both neurons and glial cells isolated from developing rat brain and maintained in vitro. Similar findings hold either in medium supplemented with serum or under serum-free conditions. PDGF receptor beta subunit (PDGF-Rbeta)-like immunoreactivity was found encrusting the surface of cultured neurons. Virtually all neurons in this study contained PDGF-Rbeta on the surface of the perikaryon and on neuronal processes down to their fine distal tips. PDGF receptor was found on neurons cultured in serum-containing or serum-free medium, and in cultures with few glial cells as well as neuronal-glial co-cultures. Neurons and glial cells also contain PDGF subunits (designated PDGF-A and PDGF-B), revealed by immunofluorescence staining. Isoform-specific antibodies stain cultured neurons and glia in either serum-containing or serum-free medium. The identity of stained cells was confirmed using double- or triple-labeling immunofluorescence procedures for simultaneous localization of PDGF isoforms, PDGF receptor, phosphorylated neurofilament protein, and/or glial fibrillary acidic protein. These studies indicate that both neurons and glia contain platelet-derived growth factor and carry the PDGF receptor on their cell surface in vitro. While the localization of PDGF and its receptor have previously been considered separately, the present study demonstrates that both the growth factor and the receptor are expressed by the same population of neurons, indicating that PDGF may act us an autocrine factor regulating neuronal differentiation.
血小板衍生生长因子 (PDGF) 是中枢神经系统中神经胶质细胞的有效有丝分裂原和分化信号。有几条证据表明神经元是 PDGF 的一个来源。我们提供的数据表明，神经元可能也对 PDGF 信号做出反应。免疫荧光技术已被用于证明 PDGF 及其受体存在于从发育中的大鼠大脑中分离出来并在体外培养的神经元和神经胶质细胞中。在含有血清或无血清的培养基中，都有类似的发现。PDGF 受体β亚基（PDGF-Rβ）样免疫反应性被发现包裹在培养神经元的表面。在这项研究中，几乎所有神经元的胞体和神经元突起的远端末梢都含有 PDGF-Rβ。在含有血清或无血清的培养基中培养的神经元以及含有少量神经胶质细胞和神经元-神经胶质共培养物的神经元都存在 PDGF 受体。神经元和神经胶质细胞还含有 PDGF 亚基（称为 PDGF-A 和 PDGF-B），这是通过免疫荧光染色显示的。同种型特异性抗体可在含有血清或无血清的培养基中染色培养的神经元和神经胶质细胞。使用双重或三重标记免疫荧光程序同时定位 PDGF 同工型、PDGF 受体、磷酸化神经丝蛋白和/或神经胶质酸性蛋白，可确认染色细胞的身份。这些研究表明，神经元和神经胶质细胞都含有血小板衍生生长因子，并在体外的细胞表面携带 PDGF 受体。虽然 PDGF 的定位和受体以前被认为是分开的，但本研究表明，生长因子和受体都是由同一群神经元表达的，这表明 PDGF 可能作为一种调节神经元分化的自分泌因子发挥作用。
