Kengaku M, Kawata A, Kawashima S, Nakane M
Department of Molecular Neurobiology, Tokyo Metropolitan Institute for Neurosciences, Japan.
Brain Res Dev Brain Res. 1991 Aug 19;61(2):281-4. doi: 10.1016/0165-3806(91)90144-8.
We have recently shown that the enhanced expression of choline acetyltransferase (ChAT) activity in co-cultures of spinal cord motoneurons and muscle cells was blocked by transforming growth factor-beta (TGF-beta) (Dev. Brain Res., 57, 129-137, 1990). This study was performed to investigate the role of fibronectin in this effect. TGF-beta increased fibronectin level about 2-fold in extracellular matrix of spinal cord cells and skeletal myotubes in culture. Addition of a synthetic polypeptide that competitively inhibits fibronectin binding to its cell surface receptor recovered the TGF-beta-induced suppression of ChAT activity in co-cultures. The polypeptide did not affect ChAT activity in cultures of spinal cord cells alone or in co-cultures without TGF-beta. These results indicate that TGF-beta inhibits the stimulation of ChAT activity in spinal cord neurons in co-culture through a change in the composition and/or amount of fibronectin in the extracellular matrix at neuromuscular contacts.
我们最近发现，脊髓运动神经元与肌肉细胞共培养物中胆碱乙酰转移酶（ChAT）活性的增强表达被转化生长因子-β（TGF-β）所阻断（《发育脑研究》，57卷，129 - 137页，1990年）。本研究旨在探讨纤连蛋白在此效应中的作用。TGF-β使培养的脊髓细胞和骨骼肌肌管的细胞外基质中的纤连蛋白水平增加了约2倍。添加一种竞争性抑制纤连蛋白与其细胞表面受体结合的合成多肽，可恢复共培养物中TGF-β诱导的ChAT活性抑制。该多肽对单独的脊髓细胞培养物或无TGF-β的共培养物中的ChAT活性没有影响。这些结果表明，TGF-β通过改变神经肌肉接触处细胞外基质中纤连蛋白的组成和/或数量，抑制共培养的脊髓神经元中ChAT活性的刺激。
