Since it is known that sialic acid participates in neuronal plasticity, it is resonable to investigate its role in microglia-neuron interactions. In this study, we tested the effects of enzymatic removal of sialic acid on neurite and cell body density in microglia-neuron co-cultures. Additionaly, we analyzed the expression of Siglec-F protein, putative receptor for sialic acids, in microglial cells as well as its affinity to neurons. The results showed that removal of sialic acids affects neuronal integrity and changes microglial morphology. In presence of microglial cells, endoneuraminidase and α-neuraminidase significantly reduced neurite density (p<0.05). Endoneuraminidase (p<0.05) and α-neuraminidase (p>0.05) decreased the number of neuronal cell bodies in comparison to control co-cultures. Neuraminidases-treated neurons showed reduced binding of Siglec-F protein, which we found in microglial cells. Our results suggest that interactions between sialic acids and Siglec receptors may protect neuronal integrity during neurodegenerative processes.

中文翻译：

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唾液酸参与小胶质细胞-神经元相互作用。

由于已知唾液酸参与神经元可塑性，因此研究其在小胶质细胞-神经元相互作用中的作用是合理的。在这项研究中，我们测试了小胶质细胞-神经元共培养物中酶法去除唾液酸对神经突和细胞体密度的影响。此外，我们分析了唾液酸的推定受体Siglec-F蛋白在小胶质细胞中的表达及其对神经元的亲和力。结果表明，唾液酸的去除会影响神经元完整性并改变小胶质细胞形态。在存在小胶质细胞的情况下，神经内酰胺酶和α-神经酰胺酶显着降低了神经突密度（p <0.05）。与对照共培养相比，神经内酰胺酶（p <0.05）和α-神经氨酸酶（p> 0.05）减少了神经元细胞体的数量。神经氨酸酶处理的神经元显示出我们在小胶质细胞中发现的Siglec-F蛋白结合减少。我们的结果表明，唾液酸和Siglec受体之间的相互作用可能在神经变性过程中保护神经元完整性。