The Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong, P.R. China.
J Neurosci Res. 2010 Jul;88(9):1858-71. doi: 10.1002/jnr.22355.
Src-suppressed C kinase substrate (SSeCKS) is involved in inflammation in the central nervous system (CNS), and plays a role in control of cell signaling and cytoskeletal arrangement. However, the expression and function of SSeCKS and its function in multiple sclerosis (MS) and its common animal model, experimental autoimmune encephalomyelitis (EAE) remained to be elucidated. In the present study, we first reported that SSeCKS was remarkably increased in astrocytes of EAE rats in vivo. TNF-alpha and NO were significantly induced in astrocytes stimulated with LPS/IFN-gamma in vitro, which was blocked in astrocytes transfected with SSeCKS siRNA. These results indicated that SSeCKS played a role in the production of TNF-alpha and NO in astrocytes with inflammatory stimulation. As excessive release of TNF-alpha and NO were major mediators in autoimmune diseases and correlated with oligodendrocyte cell death, we further investigated whether SSeCKS participated in oligodendrocyte apoptosis. Conditioned media (CM) from astrocytes treated with LPS/IFN-gamma decreased oligodendrocyte cell viability, while siRNA targeted to SSeCKS in astrocytes inhibited oligodendrocyte cell death. The results from antibody neutralization and NO inhibition suggested that the oligodendrocyte apoptosis may be due to the production of astrocyte-derived proinflammatory factors (TNF-alpha and NO). These findings revealed that there was a pathogenic interaction between SSeCKS expression in astrocytes and oligodendrocyte apoptosis. Understanding the mechanism of SSeCKS in the pathogenesis of EAE may contribute to the development of new therapeutic strategies against EAE and MS.
Src 抑制型蛋白激酶 C 底物(SSeCKS)参与中枢神经系统(CNS)的炎症反应,并在细胞信号转导和细胞骨架排列的控制中发挥作用。然而,SSeCKS 的表达和功能,以及其在多发性硬化症(MS)及其常见动物模型实验性自身免疫性脑脊髓炎(EAE)中的作用仍有待阐明。在本研究中,我们首次报道 SSeCKS 在体内 EAE 大鼠星形胶质细胞中显著增加。体外用 LPS/IFN-γ刺激星形胶质细胞时,TNF-α和 NO 明显诱导,而用 SSeCKS siRNA 转染的星形胶质细胞中则被阻断。这些结果表明 SSeCKS 在炎症刺激的星形胶质细胞中 TNF-α和 NO 的产生中起作用。由于 TNF-α和 NO 的过度释放是自身免疫疾病的主要介质,并且与少突胶质细胞死亡相关,我们进一步研究了 SSeCKS 是否参与少突胶质细胞凋亡。用 LPS/IFN-γ处理的星形胶质细胞的条件培养基(CM)降低了少突胶质细胞的活力,而针对星形胶质细胞中的 SSeCKS 的 siRNA 则抑制了少突胶质细胞的死亡。抗体中和和 NO 抑制的结果表明,少突胶质细胞凋亡可能是由于星形胶质细胞衍生的促炎因子(TNF-α和 NO)的产生所致。这些发现表明星形胶质细胞中 SSeCKS 的表达与少突胶质细胞凋亡之间存在致病相互作用。了解 SSeCKS 在 EAE 发病机制中的作用可能有助于开发针对 EAE 和 MS 的新治疗策略。