Department of Intensive Care Unit, Hunan Provincial People's Hospital, Hunan Normal University, Changsha, Hunan, China.
Department of Neurology, Second Xiangya Hospital, Central South University, Changsha, Hunan, China.
PLoS One. 2019 Mar 7;14(3):e0213410. doi: 10.1371/journal.pone.0213410. eCollection 2019.
Recent research has demonstrated that small heat shock protein (sHsp) phosphorylation plays a variety of roles in neural cells. While the phosphorylation of serine 16 (Ser16) is blocked, Hsp20 no longer has neuroprotective effects. To further investigate the mechanism underlying this process, oxygen-glucose deprivation and reperfusion (OGD/R) was used with human SH-SY5Y cells and mouse N2a neuroblastoma cells. When SH-SY5Y and N2a cells were transfected with pEGFP-Hsp20(WT), pEGFP-Hsp20(S16A), and pEGFP-Hsp20(S16D) plasmids, the Golgi apparatus (GA) became more swollen and scattered, and many small fragments formed in the MOCK and S16A groups after OGD/R (P < 0.05). Meanwhile, the endoplasmic reticulum (ER) network was reduced, and the lamellar structure increased. However, these changes were not as obvious in the WT and S16D groups. Additionally, after OGD/R, Golgi Stress related protein contents were increased in the WT and S16D groups compared with the MOCK and S16A groups (P < 0.05). However, ER Stress related protein contents were decreased in the WT and S16D groups compared with the MOCK and S16A groups (P < 0.05). Our study demonstrates that Hsp20 phosphorylation on Ser16 protects against not only OGD/R-induced GA fragmentation in SH-SY5Y cells and N2a cells via Golgi stress but also OGD/R-induced ER structural changes in SH-SY5Y cells via ER stress. These findings suggest that Hsp20 is a potential drug target for ischemia stroke treatment.
最近的研究表明，小分子热休克蛋白 (sHsp) 的磷酸化在神经细胞中发挥多种作用。当丝氨酸 16 (Ser16) 的磷酸化被阻断时，Hsp20 不再具有神经保护作用。为了进一步研究这一过程的机制，使用人 SH-SY5Y 细胞和小鼠 N2a 神经母细胞瘤细胞进行了氧葡萄糖剥夺和再灌注 (OGD/R)。当 SH-SY5Y 和 N2a 细胞转染 pEGFP-Hsp20(WT)、pEGFP-Hsp20(S16A) 和 pEGFP-Hsp20(S16D) 质粒时，高尔基器 (GA) 变得更加肿胀和分散，并且在 OGD/R 后 MOCK 和 S16A 组中形成了许多小片段 (P < 0.05)。同时，内质网 (ER) 网络减少，层状结构增加。然而，WT 和 S16D 组的这些变化并不明显。此外，OGD/R 后，与 MOCK 和 S16A 组相比，WT 和 S16D 组的高尔基体应激相关蛋白含量增加 (P < 0.05)。然而，与 MOCK 和 S16A 组相比，WT 和 S16D 组的内质网应激相关蛋白含量减少 (P < 0.05)。我们的研究表明，Hsp20 在 Ser16 上的磷酸化不仅通过高尔基体应激保护 SH-SY5Y 细胞和 N2a 细胞免受 OGD/R 诱导的 GA 片段化，而且通过内质网应激保护 SH-SY5Y 细胞免受 OGD/R 诱导的 ER 结构变化。这些发现表明 Hsp20 是缺血性中风治疗的潜在药物靶点。
