Cerebral ischemia/reperfusion (I/R) injury is a leading cause of learning and memory dysfunction. Hydrogen sulfide (H2S) has been shown to confer neuroprotection in various neurodegenerative diseases, including cerebral I/R-induced hippocampal CA1 injury. However, the underlying mechanisms have not been completely understood. In the present study, rats were pretreated with SAM/NaHS (SAM, an H2S agonist, and NaHS, an H2S donor) only or SAM/NaHS combined with CaM (an activator of CaMKII) prior to cerebral ischemia. The Morris water maze test demonstrated that SAM/NaHS could alleviate learning and memory impairment induced by cerebral I/R injury. Cresyl violet staining was used to show the survival of hippocampal CA1 pyramidal neurons. SAM/NaHS significantly increased the number of surviving cells, whereas CaM weakened the protection induced by SAM/NaHS. The immunohistochemistry results indicated that the number of Iba1-positive microglia significantly increased after cerebral I/R. Compared with the I/R group, the number of Iba1-positive microglia in the SAM/NaHS groups significantly decreased. Co-Immunoprecipitation and immunoblotting were conducted to demonstrate that SAM/NaHS suppressed the assembly of CaMKII with the ASK1-MKK3-p38 signal module after cerebral I/R, which decreased the phosphorylation of p38. In contrast, CaM significantly inhibited the effects of SAM/NaHS. Taken together, the results suggested that SAM/NaHS could suppress cerebral I/R injury by downregulating p38 phosphorylation via decreasing the assembly of CaMKII with the ASK1-MKK3-p38 signal module.

中文翻译：

---

H2S通过减少带有ASK1-MKK3-p38信号模块的CaMKII的装配来减轻缺血性中风后的损伤。

脑缺血/再灌注（I / R）损伤是学习和记忆功能障碍的主要原因。硫化氢（H2S）已被证明在各种神经退行性疾病（包括脑I / R诱导的海马CA1损伤）中具有神经保护作用。但是，尚未完全理解其基本机制。在本研究中，大鼠仅在脑缺血之前用SAM / NaHS（H2S激动剂SAM和H2S供体NaHS）或SAM / NaHS和CaM（CaMKII的激活剂）联合治疗。莫里斯水迷宫测试表明，SAM / NaHS可以减轻脑I / R损伤引起的学习和记忆障碍。甲酚紫染色用于显示海马CA1锥体神经元的存活。SAM / NaHS显着增加了存活细胞的数量，CaM削弱了SAM / NaHS诱导的保护作用。免疫组化结果表明，脑I / R后Iba1阳性小胶质细胞数量明显增加。与I / R组相比，SAM / NaHS组中Iba1阳性小胶质细胞的数量明显减少。进行了免疫共沉淀和免疫印迹实验，以证明SAM / NaHS在脑I / R后抑制了带有ASK1-MKK3-p38信号模块的CaMKII的装配，从而降低了p38的磷酸化。相反，CaM显着抑制SAM / NaHS的作用。两者合计，结果表明SAM / NaHS可以通过减少带有ASK1-MKK3-p38信号模块的CaMKII的组装而下调p38磷酸化来抑制脑I / R损伤。免疫组化结果表明，脑I / R后Iba1阳性小胶质细胞数量明显增加。与I / R组相比，SAM / NaHS组中Iba1阳性小胶质细胞的数量明显减少。进行了免疫共沉淀和免疫印迹实验，以证明SAM / NaHS在脑I / R后抑制了带有ASK1-MKK3-p38信号模块的CaMKII的装配，从而降低了p38的磷酸化。相反，CaM显着抑制SAM / NaHS的作用。两者合计，结果表明SAM / NaHS可以通过减少带有ASK1-MKK3-p38信号模块的CaMKII的组装而下调p38磷酸化来抑制脑I / R损伤。免疫组化结果表明，脑I / R后Iba1阳性小胶质细胞数量明显增加。与I / R组相比，SAM / NaHS组中Iba1阳性小胶质细胞的数量明显减少。进行了免疫共沉淀和免疫印迹实验，以证明SAM / NaHS在脑I / R后抑制了带有ASK1-MKK3-p38信号模块的CaMKII的装配，从而降低了p38的磷酸化。相反，CaM显着抑制SAM / NaHS的作用。两者合计，结果表明SAM / NaHS可以通过减少与ASK1-MKK3-p38信号模块的CaMKII的组装来下调p38磷酸化，从而抑制脑I / R损伤。SAM / NaHS组中Iba1阳性小胶质细胞的数量显着减少。进行了免疫共沉淀和免疫印迹实验，以证明SAM / NaHS在脑I / R后抑制了带有ASK1-MKK3-p38信号模块的CaMKII的装配，从而降低了p38的磷酸化。相反，CaM显着抑制SAM / NaHS的作用。两者合计，结果表明SAM / NaHS可以通过减少与ASK1-MKK3-p38信号模块的CaMKII的组装来下调p38磷酸化，从而抑制脑I / R损伤。SAM / NaHS组中Iba1阳性小胶质细胞的数量显着减少。进行了免疫共沉淀和免疫印迹实验，以证明SAM / NaHS在脑I / R后抑制了带有ASK1-MKK3-p38信号模块的CaMKII的装配，从而降低了p38的磷酸化。相反，CaM显着抑制SAM / NaHS的作用。两者合计，结果表明SAM / NaHS可以通过减少带有ASK1-MKK3-p38信号模块的CaMKII的组装而下调p38磷酸化来抑制脑I / R损伤。CaM显着抑制SAM / NaHS的作用。两者合计，结果表明SAM / NaHS可以通过减少带有ASK1-MKK3-p38信号模块的CaMKII的组装而下调p38磷酸化来抑制脑I / R损伤。CaM显着抑制SAM / NaHS的作用。两者合计，结果表明SAM / NaHS可以通过减少带有ASK1-MKK3-p38信号模块的CaMKII的组装而下调p38磷酸化来抑制脑I / R损伤。