School of Medicine, Southeast University, Nanjing, Jiangsu, 210009, China; Department of Thoracic and Cardiovascular Surgery, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, 210006, China.
Department of Thoracic and Cardiovascular Surgery, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, 210006, China.
Biochem Biophys Res Commun. 2022 Dec 25;636(Pt 1):112-120. doi: 10.1016/j.bbrc.2022.10.047. Epub 2022 Oct 20.
Myocytes undergoing hypoxia condition can recruit macrophages and cause pro-inflammation initiation around the injury area. Mitochondrial dysfunction is related to macrophage pyroptosis. Stomatin-like protein-2 (SLP-2) can regulate mitochondrial biogenesis and function. Whether SLP-2 could affect macrophage pyroptosis remains unclear. In this study, bone marrow derived macrophages (BMDMs) were extracted from WT and SLP-2 knocked out mice, then stimulated by LPS/Nigericin. Western blot showed that SLP-2 promoted the expression of NLRP3, GSDMD-N, caspase-11 in macrophages, which means the deficiency of SLP-2 augments macrophage pyroptosis. Higher fluorescence intensity of dihydroethidium and TUNEL represented the increased ROS releasing and macrophage programmed death in SLP-2 deficiency groups. The immunofluorescence intensity of MtioTracker Red decreased and that of mitochondrial ROS (mtROS) increased in SLP-2 deletion groups with LPS/Nigericin stimulation, representing the increased mitochondrial damage. The expression level of HIF-1α increased in SLP-2 deletion macrophages with LPS and Nigericin stimulation. The level of Parkin and the ratio of LC3II/I decreased in SLP-2 deficiency macrophages after stimulated by LPS/Nigericin, compared with untreated macrophages. H9c2 cells were cultured in hypoxia condition before being cocultured with macrophage supernatant. The cocultured H9c2 cells were injured due to the serious pyroptosis of SLP-2 deficiency macrophages. According to these results, we suggest that SLP-2 can reduce macrophage pyroptosis and relieve hypoxia H9c2 cells injury through protecting mitochondrial function.
在缺氧条件下，肌细胞可以招募巨噬细胞，并在损伤区域周围引发促炎反应。线粒体功能障碍与巨噬细胞焦亡有关。Stomatin-like protein-2（SLP-2）可以调节线粒体的生物发生和功能。SLP-2 是否会影响巨噬细胞焦亡尚不清楚。在这项研究中，从 WT 和 SLP-2 敲除小鼠中提取骨髓来源的巨噬细胞（BMDMs），然后用 LPS/Nigericin 刺激。Western blot 显示 SLP-2 促进了巨噬细胞中 NLRP3、GSDMD-N 和 caspase-11 的表达，这意味着 SLP-2 的缺乏增强了巨噬细胞焦亡。二氢乙锭和 TUNEL 的荧光强度更高代表了 SLP-2 缺陷组中 ROS 的释放和巨噬细胞程序性死亡增加。用 LPS/Nigericin 刺激后，SLP-2 缺失组的 MtioTracker Red 免疫荧光强度降低，线粒体 ROS（mtROS）增加，代表线粒体损伤增加。用 LPS 和 Nigericin 刺激后，SLP-2 缺失巨噬细胞中的 HIF-1α 表达水平增加。用 LPS/Nigericin 刺激后，SLP-2 缺陷巨噬细胞中的 Parkin 表达水平和 LC3II/I 的比值降低，与未经处理的巨噬细胞相比。H9c2 细胞在与巨噬细胞上清液共培养前在缺氧条件下培养。由于 SLP-2 缺陷巨噬细胞严重的焦亡，共培养的 H9c2 细胞受到损伤。根据这些结果，我们认为 SLP-2 可以通过保护线粒体功能来减少巨噬细胞焦亡并减轻缺氧 H9c2 细胞的损伤。
