Expression of Autophagy Signaling Molecules in the Outer Membranes of Chronic Subdural Hematomas

Abstract

Chronic subdural hematoma (CSDH) is fundamentally treatable, although it sometimes recurs. We observed, however, several cases of spontaneous resolution of CSDH outer membranes, even in a trabecular type of CSDH, after a trepanation surgical procedure. In this study, we examined the expression of molecules of the autophagy signaling pathway in CSDH outer membranes. Eight patients whose outer membranes were obtained successfully during trepanation were included in this study. By Western blot analysis, we examined the expression of mammalian target of rapamycin (mTOR); GβL; UNC-51-like kinase-1 (ULK1); Beclin-1; autophagy-related genes (Atg) 3, 5, 7, 12, 13, and 16L1β,α; the autophagy marker Light Chain3A/B (LC3A/B); and β-actin, which constitute the autophagy signaling pathway. The expression levels of Beclin-1, Atg12, and LC3A/B were also examined by immunohistochemistry. Almost all of these molecules could be detected in all samples. Beclin-1, Atg12, and LC3A/B were found to be localized in the endothelial cells of vessels and fibroblasts in CSDH. We detected molecules of the autophagy signaling pathway in CSDH outer membranes. Autophagy contributes to the tissue homeostatic process, maintaining cellular integrity by clearing debris. Our data suggest that autophagy might play an important role in the spontaneous resolution of CSDH. Therefore, these molecules may be novel therapeutic targets for the treatment of those with CSDH.