RESUMO
Accumulating evidence shows that Schwann cells' (SCs) death caused by high glucose (HG) is involved in the pathological process of diabetic peripheral neuropathy (DPN). Ferroptosis is a novel form of regulatory cell death driven by iron-dependent lipid peroxidation. However, it is not clear whether ferroptosis is involved in the death process of SCs induced by HG. The expression of ferroptosis-related indicators in the serum of DPN patients was detected by ELISA. Subsequently, using cell counting kit8, western blot, real-time PCR, and Ki-67 staining, we investigated the effects of HG on the ferroptosis of SCs and initially explored the underlying mechanism. The results showed that the serum levels of glutathione peroxidase 4 (GPX4) and glutathione in patients with DPN decreased, while malondialdehyde levels increased significantly. Then, we observed that erastin and HG induced ferroptosis in SCs, resulting in the decrease in cell activity and the expression level of GPX4 and SLC7A11, which could be effectively reversed by the ferroptosis inhibitor Fer-1. Mechanistically, HG induced ferroptosis in SCs by inhibiting the NRF2 signaling pathway. Our results showed that ferroptosis was involved in the death process of SCs induced by HG. Inhibition of ferroptosis in SCs might create a new avenue for the treatment of DPN.
RESUMO
Atypical teratoid/rhabdoid tumors are rare malignant pediatric brain tumors. This study was performed to characterize the clinicopathologic and neuroradiologic characteristics of atypical teratoid/rhabdoid tumors from 8 patients, including 5 male and 3 female infants (median age, 67 months). Neuroimaging revealed bulky masses of heterogeneous intensity with inhomogeneous enhancement. Three cases were infratentorial and 5 were supratentorial. Histopathologically, the tumors were predominantly composed of rhabdoid cells and undifferentiated small cells, mixed with some spindle or epithelial components. The tumors displayed striking polyphenotypic immunoreactivity, including varying degrees of positivity for vimentin, epithelial membrane antigen, smooth-muscle actin, cytokeratin, glial fibrillary acidic protein, neurofilament protein, synaptophysin, and CD99, and immunonegativity for desmin, placental alkaline phosphatase, and INI-1. The median survival duration was 9.5 months (range, 1-15 months) despite aggressive therapy. These results suggest that atypical teratoid/rhabdoid tumors display distinct clinicopathologic characteristics and indicate a poor prognosis. Immunohistochemistry facilitates the appropriate diagnosis of these tumors.