Effects of Methylcobalamin on Mitochondrial Alterations in Schwann Cells Under Oxidative Stress.

Background/Objectives: Peripheral neuropathy (PN) triggers early oxidative stress, disrupting Schwann cell homeostasis. In this context, mitochondria serve as a primary source and vulnerable target of reactive oxygen species (ROS). Here, we investigated whether methylcobalamin (MeCbl) mitigates oxidative stress-induced mitochondrial dysfunction. Methods: RSC96 cells were exposed to H2O2 to model oxidative injury, then treated with MeCbl. Mitochondrial network integrity was evaluated using super-resolution imaging coupled with quantitative morphometric analysis. RNA-sequencing was performed to identify differentially expressed genes (DEGs) and enriched biological pathways. Additionally, a network-pharmacology approach was employed to intersect the predicted MeCbl targets with the transcriptomic signature. Results: MeCbl treatment alleviated H2O2-induced mitochondrial fragmentation, restoring the interconnected reticulum characterized by increased branch number, total area, and a reduction in punctate mitochondria. Transcriptome analyses revealed the reprogramming of stress-response pathways. The DEGs were significantly enriched in processes including mitochondrial organization and dynamics, redox homeostasis, protein quality control, and pro-survival signaling. Network pharmacology demonstrated convergence between the MeCbl targets and DEGs at core nodes governing mitochondrial quality control and antioxidant defense, thereby providing a mechanistic basis for the imaging phenotypes. Conclusions: MeCbl improved the mitochondrial structure and remodeled the stress-response pathways in Schwann cells under oxidative stress. By linking high-resolution organelle phenotypes to molecular networks, these findings support MeCbl as a rational adjunct to mitigate oxidative stress-driven peripheral neuropathy and identify an intervenable regulatory axis for future targeted therapies.