Inhibition of the Sp1/CTR1 axis attenuates cuproptosis and alleviates axonal injury following intracerebral hemorrhage.

Intracerebral hemorrhage (ICH) causes severe neurological deficits, and secondary neuronal injury is a major barrier to recovery. Cuproptosis, a copper-dependent form of regulated cell death, has been linked to metabolic stress, but its role in axonal injury after ICH remains unclear. Here, we used in vivo rat ICH models and in vitro ICH-like neuronal injury models to examine changes in copper homeostasis, cuproptosis-associated molecular alterations, and axonal injury following ICH. Copper levels were markedly increased in perihematomal brain tissue and injured neurons, accompanied by reduced mitochondrial protein lipoylation and increased dihydrolipoamide S-acetyltransferase oligomerization, consistent with cuproptosis-associated molecular abnormalities. Specificity protein 1 (Sp1) and the copper transporter 1 (CTR1) were also significantly upregulated and showed similar temporal patterns. In parallel, ICH induced axonal injury-related molecular changes, including increased amyloid precursor protein and decreased growth-associated protein 43 expression. Pharmacological inhibition of Sp1 with plicamycin reduced CTR1 expression, attenuated copper overload, ameliorated cuproptosis-associated molecular abnormalities, and improved the measured axonal injury-related molecular and morphological changes in vivo and in vitro. These findings suggest that Sp1/CTR1-associated copper uptake regulation may contribute to secondary neuronal injury after ICH and may represent a potential therapeutic entry point for further investigation.