Diabetic neuropathic pain (DNP) is a common diabetic complication that currently lacks an efficient therapy. The aim of the current work was to uncover the anti-allodynic and neuroprotective effects of memantine in a model of mouse diabetic neuropathy and its ameliorative effect on the high-mobility group box-1 (HMGB1)/toll-like receptor 4 (TLR4)/nuclear factor-k B (NF-kB) inflammatory axis. Diabetes was prompted by an alloxan injection (180 mg/kg) to albino mice. On the ninth week after diabetes induction, DNP was confirmed. Diabetic mice were randomly allocated to two groups (six mice each); a diabetes mellitus (DM) group and DM+memantine group (10 mg/kg, daily) for five weeks. DNP-related behaviors were assessed in terms of thermal hyperalgesia and mechanical allodynia by hot-plate and von Frey filaments. Enzyme-linked immunosorbent assay (ELISA) kits were used to measure the spinal glutamate, interleukin-1 beta (IL-1β), and tumor necrosis factor-α (TNF-α). The spinal levels of N-methyl-D-aspartate type 1 receptor (NMDAR1), HMGB1, TLR4, and phosphorylated NF-kB were assessed using Western blotting. Histopathological investigation of the spinal cord and sciatic nerves, together with the spinal cord ultrastructure, was employed for assessment of the neuroprotective effect. Memantine alleviated pain indicators in diabetic mice and suppressed excessive NMDAR1 activation, glutamate, and pro-inflammatory cytokine release in the spinal cord. The current study validated the ability of memantine to combat the HMGB1/TLR4/NF-kB axis and modulate overactive glutamate spinal transmission, corroborating memantine as an appealing therapeutic target in DNP.

Background: The cardiotoxic effects of doxorubicin (DOX), a powerful chemotherapeutic drug, are widely recognized. Cuproptosis, a unique copper-dependent form of controlled cell death, may be involved in DOX-induced cardiomyopathy, according to recent findings. This study employs both in vivo and in silico procedures to investigate the protective effects of the copper chelator penicillamine (PEN) and the role of cuproptosis in DOX-related cardiotoxicity. Methods: Thirty-two adult Sprague Dawley rats were allocated into four groups (n = 8): control, DOX, DOX+PEN, and PEN. Cardiac function was assessed via echocardiography. Serum cardiac biomarkers (LDH, CK-MB, CTnI), oxidative stress markers (SOD, GPX, MDA), and expression levels of cuproptosis-related genes (FDX1, LIAS, SLC31A1, ATP7A) were evaluated. Histopathological examinations and immunohistochemical staining for FDX1, SLC31A1, and DLAT were performed. Molecular docking simulated PEN’s interaction with cuproptosis-related proteins. Network pharmacology and molecular docking studies were also conducted to identify core molecular targets and simulate PEN’s binding interactions with key cuproptosis regulators. Results: DOX administration induced significant cardiac dysfunction, oxidative stress, and upregulation of cuproptosis markers. PEN treatment mitigated these effects, improved cardiac function, reduced fibrosis, and suppressed the expression of cuproptosis-related genes and proteins. Docking results confirmed strong interactions between PEN and cuproptosis-regulatory proteins. Network pharmacology revealed 14 key overlapping targets linking PEN with cuproptosis and DOX-induced cardiotoxicity. Conclusion: This study provides experimental evidence implicating cuproptosis in DOX-induced cardiomyopathy. PEN exerts cardioprotection, potentially by targeting this pathway, offering a promising therapeutic strategy.

Darwish Badran, Ayman El-Baz El-Agroudy, Amira Adly Kassab, Khaled Saad El-Bayoumi, Zienab Helmy Eldken, Noha Ramadan Mohammed Elswaidy. Anat Cell Biol 2024;57:105-18. https://doi.org/10.5115/acb.23.217