Melittin regulates iron homeostasis and mediates macrophage polarization in rats with lumbar spinal stenosis - 15/11/22






Abstract |
Lumbar spinal stenosis (LSS) is defined as spinal canal narrowing, resulting in the compression of the nerves traversing the lower back into the leg. Inflammation is the most common cause of LSS. Elevated iron stores are often associated with chronic inflammation resulting in nerve damage-induced pain. Macrophage polarization to either the M1 (inflammatory) or M2 (anti-inflammatory) type is essential for regulating host defenses and promoting tissue repair. However, the precise role of macrophage polarization in iron release or retention in LSS pathophysiology remains elusive. Melittin, a component of bee venom, modulates iron metabolism-related macrophage polarization and is beneficial in LSS. We treated primary peritoneal macrophages with melittin and assessed macrophage polarization by immunofluorescence staining. Melittin (100 and 250 µg/kg) effects on iron deposition-induced macrophage polarization were also evaluated using immunochemistry, real-time PCR, and flow cytometry in an LSS rat model. Locomotor function was assessed using the Basso–Beattie–Bresnahan (BBB) locomotor rating scale, ladder scoring, and von Frey test for up to 3 weeks. Melittin induced M2 polarization of iron-insulted primary macrophages in vitro and increased the proportion of M2 macrophages in the damaged spinal cord in vivo. Moreover, melittin attenuated iron overload-induced M1 polarization by regulating iron metabolism-related genes in rats with LSS. In conclusion, melittin improves locomotor recovery and stimulates axonal growth following LSS. Additionally, it promotes functional recovery in LSS rat models by regulating macrophage iron metabolism, thereby activating M2 macrophages, suggesting its potential application in LSS treatment.
Le texte complet de cet article est disponible en PDF.Graphical Abstract |
Highlights |
• | Iron-related oxidative mechanisms were examined in a rat model of lumbar stenosis. |
• | Exposure to iron led to inflammatory responses via M1 macrophage polarization in vitro and in vivo. |
• | Melittin prevented iron-induced M1 macrophage activation. |
• | Melittin administration to rats with lumbar spinal stenosis improved functional recovery. |
• | Activation of M2 macrophage polarization with melittin is a novel treatment strategy. |
• | Elevated iron stores worsen chronic inflammation in LSS |
• | Melittin modulates iron metabolism-mediated macrophage polarization |
• | Melittin induces M2 polarization of macrophages with iron overload |
• | Locomotor functions recover after Melittin administration |
Abbreviations : LSS, BBB, SD, PBS, Arg1, PFA, NGS, FITC, H&E, FPN, ELISA
Keywords : Melittin, Lumbar spinal stenosis, M1 macrophages, M2 macrophages, Iron homeostasis, Iron deposition
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Vol 156
Article 113776- décembre 2022 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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