Propolis Flavonoids Ameliorate Chronic Osteomyelitis in a Rat Model by Modulating TAZ-Regulated Treg/Th17 Balance

Area of Science:

• Immunology
• Pharmacology
• Cell Biology

Background:

• Chronic osteomyelitis (COM) is a persistent bone infection requiring effective therapeutic strategies.
• Regulatory T cell (Treg) and T helper 17 (Th17) cell imbalance contributes to COM pathogenesis.
• Propolis flavonoids (PF) exhibit potential anti-inflammatory and immunomodulatory properties.

Purpose of the Study:

• To elucidate the therapeutic mechanism of propolis flavonoids (PF) in chronic osteomyelitis (COM).
• To investigate the role of transcriptional coactivator with PDZ-binding motif (TAZ) in PF-mediated Treg/Th17 cell homeostasis.
• To assess the impact of PF on bacterial clearance and bone repair in COM.

Main Methods:

• Wistar rats with induced COM were treated with PF.
• In vitro studies utilized human and rat peripheral blood mononuclear cells (PBMCs) exposed to TGF-β1, PF, and TEAD1.
• TAZ signaling components, inflammatory cytokines (IL-17, IL-21, IL-2, IL-10), T cell subsets (Th17/Treg ratios), and bacterial load were analyzed using Western blot, ELISA, flow cytometry, and CFU counts.

Main Results:

• PF treatment upregulated TAZ expression and significantly reduced bacterial burden in bone tissue.
• PF intervention promoted Th17 cell populations while decreasing Treg cells, altering the Th17/Treg ratio.
• PF modulated cytokine profiles, decreasing pro-inflammatory IL-17/IL-21 and increasing anti-inflammatory IL-10/IL-2, alongside enhanced periosteal cell proliferation.

Conclusions:

• Propolis flavonoids ameliorate chronic osteomyelitis via TAZ-dependent mechanisms.
• PF rebalances Treg/Th17 polarization, promoting bacterial clearance and reducing inflammatory pathology.
• The study highlights PF as a potential therapeutic agent for COM by restoring immune homeostasis and facilitating bone repair.