Iron Accumulation Leads to Bone Loss by Inducing Mesenchymal Stem Cell Apoptosis Through the Activation of Caspase3

Area of Science:

• Biomedical Science
• Bone Biology
• Stem Cell Research

Background:

• Osteoporosis (OP) is characterized by bone loss and microstructural degradation.
• Emerging evidence suggests iron accumulation is a potential risk factor for OP.
• Bone marrow mesenchymal stem cells (MSCs) are crucial for bone formation and implicated in OP pathogenesis.

Purpose of the Study:

• To investigate the correlation between iron accumulation and MSCs in the context of osteoporosis.
• To determine the impact of iron overload on MSC quantity, function, and apoptosis.

Main Methods:

• Utilized a mouse model with induced iron accumulation.
• Assessed bone mineral density and microarchitecture using Micro-CT.
• Quantified MSCs in bone marrow and evaluated their cell cycle, ROS levels, and apoptosis markers.
• Administered the iron chelator deferoxamine (DFO) to assess its protective effects.

Main Results:

• Iron accumulation significantly decreased serum P1NP levels, bone mineral density, and spatial structural parameters.
• A reduction in MSC quantity within the bone marrow was observed in iron-accumulated mice.
• Iron overload increased reactive oxygen species (ROS) and NOX4 expression in MSCs, leading to enhanced apoptosis.
• Deferoxamine (DFO) treatment rescued the inhibitory effects of iron accumulation on MSCs.

Conclusions:

• Iron accumulation negatively impacts bone health by reducing bone mineral density and compromising MSCs.
• Iron overload inhibits MSC proliferation and induces apoptosis, potentially through increased oxidative stress.
• Targeting iron accumulation with chelators like DFO may offer a therapeutic strategy for osteoporosis associated with iron overload.