Ischemic stroke reduces bone perfusion and alters osteovascular structure.

Area of Science:

• Neuroscience
• Orthopedics
• Vascular Biology

Background:

• Stroke patients exhibit increased bone loss and fracture risk.
• The effect of stroke on bone vasculature (osteovasculature) remains largely unknown.
• Osteovascular integrity is crucial for maintaining skeletal health.

Purpose of the Study:

• To investigate stroke-induced changes in osteovascular perfusion, structure, and composition.
• To evaluate the impact of exercise therapy on these stroke-induced changes.
• To determine if stroke effects on bone vasculature are systemic or localized.

Main Methods:

• Ischemic stroke (middle cerebral artery occlusion) or sham surgery in mice.
• Four weeks of recovery with either treadmill exercise or sedentary behavior.
• Assessment of intraosseous perfusion using laser Doppler flowmetry.
• Analysis of osteovascular structure via contrast-enhanced computed tomography and immunofluorescence microscopy.

Main Results:

• Stroke reduced bone blood flow for two weeks post-injury.
• Stroke led to increased osteovascular volume and branching, with a shift towards larger vessels.
• Exercise partially restored perfusion and volume but reduced specific bone-healing vasculature, potentially hindering early recovery.

Conclusions:

• Stroke causes systemic alterations in bone vasculature, independent of limb use.
• Early exercise interventions may have complex effects on bone healing post-stroke.
• Findings offer new insights into skeletal fragility following stroke and potential therapeutic targets.