Bone Marrow Stromal Cells With Exercise and Thyroid Hormone Effect on Post-Stroke Injuries in Middle-aged Mice

Based on our previous findings, the treatment of stem cells alone or in combination with thyroid hormone (T₃) and mild exercise could effectively reduce the risk of stroke damage in young mice. However, it is unclear whether this treatment is effective in aged or middle-aged mice. Therefore, this study designed to assess whether combination of Bone Marrow Stromal Cells (BMSCs) with T₃ and mild treadmill exercise can decrease stroke complications in middle-aged mice.

Under laser Doppler flowmetry monitoring, transient focal cerebral ischemia was produced by right Middle Cerebral Artery Occlusion (MCAO) for 45 min followed by 7 days of reperfusion in middle-aged mice. BMSCs (1×10⁵) were injected into the right cerebral ventricle 24 h after MCAO, followed by daily injection of triiodothyronine (T₃) (20 μg/100 g/d SC) and 6 days of running on a treadmill. Infarct size, neurological function, apoptotic cells and expression levels of Glial Fibrillary Acidic Protein (GFAP) were evaluated 1 week after stroke.

Post-ischemic treatment with BMSCs or with T₃ and or mild treadmill exercise alone or in combination did not significantly change neurological function, infarct size, and apoptotic cells 7 days after ischemia in middle-aged mice (P>0.05). However, the expression of GFAP significantly reduced after treatment with BMSCs and or T₃ (P<0.01).

Our findings indicate that post-stroke treatment BMSCs with exercise and thyroid hormone cannot reverse neuronal damage 7 days after ischemia in middle-aged mice. These findings further support that age is an important variable in stroke treatment.