Peripheral BDNF gene expression before and after rehabilitation in ischemic stroke: A preliminary study

Abstract

Background: Ischemic stroke is a leading global cause of disability, accounting for approximately 87% of all stroke cases. Rehabilitation strategies that promote neuroplasticity show promise in improving recovery outcomes, with increased expression of the brain-derived neurotrophic factor (BDNF) gene playing a key role in neuronal survival and synaptic plasticity. However, the effects of rehabilitation therapy on BDNF gene expression in ischemic stroke patients are rarely reported. This study aims to compare BDNF gene expression levels in ischemic stroke patients before and after rehabilitation.

Methods: In brief, total RNA was extracted from ischemic stroke patients before (n = 43) and after (n = 22) rehabilitation and converted into cDNA. Out of the 22 post-rehabilitation ischemic stroke patients, only 16 were paired. BDNF gene expression levels of pre- and post-rehabilitation were measured using a quantitative real-time polymerase chain reaction. A Mann-Whitney U test was applied to compare overall BDNF expression levels in ischemic stroke patients, while a Wilcoxon Signed-Rank test was used to assess changes in BDNF expression in the 16 paired ischemic stroke patients who completed the rehabilitation therapy.

Results: The results revealed a significant 3.81-fold increase in overall BDNF gene expression in post-rehabilitation ischemic stroke patients (p-value = 0.048), as determined by the Mann-Whitney U test. Notably, the Wilcoxon Signed-Rank test showed a highly significant 7.78-fold increase in BDNF expression in the 16 paired patients post-rehabilitation compared to pre- rehabilitation (p-value = 0.004).

Conclusions: The results support the potential of BDNF gene as a molecular marker of rehabilitation- induced neuroplasticity. These findings warrant further validation in larger studies integrating both molecular and clinical outcome measures.