Systems analysis of transcriptional data provides insights into muscle's biological response to botulinum toxin-A (BoNT-A)

Introduction:The purpose of this study is to provide athe first global transcriptomic profiling and systems analysis of BoNT-A treated muscle over a one year period. Microarray analysis was performed on rat TA muscle from 4 groups (n=4/group) at 1,4, 12 and 52 weeks after BoNT-A injection and saline injected rats at 12 weeks as control. Fold changes were computed at each time point with respect to control. Results: Dramatic transcriptional adaptation occurs at 1 week with a paradoxical increase in expression of slow and immature isoforms; increased expression of genes in competing pathways of repair and atrophy; impaired mitochondrial biogenesis and increased metal ion imbalance. ECM adaptations occurred at 4weeks to the basal lamina and fibrillar ECM. The muscle transcriptome returned to the unperturbed state 12 weeks post-injection. Conclusion: Transcriptional adaptations resemble denervated muscle albeit some differences. Overall gene expression, across time, correlates with the generally accepted BoNT-A time course.

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Mukund K, Mathewson M, Minamoto V, Ward SR, Subramaniam S, Lieber RL