1
MOLECULAR BIOLOGY OF SYRINGOMYELIA: AN INVESTIGATION FOR THE DEVELOPMENT OF NOVEL NEURORESTORATIVE TREATMENTS Ashley Wilkinson 1 , Mahmoud Abdullah 2 , Kelley Bondor 3 , Tricia Sendelbach 3 , Kim Stakleff 3 , Nic Leipzig 1 1 Department of Chemical & Biomolecular Engineering, University of Akron, OH; 2 College of Business, University of Akron, Akron, OH; 3 Akron General Medical Center, Akron, OH IMPORTANCE FOR CHIARI PATIENTS Cyst formation within the spinal cord, or syringomyelia, occurs in many Chiari patients; however, a detailed understanding of how these cysts form is not known. The goal of this work is to characterize the molecular events surrounding syrinx formation. Understanding these events will help to develop molecular targets for novel therapeutics, an approach that has been successful in treating many other neurological disorders (Figure 1). ABSTRACT In order to study the molecular events associated with syringomyelia, we will employ an established model of syrinx formation in rats. Syrinxes will be surgically induced in adult rats via excitotoxic injury to the spinal cord by quisqualic acid injection, followed by an injection of kaolin into the subarachnoid space. CT images, histological and immunochemical staining, and complete RNA sequencing will develop our knowledge of syrinx progression. Future studies will use the results of this work to target pathways of syrinx formation and enlargement for treatment of trauma and disease induced syringomyelia. DISCUSSION The results of this work are designed to identify a biomolecule or cell type to target in future studies to transform the inured environment into one conducive to healing. Total RNA sequencing from rats with induced syringomyelia will be compared to sham animals with no injury. Changes in gene expression will be relayed for development of new strategies to reduce or prevent syringomyelia damage. Studies are scheduled to commence summer of 2013. REFERENCES 1. Sekula, Jr et al. “The pathogenesis of Chiari I malformation and syringomyelia.” Neurological Research. (2011) 33:3 p232-239. 2. Yang et al. “Excitotoxic Model of Post-traumatic Syringomyelia.” Spine. (2001) 26:17 p1842-1849. 3. Stoodley et al. “Mechanisms underlying the formation and enlargement of noncommunicating syringomyelia: experimental studies.” Neurosurg Focus. (2000) 8:3. 4. Tator & Fehlings. “Review of the secondary injury theory of acute spinal cord trauma with emphasis on vascular mechanisms.” J Neurosurgery. (1991) 75 p15-26. Figure 1. Schematic of the progression of syringomyelia research. Initial development and study of syringomyelia will lead to the development of treatments to reduce syrinxes and associated complications. Conquer Chiari Research Center at the University of Akron, OH 1 st Annual Open House, April 27, 2013 INTRODUCTION Syringomyelia is a condition of the spinal cord in which a syrinx, or fluid filled cavity, forms as a result an existing condition such as trauma or hindbrain malformation. A large population of patients with Chiari I malformation develop a cannicular syrinx 1 , named so because it occurs in the central spinal canal. Previous work has shown that even in noncannicular syringomyelia, which usually occur as a result of trauma, irregular cerebrospinal fluid flow enhances the volumetric growth of cysts 2 . A better understanding of the underlying molecular pathways associated with syrinx formation will help to identify potential treatments for syringomyelia damage or prevention of syringomyelia in the future. Towards this end, laboratories across the globe have developed animal models of syringomyelia to study its progression. We propose to use an excitotoxic induction of a cyst in rats 3 to characterize syrinxes at the molecular level. Current work in our lab centers on using adult stem cells within engineered biomaterial scaffolds for neural regeneration (Figure 2). These constructs can be used as a delivery vehicle for syringomyelia treatments. Figure 2. Above: Tissue engineering strategy for returning functionality to the spinal cord is depicted. Right: Fluorescent images of subcutaneously implanted scaffolds for 21 days. The adult stem cells (blue) are expressing a large amount of neural protein (red). METHODS In order to develop and test our model, we are employing an established surgical method to induce syrinxes in rats 3 (Figure 3 & 4). This allows us to study the complex progression of syrinx formation using the following methods: • Surgically induce syrinx with a spinal cord injection of quisqualic acid followed by injection of kaolin • Allow syrinx to develop for 6 weeks Once a syrinx is present and fully developed at 6 weeks, we will study the physical and biochemical characteristics of the cyst using the following techniques: • μCT to visualize the syrinx volumetric parameters • Tissue sectioning and staining to detect immune and inflammatory responses • Total RNA sequencing for identification of irregular gene expression Figure 3. Illustration depicting the surgical technique developed by Stoodley and Brodbelt to induce a syrinx 3 . Image adapted from Tator and Fehlings 4 . Figure 4. A healthy section from the cervical spine is shown with a trichrome stain (a). In contrast, a spinal cord with syringomyelia shows the large cavity of the cyst (b) 2 . Dark purple indicates cell nuclei. a b
