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Pukale DD, Adkins-Travis K, Aryal SR, Shriver LP, Patti GJ, Leipzig ND. Investigating post-traumatic syringomyelia and local fluid osmoregulation via a rat model. Fluids Barriers CNS 2024; 21:19. [PMID: 38409031 PMCID: PMC10895764 DOI: 10.1186/s12987-024-00514-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 01/25/2024] [Indexed: 02/28/2024] Open
Abstract
BACKGROUND Syringomyelia (SM) is characterized by the development of fluid-filled cavities, referred to as syrinxes, within the spinal cord tissue. The molecular etiology of SM post-spinal cord injury (SCI) is not well understood and only invasive surgical based treatments are available to treat SM clinically. This study builds upon our previous omics studies and in vitro cellular investigations to further understand local fluid osmoregulation in post-traumatic SM (PTSM) to highlight important pathways for future molecular interventions. METHODS A rat PTSM model consisting of a laminectomy at the C7 to T1 level followed by a parenchymal injection of 2 μL quisqualic acid (QA) and an injection of 5 μL kaolin in the subarachnoid space was utilized 6 weeks after initial surgery, parenchymal fluid and cerebrospinal fluid (CSF) were collected, and the osmolality of fluids were analyzed. Immunohistochemistry (IHC), metabolomics analysis using LC-MS, and mass spectrometry-based imaging (MSI) were performed on injured and laminectomy-only control spinal cords. RESULTS We demonstrated that the osmolality of the local parenchymal fluid encompassing syrinxes was higher compared to control spinal cords after laminectomy, indicating a local osmotic imbalance due to SM injury. Moreover, we also found that parenchymal fluid is more hypertonic than CSF, indicating establishment of a local osmotic gradient in the PTSM injured spinal cord (syrinx site) forcing fluid into the spinal cord parenchyma to form and/or expand syrinxes. IHC results demonstrated upregulation of betaine, ions, water channels/transporters, and enzymes (BGT1, AQP1, AQP4, CHDH) at the syrinx site as compared to caudal and rostral sites to the injury, implying extensive local osmoregulation activities at the syrinx site. Further, metabolomics analysis corroborated alterations in osmolality at the syrinx site by upregulation of small molecule osmolytes including betaine, carnitine, glycerophosphocholine, arginine, creatine, guanidinoacetate, and spermidine. CONCLUSIONS In summary, PTSM results in local osmotic disturbance that propagates at 6 weeks following initial injury. This coincides with and may contribute to syrinx formation/expansion.
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Affiliation(s)
- Dipak D Pukale
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron, Akron, OH, 44325, USA
| | - Kayla Adkins-Travis
- Departments of Chemistry and Medicine, Center for Proteomics, Metabolomics, and Isotope Tracing, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Siddhartha R Aryal
- Department of Biomedical Engineering, The University of Akron, Akron, OH, 44325, USA
| | - Leah P Shriver
- Departments of Chemistry and Medicine, Center for Proteomics, Metabolomics, and Isotope Tracing, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Gary J Patti
- Departments of Chemistry and Medicine, Center for Proteomics, Metabolomics, and Isotope Tracing, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Nic D Leipzig
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron, Akron, OH, 44325, USA.
- Department of Biomedical Engineering, The University of Akron, Akron, OH, 44325, USA.
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Liu S, Ma L, Qi B, Li Q, Chen Z, Jian F. Suppression of TGFβR-Smad3 pathway alleviates the syrinx induced by syringomyelia. Cell Biosci 2023; 13:98. [PMID: 37248485 DOI: 10.1186/s13578-023-01048-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 05/06/2023] [Indexed: 05/31/2023] Open
Abstract
BACKGROUND Syringomyelia is a cerebrospinal fluid (CSF) disorder resulted in separation of pain and temperature, dilation of central canal and formation of syrinx in central canal. It is unclear about mechanisms of the dilation and syrinx formation. We aimed to investigate roles of ependymal cells lining central canal on the dilation, trying to reduce syrinx formation in central canal. METHODS We employed 78 Sprague-Dawley (SD) rats totally with syringomyelia to detect the contribution of ependymal cells to the dilation of central canal. Immunofluorescence was used to examine the activation of ependymal cells in 54 syringomyelia rat models. BrdU was used to indicate the proliferation of ependymal cells through intraperitoneal administration in 6 syringomyelia rat models. 18 rats with syringomyelia were injected with SIS3, an inhibitor of TGFβR-Smad3, and rats injected with DMSO were used as control. Among the 18 rats, 12 rats were used for observation of syrinx following SIS3 or DMSO administration by using magnetic resonance imaging (MRI) on day 14 and day 30 under syringomyelia without decompression. All the data were expressed as mean ± standard deviation (mean ± SD). Differences between groups were compared using the two-tailed Student's t-test or ANOVA. Differences were considered significant when *p < 0.05. RESULTS Our study showed the dilation and protrusions of central canal on day 5 and enlargement from day 14 after syringomyelia induction in rats with activation of ependymal cells lining central canal. Moreover, the ependymal cells contributed to protrusion formation possibly through migration along with central canal. Furthermore, suppression of TGFβR-Smad3 which was crucial for migration reversed the size of syrnix in central canal without treatment of decompression, suggesting TGFβR-Smad3 signal might be key for dilation of central canal and formation of syrinx. CONCLUSIONS The size of syrinx was decreased after SIS3 administration without decompression. Our study depicted the mechanisms of syrinx formation and suggested TGFβR-Smad3 signal might be key for dilation of central canal and formation of syrinx.
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Affiliation(s)
- Sumei Liu
- Department of Neurosurgery, China International Neuroscience Institute, Xuanwu Hospital Capital Medical University, 45 Changchun Street, Beijing, 100053, China
- Cell Therapy Center, Xuanwu Hospital Capital Medical University, 45 Changchun Street, Beijing, 100053, China
| | - Longbing Ma
- Department of Neurosurgery, China International Neuroscience Institute, Xuanwu Hospital Capital Medical University, 45 Changchun Street, Beijing, 100053, China
| | - Boling Qi
- Cell Therapy Center, Xuanwu Hospital Capital Medical University, 45 Changchun Street, Beijing, 100053, China
| | - Qian Li
- Department of Neurosurgery, China International Neuroscience Institute, Xuanwu Hospital Capital Medical University, 45 Changchun Street, Beijing, 100053, China
| | - Zhiguo Chen
- Cell Therapy Center, Xuanwu Hospital Capital Medical University, 45 Changchun Street, Beijing, 100053, China.
| | - Fengzeng Jian
- Department of Neurosurgery, China International Neuroscience Institute, Xuanwu Hospital Capital Medical University, 45 Changchun Street, Beijing, 100053, China.
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China.
- Lab of Spinal Cord Injury and Functional Reconstruction, Xuanwu Hospital, Capital Medical University, Beijing, China.
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China.
- National Center for Neurological Disorders, Beijing, China.
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Pukale DD, Lazarenko D, Aryal SR, Khabaz F, Shriver LP, Leipzig ND. Osmotic Contribution of Synthesized Betaine by Choline Dehydrogenase Using In Vivo and In Vitro Models of Post-traumatic Syringomyelia. Cell Mol Bioeng 2023; 16:41-54. [PMID: 36660584 PMCID: PMC9842837 DOI: 10.1007/s12195-022-00749-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 10/27/2022] [Indexed: 11/28/2022] Open
Abstract
Introduction Syringomyelia (SM) is a debilitating spinal cord disorder in which a cyst, or syrinx, forms in the spinal cord parenchyma due to congenital and acquired causes. Over time syrinxes expand and elongate, which leads to compressing the neural tissues and a mild to severe range of symptoms. In prior omics studies, significant upregulation of betaine and its synthesis enzyme choline dehydrogenase (CHDH) were reported during syrinx formation/expansion in SM injured spinal cords, but the role of betaine regulation in SM etiology remains unclear. Considering betaine's known osmoprotectant role in biological systems, along with antioxidant and methyl donor activities, this study aimed to better understand osmotic contributions of synthesized betaine by CHDH in response to SM injuries in the spinal cord. Methods A post-traumatic SM (PTSM) rat model and in vitro cellular models using rat astrocytes and HepG2 liver cells were utilized to investigate the role of betaine synthesis by CHDH. Additionally, the osmotic contributions of betaine were evaluated using a combination of experimental as well as simulation approaches. Results In the PTSM injured spinal cord CHDH expression was observed in cells surrounding syrinxes. We next found that rat astrocytes and HepG2 cells were capable of synthesizing betaine via CHDH under osmotic stress in vitro to maintain osmoregulation. Finally, our experimental and simulation approaches showed that betaine was capable of directly increasing meaningful osmotic pressure. Conclusions The findings from this study demonstrate new evidence that CHDH activity in the spinal cord provides locally synthesized betaine for osmoregulation in SM pathophysiology. Supplementary Information The online version of this article contains supplementary material available 10.1007/s12195-022-00749-5.
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Affiliation(s)
- Dipak D. Pukale
- Department of Chemical, Biomolecular, and Corrosion Engineering, University of Akron, Akron, OH 44325 USA
| | - Daria Lazarenko
- School of Polymer Science and Polymer Engineering, The University of Akron, Akron, OH 44325 USA
| | - Siddhartha R. Aryal
- Department of Biomedical Engineering, The University of Akron, Akron, OH 44325 USA
| | - Fardin Khabaz
- Department of Chemical, Biomolecular, and Corrosion Engineering, University of Akron, Akron, OH 44325 USA
- School of Polymer Science and Polymer Engineering, The University of Akron, Akron, OH 44325 USA
| | - Leah P. Shriver
- Department of Chemistry, Washington University, Saint Louis, MO 63130 USA
- Department of Medicine, Washington University, Saint Louis, MO 63130 USA
- Center for Metabolomics and Isotope Tracing, Washington University, Saint Louis, MO 63130 USA
| | - Nic D. Leipzig
- Department of Chemical, Biomolecular, and Corrosion Engineering, University of Akron, Akron, OH 44325 USA
- Department of Biomedical Engineering, The University of Akron, Akron, OH 44325 USA
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Tang H, Gu Y, Jiang L, Zheng G, Pan Z, Jiang X. The role of immune cells and associated immunological factors in the immune response to spinal cord injury. Front Immunol 2023; 13:1070540. [PMID: 36685599 PMCID: PMC9849245 DOI: 10.3389/fimmu.2022.1070540] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Accepted: 12/05/2022] [Indexed: 01/06/2023] Open
Abstract
Spinal cord injury (SCI) is a devastating neurological condition prevalent worldwide. Where the pathological mechanisms underlying SCI are concerned, we can distinguish between primary injury caused by initial mechanical damage and secondary injury characterized by a series of biological responses, such as vascular dysfunction, oxidative stress, neurotransmitter toxicity, lipid peroxidation, and immune-inflammatory response. Secondary injury causes further tissue loss and dysfunction, and the immune response appears to be the key molecular mechanism affecting injured tissue regeneration and functional recovery from SCI. Immune response after SCI involves the activation of different immune cells and the production of immunity-associated chemicals. With the development of new biological technologies, such as transcriptomics, the heterogeneity of immune cells and chemicals can be classified with greater precision. In this review, we focus on the current understanding of the heterogeneity of these immune components and the roles they play in SCI, including reactive astrogliosis and glial scar formation, neutrophil migration, macrophage transformation, resident microglia activation and proliferation, and the humoral immunity mediated by T and B cells. We also summarize findings from clinical trials of immunomodulatory therapies for SCI and briefly review promising therapeutic drugs currently being researched.
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Affiliation(s)
- Huaguo Tang
- Department of Hand and Foot Surgery, Zhejiang Rongjun Hospital, Jiaxing, China
| | - Yuanjie Gu
- Department of Hand and Foot Surgery, Zhejiang Rongjun Hospital, Jiaxing, China
| | - Lei Jiang
- Department of Hand and Foot Surgery, Zhejiang Rongjun Hospital, Jiaxing, China
| | - Gang Zheng
- Department of Neurosurgery, The Central Hospital Affiliated to Shaoxing University, Jiaxing, China
| | - Zhuoer Pan
- Department of Orthopedics, Zhejiang Rongjun Hospital, Jiaxing, China
| | - Xiugui Jiang
- Department of Hand and Foot Surgery, Zhejiang Rongjun Hospital, Jiaxing, China
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Yuan C, Guan J, Du Y, Fang Z, Wang X, Yao Q, Zhang C, Jia S, Liu Z, Wang K, Duan W, Wang X, Wang Z, Wu H, Chen Z, Jian F. Spinal Obstruction-Related vs. Craniocervical Junction-Related Syringomyelia: A Comparative Study. Front Neurol 2022; 13:900441. [PMID: 35979061 PMCID: PMC9376629 DOI: 10.3389/fneur.2022.900441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 06/23/2022] [Indexed: 01/08/2023] Open
Abstract
Background No prior reports have focused on spinal cord injury (SCI) characteristics or inflammation after destruction of the blood–spinal cord barrier by syringomyelia. This study aimed to determine the differences in syringomyelia-related central SCI between craniocervical junction (CCJ) syringomyelia and post-traumatic syringomyelia (PTS) before and after decompression. Methods In all, 106 CCJ, 26 CCJ revision and 15 PTS patients (mean history of symptoms, 71.5 ± 94.3, 88.9 ± 85.5, and 32.3 ± 48.9 months) between 2015 and 2019 were included. The symptom course was analyzed with the American Spinal Injury Association ASIA and Klekamp–Samii scoring systems, and neurological changes were analyzed by the Kaplan–Meier statistics. The mean follow-up was 20.7 ± 6.2, 21.7 ± 8.8, and 34.8 ± 19.4 months. Results The interval after injury was longer in the PTS group, but the natural history of syringomyelia was shorter (p = 0.0004 and 0.0173, respectively). The initial symptom was usually paraesthesia (p = 0.258), and the other main symptoms were hypoesthesia (p = 0.006) and abnormal muscle strength (p = 0.004), gait (p < 0.0001), and urination (p < 0.0001). SCI associated with PTS was more severe than that associated with the CCJ (p = 0.003). The cavities in the PTS group were primarily located at the thoracolumbar level, while those in the CCJ group were located at the cervical-thoracic segment at the CCJ. The syrinx/cord ratio of the PTS group was more than 75% (p = 0.009), and the intradural adhesions tended to be more severe (p < 0.0001). However, there were no significant differences in long-term clinical efficacy or peripheral blood inflammation markers (PBIMs) except for the red blood cell (RBC) count (p = 0.042). Conclusion PTS tends to progress faster than CCJ-related syringomyelia. Except for the RBC count, PBIMs showed no value in distinguishing the two forms of syringomyelia. The predictive value of the neutrophil-to-lymphocyte ratio for syringomyelia-related inflammation was negative except in the acute phase.
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Affiliation(s)
- Chenghua Yuan
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Laboratory of Spinal Cord Injury and Functional Reconstruction, Xuanwu Hospital, Capital Medical University, Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- National Center for Neurological Disorders, Beijing, China
| | - Jian Guan
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Laboratory of Spinal Cord Injury and Functional Reconstruction, Xuanwu Hospital, Capital Medical University, Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- National Center for Neurological Disorders, Beijing, China
| | - Yueqi Du
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Laboratory of Spinal Cord Injury and Functional Reconstruction, Xuanwu Hospital, Capital Medical University, Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- National Center for Neurological Disorders, Beijing, China
| | - Zeyu Fang
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Laboratory of Spinal Cord Injury and Functional Reconstruction, Xuanwu Hospital, Capital Medical University, Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- National Center for Neurological Disorders, Beijing, China
| | - Xinyu Wang
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Laboratory of Spinal Cord Injury and Functional Reconstruction, Xuanwu Hospital, Capital Medical University, Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- National Center for Neurological Disorders, Beijing, China
| | - Qingyu Yao
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Laboratory of Spinal Cord Injury and Functional Reconstruction, Xuanwu Hospital, Capital Medical University, Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- National Center for Neurological Disorders, Beijing, China
| | - Can Zhang
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Laboratory of Spinal Cord Injury and Functional Reconstruction, Xuanwu Hospital, Capital Medical University, Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- National Center for Neurological Disorders, Beijing, China
| | - Shanhang Jia
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Laboratory of Spinal Cord Injury and Functional Reconstruction, Xuanwu Hospital, Capital Medical University, Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- National Center for Neurological Disorders, Beijing, China
| | - Zhenlei Liu
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Laboratory of Spinal Cord Injury and Functional Reconstruction, Xuanwu Hospital, Capital Medical University, Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- National Center for Neurological Disorders, Beijing, China
| | - Kai Wang
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Laboratory of Spinal Cord Injury and Functional Reconstruction, Xuanwu Hospital, Capital Medical University, Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- National Center for Neurological Disorders, Beijing, China
| | - Wanru Duan
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Laboratory of Spinal Cord Injury and Functional Reconstruction, Xuanwu Hospital, Capital Medical University, Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- National Center for Neurological Disorders, Beijing, China
| | - Xingwen Wang
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Laboratory of Spinal Cord Injury and Functional Reconstruction, Xuanwu Hospital, Capital Medical University, Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- National Center for Neurological Disorders, Beijing, China
| | - Zuowei Wang
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Laboratory of Spinal Cord Injury and Functional Reconstruction, Xuanwu Hospital, Capital Medical University, Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- National Center for Neurological Disorders, Beijing, China
| | - Hao Wu
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Laboratory of Spinal Cord Injury and Functional Reconstruction, Xuanwu Hospital, Capital Medical University, Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- National Center for Neurological Disorders, Beijing, China
| | - Zan Chen
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Laboratory of Spinal Cord Injury and Functional Reconstruction, Xuanwu Hospital, Capital Medical University, Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- National Center for Neurological Disorders, Beijing, China
| | - Fengzeng Jian
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Spine Center, China International Neuroscience Institute (CHINA-INI), Beijing, China
- Laboratory of Spinal Cord Injury and Functional Reconstruction, Xuanwu Hospital, Capital Medical University, Beijing, China
- Research Center of Spine and Spinal Cord, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- National Center for Neurological Disorders, Beijing, China
- *Correspondence: Fengzeng Jian
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Pukale DD, Farrag M, Leipzig ND. Detection of locomotion deficit in a post-traumatic syringomyelia rat model using automated gait analysis technique. PLoS One 2021; 16:e0252559. [PMID: 34762669 PMCID: PMC8584658 DOI: 10.1371/journal.pone.0252559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Accepted: 10/24/2021] [Indexed: 11/24/2022] Open
Abstract
Syringomyelia (SM) is a spinal cord disorder in which a cyst (syrinx) filled with fluid forms in the spinal cord post-injury/disease, in patients syrinx symptoms include loss of pain and temperature sensation or locomotion deficit. Currently, there are no small animal models and connected tools to help study the functional impacts of SM. The objective of this study was to determine the detectability of subtle locomotion deficits due to syrinx formation/expansion in post-traumatic syringomyelia (PTSM) rat model using the recently reported method of Gait Analysis Instrumentation, and Technology Optimized for Rodents (GAITOR) with Automated Gait Analysis Through Hues and Areas (AGATHA) technique. First videos of the rats were collected while walking in an arena (using GAITOR) followed by extracting meaningful locomotion information from collected videos using AGATHA protocol. PTSM injured rats demonstrated detectable locomotion deficits in terms of duty factor imbalance, paw placement accuracy, step contact width, stride length, and phase dispersion parameters compared to uninjured rats due to SM. We concluded that this technique could detect mild and subtle locomotion deficits associated with PTSM injury, which also in future work could be used further to monitor locomotion responses after different treatment strategies for SM.
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Affiliation(s)
- Dipak D. Pukale
- Department of Chemical, Biomolecular, and Corrosion Engineering, University of Akron, Akron, Ohio, United States of America
| | - Mahmoud Farrag
- Integrated Bioscience Program, University of Akron, Akron, Ohio, United States of America
| | - Nic D. Leipzig
- Department of Chemical, Biomolecular, and Corrosion Engineering, University of Akron, Akron, Ohio, United States of America
- Integrated Bioscience Program, University of Akron, Akron, Ohio, United States of America
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7
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Pukale DD, Farrag M, Gudneppanavar R, Baumann HJ, Konopka M, Shriver LP, Leipzig ND. Osmoregulatory Role of Betaine and Betaine/γ-Aminobutyric Acid Transporter 1 in Post-Traumatic Syringomyelia. ACS Chem Neurosci 2021; 12:3567-3578. [PMID: 34550670 DOI: 10.1021/acschemneuro.1c00056] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Syringomyelia (SM) is primarily characterized by the formation of a fluid-filled cyst that forms in the parenchyma of the spinal cord following injury or other pathology. Recent omics studies in animal models have identified dysregulation of solute carriers, channels, transporters, and small molecules associated with osmolyte regulation during syrinx formation/expansion in the spinal cord. However, their connections to syringomyelia etiology are poorly understood. In this study, the biological functions of the potent osmolyte betaine and its associated solute carrier betaine/γ-aminobutyric acid (GABA) transporter 1 (BGT1) were studied in SM. First, a rat post-traumatic SM model was used to demonstrate that the BGT1 was primarily expressed in astrocytes in the vicinity of syrinxes. In an in vitro system, we found that astrocytes uptake betaine through BGT1 to regulate cell size under hypertonic conditions. Treatment with BGT1 inhibitors, especially NNC 05-2090, demonstrated midhigh micromolar range potency in vitro that reversed the osmoprotective effects of betaine. Finally, the specificity of these BGT1 inhibitors in the CNS was demonstrated in vivo, suggesting feasibility for targeting betaine transport in SM. In summary, these data provide an enhanced understanding of the role of betaine and its associated solute carrier BGT1 in cell osmoregulation and implicates the active role of betaine and BGT1 in syringomyelia progression.
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Affiliation(s)
- Dipak D. Pukale
- Department of Chemical, Biomolecular, and Corrosion Engineering, University of Akron, Akron, Ohio 44325, United States
| | - Mahmoud Farrag
- Integrated Biosciences Program, University of Akron, Akron, Ohio 44325, United States
| | | | - Hannah J. Baumann
- Department of Chemistry, University of Akron, Akron, Ohio 44325, United States
| | - Michael Konopka
- Department of Chemistry, University of Akron, Akron, Ohio 44325, United States
| | - Leah P. Shriver
- Integrated Biosciences Program, University of Akron, Akron, Ohio 44325, United States
- Department of Chemistry, University of Akron, Akron, Ohio 44325, United States
| | - Nic D. Leipzig
- Department of Chemical, Biomolecular, and Corrosion Engineering, University of Akron, Akron, Ohio 44325, United States
- Integrated Biosciences Program, University of Akron, Akron, Ohio 44325, United States
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Farrag M, Pukale DD, Leipzig ND. Micro-computed tomography utility for estimation of intraparenchymal spinal cord cystic lesions in small animals. Neural Regen Res 2021; 16:2293-2298. [PMID: 33818515 PMCID: PMC8354136 DOI: 10.4103/1673-5374.310690] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Precise assessment of spinal cord cystic lesions is crucial to formulate effective therapeutic strategies, yet histological assessment of the lesion remains the primary method despite numerous studies showing inconsistent results regarding estimation of lesion size via histology. On the other hand, despite numerous advances in micro-computed tomography (micro-CT) imaging and analysis that have allowed precise measurements of lesion size, there is not enough published data on its application to estimate intraspinal lesion size in laboratory animal models. This work attempts to show that micro-CT can be valuable for spinal cord injury research by demonstrating accurate estimation of syrinx size and compares between micro-CT and traditional histological analysis. We used a post-traumatic syringomyelia rat model to compare micro-CT analysis to conventional histological analysis. The study showed that micro-CT can detect lesions within the spinal cord very similar to histology. Importantly, micro-CT appears to provide more accurate estimates of the lesions with more measures (e.g., surface area), can detect compounds within the cord, and can be done with the tissue of interest (spinal cord) intact. In summary, the experimental work presented here provides one of the first investigations of the use of micro-CT for estimating the size of intraparenchymal cysts and detecting materials within the spinal cord. All animal procedures were approved by the University of Akron Institutional Animal Care and Use Committee (IACUC) (protocol # LRE 16-05-09 approved on May 14, 2016).
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Affiliation(s)
- Mahmoud Farrag
- Integrated Bioscience Program, The University of Akron, Akron, OH, USA
| | - Dipak D Pukale
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron, Akron, OH, USA
| | - Nic D Leipzig
- Department of Chemical, Biomolecular, and Corrosion Engineering, Integrated Bioscience Program, The University of Akron, Akron, OH, USA
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9
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Bal E, Hanalioglu S, Kopru CZ, Köse S, Basak AT, Pehlivan SB, Cetinkaya DU, Purali N, Korkusuz P, Bozkurt G. Effect of mesenchymal stem cells therapy in experimental kaolin induced syringomyelia model. J Neurosurg Sci 2020; 66:40-48. [PMID: 33056946 DOI: 10.23736/s0390-5616.20.05026-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
BACKGROUND Syringomyelia is a pathological cavitation of the spinal cord. In this study, we examined whether a syrinx cavity would limit itself with axonal regeneration and stem cell activity in the cavity, and we evaluated subjects on a functional basis. METHODS Groups were designated as kaolin, trauma, kaolin-trauma, and saline groups. Also divided out of the syringomyelia treated groups were those given human mesenchymal stem cells (hMSCs). All groups were evaluated with immunohistochemistry, electron microscopy, confocal microscopy and functionally. RESULTS The kaolin-trauma group had a significant correction of BBB score with hMSCs therapy. The syrinx cavity measurements showed significant improvement in groups treated with hMSCs. The tissue surrounding the syrinx cavity, however, appeared to be better organized in groups treated with hMSCs. The process of repair and regeneration of damaged axons in the lesion were more improved in groups treated with hMSCs. Using confocal microscopy, fluorescence of hMSCs was observed in the central canal, in the ependymal tissue, and around the lesion. CONCLUSIONS It was concluded that axonal repair accelerated in groups receiving stem cells, and thus, stem cells may be effective in recovery of neural tissue and myelin damage in syringomyelia.
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Affiliation(s)
- Ercan Bal
- Department of Neurosurgery, Ankara Yıldırım Beyazıt University School of Medicine, Ankara, Turkey -
| | - Sahin Hanalioglu
- Department of Neurosurgery, Hacettepe University School of Hospital, Ankara, Turkey
| | - Cagla Z Kopru
- Department of Histology and Embryology, Yüksek İhtisas University School of Medicine, Ankara, Turkey
| | - Sevil Köse
- Department of Medical Biology, Atilim University Faculty of Medicine, Ankara, Turkey
| | - Ahmet T Basak
- Department of Neurosurgery, Medipol Mega Hospital University of School, İstanbul, Turkey
| | - Sibel B Pehlivan
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, Ankara, Turkey
| | - Duygu U Cetinkaya
- Center for Stem Cell Research and Development (PEDI-STEM), Hacettepe University School of Medicine, Ankara Turkey
| | - Nuhan Purali
- Department of Biophysics, Hacettepe University School of Medicine, Ankara, Turkey
| | - Petek Korkusuz
- Department of Histology and Embryology, Hacettepe University School of Medicine, Ankara, Turkey
| | - Gökhan Bozkurt
- Department of Neurosurgery, Memorial Hospital, İstanbul, Turkey
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Chronic extradural compression of spinal cord leads to syringomyelia in rat model. Fluids Barriers CNS 2020; 17:50. [PMID: 32736591 PMCID: PMC7393857 DOI: 10.1186/s12987-020-00213-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Accepted: 07/20/2020] [Indexed: 11/23/2022] Open
Abstract
Background Syringomyelia is a common spinal cord lesion. However, whether CSF blockage is linked to the formation and enlargement of syringomyelia is still controversial. The current model of syringomyelia needs modification to more closely mimic the clinical situation. Methods We placed cotton strips under the T13 lamina of 40 8-week-old rats and blocked CSF flow by extradural compression. After 4 and 8 weeks, MRI was performed to evaluate the morphology of syringomyelia and the ratio of spinal cord diameter to syrinx diameter calculated. Locomotor function was evaluated weekly. Spinal cord sections, staining and immunohistochemistry were performed 8 weeks after surgery, the ratio of the central canal to the spinal cord area was calculated, and ependymal cells were counted. In another experiment, we performed decompression surgery for 8 rats with induced syringomyelia at the 8th week after surgery. During the surgery, the cotton strip was completely removed without damaging the dura mater. Then, the rats received MRI imaging during the following weeks and were sacrificed for pathological examination at the end of the experiment. Results Syringomyelia formed in 82.5% (33/40) of rats at the 8-week follow-up. The Basso, Beattie and Bresnahan (BBB) scores of rats in the experimental group decreased from 21.0±0.0 to 18.0 ±3.9 in the first week after operation but returned to normal in later weeks. The BBB score indicated that the locomotor deficit caused by compression is temporary and can spontaneously recover. MRI showed that the syrinx is located in the center of the spinal cord, which is very similar to the most common syringomyelia in humans. The ratio of the central canal to the spinal cord area reached (2.9 ± 2.0) × 10−2, while that of the sham group was (5.4 ± 1.5) × 10−4. The number of ependymal cells lining the central canal was significantly increased (101.9 ± 39.6 vs 54.5 ± 3.4). There was no syrinx or proliferative inflammatory cells in the spinal cord parenchyma. After decompression, the syringomyelia size decreased in 50% (4/8) of the rats and increased in another 50% (4/8). Conclusion Extradural blockade of CSF flow can induce syringomyelia in rats. Temporary locomotor deficit occurred in some rats. This reproducible rat model of syringomyelia, which mimics syringomyelia in humans, can provide a good model for the study of disease mechanisms and therapies.
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11
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Zhao Z, Li T, Bi N, Shi Z, Zhang Y, Li Q, Wang Y, Xie J. Continuous Hypodynamic Change of Cerebrospinal Fluid Flow as A Potential Factor Working for Experimental Scoliotic Formation. Sci Rep 2020; 10:6821. [PMID: 32321986 PMCID: PMC7176657 DOI: 10.1038/s41598-020-63822-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 04/06/2020] [Indexed: 11/10/2022] Open
Abstract
Scoliosis is often associated with syringomyelia (SM). As an important role in SM formation, the influence from abnormal cerebrospinal fluid (CSF) flow is still unclear to scoliosis. The aim of this experimental work is to explore the connection between CSF flow and scoliosis through imaging and histological analysis on the basis of a kaolin-induced scoliotic rabbit model. For imaging observation, in 40 kaolin-induced rabbits by C7 spinal cord injection, through pre- and postoperative MRI and radiography, CSF flow and scoliosis formation were detected at consecutive phases. According to the final formation of scoliosis until postoperative week 12, the kaolin-induced rabbits were divided into 2 groups. Through comparing the 2 groups, the relationship between the changes of CSF flow velocity and scoliosis formation were reviewed and analyzed. For histological observation, another 20 kaolin-induced rabbits were used for consecutive histological observations of spinal cord at postoperative 3-day, 2-week, 4-week and 6-week. After kaolin-induction, abnormal spinal coronal curve was observed from postoperative week 6 in the 37 survived rabbits. At postoperative week 12, scoliosis formation was detected in 73.0% kaolin-induced rabbits and the mean Cobb angle was 27.4°. From the comparison between scoliotic and non-scoliotic groups, the difference of the velocities of CSF flow was more obviously from postoperative week 4 to 12, especially after week 6. In the scoliotic group, the peak velocity of CSF flow was diseased gradually following scoliosis formation after induction. Moreover, the decrease of the peak velocities of CSF flow from preoperation to postoperative 12 weeks (ΔVmax), including up-flow (ΔVUmax) and down-flow (ΔVDmax), were positively correlated to the final scoliotic Cobb angle (P < 0.01). Through histological observation at different phases, the distinctive pathological changes of the spinal cord included early inflammatory reaction, adhesion and blockage in the subarachnoid space and the central canal, perivascular space enlargement, central canal expansion, which suggested the CSF flow being blocked by multiple ways after kaolin-induction. In conclusion, experimental scoliosis can be successfully induced by intraspinal kaolin injection. In this model, continuous hypodynamic change of CSF flow was correlated to the formation of scoliosis, which could be an important factor of scoliotic pathogenesis being explored furtherly.
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Affiliation(s)
- Zhi Zhao
- Department of Orthopaedics, The 2nd Affiliated Hospital of Kunming Medical University, Kunming, 6500101, Yunnan, People's Republic of China
| | - Tao Li
- Department of Orthopaedics, The 2nd Affiliated Hospital of Kunming Medical University, Kunming, 6500101, Yunnan, People's Republic of China
| | - Ni Bi
- Department of Orthopaedics, The 2nd Affiliated Hospital of Kunming Medical University, Kunming, 6500101, Yunnan, People's Republic of China
| | - Zhiyue Shi
- Department of Orthopaedics, The 2nd Affiliated Hospital of Kunming Medical University, Kunming, 6500101, Yunnan, People's Republic of China
| | - Ying Zhang
- Department of Orthopaedics, The 2nd Affiliated Hospital of Kunming Medical University, Kunming, 6500101, Yunnan, People's Republic of China
| | - Quan Li
- Department of Orthopaedics, The 2nd Affiliated Hospital of Kunming Medical University, Kunming, 6500101, Yunnan, People's Republic of China
| | - Yingsong Wang
- Department of Orthopaedics, The 2nd Affiliated Hospital of Kunming Medical University, Kunming, 6500101, Yunnan, People's Republic of China.
| | - Jingming Xie
- Department of Orthopaedics, The 2nd Affiliated Hospital of Kunming Medical University, Kunming, 6500101, Yunnan, People's Republic of China.
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Wang Q, Li ZX, Li YJ, He ZG, Chen YL, Feng MH, Li SY, Wu DZ, Xiang HB. Identification of lncRNA and mRNA expression profiles in rat spinal cords at various time‑points following cardiac ischemia/reperfusion. Int J Mol Med 2019; 43:2361-2375. [PMID: 30942426 PMCID: PMC6488167 DOI: 10.3892/ijmm.2019.4151] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Accepted: 03/20/2019] [Indexed: 12/21/2022] Open
Abstract
The identification of the expression patterns of long non-coding RNAs (lncRNAs) and mRNAs in the spinal cord under normal and cardiac ischemia/reperfusion (I/R) conditions is essential for understanding the genetic mechanisms underlying the pathogenesis of cardiac I/R injury. The present study used high-throughput RNA sequencing to investigate differential gene and lncRNA expression patterns in the spinal cords of rats during I/R-induced cardiac injury. Male Sprague Dawley rats were assigned to the following groups: i) Control; ii) 2 h (2 h post-reperfusion); and iii) 0.5 h (0.5 h post-reperfusion). Further mRNA/lncRNA microarray analysis revealed that the expression profiles of lncRNA and mRNA in the spinal cords differed markedly between the control and 2 h groups, and in total 7,980 differentially expressed (>2-fold) lncRNAs (234 upregulated, 7,746 downregulated) and 3,428 mRNAs (767 upregulated, 2,661 downregulated) were identified. Reverse transcription-quantitative polymerase chain reaction analysis was performed to determine the expression patterns of several lncRNAs. The results indicated that the expression levels of lncRNA NONRATT025386 were significantly upregulated in the 2 and 0.5 h groups when compared with those in the control group, whereas the expression levels of NONRATT016113, NONRATT018298 and NONRATT018300 were elevated in the 2 h group compared with those in the control group; however, there was no statistically significant difference between the 0.5 h and control groups. Furthermore, the expression of lncRNA NONRATT002188 was significantly downregulated in the 0.5 and 2 h groups when compared with the control group. The present study determined the expression pattern of lncRNAs and mRNAs in rat spinal cords during cardiac I/R. It was suggested that lncRNAs and mRNAs from spinal cords may be novel therapeutic targets for the treatment of I/R-induced cardiac injury.
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Affiliation(s)
- Qian Wang
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Zhi-Xiao Li
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Yu-Juan Li
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Zhi-Gang He
- Department of Emergency Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Ying-Le Chen
- Department of Anesthesiology, The First Affiliated Quanzhou Hospital of Fujian Medical University, Quanzhou, Fujian 362000, P.R. China
| | - Mao-Hui Feng
- Department of Oncology, Wuhan Peritoneal Cancer Clinical Medical Research Center, Zhongnan Hospital of Wuhan University, Hubei Key Laboratory of Tumor Biological Behaviors and Hubei Cancer Clinical Study Center, Wuhan, Hubei 430071, P.R. China
| | - Shun-Yuan Li
- Department of Anesthesiology, The First Affiliated Quanzhou Hospital of Fujian Medical University, Quanzhou, Fujian 362000, P.R. China
| | - Duo-Zhi Wu
- Department of Anesthesiology, People's Hospital of Hainan Province, Haikou, Hainan 570311, P.R. China
| | - Hong-Bing Xiang
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
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Cui L, Lu H, Lee YH. Challenges and emergent solutions for LC-MS/MS based untargeted metabolomics in diseases. MASS SPECTROMETRY REVIEWS 2018; 37:772-792. [PMID: 29486047 DOI: 10.1002/mas.21562] [Citation(s) in RCA: 192] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 02/02/2018] [Indexed: 05/03/2023]
Abstract
In the past decade, advances in liquid chromatography-mass spectrometry (LC-MS) have revolutionized untargeted metabolomics analyses. By mining metabolomes more deeply, researchers are now primed to uncover key metabolites and their associations with diseases. The employment of untargeted metabolomics has led to new biomarker discoveries and a better mechanistic understanding of diseases with applications in precision medicine. However, many major pertinent challenges remain. First, compound identification has been poor, and left an overwhelming number of unidentified peaks. Second, partial, incomplete metabolomes persist due to factors such as limitations in mass spectrometry data acquisition speeds, wide-range of metabolites concentrations, and cellular/tissue/temporal-specific expression changes that confound our understanding of metabolite perturbations. Third, to contextualize metabolites in pathways and biology is difficult because many metabolites partake in multiple pathways, have yet to be described species specificity, or possess unannotated or more-complex functions that are not easily characterized through metabolomics analyses. From a translational perspective, information related to novel metabolite biomarkers, metabolic pathways, and drug targets might be sparser than they should be. Thankfully, significant progress has been made and novel solutions are emerging, achieved through sustained academic and industrial community efforts in terms of hardware, computational, and experimental approaches. Given the rapidly growing utility of metabolomics, this review will offer new perspectives, increase awareness of the major challenges in LC-MS metabolomics that will significantly benefit the metabolomics community and also the broader the biomedical community metabolomics aspire to serve.
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Affiliation(s)
- Liang Cui
- Translational 'Omics and Biomarkers Group, KK Research Centre, KK Women's and Children's Hospital, Singapore, Singapore
- Infectious Diseases-Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Singapore, Singapore
| | - Haitao Lu
- Shanghai Center for Systems Biomedicine, Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China
| | - Yie Hou Lee
- Translational 'Omics and Biomarkers Group, KK Research Centre, KK Women's and Children's Hospital, Singapore, Singapore
- OBGYN-Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore
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Mohrman AE, Farrag M, Grimm RK, Leipzig ND. Evaluation of in situ gelling chitosan-PEG copolymer for use in the spinal cord. J Biomater Appl 2018; 33:435-446. [PMID: 30111249 DOI: 10.1177/0885328218792824] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The goal of the present work was to characterize a hydrogel material for localized spinal cord delivery. To address spinal cord injuries, an injectable in situ gelling system was tested utilizing a simple, effective, and rapid cross-linking method via Michael addition. Thiolated chitosan material and maleimide-terminated polyethylene glycol material were mixed to form a hydrogel and evaluated in vitro and in vivo. Three distinct thiolated chitosan precursors were made by varying reaction conditions; a modification of chitosan with Traut's reagent (2-iminothiolane) displayed the most attractive hydrogel properties once mixed with polyethylene glycol. The final hydrogel chosen for animal testing had a swelling ratio (Q) of 57.5 ± 3.4 and elastic modulus of 378 ± 72 Pa. After confirming low cellular toxicity in vitro, the hydrogel was injected into the spinal cord of rats for 1 and 2 weeks to assess host reaction. The rats displayed no overt functional deficits due to injection following initial surgical recovery and throughout the 2-week period after for both the saline-injected sham group and hydrogel-injected group. The saline and hydrogel-injected animals both showed a similar response from ED1+ microglia and GFAP overexpression. No significant differences were found between saline-injected and hydrogel-injected groups for any of the measures studied, but there was a trend toward decreased affected area size from 1 to 2 weeks in both groups. Access to the central nervous system is limited by the blood-brain barrier for noninvasive therapies; further development of the current system for localized drug or cellular delivery has the potential to shape treatments of spinal cord injury.
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Affiliation(s)
- Ashley E Mohrman
- Department of Chemical and Biomolecular Engineering, University of Akron, Akron, OH, USA
| | - Mahmoud Farrag
- Department of Chemical and Biomolecular Engineering, University of Akron, Akron, OH, USA
| | - Rachel K Grimm
- Department of Chemical and Biomolecular Engineering, University of Akron, Akron, OH, USA
| | - Nic D Leipzig
- Department of Chemical and Biomolecular Engineering, University of Akron, Akron, OH, USA
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