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Hong J, Chang A, Liu Y, Wang J, Fehlings MG. Incomplete Spinal Cord Injury Reverses the Level-Dependence of Spinal Cord Injury Immune Deficiency Syndrome. Int J Mol Sci 2019; 20:ijms20153762. [PMID: 31374824 PMCID: PMC6695842 DOI: 10.3390/ijms20153762] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 07/29/2019] [Accepted: 07/31/2019] [Indexed: 11/30/2022] Open
Abstract
Spinal cord injury (SCI) is associated with an increased susceptibility to infections, such as pneumonia, which is the leading cause of death in these patients. This phenomenon is referred to as SCI immune deficiency syndrome (SCI-IDS), and has been shown to be more prevalent after high-level transection in preclinical SCI models. Despite the high prevalence of contusion SCIs, the effects of this etiology have not been studied in the context of SCI-IDS. Compared to transection SCIs, which involve a complete loss of supraspinal input and lead to the disinhibition of spinally-generated activity, contusion SCIs may cause significant local deafferentation, but only a partial disruption of sympathetic tone below the level of injury. In this work, we investigate the effects of thoracic (T6-7) and cervical (C6-7) moderate–severe contusion SCIs on the spleen by characterizing splenic norepinephrine (NE) and cortisol (CORT), caspase-3, and multiple inflammation markers at 3- and 7-days post-SCI. In contrary to the literature, we observe an increase in splenic NE and CORT that correspond to an increase in caspase-3 after thoracic SCI relative to cervical SCI. Further, we found differences in expression of leptin, eotaxin, IP-10, and IL-18 that implicate alterations in splenocyte recruitment and function. These results suggest that incomplete SCI drastically alters the level-dependence of SCI-IDS.
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Affiliation(s)
- James Hong
- Institute for Medical Science, University of Toronto, Toronto, ON M5S 1A8, Canada
- Krembil Research Institute, Toronto Western Hospital, Toronto, ON M5T 0S8, Canada
| | - Alex Chang
- Krembil Research Institute, Toronto Western Hospital, Toronto, ON M5T 0S8, Canada
| | - Yang Liu
- Krembil Research Institute, Toronto Western Hospital, Toronto, ON M5T 0S8, Canada
| | - Jian Wang
- Krembil Research Institute, Toronto Western Hospital, Toronto, ON M5T 0S8, Canada
| | - Michael G Fehlings
- Krembil Research Institute, Toronto Western Hospital, Toronto, ON M5T 0S8, Canada.
- Division of Neurosurgery, Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada.
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Brakel K, Hook MA. SCI and depression: Does inflammation commandeer the brain? Exp Neurol 2019; 320:112977. [PMID: 31203113 DOI: 10.1016/j.expneurol.2019.112977] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 05/29/2019] [Accepted: 06/12/2019] [Indexed: 12/11/2022]
Abstract
The incidence of depression is almost twice as high in the spinally injured population compared to the general population. While this incidence has long been attributed to the psychological, economic, and social burdens that accompany spinal cord injury (SCI), data from animal studies indicate that the biology of SCI may play an important role in the development of depression. Inflammation has been shown to impact stress response in rodents and humans, and inflammatory cytokines have been associated with depression for decades. The inflammation inherent to SCI may disrupt necessary mechanisms of mental homeostasis, such as serotonin production, dopamine production, and the hypothalamic pituitary adrenal axis. Additionally, gut dysbiosis that occurs after SCI can exacerbate inflammation and may cause further mood and behavior changes. These mediators combined may significantly contribute to the rise in depression seen after SCI. Currently, there are no therapies specific to depression after SCI. Elucidation of the molecular pathways that contribute to SCI-specific depression is crucial for the understanding of this disease and its potential treatments.
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Affiliation(s)
- Kiralyn Brakel
- School of Medicine, Department of Neuroscience and Experimental Therapeutics, Texas A&M University, Medical Research and Education Building, Ste. 1005, 8447 Riverside Pkwy, Bryan, TX 77807, United States; Texas A&M Institute of Neuroscience, Texas A&M University, Interdisciplinary Life Sciences Building, Rm 3148, 3474 College Station, TAMU, TX, United States.
| | - Michelle A Hook
- School of Medicine, Department of Neuroscience and Experimental Therapeutics, Texas A&M University, Medical Research and Education Building, Ste. 1005, 8447 Riverside Pkwy, Bryan, TX 77807, United States; Texas A&M Institute of Neuroscience, Texas A&M University, Interdisciplinary Life Sciences Building, Rm 3148, 3474 College Station, TAMU, TX, United States
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Level-Specific Differences in Systemic Expression of Pro- and Anti-Inflammatory Cytokines and Chemokines after Spinal Cord Injury. Int J Mol Sci 2018; 19:ijms19082167. [PMID: 30044384 PMCID: PMC6122077 DOI: 10.3390/ijms19082167] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 07/23/2018] [Accepted: 07/23/2018] [Indexed: 11/17/2022] Open
Abstract
While over half of all spinal cord injuries (SCIs) occur in the cervical region, the majority of preclinical studies have focused on models of thoracic injury. However, these two levels are anatomically distinct—with the cervical region possessing a greater vascular supply, grey-white matter ratio and sympathetic outflow relative to the thoracic region. As such, there exists a significant knowledge gap in the secondary pathology at these levels following SCI. In this study, we characterized the systemic plasma markers of inflammation over time (1, 3, 7, 14, 56 days post-SCI) after moderate-severe, clip-compression cervical and thoracic SCI in a rat model. Using high-throughput ELISA panels, we observed a clear level-specific difference in plasma levels of VEGF, leptin, IP10, IL18, GCSF, and fractalkine. Overall, cervical SCI had reduced expression of both pro- and anti-inflammatory proteins relative to thoracic SCI, likely due to sympathetic dysregulation associated with higher level SCIs. However, contrary to the literature, we did not observe level-dependent splenic atrophy with our incomplete SCI model. This is the first study to compare the systemic plasma-level changes following cervical and thoracic SCI using level-matched and time-matched controls. The results of this study provide the first evidence in support of level-targeted intervention and also challenge the phenomenon of high SCI-induced splenic atrophy in incomplete SCI models.
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Aloe L, Bianchi P, De Bellis A, Soligo M, Rocco ML. Intranasal nerve growth factor bypasses the blood-brain barrier and affects spinal cord neurons in spinal cord injury. Neural Regen Res 2014; 9:1025-30. [PMID: 25206755 PMCID: PMC4146309 DOI: 10.4103/1673-5374.133161] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/20/2014] [Indexed: 01/02/2023] Open
Abstract
The purpose of this work was to investigate whether, by intranasal administration, the nerve growth factor bypasses the blood-brain barrier and turns over the spinal cord neurons and if such therapeutic approach could be of value in the treatment of spinal cord injury. Adult Sprague-Dawley rats with intact and injured spinal cord received daily intranasal nerve growth factor administration in both nostrils for 1 day or for 3 consecutive weeks. We found an increased content of nerve growth factor and enhanced expression of nerve growth factor receptor in the spinal cord 24 hours after a single intranasal administration of nerve growth factor in healthy rats, while daily treatment for 3 weeks in a model of spinal cord injury improved the deficits in locomotor behaviour and increased spinal content of both nerve growth factor and nerve growth factor receptors. These outcomes suggest that the intranasal nerve growth factor bypasses blood-brain barrier and affects spinal cord neurons in spinal cord injury. They also suggest exploiting the possible therapeutic role of intranasally delivered nerve growth factor for the neuroprotection of damaged spinal nerve cells.
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Affiliation(s)
- Luigi Aloe
- Cellular Biology and Neurobiology Institute, National Research Council (CNR), Rome, Italy
| | - Patrizia Bianchi
- Cellular Biology and Neurobiology Institute, National Research Council (CNR), Rome, Italy
| | | | - Marzia Soligo
- Intitute of Translational Pharmacology, National Research Council (CNR), Rome, Italy
| | - Maria Luisa Rocco
- Cellular Biology and Neurobiology Institute, National Research Council (CNR), Rome, Italy
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Doherty AL, Battaglino RA, Donovan J, Gagnon D, Lazzari AA, Garshick E, Zafonte R, Morse LR. Adiponectin is a candidate biomarker of lower extremity bone density in men with chronic spinal cord injury. J Bone Miner Res 2014; 29:251-9. [PMID: 23787489 PMCID: PMC3979427 DOI: 10.1002/jbmr.2020] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 06/05/2013] [Accepted: 06/11/2013] [Indexed: 02/01/2023]
Abstract
Adipose tissue is a major regulator of bone metabolism and in the general population obesity is associated with greater bone mineral density (BMD). However, bone-fat interactions are multifactorial, and may involve pathways that influence both bone formation and resorption with competing effects on the skeleton. One such pathway involves adipocyte production of adipokines that regulate bone metabolism. In this study we determined the association between BMD, walking status, and circulating adipokines (adiponectin and leptin) in 149 men with chronic spinal cord injury (SCI). Although adipokine levels did not vary significantly based on walking status, there was a significant inverse association between adiponectin and BMD in wheelchair users independent of body composition. We found no association between adiponectin and BMD in the walkers and no association between leptin and BMD in either group. These findings suggest that for subjects with chronic SCI, walking may mitigate the effect of adiponectin mediated bone loss. For wheelchair users, adipose-derived adiponectin may contribute to SCI-induced osteoporosis because the osteoprotective benefits of obesity appear to require mechanical loading during ambulation.
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Affiliation(s)
- Ashley L Doherty
- Spaulding-Harvard Spinal Cord Injury (SCI) Model System, Spaulding Rehabilitation Hospital, Boston, MA, USA
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Neuroendocrine and cardiac metabolic dysfunction and NLRP3 inflammasome activation in adipose tissue and pancreas following chronic spinal cord injury in the mouse. ASN Neuro 2013; 5:243-55. [PMID: 23924318 PMCID: PMC3789215 DOI: 10.1042/an20130021] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
CVD (cardiovascular disease) represents a leading cause of mortality in chronic SCI (spinal cord injury). Several component risk factors are observed in SCI; however, the underlying mechanisms that contribute to these risks have not been defined. Central and peripheral chronic inflammation is associated with metabolic dysfunction and CVD, including adipokine regulation of neuroendocrine and cardiac function and inflammatory processes initiated by the innate immune response. We use female C57 Bl/6 mice to examine neuroendocrine, cardiac, adipose and pancreatic signaling related to inflammation and metabolic dysfunction in response to experimentally induced chronic SCI. Using immuno-histochemical, -precipitation, and -blotting analysis, we show decreased POMC (proopiomelanocortin) and increased NPY (neuropeptide-Y) expression in the hypothalamic ARC (arcuate nucleus) and PVN (paraventricular nucleus), 1-month post-SCI. Long-form leptin receptor (Ob-Rb), JAK2 (Janus kinase)/STAT3 (signal transducer and activator of transcription 3)/p38 and RhoA/ROCK (Rho-associated kinase) signaling is significantly increased in the heart tissue post-SCI, and we observe the formation and activation of the NLRP3 (NOD-like receptor family, pyrin domain containing 3) inflammasome in VAT (visceral adipose tissue) and pancreas post-SCI. These data demonstrate neuroendocrine signaling peptide alterations, associated with central inflammation and metabolic dysfunction post-SCI, and provide evidence for the peripheral activation of signaling mechanisms involved in cardiac, VAT and pancreatic inflammation and metabolic dysfunction post-SCI. Further understanding of biological mechanisms contributing to SCI-related inflammatory processes and metabolic dysfunction associated with CVD pathology may help to direct therapeutic and rehabilitation countermeasures.
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