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Shad A, Rewell SSJ, Macowan M, Gandasasmita N, Wang J, Chen K, Marsland B, O'Brien TJ, Li J, Semple BD. Modelling lung infection with Klebsiella pneumoniae after murine traumatic brain injury. J Neuroinflammation 2024; 21:122. [PMID: 38720343 PMCID: PMC11080247 DOI: 10.1186/s12974-024-03093-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 04/05/2024] [Indexed: 05/12/2024] Open
Abstract
Pneumonia is a common comorbidity in patients with severe traumatic brain injury (TBI), and is associated with increased morbidity and mortality. In this study, we established a model of intratracheal Klebsiella pneumoniae administration in young adult male and female mice, at 4 days following an experimental TBI, to investigate how K. pneumoniae infection influences acute post-TBI outcomes. A dose-response curve determined the optimal dose of K. pneumoniae for inoculation (1 x 10^6 colony forming units), and administration at 4 days post-TBI resulted in transient body weight loss and sickness behaviors (hypoactivity and acute dyspnea). K. pneumoniae infection led to an increase in pro-inflammatory cytokines in serum and bronchoalveolar lavage fluid at 24 h post-infection, in both TBI and sham (uninjured) mice. By 7 days, when myeloperoxidase + neutrophil numbers had returned to baseline in all groups, lung histopathology was observed with an increase in airspace size in TBI + K. pneumoniae mice compared to TBI + vehicle mice. In the brain, increased neuroinflammatory gene expression was observed acutely in response to TBI, with an exacerbated increase in Ccl2 and Hmox1 in TBI + K. pneumoniae mice compared to either TBI or K. pneumoniae alone. However, the presence of neuroinflammatory immune cells in the injured brain, and the extent of damage to cortical and hippocampal brain tissue, was comparable between K. pneumoniae and vehicle-treated mice by 7 days. Examination of the fecal microbiome across a time course did not reveal any pronounced effects of either injury or K. pneumoniae on bacterial diversity or abundance. Together, these findings demonstrate that K. pneumoniae lung infection after TBI induces an acute and transient inflammatory response, primarily localized to the lungs with some systemic effects. However, this infection had minimal impact on secondary injury processes in the brain following TBI. Future studies are needed to evaluate the potential longer-term consequences of this dual-hit insult.
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Affiliation(s)
- Ali Shad
- Department of Neuroscience, The School of Translational Medicine, Monash University, Level 6 Alfred Centre, 99 Commercial Rd, Melbourne, VIC, 3004 VIC, Australia
- Alfred Health, Prahran, VIC, Australia
| | - Sarah S J Rewell
- Department of Neuroscience, The School of Translational Medicine, Monash University, Level 6 Alfred Centre, 99 Commercial Rd, Melbourne, VIC, 3004 VIC, Australia
- Alfred Health, Prahran, VIC, Australia
| | - Matthew Macowan
- Department of Immunology, The School of Translational Medicine, Monash University, Melbourne, VIC, Australia
- GIN Discovery Program, The School of Translational Medicine, Monash University, Melbourne, VIC, Australia
| | - Natasha Gandasasmita
- Department of Neuroscience, The School of Translational Medicine, Monash University, Level 6 Alfred Centre, 99 Commercial Rd, Melbourne, VIC, 3004 VIC, Australia
| | - Jiping Wang
- Department of Microbiology, Monash Biomedical Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Ke Chen
- Department of Microbiology, Monash Biomedical Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Ben Marsland
- Department of Immunology, The School of Translational Medicine, Monash University, Melbourne, VIC, Australia
- GIN Discovery Program, The School of Translational Medicine, Monash University, Melbourne, VIC, Australia
| | - Terence J O'Brien
- Department of Neuroscience, The School of Translational Medicine, Monash University, Level 6 Alfred Centre, 99 Commercial Rd, Melbourne, VIC, 3004 VIC, Australia
- Alfred Health, Prahran, VIC, Australia
- GIN Discovery Program, The School of Translational Medicine, Monash University, Melbourne, VIC, Australia
- Department of Medicine (Royal Melbourne Hospital), University of Melbourne, Parkville, VIC, Australia
| | - Jian Li
- Department of Microbiology, Monash Biomedical Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Bridgette D Semple
- Department of Neuroscience, The School of Translational Medicine, Monash University, Level 6 Alfred Centre, 99 Commercial Rd, Melbourne, VIC, 3004 VIC, Australia.
- Alfred Health, Prahran, VIC, Australia.
- Department of Medicine (Royal Melbourne Hospital), University of Melbourne, Parkville, VIC, Australia.
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Ritzel RM, Li Y, Jiao Y, Doran SJ, Khan N, Henry RJ, Brunner K, Loane DJ, Faden AI, Szeto GL, Wu J. Bi-directional neuro-immune dysfunction after chronic experimental brain injury. J Neuroinflammation 2024; 21:83. [PMID: 38581043 PMCID: PMC10996305 DOI: 10.1186/s12974-024-03082-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Accepted: 03/30/2024] [Indexed: 04/07/2024] Open
Abstract
BACKGROUND It is well established that traumatic brain injury (TBI) causes acute and chronic alterations in systemic immune function and that systemic immune changes contribute to posttraumatic neuroinflammation and neurodegeneration. However, how TBI affects bone marrow (BM) hematopoietic stem/progenitor cells chronically and to what extent such changes may negatively impact innate immunity and neurological function has not been examined. METHODS To further understand the role of BM cell derivatives on TBI outcome, we generated BM chimeric mice by transplanting BM from chronically injured or sham (i.e., 90 days post-surgery) congenic donor mice into otherwise healthy, age-matched, irradiated CD45.2 C57BL/6 (WT) hosts. Immune changes were evaluated by flow cytometry, multiplex ELISA, and NanoString technology. Moderate-to-severe TBI was induced by controlled cortical impact injury and neurological function was measured using a battery of behavioral tests. RESULTS TBI induced chronic alterations in the transcriptome of BM lineage-c-Kit+Sca1+ (LSK+) cells in C57BL/6 mice, including modified epigenetic and senescence pathways. After 8 weeks of reconstitution, peripheral myeloid cells from TBI→WT mice showed significantly higher oxidative stress levels and reduced phagocytic activity. At eight months after reconstitution, TBI→WT chimeric mice were leukopenic, with continued alterations in phagocytosis and oxidative stress responses, as well as persistent neurological deficits. Gene expression analysis revealed BM-driven changes in neuroinflammation and neuropathology after 8 weeks and 8 months of reconstitution, respectively. Chimeric mice subjected to TBI at 8 weeks and 8 months post-reconstitution showed that longer reconstitution periods (i.e., time post-injury) were associated with increased microgliosis and leukocyte infiltration. Pre-treatment with a senolytic agent, ABT-263, significantly improved behavioral performance of aged C57BL/6 mice at baseline, although it did not attenuate neuroinflammation in the acutely injured brain. CONCLUSIONS TBI causes chronic activation and progressive dysfunction of the BM stem/progenitor cell pool, which drives long-term deficits in hematopoiesis, innate immunity, and neurological function, as well as altered sensitivity to subsequent brain injury.
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Affiliation(s)
- Rodney M Ritzel
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA.
| | - Yun Li
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Yun Jiao
- Department of Chemical, Biochemical and Environmental Engineering, University of Maryland, Baltimore County, Baltimore, MD, 21250, USA
| | - Sarah J Doran
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Niaz Khan
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Rebecca J Henry
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Kavitha Brunner
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - David J Loane
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Alan I Faden
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Gregory L Szeto
- Department of Chemical, Biochemical and Environmental Engineering, University of Maryland, Baltimore County, Baltimore, MD, 21250, USA
| | - Junfang Wu
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
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Gandasasmita N, Li J, Loane DJ, Semple BD. Experimental Models of Hospital-Acquired Infections After Traumatic Brain Injury: Challenges and Opportunities. J Neurotrauma 2024; 41:752-770. [PMID: 37885226 DOI: 10.1089/neu.2023.0453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2023] Open
Abstract
Patients hospitalized after a moderate or severe traumatic brain injury (TBI) are at increased risk of nosocomial infections, including bacterial pneumonia and other upper respiratory tract infections. Infections represent a secondary immune challenge for vulnerable TBI patients that can lead to increased morbidity and poorer long-term prognosis. This review first describes the clinical significance of infections after TBI, delving into the known mechanisms by which a TBI can alter systemic immunological responses towards an immunosuppressive state, leading to promotion of increased vulnerability to infections. Pulmonary dysfunction resulting from respiratory tract infections is considered in the context of neurotrauma, including the bidirectional relationship between the brain and lungs. Turning to pre-clinical modeling, current laboratory approaches to study experimental TBI and lung infections are reviewed, to highlight findings from the limited key studies to date that have incorporated both insults. Then, practical decisions for the experimental design of animal studies of post-injury infections are discussed. Variables associated with the host animal, the infectious agent (e.g., species, strain, dose, and administration route), as well as the timing of the infection relative to the injury model are important considerations for model development. Together, the purpose of this review is to highlight the significant clinical need for increased pre-clinical research into the two-hit insult of a hospital-acquired infection after TBI to encourage further scientific enquiry in the field.
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Affiliation(s)
| | - Jian Li
- Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
- Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| | - David J Loane
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Bridgette D Semple
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
- Department of Neurology, Alfred Health, Prahran, Victoria, Australia
- Department of Medicine (Royal Melbourne Hospital), The University of Melbourne, Parkville, Victoria, Australia
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Baker TL, Wright DK, Uboldi AD, Tonkin CJ, Vo A, Wilson T, McDonald SJ, Mychasiuk R, Semple BD, Sun M, Shultz SR. A pre-existing Toxoplasma gondii infection exacerbates the pathophysiological response and extent of brain damage after traumatic brain injury in mice. J Neuroinflammation 2024; 21:14. [PMID: 38195485 PMCID: PMC10775436 DOI: 10.1186/s12974-024-03014-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Accepted: 01/04/2024] [Indexed: 01/11/2024] Open
Abstract
Traumatic brain injury (TBI) is a key contributor to global morbidity that lacks effective treatments. Microbial infections are common in TBI patients, and their presence could modify the physiological response to TBI. It is estimated that one-third of the human population is incurably infected with the feline-borne parasite, Toxoplasma gondii, which can invade the central nervous system and result in chronic low-grade neuroinflammation, oxidative stress, and excitotoxicity-all of which are also important pathophysiological processes in TBI. Considering the large number of TBI patients that have a pre-existing T. gondii infection prior to injury, and the potential mechanistic synergies between the conditions, this study investigated how a pre-existing T. gondii infection modified TBI outcomes across acute, sub-acute and chronic recovery in male and female mice. Gene expression analysis of brain tissue found that neuroinflammation and immune cell markers were amplified in the combined T. gondii + TBI setting in both males and females as early as 2-h post-injury. Glutamatergic, neurotoxic, and oxidative stress markers were altered in a sex-specific manner in T. gondii + TBI mice. Structural MRI found that male, but not female, T. gondii + TBI mice had a significantly larger lesion size compared to their uninfected counterparts at 18-weeks post-injury. Similarly, diffusion MRI revealed that T. gondii + TBI mice had exacerbated white matter tract abnormalities, particularly in male mice. These novel findings indicate that a pre-existing T. gondii infection affects the pathophysiological aftermath of TBI in a sex-dependent manner, and may be an important modifier to consider in the care and prognostication of TBI patients.
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Affiliation(s)
- Tamara L Baker
- Department of Neuroscience, Central Clinical School, Monash University, 6th Floor, The Alfred Centre, 99 Commercial Road, Melbourne, VIC, 3004, Australia
| | - David K Wright
- Department of Neuroscience, Central Clinical School, Monash University, 6th Floor, The Alfred Centre, 99 Commercial Road, Melbourne, VIC, 3004, Australia
| | - Alessandro D Uboldi
- Division of Infectious Disease and Immune Defense, , The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Christopher J Tonkin
- Division of Infectious Disease and Immune Defense, , The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Anh Vo
- Monash Health Translation Precinct, Monash University, Melbourne, VIC, Australia
| | - Trevor Wilson
- Monash Health Translation Precinct, Monash University, Melbourne, VIC, Australia
| | - Stuart J McDonald
- Department of Neuroscience, Central Clinical School, Monash University, 6th Floor, The Alfred Centre, 99 Commercial Road, Melbourne, VIC, 3004, Australia
| | - Richelle Mychasiuk
- Department of Neuroscience, Central Clinical School, Monash University, 6th Floor, The Alfred Centre, 99 Commercial Road, Melbourne, VIC, 3004, Australia
| | - Bridgette D Semple
- Department of Neuroscience, Central Clinical School, Monash University, 6th Floor, The Alfred Centre, 99 Commercial Road, Melbourne, VIC, 3004, Australia
| | - Mujun Sun
- Department of Neuroscience, Central Clinical School, Monash University, 6th Floor, The Alfred Centre, 99 Commercial Road, Melbourne, VIC, 3004, Australia
| | - Sandy R Shultz
- Department of Neuroscience, Central Clinical School, Monash University, 6th Floor, The Alfred Centre, 99 Commercial Road, Melbourne, VIC, 3004, Australia.
- Health Sciences, Vancouver Island University, Nanaimo, BC, Canada.
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Ritzel RM, Li Y, Jiao Y, Doran SJ, Khan N, Henry RJ, Brunner K, Loane DJ, Faden AI, Szeto GL, Wu J. The brain-bone marrow axis and its implications for chronic traumatic brain injury. Res Sq 2023:rs.3.rs-3356007. [PMID: 37790560 PMCID: PMC10543403 DOI: 10.21203/rs.3.rs-3356007/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Traumatic brain injury (TBI) causes acute and chronic alterations in systemic immune function which contribute to posttraumatic neuroinflammation and neurodegeneration. However, how TBI affects bone marrow (BM) hematopoietic stem/progenitor cells chronically and to what extent such changes may negatively impact innate immunity and neurological function has not been examined. To further understand the role of BM cell derivatives on TBI outcome, we generated BM chimeric mice by transplanting BM from chronically injured or sham congenic donor mice into otherwise healthy, age-matched, irradiated hosts. After 8 weeks of reconstitution, peripheral myeloid cells from TBI→WT mice showed significantly higher oxidative stress levels and reduced phagocytic activity. At eight months after reconstitution, TBI→WT chimeric mice were leukopenic, with continued alterations in phagocytosis and oxidative stress responses, as well as persistent neurological deficits. Gene expression analysis revealed BM-driven changes in neuroinflammation and neuropathology after 8 weeks and 8 months of reconstitution, respectively. Chimeric mice subjected to TBI showed that longer reconstitution periods were associated with increased microgliosis and leukocyte infiltration. Thus, TBI causes chronic activation and progressive dysfunction of the BM stem/progenitor cell pool, which drives long-term deficits in innate immunity and neurological function, as well as altered sensitivity to subsequent brain injury.
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Affiliation(s)
- Rodney M. Ritzel
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, Texas, USA
| | - Yun Li
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Yun Jiao
- Department of Chemical, Biochemical and Environmental Engineering, University of Maryland, Baltimore County, Maryland, USA
| | - Sarah J. Doran
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Niaz Khan
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Rebecca J. Henry
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Kavitha Brunner
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - David J. Loane
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Alan I. Faden
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Gregory L. Szeto
- Department of Chemical, Biochemical and Environmental Engineering, University of Maryland, Baltimore County, Maryland, USA
| | - Junfang Wu
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
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Caceres E, Olivella JC, Yanez M, Viñan E, Estupiñan L, Boada N, Martin-Loeches I, Reyes LF. Risk factors and outcomes of lower respiratory tract infections after traumatic brain injury: a retrospective observational study. Front Med (Lausanne) 2023; 10:1077371. [PMID: 37138738 PMCID: PMC10150376 DOI: 10.3389/fmed.2023.1077371] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 03/22/2023] [Indexed: 05/05/2023] Open
Abstract
Background Traumatic brain injury (TBI) is a public health problem with a high burden in terms of disability and death. Infections are a common complication, with respiratory infections being the most frequent. Most available studies have addressed the impact of ventilator-associated pneumonia (VAP) after TBI; therefore, we aim to characterize the hospital impact of a broader entity, lower respiratory tract infections (LRTIs). Methods This observational, retrospective, single-center cohort study describes the clinical features and risk factors associated with LRTIs in patients with TBI admitted to an intensive care unit (ICU). We used bivariate and multivariate logistic regressions to identify the risk factors associated with developing LRTI and determine its impact on hospital mortality. Results We included 291 patients, of whom 77% (225/291) were men. The median (IQR) age was 38 years (28-52 years). The most common cause of injury was road traffic accidents 72% (210/291), followed by falls 18% (52/291) and assault at 3% (9/291). The median (IQR) Glasgow Coma Scale (GCS) score on admission was 9 (6-14), and 47% (136/291) were classified as severe TBI, 13% (37/291) as moderate TBI, and 40% (114/291) as mild TBI. The median (IQR) injury severity score (ISS) was 24 (16-30). Nearly 48% (141/291) of patients presented at least one infection during hospitalization, and from those, 77% (109/141) were classified as LRTIs, which included tracheitis 55% (61/109), ventilator-associated pneumonia (VAP) 34% (37/109), and hospital-acquired pneumoniae (HAP) 19% (21/109). After multivariable analysis, the following variables were significantly associated with LRTIs: age (OR 1.1, 95% CI 1.01-1.2), severe TBI (OR 2.7, 95% CI 1.1-6.9), AIS thorax (OR 1.4, 95 CI 1.1-1.8), and mechanical ventilation on admission (OR 3.7, 95% CI 1.1-13.5). At the same time, hospital mortality did not differ between groups (LRTI 18.6% vs. No LRTI 20.1%, p = 0.7), and ICU and hospital length of stay (LOS) were longer in the LRTI group (median [IQR] 12 [9-17] vs. 5 [3-9], p < 0.01) and (median [IQR] 21 [13-33] vs. 10 [5-18], p = 0.01), respectively. Time on the ventilator was longer for those with LRTIs. Conclusion The most common site/location of infection in patients with TBI admitted to ICU is respiratory. Age, severe TBI, thoracic trauma, and mechanical ventilation were identified as potential risk factors. LRTI was associated with prolonged ICU, hospital stay, and more days on a ventilator, but not with mortality.
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Affiliation(s)
- Eder Caceres
- Unisabana Center for Translational Science, Universidad de La Sabana, Chía, Colombia
- Neurocritical Care Division, Critical Care Department, Clínica Universidad de La Sabana, Chía, Colombia
| | - Juan C. Olivella
- Unisabana Center for Translational Science, Universidad de La Sabana, Chía, Colombia
| | - Miguel Yanez
- Unisabana Center for Translational Science, Universidad de La Sabana, Chía, Colombia
| | - Emilio Viñan
- Unisabana Center for Translational Science, Universidad de La Sabana, Chía, Colombia
| | - Laura Estupiñan
- Unisabana Center for Translational Science, Universidad de La Sabana, Chía, Colombia
| | - Natalia Boada
- Unisabana Center for Translational Science, Universidad de La Sabana, Chía, Colombia
| | - Ignacio Martin-Loeches
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain
- Multidisciplinary Intensive Care Research Organization (MICRO), Department of Intensive Care Medicine, St. James's University Hospital, Dublin, Ireland
- Critical Care Department, Trinity Centre for Health Sciences, Dublin, Ireland
- Hospital Clínic, IDIBAPS, Universidad de Barcelona, Barcelona, Spain
| | - Luis Felipe Reyes
- Unisabana Center for Translational Science, Universidad de La Sabana, Chía, Colombia
- Facultad de Medicina, Universidad de La Sabana, Chía, Colombia
- Pandemic Science Institute, University of Oxford, Oxford, United Kingdom
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Wang Z, Guo K, Liu Y, Huang C, Wu M. Dynamic impact of virome on colitis and colorectal cancer: Immunity, inflammation, prevention and treatment. Semin Cancer Biol 2022; 86:943-954. [PMID: 34656791 PMCID: PMC9008076 DOI: 10.1016/j.semcancer.2021.10.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 09/20/2021] [Accepted: 10/08/2021] [Indexed: 02/05/2023]
Abstract
The gut microbiome includes a series of microorganism genomes, such as bacteriome, virome, mycobiome, etc. The gut microbiota is critically involved in intestine immunity and diseases, including inflammatory bowel disease (IBD) and colorectal cancer (CRC); however, the underlying mechanism remains incompletely understood. Clarifying the relationship between microbiota and inflammation may profoundly improve our understanding of etiology, disease progression, patient management, and the development of prevention and treatment. In this review, we discuss the latest studies of the influence of enteric viruses (i.e., commensal viruses, pathogenic viruses, and bacteriophages) in the initiation, progression, and complication of colitis and colorectal cancer, and their potential for novel preventative approaches and therapeutic application. We explore the interplay between gut viruses and host immune systems for its effects on the severity of inflammatory diseases and cancer, including both direct and indirect interactions between enteric viruses with other microbes and microbial products. Furthermore, the underlying mechanisms of the virome's roles in gut inflammatory response have been explained to infer potential therapeutic targets with examples in specific clinical trials. Given that very limited literature has thus far discussed these various topics with the gut virome, we believe these extensive analyses may provide insight into the understanding of the molecular pathogenesis of IBD and CRC, which could help add the design of improved therapies for these important human diseases.
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Affiliation(s)
- Zhihan Wang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, and West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu 610041, China; Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, 58202, USA
| | - Kai Guo
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Yingying Liu
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, 58202, USA
| | - Canhua Huang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, and West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu 610041, China.
| | - Min Wu
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, 58202, USA.
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Yang W, Yuan Q, Li Z, Du Z, Wu G, Yu J, Hu J. Translocation and Dissemination of Gut Bacteria after Severe Traumatic Brain Injury. Microorganisms 2022; 10. [PMID: 36296362 DOI: 10.3390/microorganisms10102082] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 10/10/2022] [Accepted: 10/18/2022] [Indexed: 12/04/2022] Open
Abstract
Enterobacteriaceae are often found in the lungs of patients with severe Traumatic Brain Injury (sTBI). However, it is unknown whether these bacteria come from the gut microbiota. To investigate this hypothesis, the mice model of sTBI was used in this study. After sTBI, Chao1 and Simpson index peaking at 7 d in the lungs (p < 0.05). The relative abundance of Acinetobacter in the lungs increased to 16.26% at 7 d after sTBI. The chao1 index of gut microbiota increased after sTBI and peaked at 7 d (p < 0.05). Three hours after sTBI, the conditional pathogens such as Lachnoclostridium, Acinetobacter, Bacteroides and Streptococcus grew significantly. At 7 d and 14 d, the histology scores in the sTBI group were significantly higher than the control group (p < 0.05). The myeloperoxidase (MPO) activity increased at all-time points after sTBI and peaked at 7 d (p < 0.05). The LBP and sCD14 peaking 7 d after sTBI (p < 0.05). The Zonulin increased significantly at 3 d after sTBI and maintained the high level (p < 0.05). SourceTracker identified that the lung tissue microbiota reflects 49.69% gut source at 7 d after sTBI. In the small intestine, sTBI induced gastrointestinal dysfunction with increased apoptosis and decreasing antimicrobial peptides. There was a negative correlation between gut conditional pathogens and the expression level of antimicrobial peptides in Paneth cells. Our data indicate that gut bacteria translocated to the lungs after sTBI, and Paneth cells may regulate gut microbiota stability and translocation.
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Zhang X, Zhou H, Shen H, Wang M. Pulmonary infection in traumatic brain injury patients undergoing tracheostomy: predicators and nursing care. BMC Pulm Med 2022; 22:130. [PMID: 35392885 DOI: 10.1186/s12890-022-01928-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 03/29/2022] [Indexed: 11/30/2022] Open
Abstract
Background Pulmonary infection is common yet serious complication in patients with severe traumatic brain injury (STBI). We aimed to evaluate the predicators of pulmonary infection in STBI patients undergoing tracheostomy, to provide evidence for the clinical nursing care of STBI patients. Methods This study was a retrospective cohort design. STBI patients undergoing tracheostomy treatment from January 1, 2019 to August 31, 2021 in our hospital were included. The characteristics of pulmonary infection and no pulmonary infection patients were analyzed. Results A total 216 STBI patients undergoing tracheostomy were included, the incidence of pulmonary infection was 26.85%. Diabetes (r = 0.782), hypoproteinemia (r = 0.804), duration of coma(r = 0.672), duration of mechanical ventilation(r = 0.724) and length of hospital stay (r = 0.655), length of hospital stay post tracheostomy (r = 0.554), mortality (r = 0.598) were all correlated with pulmonary infection (all p < 0.05). Klebsiella pneumoniae (33.87%) and Staphylococcus aureus (29.03%) were the most commonly seen pathogens in the pulmonary infection of TBI patients. Logistic regression analyses indicated that diabetes (OR 2.232, 95% CI 1.215–3.904), hypoproteinemia with plasma total protein < 60 g/L (OR 1.922, 95% CI 1.083–3.031), duration of coma ≥ 22 h (OR 2.864, 95% CI 1.344–5.012), duration of mechanical ventilation ≥ 5 days (OR 3.602, 95% CI 1.297–5.626), length of hospital stay ≥ 21 days (OR 2.048, 95% CI 1.022–3.859) were the risk factors of pulmonary infection in TBI patients undergoing tracheostomy (all p < 0.05). Conclusions Further investigations on the early preventions and treatments targeted on those risk factors are needed to reduce the pulmonary infection in clinical practice.
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Abstract
Central nervous system trauma is a common cause of morbidity and mortality. Additionally, these injuries frequently occur in younger individuals, leading to lifetime expenses for patients and caregivers and the loss of opportunity for society. Despite this prevalence and multiple attempts to design a neuroprotectant, clinical trials for a pharmacological agent for the treatment of traumatic brain injury (TBI) or spinal cord injury (SCI) have provided disappointing results. Improvements in outcome from these disease processes in the past decades have been largely due to improvements in supportive care. Among the many challenges facing patients and caregivers following neurotrauma, posttraumatic nosocomial infection is a significant and potentially reversible risk factor. Multiple animal and clinical studies have provided evidence of posttraumatic systemic immune suppression, and injuries involving the CNS may be even more prone, leading to a higher risk for in-hospital infections following neurotrauma. Patients who have experienced neurotrauma with nosocomial infection have poorer recovery and higher risks of long-term morbidity and in-hospital mortality than patients without infection. As such, the etiology and reversal of postneurotrauma immune suppression is an important topic. There are multiple possible etiologies for these posttraumatic changes including the release of damage-associated molecular patterns, the activation of immunosuppressive myeloid-derived suppressor cells, and sympathetic nervous system activation. Postinjury systemic immunosuppression, particularly following neurotrauma, provides a challenge for clinicians but also an opportunity for improvement in outcome. In this review, the authors sought to outline the evidence of postinjury systemic immune suppression in both animal models and clinical research of TBI, TBI polytrauma, and SCI.
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Affiliation(s)
- Eric A Sribnick
- 1Department of Neurosurgery, Nationwide Children's Hospital, The Ohio State University College of Medicine, Columbus.,2The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus
| | - Phillip G Popovich
- 3Department of Neuroscience.,4Center for Brain and Spinal Cord Repair.,5Belford Center for Spinal Cord Injury, and.,6Medical Scientist Training Program, The Ohio State University, College of Medicine, Columbus; and
| | - Mark W Hall
- 2The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus.,7Division of Critical Care Medicine, Department of Pediatrics, Nationwide Children's Hospital, The Ohio State University College of Medicine, Columbus, Ohio
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11
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Sribnick EA, Warner T, Hall MW. Traumatic brain injury and hemorrhage in a juvenile rat model of polytrauma leads to immunosuppression and splenic alterations. J Neuroimmunol 2021; 361:577723. [PMID: 34619426 DOI: 10.1016/j.jneuroim.2021.577723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 09/18/2021] [Indexed: 11/20/2022]
Abstract
BACKGROUND Traumatic brain injury (TBI) is a common cause of morbidity and mortality. We have previously shown that TBI with a concurrent extra-cranial injury reliably leads to post-injury suppression of the innate immune system, but the impact of this injury on the adaptive immune system is unknown. We present data showing that combined injury reduced immune response as assayed in both blood and spleen samples and that these changes parallel apoptosis in the spleen. To assess the clinical relevance of these changes, we examined lungs for spontaneous bacterial colonization. METHODS For these studies, prepubescent (28 day old) rats were injured using a controlled cortical impact model and then 25% blood volume removal by arteriotomy, and injured animals were compared with sham injured animals. Blood and spleen samples at post-injury day 1 were incubated with or without immunostimulant and examined for IFN-γ production using an Eli-Spot assay. Spleen samples were also examined for apoptosis using Annexin V staining, and lungs were harvested and plated on blood agar to examine for spontaneous bacterial colonization. RESULTS Stimulations of whole blood and spleen samples with phorbol 12-myristate 13-acetate/ionomycin (PMA/I) at post-injury day 1 were associated with significant decreases in IFN-γ-positive cells/million in injured animals. Stimulation of whole blood with either PMA/I or pokeweed mitogen led to reduced tumor necrosis factor alpha production. Spleen from injured animals showed a marked increase in apoptosis. Lung samples showed a 300% increase in colonies per plate in injured animals. CONCLUSIONS These data suggest that the combined injury can lead to adaptive immunosuppression, and our findings further suggest a potential role for the spleen in altering leukocyte function following injury.
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12
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Lassarén P, Lindblad C, Frostell A, Carpenter KLH, Guilfoyle MR, Hutchinson PJA, Helmy A, Thelin EP. Systemic inflammation alters the neuroinflammatory response: a prospective clinical trial in traumatic brain injury. J Neuroinflammation 2021; 18:221. [PMID: 34563211 PMCID: PMC8464153 DOI: 10.1186/s12974-021-02264-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 08/30/2021] [Indexed: 01/31/2023] Open
Abstract
Background Neuroinflammation following traumatic brain injury (TBI) has been shown to be associated with secondary injury development; however, how systemic inflammatory mediators affect this is not fully understood. The aim of this study was to see how systemic inflammation affects markers of neuroinflammation, if this inflammatory response had a temporal correlation between compartments and how different compartments differ in cytokine composition. Methods TBI patients recruited to a previous randomised controlled trial studying the effects of the drug anakinra (Kineret®), a human recombinant interleukin-1 receptor antagonist (rhIL1ra), were used (n = 10 treatment arm, n = 10 control arm). Cytokine concentrations were measured in arterial and jugular venous samples twice a day, as well as in microdialysis-extracted brain extracellular fluid (ECF) following pooling every 6 h. C-reactive protein level (CRP), white blood cell count (WBC), temperature and confirmed systemic clinical infection were used as systemic markers of inflammation. Principal component analyses, linear mixed-effect models, cross-correlations and multiple factor analyses were used. Results Jugular and arterial blood held similar cytokine information content, but brain-ECF was markedly different. No clear arterial to jugular gradient could be seen. No substantial delayed temporal associations between blood and brain compartments were detected. The development of a systemic clinical infection resulted in a significant decrease of IL1-ra, G-CSF, PDGF-ABBB, MIP-1b and RANTES (p < 0.05, respectively) in brain-ECF, even if adjusting for injury severity and demographic factors, while an increase in several cytokines could be seen in arterial blood. Conclusions Systemic inflammation, and infection in particular, alters cytokine levels with different patterns seen in brain and in blood. Cerebral inflammatory monitoring provides independent information from arterial and jugular samples, which both demonstrate similar information content. These findings could present potential new treatment options in severe TBI patients, but novel prospective trials are warranted to confirm these associations. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s12974-021-02264-2.
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Affiliation(s)
- Philipp Lassarén
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Caroline Lindblad
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Arvid Frostell
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Neurosurgery, Karolinska University Hospital, Stockholm, Sweden
| | - Keri L H Carpenter
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.,Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Mathew R Guilfoyle
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Peter J A Hutchinson
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.,Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Adel Helmy
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Eric Peter Thelin
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden. .,Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK. .,Department of Neurology, Karolinska University Hospital, Stockholm, Sweden.
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13
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Mastorakos P, Russo MV, Zhou T, Johnson K, McGavern DB. Antimicrobial immunity impedes CNS vascular repair following brain injury. Nat Immunol 2021; 22:1280-1293. [PMID: 34556874 PMCID: PMC8488012 DOI: 10.1038/s41590-021-01012-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 07/27/2021] [Indexed: 12/14/2022]
Abstract
Traumatic brain injury (TBI) and cerebrovascular injury are leading causes of disability and mortality worldwide. Systemic infections often accompany these disorders and can worsen outcomes. Recovery after brain injury depends on innate immunity, but the effect of infections on this process is not well understood. Here, we demonstrate that systemically introduced microorganisms and microbial products interfered with meningeal vascular repair after TBI in a type I interferon (IFN-I)-dependent manner, with sequential infections promoting chronic disrepair. Mechanistically, we discovered that MDA5-dependent detection of an arenavirus encountered after TBI disrupted pro-angiogenic myeloid cell programming via induction of IFN-I signaling. Systemic viral infection similarly blocked restorative angiogenesis in the brain parenchyma after intracranial hemorrhage, leading to chronic IFN-I signaling, blood-brain barrier leakage and a failure to restore cognitive-motor function. Our findings reveal a common immunological mechanism by which systemic infections deviate reparative programming after central nervous system injury and offer a new therapeutic target to improve recovery.
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Affiliation(s)
- Panagiotis Mastorakos
- Viral Immunology & Intravital Imaging Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.,Department of Surgical Neurology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Matthew V Russo
- Viral Immunology & Intravital Imaging Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Tianzan Zhou
- Viral Immunology & Intravital Imaging Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Kory Johnson
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Dorian B McGavern
- Viral Immunology & Intravital Imaging Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
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14
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Levochkina M, McQuillan L, Awan N, Barton D, Maczuzak J, Bianchine C, Trombley S, Kotes E, Wiener J, Wagner A, Calcagno J, Maza A, Nierstedt R, Ferimer S, Wagner A. Neutrophil-to-Lymphocyte Ratios and Infections after Traumatic Brain Injury: Associations with Hospital Resource Utilization and Long-Term Outcome. J Clin Med 2021; 10:jcm10194365. [PMID: 34640381 PMCID: PMC8509449 DOI: 10.3390/jcm10194365] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/20/2021] [Accepted: 09/24/2021] [Indexed: 12/30/2022] Open
Abstract
Traumatic brain injury (TBI) induces immune dysfunction that can be captured clinically by an increase in the neutrophil-to-lymphocyte ratio (NLR). However, few studies have characterized the temporal dynamics of NLR post-TBI and its relationship with hospital-acquired infections (HAI), resource utilization, or outcome. We assessed NLR and HAI over the first 21 days post-injury in adults with moderate-to-severe TBI (n = 196) using group-based trajectory (TRAJ), changepoint, and mixed-effects multivariable regression analysis to characterize temporal dynamics. We identified two groups with unique NLR profiles: a high (n = 67) versus a low (n = 129) TRAJ group. High NLR TRAJ had higher rates (76.12% vs. 55.04%, p = 0.004) and earlier time to infection (p = 0.003). In changepoint-derived day 0–5 and 6–20 epochs, low lymphocyte TRAJ, early in recovery, resulted in more frequent HAIs (p = 0.042), subsequently increasing later NLR levels (p ≤ 0.0001). Both high NLR TRAJ and HAIs increased hospital length of stay (LOS) and days on ventilation (p ≤ 0.05 all), while only high NLR TRAJ significantly increased odds of unfavorable six-month outcome as measured by the Glasgow Outcome Scale (GOS) (p = 0.046) in multivariable regression. These findings provide insight into the temporal dynamics and interrelatedness of immune factors which collectively impact susceptibility to infection and greater hospital resource utilization, as well as influence recovery.
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Affiliation(s)
- Marina Levochkina
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15213, USA; (M.L.); (L.M.); (N.A.); (J.M.); (C.B.); (S.T.); (E.K.); (J.W.); (A.W.); (J.C.); (A.M.); (R.N.)
- Department of Infectious Diseases & Microbiology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Leah McQuillan
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15213, USA; (M.L.); (L.M.); (N.A.); (J.M.); (C.B.); (S.T.); (E.K.); (J.W.); (A.W.); (J.C.); (A.M.); (R.N.)
| | - Nabil Awan
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15213, USA; (M.L.); (L.M.); (N.A.); (J.M.); (C.B.); (S.T.); (E.K.); (J.W.); (A.W.); (J.C.); (A.M.); (R.N.)
- Department of Biostatistics, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - David Barton
- Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA;
| | - John Maczuzak
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15213, USA; (M.L.); (L.M.); (N.A.); (J.M.); (C.B.); (S.T.); (E.K.); (J.W.); (A.W.); (J.C.); (A.M.); (R.N.)
| | - Claudia Bianchine
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15213, USA; (M.L.); (L.M.); (N.A.); (J.M.); (C.B.); (S.T.); (E.K.); (J.W.); (A.W.); (J.C.); (A.M.); (R.N.)
| | - Shannon Trombley
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15213, USA; (M.L.); (L.M.); (N.A.); (J.M.); (C.B.); (S.T.); (E.K.); (J.W.); (A.W.); (J.C.); (A.M.); (R.N.)
| | - Emma Kotes
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15213, USA; (M.L.); (L.M.); (N.A.); (J.M.); (C.B.); (S.T.); (E.K.); (J.W.); (A.W.); (J.C.); (A.M.); (R.N.)
| | - Joshua Wiener
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15213, USA; (M.L.); (L.M.); (N.A.); (J.M.); (C.B.); (S.T.); (E.K.); (J.W.); (A.W.); (J.C.); (A.M.); (R.N.)
| | - Audrey Wagner
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15213, USA; (M.L.); (L.M.); (N.A.); (J.M.); (C.B.); (S.T.); (E.K.); (J.W.); (A.W.); (J.C.); (A.M.); (R.N.)
| | - Jason Calcagno
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15213, USA; (M.L.); (L.M.); (N.A.); (J.M.); (C.B.); (S.T.); (E.K.); (J.W.); (A.W.); (J.C.); (A.M.); (R.N.)
| | - Andrew Maza
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15213, USA; (M.L.); (L.M.); (N.A.); (J.M.); (C.B.); (S.T.); (E.K.); (J.W.); (A.W.); (J.C.); (A.M.); (R.N.)
| | - Ryan Nierstedt
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15213, USA; (M.L.); (L.M.); (N.A.); (J.M.); (C.B.); (S.T.); (E.K.); (J.W.); (A.W.); (J.C.); (A.M.); (R.N.)
| | - Stephanie Ferimer
- Division of Pediatric Rehabilitation Medicine, Department of Orthopaedics, West Virginia University, Morgantown, WV 26506, USA;
| | - Amy Wagner
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15213, USA; (M.L.); (L.M.); (N.A.); (J.M.); (C.B.); (S.T.); (E.K.); (J.W.); (A.W.); (J.C.); (A.M.); (R.N.)
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Clinical and Translational Science Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Correspondence:
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15
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Chao K, Wang D, Yang H, Ma N, Liu Q, Sun X, Sun R. Beneficial Effect of Immune-Enhanced Enteral Nutrition on Immune Function in Patients With Severe Neurological Diseases: A Single-Center Randomized Controlled Trial. Front Nutr 2021; 8:685422. [PMID: 34497819 PMCID: PMC8419436 DOI: 10.3389/fnut.2021.685422] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 07/26/2021] [Indexed: 12/15/2022] Open
Abstract
Background: Undernutrition is the main reason for the use of artificial nutrition in patients with severe neurological diseases. However, the clinical and immunological outcomes of enteral nutrition supplemented with immunomodulatory nutrients in these patients remain unclear. Methods: In this single-center, randomized controlled study, 57 patients with severe neurological diseases were randomly divided into the following two groups according to the type of enteral nutrition they would receive: immune-enhancing (IE) (n = 27) and non-IE (NIE) (n = 30). The IE and NIE groups received enteral nutrition supplemented with immunomodulatory nutrients and standard enteral nutrition, respectively. We compared the nutritional status and the state of cellular immunity between the patients of the two groups. Clinical and immunological variables were evaluated following nutritional treatment. Results: Feeding intolerance was lower in the IE than that in the NIE group (P = 0.04). However, there were no significant differences between the results of the two groups in terms of length of stay in the intensive care unit or hospital, extubation time, or body mass index (P > 0.05). The CD4+ T-lymphocyte count and CD4+/CD8+ ratio in the peripheral blood increased significantly in the IE group. The expression of CD28 activated cell surface markers was higher in the IE than in the NIE group. In addition, increased plasma interferon-γ levels were recorded in the IE group, whereas the levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-8, and IL-10 decreased. Conclusions: Immune-enhanced enteral nutrition could improve the immune status and feeding tolerance in patients with severe neurological diseases. Trial Registration:www.chictr.org.cn/index.aspx, identifier: ChiCTR-IPR-17013909.
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Affiliation(s)
- Ke Chao
- Extracardiac Care Unit, Henan Provincial Chest Hospital, Zhengzhou, China
| | - Dong Wang
- Intensive Care Unit, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Hongfu Yang
- Intensive Care Unit, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Ning Ma
- Intensive Care Unit, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Qilong Liu
- Intensive Care Unit, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Xiaoge Sun
- Intensive Care Unit, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Rongqing Sun
- Intensive Care Unit, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
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16
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Bietar B, Lehmann C, Stadnyk AW. Effects of CNS Injury-Induced Immunosuppression on Pulmonary Immunity. Life (Basel) 2021; 11:576. [PMID: 34207063 DOI: 10.3390/life11060576] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 06/14/2021] [Accepted: 06/15/2021] [Indexed: 11/17/2022] Open
Abstract
Patients suffering from stroke, traumatic brain injury, or other forms of central nervous system (CNS) injury have an increased risk of nosocomial infections due to CNS injury-induced immunosuppression (CIDS). Immediately after CNS-injury, the response in the brain is pro-inflammatory; however, subsequently, local and systemic immunity is suppressed due to the compensatory release of immunomodulatory neurotransmitters. CIDS makes patients susceptible to contracting infections, among which pneumonia is very common and often lethal. Ventilator-acquired pneumonia has a mortality of 20–50% and poses a significant risk to vulnerable patients such as stroke survivors. The mechanisms involved in CIDS are not well understood. In this review, we consolidate the evidence for cellular processes underlying the pathogenesis of CIDS, the emerging treatments, and speculate further on the immune elements at play.
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17
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Schwab N, Ju Y, Hazrati LN. Early onset senescence and cognitive impairment in a murine model of repeated mTBI. Acta Neuropathol Commun 2021; 9:82. [PMID: 33964983 PMCID: PMC8106230 DOI: 10.1186/s40478-021-01190-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 05/03/2021] [Indexed: 12/19/2022] Open
Abstract
Mild traumatic brain injury (mTBI) results in broad neurological symptoms and an increased risk of being diagnosed with a neurodegenerative disease later in life. While the immediate oxidative stress response and post-mortem pathology of the injured brain has been well studied, it remains unclear how early pathogenic changes may drive persistent symptoms and confer susceptibility to neurodegeneration. In this study we have used a mouse model of repeated mTBI (rmTBI) to identify early gene expression changes at 24 h or 7 days post-injury (7 dpi). At 24 h post-injury, gene expression of rmTBI mice shows activation of the DNA damage response (DDR) towards double strand DNA breaks, altered calcium and cell–cell signalling, and inhibition of cell death pathways. By 7 dpi, rmTBI mice had a gene expression signature consistent with induction of cellular senescence, activation of neurodegenerative processes, and inhibition of the DDR. At both timepoints gliosis, microgliosis, and axonal damage were evident in the absence of any gross lesion, and by 7 dpi rmTBI also mice had elevated levels of IL1β, p21, 53BP1, DNA2, and p53, supportive of DNA damage-induced cellular senescence. These gene expression changes reflect establishment of processes usually linked to brain aging and suggests that cellular senescence occurs early and most likely prior to the accumulation of toxic proteins. These molecular changes were accompanied by spatial learning and memory deficits in the Morris water maze. To conclude, we have identified DNA damage-induced cellular senescence as a repercussion of repeated mild traumatic brain injury which correlates with cognitive impairment. Pathways involved in senescence may represent viable treatment targets of post-concussive syndrome. Senescence has been proposed to promote neurodegeneration and appears as an effective target to prevent long-term complications of mTBI, such as chronic traumatic encephalopathy and other related neurodegenerative pathologies.
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18
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Faden AI, Barrett JP, Stoica BA, Henry RJ. Bidirectional Brain-Systemic Interactions and Outcomes After TBI. Trends Neurosci 2021; 44:406-418. [PMID: 33495023 DOI: 10.1016/j.tins.2020.12.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 12/23/2020] [Accepted: 12/31/2020] [Indexed: 12/16/2022]
Abstract
Traumatic brain injury (TBI) is a debilitating disorder associated with chronic progressive neurodegeneration and long-term neurological decline. Importantly, there is now substantial and increasing evidence that TBI can negatively impact systemic organs, including the pulmonary, gastrointestinal (GI), cardiovascular, renal, and immune system. Less well appreciated, until recently, is that such functional changes can affect both the response to subsequent insults or diseases, as well as contribute to chronic neurodegenerative processes and long-term neurological outcomes. In this review, we summarize evidence showing bidirectional interactions between the brain and systemic organs following TBI and critically assess potential underlying mechanisms.
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Affiliation(s)
- Alan I Faden
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - James P Barrett
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Bogdan A Stoica
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Rebecca J Henry
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, USA
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Hanscom M, Loane DJ, Aubretch T, Leser J, Molesworth K, Hedgekar N, Ritzel RM, Abulwerdi G, Shea-Donohue T, Faden AI. Acute colitis during chronic experimental traumatic brain injury in mice induces dysautonomia and persistent extraintestinal, systemic, and CNS inflammation with exacerbated neurological deficits. J Neuroinflammation 2021; 18:24. [PMID: 33461596 PMCID: PMC7814749 DOI: 10.1186/s12974-020-02067-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 12/21/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Disruptions of brain-gut axis have been implicated in the progression of a variety of gastrointestinal (GI) disorders and central nervous system (CNS) diseases and injuries, including traumatic brain injury (TBI). TBI is a chronic disease process characterized by persistent secondary injury processes which can be exacerbated by subsequent challenges. Enteric pathogen infection during chronic TBI worsened cortical lesion volume; however, the pathophysiological mechanisms underlying the damaging effects of enteric challenge during chronic TBI remain unknown. This preclinical study examined the effect of intestinal inflammation during chronic TBI on associated neurobehavioral and neuropathological outcomes, systemic inflammation, and dysautonomia. METHODS Dextran sodium sulfate (DSS) was administered to adult male C57BL/6NCrl mice 28 days following craniotomy (Sham) or TBI for 7 days to induce intestinal inflammation, followed by a return to normal drinking water for an additional 7 to 28 days for recovery; uninjured animals (Naïve) served as an additional control group. Behavioral testing was carried out prior to, during, and following DSS administration to assess changes in motor and cognitive function, social behavior, and mood. Electrocardiography was performed to examine autonomic balance. Brains were collected for histological and molecular analyses of injury lesion, neurodegeneration, and neuroinflammation. Blood, colons, spleens, mesenteric lymph nodes (mLNs), and thymus were collected for morphometric analyses and/or immune characterization by flow cytometry. RESULTS Intestinal inflammation 28 days after craniotomy or TBI persistently induced, or exacerbated, respectively, deficits in fine motor coordination, cognition, social behavior, and anxiety-like behavior. Behavioral changes were associated with an induction, or exacerbation, of hippocampal neuronal cell loss and microglial activation in Sham and TBI mice administered DSS, respectively. Acute DSS administration resulted in a sustained systemic immune response with increases in myeloid cells in blood and spleen, as well as myeloid cells and lymphocytes in mesenteric lymph nodes. Dysautonomia was also induced in Sham and TBI mice administered DSS, with increased sympathetic tone beginning during DSS administration and persisting through the first recovery week. CONCLUSION Intestinal inflammation during chronic experimental TBI causes a sustained systemic immune response and altered autonomic balance that are associated with microglial activation, increased neurodegeneration, and persistent neurological deficits.
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Affiliation(s)
- Marie Hanscom
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, 685 West Baltimore Street, MSTF #6-016, Baltimore, MD, 21201, USA.
| | - David J Loane
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, 685 West Baltimore Street, MSTF #6-016, Baltimore, MD, 21201, USA
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College, Dublin, Ireland
| | - Taryn Aubretch
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, 685 West Baltimore Street, MSTF #6-016, Baltimore, MD, 21201, USA
| | - Jenna Leser
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, 685 West Baltimore Street, MSTF #6-016, Baltimore, MD, 21201, USA
| | - Kara Molesworth
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, 685 West Baltimore Street, MSTF #6-016, Baltimore, MD, 21201, USA
| | - Nivedita Hedgekar
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, 685 West Baltimore Street, MSTF #6-016, Baltimore, MD, 21201, USA
| | - Rodney M Ritzel
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, 685 West Baltimore Street, MSTF #6-016, Baltimore, MD, 21201, USA
| | - Gelareh Abulwerdi
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, 685 West Baltimore Street, MSTF #6-016, Baltimore, MD, 21201, USA
| | - Terez Shea-Donohue
- Division of Translational Radiation Sciences (DTRS), Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Alan I Faden
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, 685 West Baltimore Street, MSTF #6-016, Baltimore, MD, 21201, USA
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20
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Abstract
Acute and chronic lung inflammation is a risk factor for various diseases involving lungs and extrapulmonary organs. Intercellular and interorgan networks, including crosstalk between lung and brain, intestine, heart, liver, and kidney, coordinate host immunity against infection, protect tissue, and maintain homeostasis. However, this interaction may be counterproductive and cause acute or chronic comorbidities due to dysregulated inflammation in the lung. In this chapter, we review the relationship of the lung with other key organs during normal cell processes and disease development. We focus on how pneumonia may lead to a systemic pathophysiological response to acute lung injury and chronic lung disease through organ interactions, which can facilitate the development of undesirable and even deleterious extrapulmonary sequelae.
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21
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Wirtz MR, Moekotte J, Balvers K, Admiraal MM, Pittet JF, Colombo J, Wagener BM, Goslings JC, Juffermans N. Autonomic nervous system activity and the risk of nosocomial infection in critically ill patients with brain injury. Intensive Care Med Exp 2020; 8:69. [PMID: 33237337 PMCID: PMC7688871 DOI: 10.1186/s40635-020-00359-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 11/13/2020] [Indexed: 12/17/2022] Open
Abstract
PURPOSE Nosocomial infection contributes to adverse outcome after brain injury. This study investigates whether autonomic nervous system activity is associated with a decreased host immune response in patients following stroke or traumatic brain injury (TBI). METHODS A prospective study was performed in adult patients with TBI or stroke who were admitted to the Intensive Care Unit of our tertiary university hospital between 2013 and 2016. Heart rate variability (HRV) was recorded daily and assessed for autonomic nervous system activity. Outcomes were nosocomial infections and immunosuppression, which was assessed ex vivo using whole blood stimulations with plasma of patients with infections, matched non-infected patients and healthy controls. RESULTS Out of 64 brain injured patients, 23 (36%) developed an infection during their hospital stay. The ability of brain injured patients to generate a host response to the bacterial endotoxin lipopolysaccharides (LPS) was diminished compared to healthy controls (p < 0.001). Patients who developed an infection yielded significantly lower TNF-α values (86 vs 192 pg/mL, p = 0.030) and a trend towards higher IL-10 values (122 vs 84 pg/mL, p = 0.071) following ex vivo whole blood stimulations when compared to patients not developing an infection. This decreased host immune response was associated with altered admission HRV values. Brain injured patients who developed an infection showed increased normalized high-frequency power compared to patients not developing an infection (0.54 vs 0.36, p = 0.033), whereas normalized low-frequency power was lower in infected patients (0.46 vs 0.64, p = 0.033). CONCLUSION Brain injured patients developing a nosocomial infection show parasympathetic predominance in the acute phase following brain injury, reflected by alterations in HRV, which parallels a decreased ability to generate an immune response to stimulation with LPS.
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Affiliation(s)
- Mathijs R Wirtz
- Department of Intensive Care Medicine, Onze Lieve Vrouwe Gasthuis and Amsterdam University Medical Centers, Amsterdam, The Netherlands. .,Laboratory of Experimental Intensive Care and Anesthesiology of the Amsterdam University Medical Center, Amsterdam, The Netherlands. .,Trauma Unit, Department of Surgery, Amsterdam University Medical Center, Amsterdam, The Netherlands.
| | - Jiri Moekotte
- Department of Intensive Care Medicine, Onze Lieve Vrouwe Gasthuis and Amsterdam University Medical Centers, Amsterdam, The Netherlands.,Laboratory of Experimental Intensive Care and Anesthesiology of the Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Kirsten Balvers
- Department of Intensive Care Medicine, Onze Lieve Vrouwe Gasthuis and Amsterdam University Medical Centers, Amsterdam, The Netherlands.,Laboratory of Experimental Intensive Care and Anesthesiology of the Amsterdam University Medical Center, Amsterdam, The Netherlands.,Trauma Unit, Department of Surgery, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Marjolein M Admiraal
- Department of Intensive Care Medicine, Onze Lieve Vrouwe Gasthuis and Amsterdam University Medical Centers, Amsterdam, The Netherlands.,Laboratory of Experimental Intensive Care and Anesthesiology of the Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Jean-Francois Pittet
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Joe Colombo
- Department of Cardiology, Drexel University College of Medicine, and ANSAR Medical Technologies, Inc., Philadelphia, PA, USA
| | - Brant M Wagener
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - J Carel Goslings
- Trauma Unit, Department of Surgery, Onze Lieve Vrouwe Gasthuis, Amsterdam, The Netherlands
| | - Nicole Juffermans
- Department of Intensive Care Medicine, Onze Lieve Vrouwe Gasthuis and Amsterdam University Medical Centers, Amsterdam, The Netherlands.,Laboratory of Experimental Intensive Care and Anesthesiology of the Amsterdam University Medical Center, Amsterdam, The Netherlands
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22
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Baker TL, Sun M, Semple BD, Tyebji S, Tonkin CJ, Mychasiuk R, Shultz SR. Catastrophic consequences: can the feline parasite Toxoplasma gondii prompt the purrfect neuroinflammatory storm following traumatic brain injury? J Neuroinflammation 2020; 17:222. [PMID: 32711529 PMCID: PMC7382044 DOI: 10.1186/s12974-020-01885-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 07/02/2020] [Indexed: 12/02/2022] Open
Abstract
Traumatic brain injury (TBI) is one of the leading causes of morbidity and mortality worldwide; however, treatment development is hindered by the heterogenous nature of TBI presentation and pathophysiology. In particular, the degree of neuroinflammation after TBI varies between individuals and may be modified by other factors such as infection. Toxoplasma gondii, a parasite that infects approximately one-third of the world’s population, has a tropism for brain tissue and can persist as a life-long infection. Importantly, there is notable overlap in the pathophysiology between TBI and T. gondii infection, including neuroinflammation. This paper will review current understandings of the clinical problems, pathophysiological mechanisms, and functional outcomes of TBI and T. gondii, before considering the potential synergy between the two conditions. In particular, the discussion will focus on neuroinflammatory processes such as microglial activation, inflammatory cytokines, and peripheral immune cell recruitment that occur during T. gondii infection and after TBI. We will present the notion that these overlapping pathologies in TBI individuals with a chronic T. gondii infection have the strong potential to exacerbate neuroinflammation and related brain damage, leading to amplified functional deficits. The impact of chronic T. gondii infection on TBI should therefore be investigated in both preclinical and clinical studies as the possible interplay could influence treatment strategies.
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Affiliation(s)
- Tamara L Baker
- Department of Neuroscience, Monash University, 6th Floor, The Alfred Centre, 99 Commercial Road, Melbourne, VIC, 3004, Australia
| | - Mujun Sun
- Department of Neuroscience, Monash University, 6th Floor, The Alfred Centre, 99 Commercial Road, Melbourne, VIC, 3004, Australia
| | - Bridgette D Semple
- Department of Neuroscience, Monash University, 6th Floor, The Alfred Centre, 99 Commercial Road, Melbourne, VIC, 3004, Australia.,Department of Medicine, The University of Melbourne, Parkville, VIC, Australia
| | - Shiraz Tyebji
- Division of Infectious Diseases and Defence, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
| | - Christopher J Tonkin
- Division of Infectious Diseases and Defence, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
| | - Richelle Mychasiuk
- Department of Neuroscience, Monash University, 6th Floor, The Alfred Centre, 99 Commercial Road, Melbourne, VIC, 3004, Australia
| | - Sandy R Shultz
- Department of Neuroscience, Monash University, 6th Floor, The Alfred Centre, 99 Commercial Road, Melbourne, VIC, 3004, Australia. .,Department of Medicine, The University of Melbourne, Parkville, VIC, Australia.
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23
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Sun M, Brady RD, Wanrooy B, Mychasiuk R, Yamakawa GR, Casillas-Espinosa PM, Wong CHY, Shultz SR, McDonald SJ. Experimental traumatic brain injury does not lead to lung infection. J Neuroimmunol 2020; 343:577239. [PMID: 32302792 DOI: 10.1016/j.jneuroim.2020.577239] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 03/23/2020] [Accepted: 04/08/2020] [Indexed: 12/13/2022]
Abstract
Traumatic brain injury (TBI) patients often experience post-traumatic infections, especially in the lung. Pulmonary infection is associated with unfavorable outcomes and increased mortality rates in TBI patients; however, our understanding of the underlying mechanisms is poor. Here we used a lateral fluid percussion injury (LFPI) model in rats to investigate whether TBI could lead to spontaneous lung infection. Analysis of bacterial load in lung tissue indicated no occurrence of spontaneous lung infection at 24 h, 48 h, and 7 d following LFPI. This may suggest that exogenous infectious agents play a crucial role in post-TBI infection in patients.
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Affiliation(s)
- Mujun Sun
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia.
| | - Rhys D Brady
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia; Department of Medicine, The University of Melbourne, Melbourne, VIC 3052, Australia.
| | - Brooke Wanrooy
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash University, Melbourne, VIC 3168, Australia.
| | - Richelle Mychasiuk
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia.
| | - Glenn R Yamakawa
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia.
| | - Pablo M Casillas-Espinosa
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia; Department of Medicine, The University of Melbourne, Melbourne, VIC 3052, Australia.
| | - Connie H Y Wong
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash University, Melbourne, VIC 3168, Australia.
| | - Sandy R Shultz
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia; Department of Medicine, The University of Melbourne, Melbourne, VIC 3052, Australia.
| | - Stuart J McDonald
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia; Department of Physiology, Anatomy and Microbiology, School of Life Sciences, La Trobe University, Melbourne, VIC 3086, Australia.
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