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O'Connell CJ, Reeder EL, Hymore JA, Brown RS, Notorgiacomo GA, Collins SM, Gudelsky GA, Robson MJ. Transcriptomic dynamics governing serotonergic dysregulation in the dorsal raphe nucleus following mild traumatic brain injury. Exp Neurol 2024; 374:114695. [PMID: 38246304 DOI: 10.1016/j.expneurol.2024.114695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 12/15/2023] [Accepted: 01/18/2024] [Indexed: 01/23/2024]
Abstract
Mild traumatic brain injury (mTBI) is a leading cause of disability in the United States, with neuropsychiatric disturbances such as depression, anxiety, PTSD, and social disturbances being common comorbidities following injury. The molecular mechanisms driving neuropsychiatric complications following neurotrauma are not well understood and current FDA-approved pharmacotherapies employed to ameliorate these comorbidities lack desired efficacy. Concerted efforts to understand the molecular mechanisms of and identify novel drug candidates for treating neurotrauma-elicited neuropsychiatric sequelae are clearly needed. Serotonin (5-HT) is linked to the etiology of neuropsychiatric disorders, however our understanding of how various forms of TBI directly affect 5-HT neurotransmission is limited. 5-HT neurons originate in the raphe nucleus (RN) of the midbrain and project throughout the brain to regulate diverse behavioral phenotypes. We hypothesize that the characterization of the dynamics governing 5-HT neurotransmission after injury will drive the discovery of novel drug targets and lead to a greater understanding of the mechanisms associated with neuropsychiatric disturbances following mild TBI (mTBI). Herein, we provide evidence that closed-head mTBI alters total DRN 5-HT levels, with RNA sequencing of the DRN revealing injury-derived alterations in transcripts required for the development, identity, and functional stability of 5-HT neurons. Further, using gene ontology analyses combined with immunohistological analyses, we have identified a novel mechanism of transcriptomic control within 5-HT neurons that may directly influence 5-HT neuron identity/function post-injury. These studies provide molecular evidence of injury-elicited 5-HT neuron dysregulation, data which may expedite the identification of novel therapeutic targets to attenuate TBI-elicited neuropsychiatric sequelae.
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Affiliation(s)
- Christopher J O'Connell
- University of Cincinnati, James L. Winkle College of Pharmacy, Division of Pharmaceutical Sciences, Cincinnati, OH, USA
| | - Evan L Reeder
- University of Cincinnati, James L. Winkle College of Pharmacy, Division of Pharmaceutical Sciences, Cincinnati, OH, USA
| | - Jacob A Hymore
- University of Cincinnati, James L. Winkle College of Pharmacy, Division of Pharmaceutical Sciences, Cincinnati, OH, USA
| | - Ryan S Brown
- University of Cincinnati, James L. Winkle College of Pharmacy, Division of Pharmaceutical Sciences, Cincinnati, OH, USA
| | | | - Sean M Collins
- University of Cincinnati, James L. Winkle College of Pharmacy, Division of Pharmaceutical Sciences, Cincinnati, OH, USA
| | - Gary A Gudelsky
- University of Cincinnati, James L. Winkle College of Pharmacy, Division of Pharmaceutical Sciences, Cincinnati, OH, USA; Neuroscience Graduate Program, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Matthew J Robson
- University of Cincinnati, James L. Winkle College of Pharmacy, Division of Pharmaceutical Sciences, Cincinnati, OH, USA; Neuroscience Graduate Program, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
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Packer JM, Bray CE, Beckman NB, Wangler LM, Davis AC, Goodman EJ, Klingele NE, Godbout JP. Impaired cortical neuronal homeostasis and cognition after diffuse traumatic brain injury are dependent on microglia and type I interferon responses. Glia 2024; 72:300-321. [PMID: 37937831 PMCID: PMC10764078 DOI: 10.1002/glia.24475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 09/14/2023] [Accepted: 09/20/2023] [Indexed: 11/09/2023]
Abstract
Neuropsychiatric complications including depression and cognitive decline develop in the years after traumatic brain injury (TBI), negatively affecting quality of life. Microglial and type 1 interferon (IFN-I) responses are associated with the transition from acute to chronic neuroinflammation after diffuse TBI in mice. Thus, the purpose of this study was to determine if impaired neuronal homeostasis and increased IFN-I responses intersected after TBI to cause cognitive impairment. Here, the RNA profile of neurons and microglia after TBI (single nucleus RNA-sequencing) with or without microglia depletion (CSF1R antagonist) was assessed 7 dpi. There was a TBI-dependent suppression of cortical neuronal homeostasis with reductions in CREB signaling, synaptogenesis, and synaptic migration and increases in RhoGDI and PTEN signaling (Ingenuity Pathway Analysis). Microglial depletion reversed 50% of TBI-induced gene changes in cortical neurons depending on subtype. Moreover, the microglial RNA signature 7 dpi was associated with increased stimulator of interferon genes (STING) activation and IFN-I responses. Therefore, we sought to reduce IFN-I signaling after TBI using STING knockout mice and a STING antagonist, chloroquine (CQ). TBI-associated cognitive deficits in novel object location and recognition (NOL/NOR) tasks at 7 and 30 dpi were STING dependent. In addition, TBI-induced STING expression, microglial morphological restructuring, inflammatory (Tnf, Cd68, Ccl2) and IFN-related (Irf3, Irf7, Ifi27) gene expression in the cortex were attenuated in STINGKO mice. CQ also reversed TBI-induced cognitive deficits and reduced TBI-induced inflammatory (Tnf, Cd68, Ccl2) and IFN (Irf7, Sting) cortical gene expression. Collectively, reducing IFN-I signaling after TBI with STING-dependent interventions attenuated the prolonged microglial activation and cognitive impairment.
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Affiliation(s)
- Jonathan M Packer
- Department of Neuroscience, The Ohio State University, Columbus, Ohio, USA
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, Ohio, USA
| | - Chelsea E Bray
- College of Medicine, The Ohio State University, Columbus, United States
| | - Nicolas B Beckman
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, Ohio, USA
| | - Lynde M Wangler
- Department of Neuroscience, The Ohio State University, Columbus, Ohio, USA
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, Ohio, USA
| | - Amara C Davis
- Department of Neuroscience, The Ohio State University, Columbus, Ohio, USA
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, Ohio, USA
| | - Ethan J Goodman
- Department of Neuroscience, The Ohio State University, Columbus, Ohio, USA
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, Ohio, USA
| | - Nathaniel E Klingele
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, Ohio, USA
| | - Jonathan P Godbout
- Department of Neuroscience, The Ohio State University, Columbus, Ohio, USA
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, Ohio, USA
- College of Medicine, The Ohio State University, Columbus, United States
- Chronic Brain Injury Program, The Ohio State University, Columbus, Ohio, USA
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