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McCamy KM, Rees KA, Winzer-Serhan UH. Peripheral immune challenges elicit differential up-regulation of hippocampal cytokine and chemokine mRNA expression in a mouse model of the 15q13.3 microdeletion syndrome. Cytokine 2022; 159:156005. [PMID: 36084604 DOI: 10.1016/j.cyto.2022.156005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 04/06/2022] [Accepted: 08/05/2022] [Indexed: 11/03/2022]
Abstract
The human heterozygous 15q13.3 microdeletion is associated with neuropathological disorders, most prominently with epilepsy and intellectual disability. The 1.5 Mb deletion encompasses six genes (FAN1 [MTMR15], MTMR10, TRPM1, KLF13, OTUD7A, and CHRNA7); all but one (TRPM1) are expressed in the brain. The 15q13.3 microdeletion causes highly variable neurological symptoms, and confounding factors may contribute to a more severe phenotype. CHRNA7 and KLF13 are involved in immune system regulation and altered immune responses may contribute to neurological deficits. We used the Df[h15q13]/+ transgenic mouse model with a heterozygous deletion of the orthologous region (Het) to test the hypothesis that the microdeletion increases innate immune responses compared to wild type (WT). Male and female mice were acutely challenged with the bacteriomimetic lipopolysaccharide (LPS, 0.1 mg/kg, i.p.) or the viral mimetic polyinosinic:polycytidylic acid (Poly(I:C), 5 mg/kg). Hippocampal mRNA expression of pro-inflammatory cytokines and chemokines were determined three hours after injection using quantitative PCR analysis. In controls, expression was not affected by sex or genotype. LPS and Poly(I:C) resulted in significantly increased hippocampal expression of cytokines, chemokines, and interferon-γ (IFNγ), with more robust increases for TNF-α, IL-6, IL-1β, CXCL1, and CCL2 by LPS, higher induction of IFNγ by Poly(I:C), and similar increases of CCL4 and CCL5 by both agents. Generally, Hets exhibited stronger responses than WT mice, and significant effects of genotype or genotype × treatment interactions were detected for CXCL1 and CCL5, and IL-6, IL-1β, and CCL4, respectively, after LPS. Sex differences were detected for some targets. LPS but not Poly(I:C), reduced overnight burrowing independent of sex or genotype, suggesting that LPS induced sickness behavior. Thus, mice carrying the microdeletion have an increased innate immune response following a LPS challenge, but further studies will have to determine the extent and mechanisms of altered immune activation and subsequent contributions to 15q13.3 microdeletion associated deficits.
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Affiliation(s)
- Kristin M McCamy
- Department of Neuroscience & Experimental Therapeutics, College of Medicine, Texas A&M Health Science Center, Bryan, TX 77807, United States
| | - Katherine A Rees
- Department of Neuroscience & Experimental Therapeutics, College of Medicine, Texas A&M Health Science Center, Bryan, TX 77807, United States
| | - Ursula H Winzer-Serhan
- Department of Neuroscience & Experimental Therapeutics, College of Medicine, Texas A&M Health Science Center, Bryan, TX 77807, United States.
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Complement as a powerful "influencer" in the brain during development, adulthood and neurological disorders. Adv Immunol 2021; 152:157-222. [PMID: 34844709 DOI: 10.1016/bs.ai.2021.09.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The complement system was long considered as only a powerful effector arm of the immune system that, while critically protective, could lead to inflammation and cell death if overactivated, even in the central nervous system (CNS). However, in the past decade it has been recognized as playing critical roles in key physiological processes in the CNS, including neurogenesis and synaptic remodeling in the developing and adult brain. Inherent in these processes are the interactions with cells in the brain, and the cascade of interactions and functional consequences that ensue. As a result, investigations of therapeutic approaches for both suppressing excessive complement driven neurotoxicity and aberrant sculpting of neuronal circuits, require broad (and deep) knowledge of the functional activities of multiple components of this highly evolved and regulated system to avoid unintended negative consequences in the clinic. Advances in basic science are beginning to provide a roadmap for translation to therapeutics, with both small molecule and biologics. Here, we present examples of the critical roles of proper complement function in the development and sculpting of the nervous system, and in enabling rapid protection from infection and clearance of dying cells. Microglia are highlighted as important command centers that integrate signals from the complement system and other innate sensors that are programed to provide support and protection, but that direct detrimental responses to aberrant activation and/or regulation of the system. Finally, we present promising research areas that may lead to effective and precision strategies for complement targeted interventions to promote neurological health.
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Petrisko TJ, Konat GW. Peripheral viral challenge increases c-fos level in cerebral neurons. Metab Brain Dis 2021; 36:1995-2002. [PMID: 34406561 DOI: 10.1007/s11011-021-00819-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 08/05/2021] [Indexed: 12/01/2022]
Abstract
Peripheral viral infection can substantially alter brain function. We have previously shown that intraperitoneal (i.p.) injection of a viral mimetic, polyinosinic-polycytidylic acid (PIC), engenders hyperexcitability of cerebral neurons. Because neuronal activity is invariably associated with their expression of the Cfos gene, the present study was undertaken to determine whether PIC challenge also increases neuronal c-fos protein level. Female C57BL/6 mice were i.p. injected with PIC, and neuronal c-fos was analyzed in the motor cortex by immunohistochemistry. PIC challenge instigated a robust increase in the number of c-fos-positive neurons. This increase reached approximately tenfold over control at 24 h. Also, the c-fos staining intensity of individual neurons increased. AMG-487, a specific inhibitor of the chemokine receptor CXCR3, profoundly attenuated the accumulation of neuronal c-fos, indicating the activation of CXCL10/CXCR3 axis as the trigger of the process. Together, these results show that the accumulation of c-fos is a viable readout to assess the response of cerebral neurons to peripheral PIC challenge, and to elucidate the underlying molecular mechanisms.
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Affiliation(s)
- Tiffany J Petrisko
- Department of Biochemistry, Department of Neuroscience and Rockefeller Neuroscience Institute, West Virginia University School of Medicine, Morgantown, WV, 26506, USA
| | - Gregory W Konat
- Department of Biochemistry, Department of Neuroscience and Rockefeller Neuroscience Institute, West Virginia University School of Medicine, Morgantown, WV, 26506, USA.
- Department of Biochemistry, West Virginia University School of Medicine, 4052 HSCN, P.O. Box 9128, Morgantown, WV, 26506-9128, USA.
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Petrisko TJ, Bloemer J, Pinky PD, Srinivas S, Heslin RT, Du Y, Setti SE, Hong H, Suppiramaniam V, Konat GW, Reed MN. Neuronal CXCL10/CXCR3 Axis Mediates the Induction of Cerebral Hyperexcitability by Peripheral Viral Challenge. Front Neurosci 2020; 14:220. [PMID: 32265633 PMCID: PMC7105801 DOI: 10.3389/fnins.2020.00220] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 02/28/2020] [Indexed: 12/20/2022] Open
Abstract
Peripheral infections can potently exacerbate neuropathological conditions, though the underlying mechanisms are poorly understood. We have previously demonstrated that intraperitoneal (i.p.) injection of a viral mimetic, polyinosinic-polycytidylic acid (PIC) induces a robust generation of CXCL10 chemokine in the hippocampus. The hippocampus also features hyperexcitability of neuronal circuits following PIC challenge. The present study was undertaken to determine the role of CXCL10 in mediating the development of hyperexcitability in response to PIC challenge. Briefly, young female C57BL/6 mice were i.p. injected with PIC, and after 24 h, the brains were analyzed by confocal microscopy. CXCL10 staining of neuronal perikarya and a less intense staining of the neuropil was observed in the hippocampus and cortex. CXCL10 staining was also evident in a subpopulation of astrocytes, whereas microglia were CXCL10 negative. CXCR3, the cognate receptor of CXCL10 was present exclusively on neurons, indicating that the CXCL10/CXCR3 axis operates through an autocrine/paracrine neuronal signaling. Blocking cerebral CXCR3 through intracerebroventricular injection of a specific inhibitor, AMG487, abrogated PIC challenge-induced increase in basal synaptic transmission and long-term potentiation (LTP), as well as the reduction of paired-pulse facilitation (PPF), in the hippocampus. The PIC-mediated abolishment of hippocampal long-term depression (LTD) was also restored after administration of AMG487. Moreover, CXCR3 inhibition attenuated seizure hypersensitivity induced by PIC challenge. The efficacy of AMG487 strongly strengthens the notion that CXCL10/CXCR3 axis mediates the induction of cerebral hyperexcitability by PIC challenge.
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Affiliation(s)
- Tiffany J Petrisko
- Departments of Biochemistry and Neuroscience, West Virginia University School of Medicine, Morgantown, WV, United States
| | - Jenna Bloemer
- Drug Discovery and Development, School of Pharmacy, Auburn University, Auburn, AL, United States
| | - Priyanka D Pinky
- Drug Discovery and Development, School of Pharmacy, Auburn University, Auburn, AL, United States
| | - Sriraja Srinivas
- Drug Discovery and Development, School of Pharmacy, Auburn University, Auburn, AL, United States
| | - Ryan T Heslin
- Drug Discovery and Development, School of Pharmacy, Auburn University, Auburn, AL, United States
| | - Yifeng Du
- Drug Discovery and Development, School of Pharmacy, Auburn University, Auburn, AL, United States
| | - Sharay E Setti
- Drug Discovery and Development, School of Pharmacy, Auburn University, Auburn, AL, United States
| | - Hao Hong
- Department of Pharmacy, The First Affiliated Hospital of Xiamen University, Xiamen, China.,Key Laboratory of Neuropsychiatric Diseases, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
| | - Vishnu Suppiramaniam
- Drug Discovery and Development, School of Pharmacy, Auburn University, Auburn, AL, United States.,Center for Neuroscience Initiative, Auburn University, Auburn, AL, United States
| | - Gregory W Konat
- Departments of Biochemistry and Neuroscience, West Virginia University School of Medicine, Morgantown, WV, United States
| | - Miranda N Reed
- Drug Discovery and Development, School of Pharmacy, Auburn University, Auburn, AL, United States.,Center for Neuroscience Initiative, Auburn University, Auburn, AL, United States
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Petrisko TJ, Konat GW. Peripheral viral challenge exacerbates experimental autoimmune encephalomyelitis. Metab Brain Dis 2019; 34:675-679. [PMID: 30637619 DOI: 10.1007/s11011-019-0383-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 01/03/2019] [Indexed: 10/27/2022]
Abstract
Peripheral viral infections are potent triggers of exacerbation in multiple sclerosis (MS). Here, we used a preclinical model of MS, the experimental autoimmune encephalomyelitis (EAE) to corroborate this comorbidity in an experimental setting. EAE was induced by immunization of mice with MOG peptide, and paralysis was scored using a 5-point scale. At the onset of the chronic phase of the disease (Days 42-58 after MOG injection) the animals were divided into low responders (LR) and high responders (HR) with the mean score of 1.5 and 2.5, respectively. The acute phase response (APR) was induced by intraperitoneal injections of a viral mimetic, polyinosinic-polycytidylic acid (PIC). Two daily injections were performed on Days 42 and 44 (PIC42,44 challenge) and on Days 54, 55 and 56 (PIC54,55,56 challenge). PIC42,44 challenge had no effect of EAE disease, whereas PIC54,55,56 challenge rapidly increased paralysis but only in HR group. This exacerbation ultimately led to animal death by Day 58. These results demonstrate that antiviral APR is a potent exacerbator of EAE, and that this activity directly correlates with the severity of the disease. This in turn, indicates that antiviral APR might play a pivot role in linking peripheral viral infections with MS exacerbations.
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Affiliation(s)
- Tiffany J Petrisko
- Departments of Biochemistry and Neuroscience, Rockefeller Neuroscience Institute, West Virginia University School of Medicine, 4052 HSCN, P.O. Box 9128, Morgantown, WV, 26506-9128, USA
| | - Gregory W Konat
- Departments of Biochemistry and Neuroscience, Rockefeller Neuroscience Institute, West Virginia University School of Medicine, 4052 HSCN, P.O. Box 9128, Morgantown, WV, 26506-9128, USA.
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