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Nikodemova M, Oberto JR, Kaye EL, Berschel MR, Michaelson AL, Watters JJ, Mitchell GS. Acute postnatal inflammation alters adult microglial responses to LPS that are sex-, region- and timing of postnatal inflammation-dependent. J Neuroinflammation 2024; 21:256. [PMID: 39390483 DOI: 10.1186/s12974-024-03245-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Accepted: 09/26/2024] [Indexed: 10/12/2024] Open
Abstract
BACKGROUND Adverse events in early life can have impact lasting into adulthood. We investigated the long-term effects of systemic inflammation during postnatal development on adult microglial responses to lipopolysaccharide (LPS) in two CNS regions (cortex, cervical spinal cord) in male and female rats. METHODS Inflammation was induced in Sprague-Dawley rats by LPS (1 mg/kg) administered intraperitoneally during postnatal development at P7, P12 or P18. As adults (12 weeks of age), the rats received a second LPS dose (1 mg/kg). Control rats received saline. Microglia were isolated 3 h post-LPS followed by gene expression analysis via qRT-PCR for pro-inflammatory (IL-6, iNOS, Ptgs2, C/EBPb, CD14, CXCL10), anti-inflammatory (CD68, Arg-1), and homeostatic genes (P2Y12, Tmemm119). CSF-1 and CX3CL1 mRNAs were analyzed in microglia-free homogenates. RESULTS Basal gene expression in adult microglia was largely unaffected by postnatal inflammation. Adult cortical microglial pro-inflammatory gene responses to LPS were either unchanged or attenuated in rats exposed to LPS during postnatal development. Ptgs2, C/EBPb, CXCL10 and Arg-1 were the most affected genes, with expression significantly downregulated vs. rats without postnatal LPS. Spinal microglia were affected most by LPS at P18, with mixed and sometimes opposing effects on proinflammatory genes in males vs. females. Overall, male cortical vs. spinal microglia were more affected by postnatal LPS. Females were affected in both cortex and spinal cord, but the effect was dependent on timing of postnatal LPS. Overall, inflammatory challenge at P18 had greater effect on adult microglia vs. challenge at P12 or P7. CONCLUSIONS Long-lasting effects of postnatal inflammation on adult microglia depend on postnatal timing, CNS region and sex.
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Affiliation(s)
- Maria Nikodemova
- Breathing Research and Therapeutic Center, Department of Physical Therapy and McKnight Brain Institute, University of Florida, Gainesville, FL, 32610, USA.
| | - Jose R Oberto
- Breathing Research and Therapeutic Center, Department of Physical Therapy and McKnight Brain Institute, University of Florida, Gainesville, FL, 32610, USA
| | - Ethan L Kaye
- Breathing Research and Therapeutic Center, Department of Physical Therapy and McKnight Brain Institute, University of Florida, Gainesville, FL, 32610, USA
| | - Mackenzie R Berschel
- Breathing Research and Therapeutic Center, Department of Physical Therapy and McKnight Brain Institute, University of Florida, Gainesville, FL, 32610, USA
| | - Alysha L Michaelson
- Breathing Research and Therapeutic Center, Department of Physical Therapy and McKnight Brain Institute, University of Florida, Gainesville, FL, 32610, USA
| | - Jyoti J Watters
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, 53706, USA
| | - Gordon S Mitchell
- Breathing Research and Therapeutic Center, Department of Physical Therapy and McKnight Brain Institute, University of Florida, Gainesville, FL, 32610, USA
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Freuchet A, Pinçon A, Sette A, Lindestam Arlehamn CS. Inflammation and heterogeneity in synucleinopathies. Front Immunol 2024; 15:1432342. [PMID: 39281666 PMCID: PMC11392857 DOI: 10.3389/fimmu.2024.1432342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Accepted: 08/15/2024] [Indexed: 09/18/2024] Open
Abstract
Neurodegenerative diseases represent a huge healthcare challenge which is predicted to increase with an aging population. Synucleinopathies, including Parkinson's disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA), present complex challenges in understanding their onset and progression. They are characterized by the abnormal aggregation of α-synuclein in the brain leading to neurodegeneration. Accumulating evidence supports the existence of distinct subtypes based on the site of α-synuclein aggregation initiation, genetics, and, more recently, neuroinflammation. Mediated by both central nervous system-resident cells, peripheral immune cells, and gut dysbiosis, neuroinflammation appears as a key process in the onset and progression of neuronal loss. Sex-based differences add another layer of complexity to synucleinopathies, influencing disease prevalence - with a known higher incidence of PD in males compared to females - as well as phenotype and immune responses. Biological sex affects neuroinflammatory pathways and the immune response, suggesting the need for sex-specific therapeutic strategies and biomarker identification. Here, we review the heterogeneity of synucleinopathies, describing the etiology, the mechanisms by which the inflammatory processes contribute to the pathology, and the consideration of sex-based differences to highlight the need for personalized therapeutics.
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Affiliation(s)
- Antoine Freuchet
- Center for Autoimmunity and Inflammation, La Jolla Institute for Immunology, San Diego, CA, United States
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, United States
| | - Anaëlle Pinçon
- Center for Autoimmunity and Inflammation, La Jolla Institute for Immunology, San Diego, CA, United States
- Master de Biologie, Ecole Normale Superieure de Lyon, University of Lyon, Lyon, France
| | - Alessandro Sette
- Center for Autoimmunity and Inflammation, La Jolla Institute for Immunology, San Diego, CA, United States
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, United States
- Department of Medicine, University of California, San Diego, San Diego, CA, United States
| | - Cecilia S Lindestam Arlehamn
- Center for Autoimmunity and Inflammation, La Jolla Institute for Immunology, San Diego, CA, United States
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, United States
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Nikodemova M, Oberto JR, Berschel MR, Michaelson AL, Watters JJ, Mitchell GS. Acute Postnatal Inflammation Alters Adult Microglial Responses to LPS that Are Sex-, Region- and Timing of Postnatal Inflammation-Dependent. RESEARCH SQUARE 2024:rs.3.rs-4565866. [PMID: 38978595 PMCID: PMC11230508 DOI: 10.21203/rs.3.rs-4565866/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Background Adverse events in early life can have impact lasting into adulthood. We investigated the long-term effects of systemic inflammation during postnatal development on adult microglial responses to LPS in two CNS regions (cortex, cervical spinal cord) in male and female rats. Methods Inflammation was induced in Sprague-Dawley rats by lipopolysaccharide (LPS, 1 mg/kg) administered intraperitoneally during postnatal development at P7, P12 or P18. As adults (12 weeks of age), the rats received a second LPS dose (1 mg/kg). Control rats received saline. Microglia were isolated 3 hours post-LPS from the cortex and cervical spinal cord. Gene expression was assessed via qRT-PCR for pro-inflammatory (IL-6, iNOS, Ptgs2, C/EBPb, CD14, CXCL10), anti-inflammatory (CD68, Arg-1), and homeostatic genes (P2Y12, Tmemm119). CSF-1 and CX3CL1 mRNA was analyzed in microglia-free homogenates. Results Basal gene expression in adult microglia was largely unaffected by early life LPS. Changes in adult microglial pro-inflammatory genes in response to LPS were either unchanged or attenuated in rats exposed to LPS during postnatal development. Ptgs2, C/EBPb, CXCL10 and Arg-1 were the genes most affected, with expression levels significantly downregulated vs control rats without postnatal LPS exposure. Cortical microglia were affected more by postnatal inflammation than spinal microglia, and males were more impacted than females. Overall, inflammatory challenge at P18 had the greatest effect on adult microglial gene expression, whereas challenge at P7 had less impact. Microglial homeostatic genes were unaffected by postnatal LPS. Conclusions Long-lasting effects of postnatal inflammation on adult microglia depend on the timing of postnatal inflammation, CNS region and sex.
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Weyer MP, Strehle J, Schäfer MKE, Tegeder I. Repurposing of pexidartinib for microglia depletion and renewal. Pharmacol Ther 2024; 253:108565. [PMID: 38052308 DOI: 10.1016/j.pharmthera.2023.108565] [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: 09/28/2023] [Revised: 11/20/2023] [Accepted: 11/22/2023] [Indexed: 12/07/2023]
Abstract
Pexidartinib (PLX3397) is a small molecule receptor tyrosine kinase inhibitor of colony stimulating factor 1 receptor (CSF1R) with moderate selectivity over other members of the platelet derived growth factor receptor family. It is approved for treatment of tenosynovial giant cell tumors (TGCT). CSF1R is highly expressed by microglia, which are macrophages of the central nervous system (CNS) that defend the CNS against injury and pathogens and contribute to synapse development and plasticity. Challenged by pathogens, apoptotic cells, debris, or inflammatory molecules they adopt a responsive state to propagate the inflammation and eventually return to a homeostatic state. The phenotypic switch may fail, and disease-associated microglia contribute to the pathophysiology in neurodegenerative or neuropsychiatric diseases or long-lasting detrimental brain inflammation after brain, spinal cord or nerve injury or ischemia/hemorrhage. Microglia also contribute to the growth permissive tumor microenvironment of glioblastoma (GBM). In rodents, continuous treatment for 1-2 weeks via pexidartinib food pellets leads to a depletion of microglia and subsequent repopulation from the remaining fraction, which is aided by peripheral monocytes that search empty niches for engraftment. The putative therapeutic benefit of such microglia depletion or forced renewal has been assessed in almost any rodent model of CNS disease or injury or GBM with heterogeneous outcomes, but a tendency of partial beneficial effects. So far, microglia monitoring e.g. via positron emission imaging is not standard of care for patients receiving Pexidartinib (e.g. for TGCT), so that the depletion and repopulation efficiency in humans is still largely unknown. Considering the virtuous functions of microglia, continuous depletion is likely no therapeutic option but short-lasting transient partial depletion to stimulate microglia renewal or replace microglia in genetic disease in combination with e.g. stem cell transplantation or as part of a multimodal concept in treatment of glioblastoma appears feasible. The present review provides an overview of the preclinical evidence pro and contra microglia depletion as a therapeutic approach.
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Affiliation(s)
- Marc-Philipp Weyer
- Institute of Clinical Pharmacology, Goethe-University Frankfurt, Faculty of Medicine, Frankfurt, Germany
| | - Jenny Strehle
- Department of Anesthesiology, University Medical Center Johannes Gutenberg-University Mainz, Germany
| | - Michael K E Schäfer
- Department of Anesthesiology, University Medical Center Johannes Gutenberg-University Mainz, Germany
| | - Irmgard Tegeder
- Institute of Clinical Pharmacology, Goethe-University Frankfurt, Faculty of Medicine, Frankfurt, Germany.
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Leńska-Mieciek M, Madetko-Alster N, Alster P, Królicki L, Fiszer U, Koziorowski D. Inflammation in multiple system atrophy. Front Immunol 2023; 14:1214677. [PMID: 37426656 PMCID: PMC10327640 DOI: 10.3389/fimmu.2023.1214677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Accepted: 06/06/2023] [Indexed: 07/11/2023] Open
Abstract
Misfolding protein aggregation inside or outside cells is the major pathological hallmark of several neurodegenerative diseases. Among proteinopathies are neurodegenerative diseases with atypical Parkinsonism and an accumulation of insoluble fibrillary alpha-synuclein (synucleinopathies) or hyperphosphorylated tau protein fragments (tauopathies). As there are no therapies available to slow or halt the progression of these disea ses, targeting the inflammatory process is a promising approach. The inflammatory biomarkers could also help in the differential diagnosis of Parkinsonian syndromes. Here, we review inflammation's role in multiple systems atrophy pathogenesis, diagnosis, and treatment.
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Affiliation(s)
- Marta Leńska-Mieciek
- Department of Neurology and Epileptology, Centre of Postgraduate Medical Education, Warsaw, Poland
| | | | - Piotr Alster
- Department of Neurology, Medical University of Warsaw, Warsaw, Poland
| | - Leszek Królicki
- Department of Nuclear Medicine, Medical University of Warsaw, Warsaw, Poland
| | - Urszula Fiszer
- Department of Neurology and Epileptology, Centre of Postgraduate Medical Education, Warsaw, Poland
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