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Increased levels of a pro-inflammatory IgG receptor in the midbrain of people with schizophrenia
BACKGROUND: There is growing evidence that neuroinflammation may contribute to schizophrenia neuropathology. Elevated pro-inflammatory cytokines are evident in the midbrain from schizophrenia subjects, findings that are driven by a subgroup of patients, characterised as a “high inflammation” biotype...
Autores principales: | , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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BioMed Central
2022
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9287858/ https://www.ncbi.nlm.nih.gov/pubmed/35841099 http://dx.doi.org/10.1186/s12974-022-02541-8 |
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author | Petty, A. Glass, L. J. Rothmond, D. A. Purves-Tyson, T. Sweeney, A. Kondo, Y. Kubo, S. Matsumoto, M. Weickert, C. Shannon |
author_facet | Petty, A. Glass, L. J. Rothmond, D. A. Purves-Tyson, T. Sweeney, A. Kondo, Y. Kubo, S. Matsumoto, M. Weickert, C. Shannon |
author_sort | Petty, A. |
collection | PubMed |
description | BACKGROUND: There is growing evidence that neuroinflammation may contribute to schizophrenia neuropathology. Elevated pro-inflammatory cytokines are evident in the midbrain from schizophrenia subjects, findings that are driven by a subgroup of patients, characterised as a “high inflammation” biotype. Cytokines trigger the release of antibodies, of which immunoglobulin G (IgG) is the most common. The level and function of IgG is regulated by its transporter (FcGRT) and by pro-inflammatory IgG receptors (including FcGR3A) in balance with the anti-inflammatory IgG receptor FcGR2B. Testing whether abnormalities in IgG activity contribute to the neuroinflammatory abnormalities schizophrenia patients, particularly those with elevated cytokines, may help identify novel treatment targets. METHODS: Post-mortem midbrain tissue from healthy controls and schizophrenia cases (n = 58 total) was used to determine the localisation and abundance of IgG and IgG transporters and receptors in the midbrain of healthy controls and schizophrenia patients. Protein levels of IgG and FcGRT were quantified using western blot, and gene transcript levels of FcGRT, FcGR3A and FcGR2B were assessed using qPCR. The distribution of IgG in the midbrain was assessed using immunohistochemistry and immunofluorescence. Results were compared between diagnostic (schizophrenia vs control) and inflammatory (high vs low inflammation) groups. RESULTS: We found that IgG and FcGRT protein abundance (relative to β-actin) was unchanged in people with schizophrenia compared with controls irrespective of inflammatory subtype. In contrast, FcGRT and FcGR3A mRNA levels were elevated in the midbrain from “high inflammation” schizophrenia cases (FcGRT; p = 0.02, FcGR3A; p < 0.0001) in comparison to low-inflammation patients and healthy controls, while FcGR2B mRNA levels were unchanged. IgG immunoreactivity was evident in the midbrain, and approximately 24% of all individuals (control subjects and schizophrenia cases) showed diffusion of IgG from blood vessels into the brain. However, the intensity and distribution of IgG was comparable across schizophrenia cases and control subjects. CONCLUSION: These findings suggest that an increase in the pro-inflammatory Fcγ receptor FcGR3A, rather than an overall increase in IgG levels, contribute to midbrain neuroinflammation in schizophrenia patients. However, more precise information about IgG-Fcγ receptor interactions is needed to determine their potential role in schizophrenia neuropathology. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12974-022-02541-8. |
format | Online Article Text |
id | pubmed-9287858 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-92878582022-07-17 Increased levels of a pro-inflammatory IgG receptor in the midbrain of people with schizophrenia Petty, A. Glass, L. J. Rothmond, D. A. Purves-Tyson, T. Sweeney, A. Kondo, Y. Kubo, S. Matsumoto, M. Weickert, C. Shannon J Neuroinflammation Research BACKGROUND: There is growing evidence that neuroinflammation may contribute to schizophrenia neuropathology. Elevated pro-inflammatory cytokines are evident in the midbrain from schizophrenia subjects, findings that are driven by a subgroup of patients, characterised as a “high inflammation” biotype. Cytokines trigger the release of antibodies, of which immunoglobulin G (IgG) is the most common. The level and function of IgG is regulated by its transporter (FcGRT) and by pro-inflammatory IgG receptors (including FcGR3A) in balance with the anti-inflammatory IgG receptor FcGR2B. Testing whether abnormalities in IgG activity contribute to the neuroinflammatory abnormalities schizophrenia patients, particularly those with elevated cytokines, may help identify novel treatment targets. METHODS: Post-mortem midbrain tissue from healthy controls and schizophrenia cases (n = 58 total) was used to determine the localisation and abundance of IgG and IgG transporters and receptors in the midbrain of healthy controls and schizophrenia patients. Protein levels of IgG and FcGRT were quantified using western blot, and gene transcript levels of FcGRT, FcGR3A and FcGR2B were assessed using qPCR. The distribution of IgG in the midbrain was assessed using immunohistochemistry and immunofluorescence. Results were compared between diagnostic (schizophrenia vs control) and inflammatory (high vs low inflammation) groups. RESULTS: We found that IgG and FcGRT protein abundance (relative to β-actin) was unchanged in people with schizophrenia compared with controls irrespective of inflammatory subtype. In contrast, FcGRT and FcGR3A mRNA levels were elevated in the midbrain from “high inflammation” schizophrenia cases (FcGRT; p = 0.02, FcGR3A; p < 0.0001) in comparison to low-inflammation patients and healthy controls, while FcGR2B mRNA levels were unchanged. IgG immunoreactivity was evident in the midbrain, and approximately 24% of all individuals (control subjects and schizophrenia cases) showed diffusion of IgG from blood vessels into the brain. However, the intensity and distribution of IgG was comparable across schizophrenia cases and control subjects. CONCLUSION: These findings suggest that an increase in the pro-inflammatory Fcγ receptor FcGR3A, rather than an overall increase in IgG levels, contribute to midbrain neuroinflammation in schizophrenia patients. However, more precise information about IgG-Fcγ receptor interactions is needed to determine their potential role in schizophrenia neuropathology. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12974-022-02541-8. BioMed Central 2022-07-15 /pmc/articles/PMC9287858/ /pubmed/35841099 http://dx.doi.org/10.1186/s12974-022-02541-8 Text en © The Author(s) 2022 https://creativecommons.org/licenses/by/4.0/Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) . The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/ (https://creativecommons.org/publicdomain/zero/1.0/) ) applies to the data made available in this article, unless otherwise stated in a credit line to the data. |
spellingShingle | Research Petty, A. Glass, L. J. Rothmond, D. A. Purves-Tyson, T. Sweeney, A. Kondo, Y. Kubo, S. Matsumoto, M. Weickert, C. Shannon Increased levels of a pro-inflammatory IgG receptor in the midbrain of people with schizophrenia |
title | Increased levels of a pro-inflammatory IgG receptor in the midbrain of people with schizophrenia |
title_full | Increased levels of a pro-inflammatory IgG receptor in the midbrain of people with schizophrenia |
title_fullStr | Increased levels of a pro-inflammatory IgG receptor in the midbrain of people with schizophrenia |
title_full_unstemmed | Increased levels of a pro-inflammatory IgG receptor in the midbrain of people with schizophrenia |
title_short | Increased levels of a pro-inflammatory IgG receptor in the midbrain of people with schizophrenia |
title_sort | increased levels of a pro-inflammatory igg receptor in the midbrain of people with schizophrenia |
topic | Research |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9287858/ https://www.ncbi.nlm.nih.gov/pubmed/35841099 http://dx.doi.org/10.1186/s12974-022-02541-8 |
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