1
|
Farris T, González-Ochoa S, Mohammed M, Rajakaruna H, Tonello J, Kanagasabai T, Korolkova O, Shimamoto A, Ivanova A, Shanker A. Loss of Mitochondrial Tusc2/Fus1 Triggers a Brain Pro-Inflammatory Microenvironment and Early Spatial Memory Impairment. Int J Mol Sci 2024; 25:7406. [PMID: 39000512 PMCID: PMC11242373 DOI: 10.3390/ijms25137406] [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: 05/02/2024] [Revised: 07/01/2024] [Accepted: 07/03/2024] [Indexed: 07/16/2024] Open
Abstract
Brain pathological changes impair cognition early in disease etiology. There is an urgent need to understand aging-linked mechanisms of early memory loss to develop therapeutic strategies and prevent the development of cognitive impairment. Tusc2 is a mitochondrial-resident protein regulating Ca2+ fluxes to and from mitochondria impacting overall health. We previously reported that Tusc2-/- female mice develop chronic inflammation and age prematurely, causing age- and sex-dependent spatial memory deficits at 5 months old. Therefore, we investigated Tusc2-dependent mechanisms of memory impairment in 4-month-old mice, comparing changes in resident and brain-infiltrating immune cells. Interestingly, Tusc2-/- female mice demonstrated a pro-inflammatory increase in astrocytes, expression of IFN-γ in CD4+ T cells and Granzyme-B in CD8+T cells. We also found fewer FOXP3+ T-regulatory cells and Ly49G+ NK and Ly49G+ NKT cells in female Tusc2-/- brains, suggesting a dampened anti-inflammatory response. Moreover, Tusc2-/- hippocampi exhibited Tusc2- and sex-specific protein changes associated with brain plasticity, including mTOR activation, and Calbindin and CamKII dysregulation affecting intracellular Ca2+ dynamics. Overall, the data suggest that dysregulation of Ca2+-dependent processes and a heightened pro-inflammatory brain microenvironment in Tusc2-/- mice could underlie cognitive impairment. Thus, strategies to modulate the mitochondrial Tusc2- and Ca2+- signaling pathways in the brain should be explored to improve cognitive health.
Collapse
Affiliation(s)
- Tonie Farris
- Department of Biomedical Sciences, School of Graduate Studies, Meharry Medical College, Nashville, TN 37208, USA; (T.F.); (M.M.); (T.K.)
- Department of Biochemistry, Cancer Biology, Neuroscience & Pharmacology, School of Medicine, Meharry Medical College, Nashville, TN 37208, USA; (S.G.-O.); (J.T.); (O.K.); (A.S.)
| | - Salvador González-Ochoa
- Department of Biochemistry, Cancer Biology, Neuroscience & Pharmacology, School of Medicine, Meharry Medical College, Nashville, TN 37208, USA; (S.G.-O.); (J.T.); (O.K.); (A.S.)
| | - Muna Mohammed
- Department of Biomedical Sciences, School of Graduate Studies, Meharry Medical College, Nashville, TN 37208, USA; (T.F.); (M.M.); (T.K.)
- Department of Biochemistry, Cancer Biology, Neuroscience & Pharmacology, School of Medicine, Meharry Medical College, Nashville, TN 37208, USA; (S.G.-O.); (J.T.); (O.K.); (A.S.)
| | - Harshana Rajakaruna
- The Office for Research and Innovation, Meharry Medical College, Nashville, TN 37208, USA;
| | - Jane Tonello
- Department of Biochemistry, Cancer Biology, Neuroscience & Pharmacology, School of Medicine, Meharry Medical College, Nashville, TN 37208, USA; (S.G.-O.); (J.T.); (O.K.); (A.S.)
| | - Thanigaivelan Kanagasabai
- Department of Biomedical Sciences, School of Graduate Studies, Meharry Medical College, Nashville, TN 37208, USA; (T.F.); (M.M.); (T.K.)
- Department of Biochemistry, Cancer Biology, Neuroscience & Pharmacology, School of Medicine, Meharry Medical College, Nashville, TN 37208, USA; (S.G.-O.); (J.T.); (O.K.); (A.S.)
| | - Olga Korolkova
- Department of Biochemistry, Cancer Biology, Neuroscience & Pharmacology, School of Medicine, Meharry Medical College, Nashville, TN 37208, USA; (S.G.-O.); (J.T.); (O.K.); (A.S.)
| | - Akiko Shimamoto
- Department of Biochemistry, Cancer Biology, Neuroscience & Pharmacology, School of Medicine, Meharry Medical College, Nashville, TN 37208, USA; (S.G.-O.); (J.T.); (O.K.); (A.S.)
| | - Alla Ivanova
- Department of Biomedical Sciences, School of Graduate Studies, Meharry Medical College, Nashville, TN 37208, USA; (T.F.); (M.M.); (T.K.)
- Department of Biochemistry, Cancer Biology, Neuroscience & Pharmacology, School of Medicine, Meharry Medical College, Nashville, TN 37208, USA; (S.G.-O.); (J.T.); (O.K.); (A.S.)
| | - Anil Shanker
- Department of Biochemistry, Cancer Biology, Neuroscience & Pharmacology, School of Medicine, Meharry Medical College, Nashville, TN 37208, USA; (S.G.-O.); (J.T.); (O.K.); (A.S.)
- The Office for Research and Innovation, Meharry Medical College, Nashville, TN 37208, USA;
| |
Collapse
|
2
|
Leadbetter EA, Karlsson MCI. Invariant natural killer T cells balance B cell immunity. Immunol Rev 2021; 299:93-107. [PMID: 33438287 DOI: 10.1111/imr.12938] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 11/21/2020] [Accepted: 12/04/2020] [Indexed: 12/21/2022]
Abstract
Invariant natural killer T (iNKT) cells mediate rapid immune responses which bridge the gap between innate and adaptive responses to pathogens while also providing key regulation to maintain immune homeostasis. Both types of important iNKT immune responses are mediated through interactions with innate and adaptive B cells. As such, iNKT cells sit at the decision-making fulcrum between regulating inflammatory or autoreactive B cells and supporting protective or regulatory B cell populations. iNKT cells interpret the signals in their environment to set the tone for subsequent adaptive responses, with outcomes ranging from getting licensed to maintain homeostasis as an iNKT regulatory cell (iNKTreg ) or being activated to become an iNKT follicular helper (iNKTFH ) cell supporting pathogen-specific effector B cells. Here we review iNKT and B cell cooperation across the spectrum of immune outcomes, including during allergy and autoimmune disease, tumor surveillance and immunotherapy, or pathogen defense and vaccine responses. Because of their key role as influencers, iNKT cells provide a valuable target for therapeutic interventions. Understanding the nature of the interactions between iNKT and B cells will enable the development of clinical interventions to strategically target regulatory iNKT and B cell populations or inflammatory ones, depending on the circumstance.
Collapse
Affiliation(s)
- Elizabeth A Leadbetter
- Department of Microbiology, Immunology and Molecular Genetics, UT Health San Antonio, San Antonio, TX, USA
| | - Mikael C I Karlsson
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|
3
|
Brailey PM, Lebrusant‐Fernandez M, Barral P. NKT cells and the regulation of intestinal immunity: a two‐way street. FEBS J 2020; 287:1686-1699. [PMID: 32022989 DOI: 10.1111/febs.15238] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 01/17/2020] [Accepted: 02/03/2020] [Indexed: 12/14/2022]
Abstract
The mammalian gastrointestinal compartment is colonised by millions of microorganisms that have a central influence on human health. Intestinal homeostasis requires a continuous dialogue between the commensal bacteria and intestinal immune cells. While interactions between host and commensal bacteria are normally beneficial, allowing training and functional tuning of immune cells, dysregulated immune system-microbiota crosstalk can favour the development of chronic inflammatory diseases, as it is the case for inflammatory bowel disease (IBD). Natural killer T (NKT) cells, which recognise CD1-restricted microbial and self-lipids, contribute to the regulation of mucosal immunity by controlling intestinal homeostasis and participating in the development of IBD. Here, we provide an overview of the recently identified pathways underlying the crosstalk between commensal bacteria and NKT cells and discuss the effect of these interactions in intestinal health and disease.
Collapse
Affiliation(s)
- Phillip M. Brailey
- The Peter Gorer Department of Immunobiology King’s College London UK
- The Francis Crick Institute London UK
| | - Marta Lebrusant‐Fernandez
- The Peter Gorer Department of Immunobiology King’s College London UK
- The Francis Crick Institute London UK
| | - Patricia Barral
- The Peter Gorer Department of Immunobiology King’s College London UK
- The Francis Crick Institute London UK
| |
Collapse
|