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Shih WC, Jang IH, Kruglov V, Dickey D, Cholensky S, Bernlohr DA, Camell CD. Role for BLT1 in regulating inflammation within adipose tissue immune cells of aged mice. Immun Ageing 2024; 21:57. [PMID: 39187841 PMCID: PMC11346001 DOI: 10.1186/s12979-024-00461-0] [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: 04/13/2024] [Accepted: 08/15/2024] [Indexed: 08/28/2024]
Abstract
BACKGROUND Aging is a complex biological process characterized by obesity and immunosenescence throughout the organism. Immunosenescence involves a decline in immune function and the increase in chronic-low grade inflammation, called inflammaging. Adipose tissue expansion, particularly that of visceral adipose tissue (VAT), is associated with an increase in pro-inflammatory macrophages that play an important role in modulating immune responses and producing inflammatory cytokines. The leukotriene B4 receptor 1 (BLT1) is a regulator of obesity-induced inflammation. Its ligand, LTB4, acts as a chemoattractant for immune cells and induces inflammation. Studies have shown that BLT1 is crucial for cytokine production during lipopolysaccharide (LPS) endotoxemia challenge in younger organisms. However, the expression patterns and function of BLT1 in older organisms remains unknown. RESULTS In this study, we investigated BLT1 expression in immune cell subsets within the VAT of aged male and female mice. Moreover, we examined how antagonizing BLT1 signaling could alter the inflammatory response to LPS in aged mice. Our results demonstrate that aged mice exhibit increased adiposity and inflammation, characterized by elevated frequencies of B and T cells, along with pro-inflammatory macrophages in VAT. BLT1 expression is the highest in VAT macrophages. LPS and LTB4 treatment result in increased BLT1 in young and aged bone marrow-derived macrophages (BMDMs). However, LTB4 treatment resulted in amplified Il6 from aged, but not young BMDMs. Treatment of aged mice with the BLT1 antagonist, U75302, followed by LPS-induced endotoxemia resulted in an increase in anti-inflammatory macrophages, reduced phosphorylated NFκB and reduced Il6. CONCLUSIONS This study provides valuable insights into the age- and sex- specific changes in BLT1 expression on immune cell subsets within VAT. This study offers support for the potential of BLT1 in modulating inflammation in aging.
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Affiliation(s)
- Wei-Ching Shih
- Department of Pharmacology, Molecular Pharmacology and Therapeutics Graduate Program, University of Minnesota, Minneapolis, MN, USA
| | - In Hwa Jang
- Department of Biochemistry, Molecular Biology and Biophysics, Institute on the Biology of Aging and Metabolism, University of Minnesota, Minneapolis, MN, USA
- Center for Immunology, University of Minnesota, Minneapolis, MN, USA
| | - Victor Kruglov
- Department of Biochemistry, Molecular Biology and Biophysics, Institute on the Biology of Aging and Metabolism, University of Minnesota, Minneapolis, MN, USA
| | - Deborah Dickey
- Department of Biochemistry, Molecular Biology and Biophysics, Institute on the Biology of Aging and Metabolism, University of Minnesota, Minneapolis, MN, USA
| | - Stephanie Cholensky
- Department of Biochemistry, Molecular Biology and Biophysics, Institute on the Biology of Aging and Metabolism, University of Minnesota, Minneapolis, MN, USA
- Center for Immunology, University of Minnesota, Minneapolis, MN, USA
| | - David A Bernlohr
- Department of Biochemistry, Molecular Biology and Biophysics, Institute on the Biology of Aging and Metabolism, University of Minnesota, Minneapolis, MN, USA
| | - Christina D Camell
- Department of Pharmacology, Molecular Pharmacology and Therapeutics Graduate Program, University of Minnesota, Minneapolis, MN, USA.
- Department of Biochemistry, Molecular Biology and Biophysics, Institute on the Biology of Aging and Metabolism, University of Minnesota, Minneapolis, MN, USA.
- Center for Immunology, University of Minnesota, Minneapolis, MN, USA.
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Leysen H, Walter D, Clauwaert L, Hellemans L, van Gastel J, Vasudevan L, Martin B, Maudsley S. The Relaxin-3 Receptor, RXFP3, Is a Modulator of Aging-Related Disease. Int J Mol Sci 2022; 23:4387. [PMID: 35457203 PMCID: PMC9027355 DOI: 10.3390/ijms23084387] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 04/08/2022] [Accepted: 04/12/2022] [Indexed: 12/12/2022] Open
Abstract
During the aging process our body becomes less well equipped to deal with cellular stress, resulting in an increase in unrepaired damage. This causes varying degrees of impaired functionality and an increased risk of mortality. One of the most effective anti-aging strategies involves interventions that combine simultaneous glucometabolic support with augmented DNA damage protection/repair. Thus, it seems prudent to develop therapeutic strategies that target this combinatorial approach. Studies have shown that the ADP-ribosylation factor (ARF) GTPase activating protein GIT2 (GIT2) acts as a keystone protein in the aging process. GIT2 can control both DNA repair and glucose metabolism. Through in vivo co-regulation analyses it was found that GIT2 forms a close coexpression-based relationship with the relaxin-3 receptor (RXFP3). Cellular RXFP3 expression is directly affected by DNA damage and oxidative stress. Overexpression or stimulation of this receptor, by its endogenous ligand relaxin 3 (RLN3), can regulate the DNA damage response and repair processes. Interestingly, RLN3 is an insulin-like peptide and has been shown to control multiple disease processes linked to aging mechanisms, e.g., anxiety, depression, memory dysfunction, appetite, and anti-apoptotic mechanisms. Here we discuss the molecular mechanisms underlying the various roles of RXFP3/RLN3 signaling in aging and age-related disorders.
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Affiliation(s)
- Hanne Leysen
- Receptor Biology Laboratory, University of Antwerp, 2610 Wilrijk, Belgium; (H.L.); (D.W.); (L.C.); (L.H.); (J.v.G.)
| | - Deborah Walter
- Receptor Biology Laboratory, University of Antwerp, 2610 Wilrijk, Belgium; (H.L.); (D.W.); (L.C.); (L.H.); (J.v.G.)
| | - Lore Clauwaert
- Receptor Biology Laboratory, University of Antwerp, 2610 Wilrijk, Belgium; (H.L.); (D.W.); (L.C.); (L.H.); (J.v.G.)
| | - Lieselot Hellemans
- Receptor Biology Laboratory, University of Antwerp, 2610 Wilrijk, Belgium; (H.L.); (D.W.); (L.C.); (L.H.); (J.v.G.)
| | - Jaana van Gastel
- Receptor Biology Laboratory, University of Antwerp, 2610 Wilrijk, Belgium; (H.L.); (D.W.); (L.C.); (L.H.); (J.v.G.)
- SGS Belgium, Intercity Business Park, Generaal De Wittelaan 19-A5, 2800 Mechelen, Belgium
| | | | - Bronwen Martin
- Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, 2610 Wilrijk, Belgium;
| | - Stuart Maudsley
- Receptor Biology Laboratory, University of Antwerp, 2610 Wilrijk, Belgium; (H.L.); (D.W.); (L.C.); (L.H.); (J.v.G.)
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