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Jain N, Lord JM, Vogel V. Mechanoimmunology: Are inflammatory epigenetic states of macrophages tuned by biophysical factors? APL Bioeng 2022; 6:031502. [PMID: 36051106 PMCID: PMC9427154 DOI: 10.1063/5.0087699] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 07/26/2022] [Indexed: 11/17/2022] Open
Abstract
Many inflammatory diseases that are responsible for a majority of deaths are still uncurable, in part as the underpinning pathomechanisms and how to combat them is still poorly understood. Tissue-resident macrophages play pivotal roles in the maintenance of tissue homeostasis, but if they gradually convert to proinflammatory phenotypes, or if blood-born proinflammatory macrophages persist long-term after activation, they contribute to chronic inflammation and fibrosis. While biochemical factors and how they regulate the inflammatory transcriptional response of macrophages have been at the forefront of research to identify targets for therapeutic interventions, evidence is increasing that physical factors also tune the macrophage phenotype. Recently, several mechanisms have emerged as to how physical factors impact the mechanobiology of macrophages, from the nuclear translocation of transcription factors to epigenetic modifications, perhaps even DNA methylation. Insight into the mechanobiology of macrophages and associated epigenetic modifications will deliver novel therapeutic options going forward, particularly in the context of increased inflammation with advancing age and age-related diseases. We review here how biophysical factors can co-regulate pro-inflammatory gene expression and epigenetic modifications and identify knowledge gaps that require urgent attention if this therapeutic potential is to be realized.
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Affiliation(s)
| | | | - Viola Vogel
- Department of Health Sciences and Technology, Institute of Translational Medicine, ETH Zurich, Zurich, Switzerland
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Sarsenbayeva A, Pereira MJ, Nandi Jui B, Ahmed F, Dipta P, Fanni G, Almby K, Kristófi R, Hetty S, Eriksson JW. Excess glucocorticoid exposure contributes to adipose tissue fibrosis which involves macrophage interaction with adipose precursor cells. Biochem Pharmacol 2022; 198:114976. [PMID: 35202577 DOI: 10.1016/j.bcp.2022.114976] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 02/17/2022] [Accepted: 02/17/2022] [Indexed: 12/12/2022]
Abstract
Chronic exposure to elevated glucocorticoid levels, as seen in patients with Cushing's syndrome, can induce adipose tissue fibrosis. Macrophages play a pivotal role in adipose tissue remodelling. We used the synthetic glucocorticoid analogue dexamethasone to address glucocorticoid effects on adipose tissue fibrosis, in particular involving macrophage to preadipocyte communication. We analysed the direct effects of dexamethasone at a supra-physiological level, 0.3 µM, on gene expression of pro-fibrotic markers in human subcutaneous adipose tissue. The effects of dexamethasone on the differentiation of human SGBS preadipocytes were assessed in the presence or absence of THP1-macrophages or macrophage-conditioned medium. We measured the expression of different pro-fibrotic factors, including α-smooth muscle actin gene (ACTA2) and protein (α-SMA). Dexamethasone increased the expression of pro-fibrotic genes, e.g. CTGF, COL6A3, FN1, in adipose tissue. Macrophages abolished preadipocyte differentiation and increased the expression of the ACTA2 gene and α-SMA protein in preadipocytes after differentiation. Exposure to dexamethasone during differentiation reduced adipogenesis in preadipocytes, and elevated the expression of pro-fibrotic genes. Moreover, dexamethasone added together with macrophages further increased ACTA2 and α-SMA expression in preadipocytes, making them more myofibroblast-like. Cells differentiated in the presence of conditioned media from macrophages pretreated with or without dexamethasone had a higher expression of profibrotic genes compared to control cells. Our data suggest that macrophages promote adipose tissue fibrosis by directly interfering with preadipocyte differentiation and stimulating gene expression of pro-fibrotic factors. Excess glucocorticoid exposure also has pro-fibrotic effect on adipose tissue, but this requires the presence of macrophages.
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Affiliation(s)
- Assel Sarsenbayeva
- Department of Medical Sciences, Clinical Diabetes and Metabolism, Uppsala University, Uppsala, Sweden
| | - Maria J Pereira
- Department of Medical Sciences, Clinical Diabetes and Metabolism, Uppsala University, Uppsala, Sweden
| | - Bipasha Nandi Jui
- Department of Medical Sciences, Clinical Diabetes and Metabolism, Uppsala University, Uppsala, Sweden
| | - Fozia Ahmed
- Department of Medical Sciences, Clinical Diabetes and Metabolism, Uppsala University, Uppsala, Sweden
| | - Priya Dipta
- Department of Pharmacology, Faculty of Medicine, Hadassah Medical Centre, Jerusalem, Israel
| | - Giovanni Fanni
- Department of Medical Sciences, Clinical Diabetes and Metabolism, Uppsala University, Uppsala, Sweden
| | - Kristina Almby
- Department of Medical Sciences, Clinical Diabetes and Metabolism, Uppsala University, Uppsala, Sweden
| | - Robin Kristófi
- Department of Medical Sciences, Clinical Diabetes and Metabolism, Uppsala University, Uppsala, Sweden
| | - Susanne Hetty
- Department of Medical Sciences, Clinical Diabetes and Metabolism, Uppsala University, Uppsala, Sweden
| | - Jan W Eriksson
- Department of Medical Sciences, Clinical Diabetes and Metabolism, Uppsala University, Uppsala, Sweden.
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