Role of IL-18 in adipose tissue remodeling and metabolic dysfunction.
Int J Obes (Lond) 2024:10.1038/s41366-024-01507-5. [PMID:
38459259 DOI:
10.1038/s41366-024-01507-5]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 02/15/2024] [Accepted: 02/26/2024] [Indexed: 03/10/2024]
Abstract
BACKGROUND/OBJECTIVES
Proinflammatory cytokines are increased in obese adipose tissue, including inflammasome key masters. Conversely, IL-18 protects against obesity and metabolic dysfunction. We focused on the IL-18 effect in controlling adipose tissue remodeling and metabolism.
MATERIALS/SUBJECTS AND METHODS
We used C57BL/6 wild-type (WT) and interleukine-18 deficient (IL-18-/-) male mice fed a chow diet and samples from bariatric surgery patients.
RESULTS
IL-18-/- mice showed increased adiposity and proinflammatory cytokine levels in adipose tissue, leading to glucose intolerance. IL-18 was widely secreted by stromal vascular fraction but not adipocytes from mice's fatty tissue. Chimeric model experiments indicated that IL-18 controls adipose tissue expansion through its presence in tissues other than bone marrow. However, IL-18 maintains glucose homeostasis when present in bone marrow cells. In humans with obesity, IL-18 expression in omental tissue was not correlated with BMI or body fat mass but negatively correlated with IRS1, GLUT-4, adiponectin, and PPARy expression. Also, the IL-18RAP receptor was negatively correlated with IL-18 expression.
CONCLUSIONS
IL-18 signaling may control adipose tissue expansion and glucose metabolism, as its absence leads to spontaneous obesity and glucose intolerance in mice. We suggest that resistance to IL-18 signaling may be linked with worse glucose metabolism in humans with obesity.
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