Table 1.
Summary of preclinical studies associated with Metrnl in inflammation and immunology.
| Year | Ref. | Methods | Main findings | |
|---|---|---|---|---|
| Immunology | Inflammation | |||
| 2014 | (15) | Mouse; in vitro | Trigger Type 2 immune cascade activation, promote M2 alternative activation of macrophages | Increase anti-inflammatory cytokines |
| 2015 | (9) | In vitro | Produced by M2-like macrophages | Overexpression in skin lesions of skin inflammatory diseases |
| 2016 | (16) | Mouse | Intestinal epithelial cells Metrnl-KO mouse: decrease gut antimicrobial peptides | – |
| 2018 | (17) | Mouse; in vitro | Metrnl−/− mice: develop inflammatory lesions easier, B-cell immune system defects | Induced by IL-4, IL-12, IL-17α, and TNF-α; inhibited by IFN-γ and TGF-β |
| 2019 | (18) | Mouse | Metrnl treatment in Crohn’s disease-like mouse: ameliorate mesenteric lesions via STAT5/PPAR-γ | Decrease inflammatory score and pro-inflammatory cytokines |
| 2020 | (19) | Mouse | Intestinal epithelial cells Metrnl-KO mouse: deteriorate ulcerative colitis via autophagy-related AMPK-mTOR-p70S6K pathway | Increase TNF-α, IL-6, and IL-1β |
| 2020 | (20) | In vitro | Metrnl overexpression in H9C2 cells: attenuate cardiomyocytes apoptosis via AMPK-PAK2 | Inhibit inflammation and endoplasmic reticulum stress |
| 2020 | (21) | Mouse; in vitro | Improve muscle regeneration by infiltrating immune cells via Stat3/IGF-1 | Induce macrophage differentiate into inflammatory phenotype |
| 2021 | (22) | Mouse | Metrnl treatment in non-obese diabetic mice: delay onset, ameliorate islet lymphocyte infiltration | Increase IL-4, IL-10, and Foxp3; decrease IL-2, IL-17, and IFN-γ; suppress Treg cells |
| 2021 | (23) | Mouse; in vitro | – | Inhibit IL-1β in macrophages; associated with NLRP3 inflammasome activation |
| 2021 | (24) | In vitro | LPS-treated cells: ameliorate endothelial inflammation via AMPK and PPARδ- pathways | Suppress TNF-α, MCP-1, NFκB and IκB phos-phorylations, and inflammatory markers |
| 2022 | (25) | Mouse; in vitro | Impair the maturation and functions of DCs, block the development of airway hyper-reactivity | Decrease DC-mediated Th2 immune responses and inflammation |
| 2022 | (26) | In vitro (fish) | Up-regulate Type 1 immune response | Increase IL-1β, IL-6, IL-8, IL-17A and TNF-α |