Document Type
Article
Publication Date
9-18-2025
Abstract
Macrophages are involved in several critical activities associated with tissue repair and regeneration. Current approaches in regenerative medicine are focusing on leveraging the innate immune response to accelerate tissue regeneration and improve long-term healing outcomes. Of particular interest in this regard are the currently known, four main M2 macrophage subtypes: M2interleukin (IL)-4,IL-13, M2IC, M2IL-10, M2non-selective adenosine receptor agonists (NECA) (M2IL-4,IL-13 → M2(NECA). In this study, rat bone marrow-derived macrophages (M₀) were polarized to each of the four subtypes M2IL-4,IL-13 → M2NECA and cultured for 72 h in vitro. Luminex assay results highlighted increased production of tissue inhibitor of metalloproteinases-1 (TIMP-1) for M2IL-4,IL-13, higher amounts of transforming growth factor-beta 1 (TGF-β1) for M2IL-10, and elevated vascular endothelial growth factor A (VEGF-A) from M2NECA. Co-culture experiments performed with M2IL-10 macrophages and L929 fibroblasts highlighted the increased production of soluble collagen within the media as well as higher amounts of collagen in the extracellular matrix. Human umbilical vein endothelial cells (HUVECs) were co-cultured with M2NECA macrophages, which demonstrated an increase in intercellular adhesion molecule (ICAM) and platelet endothelial cell adhesion molecule (PECAM), as well as increased formation of endothelial tubes. The findings of this study emphasize a critical demand for further characterization and analyses of distinct M₂ subtypes and careful selection of specific macrophage populations for regeneration of specific tissue types. The current, broad classification of “M₂” may be sufficient in many general tissue engineering applications, but, as conditions are constantly in flux within the microenvironment in vivo, a higher degree of specificity and control over the initial M₂ subtype could result in more consistent long-term outcomes where macrophages are utilized as part of an overall regenerative strategy.
Keywords
m2 macrophages, macrophages, tissue repair
Language
English
Publication Title
Journal of Biomedical Materials Research Part A
Grant
R21HD095439
Rights
© 2024 The Author(s). This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/BY-NC-ND/4.0/), which permits non-commercial copying and redistribution of the material in any medium or format, provided the original work is not changed in any way and is properly cited.
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Recommended Citation
Isali I , McClellan P , Wong TR , et al. Differential effects of macrophage subtype-specific cytokines on fibroblast proliferation and endothelial cell function in co-culture system. J Biomed Mater Res. 2025; 113(1):e37799. doi:10.1002/jbm.a.37799
Manuscript Version
Final Publisher Version