Related Experiment Video
Updated: Mar 25, 2026
Investigation of Macrophage Polarization Using Bone Marrow Derived Macrophages
Published on: June 23, 2013
Dynamic macrophage polarization-specific miRNA patterns reveal increased soluble VEGF receptor 1 by miR-125a-5p
David W Melton1, XiuFen Lei2, Jonathan A L Gelfond3
1Department of Surgery, University of Texas Health Science Center, San Antonio, Texas; Sam and Ann Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center, San Antonio, Texas; and South Texas Veterans Health Care System, San Antonio, Texas.
Abstract:
Dynamic, epigenetic mechanisms can regulate macrophage phenotypes following exposure to different stimulating conditions and environments. However, temporal patterns of microRNAs (miRNAs or miRs) across multiple macrophage polarization phenotypes have not been defined. We determined miRNA expression in bone marrow-derived murine macrophages over multiple time points (0.5, 1, 3, 24 h) following exposure to cytokines and/or LPS. We hypothesized that dynamic changes in miRNAs regulate macrophage phenotypes. Changes in macrophage polarization markers were detected as early as 0.5 and as late as 24 h; however, robust responses for most markers occurred within 3 h. In parallel, many polarization-specific miRNAs were also changed by 3 h and expressed divergent patterns between M1 and M2a conditions, with increased expression in M1 (miR-155, 199a-3p, 214-3p, 455-3p, and 125a) or M2a (miR-511 and 449a). Specifically, miR-125a-5p exhibited divergent patterns: increased at 12-24 h in M1 macrophages and decreasing trend in M2a. VEGF in the culture media of macrophages was dependent upon the polarization state, with greatly diminished VEGF in M2a compared with M1 macrophage culture media despite similar VEGF in cell lysates. Inhibition of miR-125a-5p in media-only controls (MO) and M1 macrophages greatly increased expression and secretion of soluble VEGF receptor-1 (sVEGFR1) leading to diminished VEGF in the culture media, partially converting MO and M1 into an M2a phenotype. Thus, the divergent expression patterns of polarization-specific miRNAs led to the identification and demonstrated the regulation of a specific macrophage polarization phenotype, sVEGFR1 by inhibition of miR-125a-5p.
Insights
Dynamic microRNA changes regulate macrophage polarization. Specific microRNAs (miRs) like miR-125a-5p control vascular endothelial growth factor (VEGF) secretion, influencing macrophage phenotypes.
Area of Science:
- Immunology
- Epigenetics
- Molecular Biology
Background:
- Macrophage polarization is crucial for immune responses.
- Epigenetic regulation, including microRNAs (miRNAs), influences macrophage phenotypes.
- Temporal miRNA expression patterns during macrophage polarization remain largely undefined.
Purpose of the Study:
- To define temporal miRNA expression profiles during macrophage polarization.
- To investigate the role of dynamic miRNA changes in regulating macrophage phenotypes.
- To identify specific miRNAs involved in M1 and M2a macrophage polarization.
Main Methods:
- Murine bone marrow-derived macrophages were stimulated with cytokines and LPS.
- miRNA expression was analyzed at multiple time points (0.5-24 h).
- Macrophage polarization markers and VEGF secretion were quantified.
Main Results:
- Macrophage polarization markers and specific miRNAs (e.g., miR-155, miR-125a-5p) showed dynamic changes within 3-24 h.
- miR-125a-5p exhibited divergent expression patterns in M1 and M2a macrophages.
- Inhibition of miR-125a-5p increased soluble VEGF receptor-1 (sVEGFR1) and decreased VEGF secretion, shifting M1 towards an M2a phenotype.
Conclusions:
- Dynamic miRNA expression patterns are critical for regulating macrophage polarization.
- miR-125a-5p plays a key role in controlling VEGF secretion and macrophage phenotype.
- miRNAs represent potential therapeutic targets for modulating macrophage function.
Related Concept Videos
01:16TGF - β Signaling Pathway
01:24Regulation of Angiogenesis and Blood Supply