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Updated: Jul 5, 2026
Generation and Identification of GM-CSF Derived Alveolar-like Macrophages and Dendritic Cells From Mouse Bone Marrow
Published on: June 25, 2016
Deacetylase activity is required for STAT5-dependent GM-CSF functional activity in macrophages and differentiation to
Carlos Sebastián1, Maria Serra, Andrée Yeramian
1Institute for Research in Biomedicine and University of Barcelona, Barcelona Science Park, Josep Samitier 105, Barcelona, Spain.
Abstract:
After interaction with its receptor, GM-CSF induces phosphorylation of the beta-chain in two distinct domains in macrophages. One induces activation of mitogen-activated protein kinases and the PI3K/Akt pathway, and the other induces JAK2-STAT5. In this study we describe how trichostatin A (TSA), which inhibits deacetylase activity, blocks JAK2-STAT5-dependent gene expression but not the expression of genes that depend on the signal transduction induced by the other domain of the receptor. TSA treatment inhibited the GM-CSF-dependent proliferation of macrophages by interfering with c-myc and cyclin D1 expression. However, M-CSF-dependent proliferation, which requires ERK1/2, was unaffected. Protection from apoptosis, which involves Akt phosphorylation and p21(waf-1) expression, was not modified by TSA. GM-CSF-dependent expression of MHC class II molecules was inhibited because CIITA was not induced. The generation of dendritic cells was also impaired by TSA treatment because of the inhibition of IRF4, IRF2, and RelB expression. TSA mediates its effects by preventing the recruitment of RNA polymerase II to the promoter of STAT5 target genes and by inhibiting their expression. However, this drug did not affect STAT5A or STAT5B phosphorylation or DNA binding. These results in GM-CSF-treated macrophages reveal a relationship between histone deacetylase complexes and STAT5 in the regulation of gene expression.
Insights
Trichostatin A (TSA) inhibits histone deacetylase activity, blocking JAK2-STAT5-dependent gene expression in macrophages. This impacts GM-CSF-induced proliferation and dendritic cell generation, revealing a link between histone deacetylases and STAT5 in gene regulation.
Area of Science:
- Immunology
- Molecular Biology
- Epigenetics
Background:
- Granulocyte-macrophage colony-stimulating factor (GM-CSF) signaling involves beta-chain phosphorylation, activating distinct pathways including PI3K/Akt and JAK2-STAT5.
- Histone deacetylase (HDAC) inhibitors, like trichostatin A (TSA), modulate gene expression through epigenetic mechanisms.
Purpose of the Study:
- To investigate the role of histone deacetylase activity in GM-CSF-induced signaling pathways in macrophages.
- To determine the specific effects of TSA on GM-CSF-dependent cellular functions and gene expression.
- To elucidate the relationship between HDACs and STAT5 in regulating gene expression.
Main Methods:
- Treatment of macrophages with GM-CSF and TSA.
- Analysis of signaling pathway activation (e.g., phosphorylation of Akt, STAT5).
- Assessment of gene expression (e.g., c-myc, cyclin D1, CIITA, IRF4, IRF2, RelB) using techniques like RNA polymerase II recruitment assays.
- Evaluation of cellular functions including proliferation, apoptosis resistance, and dendritic cell generation.
Main Results:
- TSA selectively inhibited JAK2-STAT5-dependent gene expression, while sparing pathways activated by the other beta-chain domain.
- TSA impaired GM-CSF-induced macrophage proliferation by affecting c-myc and cyclin D1 expression but did not alter M-CSF-dependent proliferation or Akt-mediated apoptosis protection.
- TSA blocked GM-CSF-dependent MHC class II expression and dendritic cell generation by inhibiting key transcription factors, without affecting STAT5 phosphorylation or DNA binding.
Conclusions:
- Histone deacetylase activity, specifically through TSA, plays a critical role in regulating JAK2-STAT5-dependent gene expression in GM-CSF-stimulated macrophages.
- TSA interferes with the recruitment of RNA polymerase II to STAT5 target gene promoters, highlighting an epigenetic control mechanism.
- These findings reveal a functional interplay between histone deacetylase complexes and STAT5 in the context of GM-CSF signaling and macrophage biology.
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