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Updated: Aug 22, 2026
Isolation of Peritoneum-derived Mast Cells and Their Functional Characterization with Ca2+-imaging and Degranulation Assays
Published on: July 4, 2018
MITF is necessary for generation of prostaglandin D2 in mouse mast cells
1Department of Pathology, Osaka University Medical School, Suita, Osaka 565-0871, Japan. morii@patho.med.osaka-u.ac.jp
Abstract:
Mast cells generate eicosanoids that are linked to asthma and other inflammatory diseases. A basic-helix-loop-helix leucine zipper transcription factor termed MITF is essential for the development of mast cells. Although other substances also linked to inflammatory reactions (such as various proteases and serotonin) require MITF for their expression, the role of MITF in eicosanoid generation has not been studied. We examined eicosanoid generation in bone marrow-derived mast cells (BMMCs) of tg/tg mice that lack MITF. Most eicosanoids generated by BMMCs are either prostaglandin (PG) D2 or leukotriene C4. The former is synthesized via the cyclooxygenase pathway, whereas the latter is synthesized via the 5-lipoxygenase pathway. In response to stimulation with IgE and antigens, BMMCs of tg/tg mice synthesized leukotriene C4 normally. However, neither immediate nor delayed PGD2 production was detected in these BMMCs. This indicates that MITF is a transcription factor that specifically activates the cyclooxygenase pathway, but not the 5-lipoxygenase pathway. Significant decreases in expression of hematopoietic PGD2 synthase (hPGDS, a terminal synthase for PGD2) were observed at both mRNA and protein levels in tg/tg BMMCs. MITF transactivated the hPGDS gene via a CACCTG motif located in the promoter region. MITF appeared to be essential for generation of PGD2 by enhancing expression of the hPGDS gene in BMMCs.
Insights
Microphthalmia-associated transcription factor (MITF) is crucial for prostaglandin D2 (PGD2) generation in mast cells. MITF specifically activates the cyclooxygenase pathway by enhancing hematopoietic PGD2 synthase expression.
Area of Science:
- Immunology
- Molecular Biology
- Cell Biology
Background:
- Mast cells are key players in inflammatory diseases, producing eicosanoids like prostaglandin D2 (PGD2) and leukotriene C4.
- Microphthalmia-associated transcription factor (MITF) is essential for mast cell development and regulates inflammatory mediators.
- The specific role of MITF in mast cell eicosanoid generation remained uninvestigated.
Purpose of the Study:
- To elucidate the role of MITF in eicosanoid generation by mast cells.
- To determine if MITF influences prostaglandin D2 (PGD2) or leukotriene C4 synthesis.
- To investigate the molecular mechanism by which MITF affects PGD2 production.
Main Methods:
- Utilized bone marrow-derived mast cells (BMMCs) from MITF-deficient (tg/tg) mice.
- Stimulated BMMCs with IgE and antigens to assess eicosanoid production.
- Quantified PGD2 and leukotriene C4 generation using established assays.
- Analyzed mRNA and protein expression levels of key enzymes, including hematopoietic PGD2 synthase (hPGDS).
- Investigated MITF's interaction with the hPGDS gene promoter region.
Main Results:
- MITF-deficient BMMCs produced normal levels of leukotriene C4, indicating intact 5-lipoxygenase pathway activity.
- Neither immediate nor delayed PGD2 production was detected in MITF-deficient BMMCs.
- Expression of hematopoietic PGD2 synthase (hPGDS) was significantly reduced at both mRNA and protein levels in MITF-deficient BMMCs.
- MITF directly transactivated the hPGDS gene through a CACCTG motif in its promoter.
Conclusions:
- MITF is essential for prostaglandin D2 (PGD2) generation in mast cells.
- MITF specifically regulates the cyclooxygenase pathway, not the 5-lipoxygenase pathway, in mast cell eicosanoid synthesis.
- MITF enhances PGD2 production by upregulating the expression of hematopoietic PGD2 synthase (hPGDS).
