Abstract
Background: Experiments using Cre recombinase to study smooth muscle specific functions rely on strict specificity of Cre transgene expression. Therefore, accurate determination of Cre activity is critical to the interpretation of experiments using smooth muscle specific Cre. Methods and results: Two lines of smooth muscle protein 22 α-Cre (SM22α-Cre) mice were bred to floxed mice in order to define Cre transgene expression. Southern blotting demonstrated that SM22α-Cre was expressed not only in tissues abundant of smooth muscle, but also in spleen, which consists largely of immune cells including myeloid and lymphoid cells. PCR detected SM22α-Cre expression in peripheral blood and peritoneal macrophages. Analysis of SM22α-Cre mice crossed with a recombination detector GFP mouse revealed GFP expression, and hence recombination, in circulating neutrophils and monocytes by flow cytometry. Conclusions: SM22α-Cre mediates recombination not only in smooth muscle cells, but also in myeloid cells including neutrophils, monocytes, and macrophages. Given the known contributions of myeloid cells to cardiovascular phenotypes, caution should be taken when interpreting data using SM22α-Cre mice to investigate smooth muscle specific functions. Strategies such as bone marrow transplantation may be necessary when SM22α-Cre is used to differentiate the contribution of smooth muscle cells versus myeloid cells to observed phenotypes.
Original language | English (US) |
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Pages (from-to) | 639-642 |
Number of pages | 4 |
Journal | Biochemical and Biophysical Research Communications |
Volume | 422 |
Issue number | 4 |
DOIs | |
State | Published - Jun 15 2012 |
Externally published | Yes |
Keywords
- Macrophages
- Monocytes
- Myeloid cells
- Neutrophils
- SM22α-Cre
- Smooth muscle cells
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Molecular Biology
- Cell Biology