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Published on: June 15, 2017
Generation of transgenic mice that conditionally express microRNA miR-145
Dwitiya Sawant1, Emilie Klevenow1,2, Jeremy T Baeten1,3
1Center for Cardiovascular Research and The Heart Center, Nationwide Children's Hospital, Columbus, Ohio, USA.
Abstract:
MicroRNAs are modulators of cellular phenotypes and their functions contribute to development, homeostasis, and disease. miR-145 is a conserved microRNA that has been implicated in regulating an array of phenotypes. These include supporting smooth muscle differentiation, repression of stem cell pluripotency, and inhibition of tumor growth and metastasis. Previously, our lab demonstrated that miR-145 acts to suppress cardiac fibrosis through inhibition of the TGF-β signaling pathway. The range of effects that miR-145 has on different cell types makes it an attractive microRNA for further study. Here we describe the generation of transgenic mice that conditionally express miR-145 through Cre recombinase-mediated activation. Characterization of individual founder lines indicates that overexpression of miR-145 in the developing cardiovascular system has detrimental effects, with three independent miR-145 transgenic lines exhibiting Cre-dependent lethality. Expression analysis demonstrates that the transgene is robustly expressed and our analysis reveals a novel downstream target of miR-145, Tnnt2. The miR-145 transgenic mice represent a valuable tool to understand the role of miR-145 in diverse cell types and to address its potential as a therapeutic mediator for the treatment of disease.
Insights
We generated transgenic mice to study microRNA-145 (miR-145) function. Overexpression of miR-145 in the cardiovascular system led to lethality, revealing its critical role in development.
Area of Science:
- Molecular Biology
- Genetics
- Cardiovascular Biology
Background:
- MicroRNAs (miRNAs) regulate cellular phenotypes, impacting development, homeostasis, and disease.
- miR-145 is a conserved miRNA involved in smooth muscle differentiation, stem cell pluripotency, and tumor suppression.
- Previous studies showed miR-145 suppresses cardiac fibrosis by inhibiting the TGF-β pathway.
Purpose of the Study:
- To generate and characterize transgenic mice for conditional miR-145 expression.
- To investigate the role of miR-145 in the cardiovascular system.
- To identify novel downstream targets of miR-145.
Main Methods:
- Generation of Cre-inducible transgenic mice for miR-145 overexpression.
- Phenotypic characterization of founder lines, including survival analysis.
- Gene expression analysis to identify downstream targets.
Main Results:
- Conditional overexpression of miR-145 in the developing cardiovascular system resulted in Cre-dependent lethality in three independent lines.
- The miR-145 transgene was robustly expressed.
- A novel downstream target of miR-145, Tnnt2, was identified.
Conclusions:
- Conditional miR-145 expression in the developing cardiovascular system is essential and its dysregulation is detrimental.
- The generated miR-145 transgenic mice are a valuable tool for studying miRNA function in various cell types.
- These mice can aid in understanding miR-145's therapeutic potential for diseases.
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