Abstract: SA-PO737
Development of a New Macrophage-Specific TRAP Mouse (MacTRAP) and Definition of the Renal Macrophage Translational Signature
Session Information
- CKD: Mechanisms - III
November 09, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: CKD (Non-Dialysis)
- 2103 CKD (Non-Dialysis): Mechanisms
Authors
- Hofmeister, Andreas, Philipps-Universität Marburg, Marburg, Germany
- Thomassen, Maximilian Claudius, Universitätsklinikum Marburg, Marburg, Germany
- Markert, Sabrina, Philipps Universität Marburg, Marburg, Germany
- Marquardt, André, Universitätsklinikum Würzburg, Würzburg, Germany
- Preußner, Mathieu, Philipps-Universität Marburg, Marburg, Germany
- Hoyer, Joachim, Philipps Universität Marburg, Marburg, Germany
- Humphreys, Benjamin D., Washington University School of Medicine, Clayton, Missouri, United States
- Grgic, Ivica, Philipps-Universität Marburg, Marburg, Germany
Background
Tissue macrophages play an important role in organ homeostasis and immunity as well as pathogenesis of inflammatory-driven diseases including organ fibrosis, atherosclerosis and autoimmune disorders. One major challenge has been as how to selectively study resident macrophages in vivo in highly heterogeneous organs such as kidney.
Methods
To address this problem, we adopted a translational ribosome affinity purification (TRAP) - approach and designed a transgene that expresses an enhanced green fluorescent protein (eGFP)-tagged ribosomal protein (L10a) under the control of the macrophage-specific c-fms promoter, a driver of the macrophage colony-stimulating factor 1 receptor (Csf1r), to generate c-fms-eGFP-L10a transgenic mice (MacTRAP).
Results
Rigorous characterization and validation found no gross anatomical, behavioral or developmental abnormalities in MacTRAP mice and confirmed transgene expression across various organs. Immunohistological analyses of MacTRAP kidneys identified eGFP-L10a-expressing cells in the tubulointerstitial compartment that stained positive for macrophage marker F4/80. Following induction of kidney fibrosis we observed a robust upregulation of eGFP-L10a along with classical macrophage and fibrotic markers, validating MacTRAP responsiveness upon proinflammatory challenge. Using TRAP, we successfully extracted macrophage-specific polysomal RNA from MacTRAP kidneys and conducted RNA sequencing followed by extensive bioinformatical analyses, hereby establishing a comprehensive in vivo gene expression and pathway signature of resident renal macrophages and closely related dendritic cells.
Conclusion
In summary, we have created, validated and applied a novel and responsive macrophage-specific TRAP mouse line, defining the translational profile of renal macrophages and dendritic cells. This new and broadly applicable tool may be of great value for the study of macrophage biology in different organs and various models of injury and disease.
Funding
- Government Support - Non-U.S.