Radiological assessment of effectiveness of soluble RAGE in attenuating Angiotensin II-induced LVH mouse model using in vivo 9.4T MRI.

We investigated the effectiveness of soluble Receptor for Advanced Glycation Endproducts (sRAGE) in attenuating angiotensin II (AngII)-induced left ventricular hypertrophy (LVH) using in vivo 9.4T cine-magnetic resonance imaging (CINE-MRI). Mice were divided into four groups: AngII (n = 9), saline (n = 10), sRAGE (n = 10), and AngII + sRAGE (n = 10). CINE-MRI was performed in each group after administration of the AngII or sRAGE, and CINE-MR images were analyzed to obtain parameters indicating cardiac anatomical and functional changes including end-diastolic and end-systolic blood volume, end-diastolic and end-systolic myocardial volume, ejection fraction, end-diastolic and end-systolic myocardial mass, and LV wall thickness. LVH observed in AngII group was significantly attenuated by sRAGE. These trends were also observed in histological analysis, demonstrating that cardiac function tracking using in vivo and real-time 9.4T MR imaging provides valuable information about the cardiac remodeling induced by AngII and sRAGE in an AngII-induced LV hypertrophy mice model.

Purification and Characterization of the Soluble form of the Receptor for Advanced Glycation End-Products (sRAGE): A Novel Fast, Economical and Convenient Method.

The receptor for advanced glycation end-products (RAGE) is a multi-ligand receptor which belongs to the pattern recognition receptor family and can bind to various ligands such as advanced glycation end-products (AGEs), members of the S100 protein family, glycosaminoglycans, amyloid ß peptides, high-mobility group box-1 (HMGB1) and nucleic acids through its extracellular domain. The RAGE-ligand interaction leads to the activation of MAP kinase and NF-kB signaling pathways. Further ligand-induced up-regulation of RAGE is involved in various patho-physiological situations including late diabetic complications, Alzheimer disease and several other neurodegenerative diseases. A secreted soluble isoform of RAGE (sRAGE), corresponding to the extracellular domain only, has the ability to block RAGE-associated cellular activation and signaling. Further application of recombinant sRAGE has been shown to block RAGE-mediated pathophysiological conditions in various models of cancer or multiple sclerosis. These finding demonstrates sRAGE as a therapeutic tool to block RAGE-associated inflammatory signaling. In this manuscript, we describe a two-step simple, novel and convenient method for expressing and purifying scalable quantities of biologically active murine form of sRAGE by using E.coli as an expression host. The method we propose has several advantages over the current available methods particularly in terms of yield and quality of preparation. The sRAGE produced by this expression system retains all the secondary structural properties as analyzed by the ligand binding affinities. The produced protein also retains all the DNA-RAGE binding functional properties and thus can be a valuable tool for studying dynamics of this novel RAGE ligand. Moreover this method can be utilized by researchers to generate biologically active endotoxin-free sRAGE for in vivo applications to study and treat RAGE-associated pathologies.