Identification, classification, and expression ofRAGEgene splice variants

Abstract

The receptor for advanced glycation end-products (RAGE) is a single-transmembrane, multiligand receptor of the immunoglobulin superfamily. RAGE up-regulation is implicated in numerous pathological states including vascular disease, diabetes, cancer, and neurodegeneration. The understanding of the regulation of RAGE is important in both disease pathogenesis and normal homeostasis. Here, we demonstrate the characterization and identification of human RAGE splice variants by analysis of RAGE cDNA from tissue and cells. We identified a vast range of splice forms that lead to changes in the protein coding region of RAGE, which we have classified according to the Human Gene Nomenclature Committee (HGNC). These resulted in protein changes in the ligand-binding domain of RAGE or the removal of the transmembrane domain and cytosolic tail. Analysis of splice variants for premature termination codons reveals approximately 50% of identified variants are targeted to the nonsense-mediated mRNA decay pathway. Expression analysis revealed the RAGE_v1 variant to be the primary secreted soluble isoform of RAGE. Taken together, identification of functional splice variants of RAGE underscores the biological diversity of the RAGE gene and will aid in the understanding of the gene in the normal and pathological state.

Levels of soluble receptor for AGE are cross-sectionally associated with cardiovascular disease in type 1 diabetes, and this association is partially mediated by endothelial and renal dysfunction and by low-grade inflammation: the EURODIAB Prospective Complications Study

“…Indeed, the regulatory mechanisms for proteolytic shedding of cellbound RAGE to generate sRAGE and for alternative splicing to generate esRAGE are still unclear. Recently, new splice variants have been discovered [6] and further studies are necessary to establish which variants of sRAGE are measured by these assays and whether different soluble forms of RAGE have different (patho) physiological functions.…”

“…In addition to cell-bound RAGE, soluble forms of RAGE appear in the plasma [4,5], as different splice variants of RAGE (e.g. endogenous secretory receptor for AGE [esRAGE]) leaking through the transmembrane and cytosolic domain [4,6], and as a proteolytically cleaved form of RAGE (sRAGE), which is most probably shed into the circulation by the sheddase, known as a disintegrin and metalloprotease 10 (ADAM 10) [7]. The functional role of these soluble forms of RAGE in the circulation remains unclear, but they may reflect the activity of the AGE-RAGE axis.…”

Soluble Receptor for Advanced Glycation End Products: A Biomarker for Microangiopathy in Type II Diabetes

“…A publication summarizing the work of many laboratories showed that extensive splicing of RAGE transcripts led to as many as 20 splice variants [4]. In endothelial cells, only three isoforms of RAGE were detected at significant levels: N-truncated (Nt-RAGE), Full Length (FL-RAGE) and endogenous secretory (esRAGE).With the exception of lung tissues where constitutive expression of FL-RAGE is abundant, RAGE is expressed at low levels in most other tissues, including normal brain tissue.…”

Perspectives on RAGE signaling and its role in cardiovascular disease

“…Over 20 different splice variants of RAGE have been identified [Hudson et al, 2008;Sparvero et al, 2009]. The RAGE gene and its exons, introns, and domains are diagrammed in Figure 1.…”

“…Note the transmembrane domain and cytoplasmic tail. Derived from data in Hudson et al [2008]; Sparvero et al [2009]. signals with a complex inflammatory response that modulate their contractility.…”