Intraluminal Blockade of Cell-Surface CD74 and Glucose Regulated Protein 78 Prevents Substance P-Induced Bladder Inflammatory Changes in the RatReportar como inadecuado




Intraluminal Blockade of Cell-Surface CD74 and Glucose Regulated Protein 78 Prevents Substance P-Induced Bladder Inflammatory Changes in the Rat - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Background

Macrophage migration inhibitory factor MIF is a pro-inflammatory cytokine constitutively expressed by urothelial cells. During inflammatory stimuli, MIF is released into the lumen complexed to other proteins and these complexes can bind to urothelial cell-surface receptors to activate signaling pathways. Since MIF is complexed to α1-inhibitor III A1-I3; a member of the α2-macroglubulin family and glucose regulated protein 78 GRP78 is a receptor for A1-I3 the goals of this study were to determine if substance P elicits urothelial cell-surface expression of GRP78 and to assess the functional role of CD74 receptor for MIF or GRP78 in substance P-induced bladder inflammatory changes.

Methodology-Principal Findings

Anesthetized male Sprague-Dawley rats received either saline or substance P s.c., bladders were collected 1 hour after treatment and processed for histology or protein-mRNA. The expression of GRP78 at urothelial cell-surface was determined by performing in vivo biotinylation of urothelial cell-surface proteins. Finally, in order to determine the effects of receptor blockade on substance P-induced MIF release and inflammatory changes, rats received either intraluminal antibodies to CD74, GRP78, both, or non-specific IgG as a control.GRP78 and MIF immunostaining was simultaneously visualized in umbrella cells only after substance P treatment. Immunoprecipitation studies showed GRP78-MIF complexes increased after substance P while in vivo biotinylation confirmed substance P-induced GRP78 cell-surface expression in urothelial cells. Intraluminal blockade of CD74 and-or GRP78 prevented substance P-induced changes, including bladder edema, intraluminal MIF release by urothelial cells and production of inflammatory cytokines by urothelial cells.

Conclusions-Significance

GRP78 is expressed on the surface of urothelial cells after substance P treatment where it can bind MIF complexes. Blocking CD74 receptor for MIF and-or GRP78 prevented substance P-induced inflammatory changes in bladder and urothelium, indicating that these urothelial receptors are effective targets for disrupting MIF-mediated bladder inflammation.



Autor: Pedro L. Vera , Xihai Wang, Richard J. Bucala, Katherine L. Meyer-Siegler

Fuente: http://plos.srce.hr/



DESCARGAR PDF




Documentos relacionados