title: The level of CD147 expression correlates with cyclophilin-induced signalling and chemotaxis.
abstract: BACKGROUND
  Previous studies identified CD147 as the chemotactic receptor on inflammatory leukocytes for extracellular cyclophilins (eCyp). However, CD147 is not known to associate with signal transducing molecules, so other transmembrane proteins, such as proteoglycans, integrins, and CD98, were suggested as receptor or co-receptor for eCyp. CD147 is ubiquitously expressed on many cell types, but relationship between the level of CD147 expression and cellular responses to eCyp has never been analyzed. Given the role of eCyp in pathogenesis of many diseases, it is important to know whether cellular responses to eCyp are regulated at the level of CD147 expression.
  
  
  RESULTS
  Here, we manipulated CD147 expression levels on HeLa cells using RNAi and investigated the signalling and chemotactic responses to eCypA. Both Erk activation and chemotaxis correlated with the level of CD147 expression, with cells exhibiting low level expression being practically unresponsive to eCypA.
  
  
  CONCLUSIONS
  Our results provide the first demonstration of a chemotactic response of HeLa cells to eCypA, establish a correlation between the level of CD147 expression and the magnitude of cellular responses to eCypA, and indicate that CD147 may be a limiting factor in the receptor complex determining cyclophilin-induced Erk activation and cell migration.
authors: The George Washington University, Washington, DC 20037, USA. mtmmib@gwumc.edu.
authors: Alexander
authors: A
authors: Trachtenberg
authors: Tatiana
authors: T
authors: Pushkarsky
authors: Shannon
authors: S
authors: Heine
authors: Stephanie
authors: S
authors: Constant
authors: Beda
authors: B
authors: Brichacek
authors: Michael
authors: M
authors: Bukrinsky