Inhibition of Scavenger
Receptor A Expression Treated with PMA by the Inhibitor of Tyrosine Protein
Kinase Genistein
JIN Yan, CHEN Qi*, WEI En-Hui, JIANG Li, FAN
Le-Ming, WANG Nan, CHEN Xiu-Ying
( Atherosclerosis Research Center, Nanjing Medical University, Nanjing 210029,
China )
Abstract In order to
investigate the relationship between scavenger receptor type A and cell signal
transduction, human U937 macrophages were treated with tyrosine protein kinase
inhibitor genistein, then the cells were incubated with ［125I］ox-LDL or ox-LDL, and the
cellular degradation of ［125I］ox-LDL or binding were
measured separately. Then the effect of the drug on cell surface expression of
SR-A were measured by means of autoradiography, it was found that genistein
could reduce cellular SR-A mRNA transcription by RT-PCR. The results
indicated that genistein could reduce U937 macrophages to bind lipids and
reduce SR-A expression by suppression of transcription, and could
reduce degradation of lipids by U937 macrophage and accumulation of cholesterol
within the cells. It suggests that the function of scavenger receptors may be
correlated with cell tyrosine protein kinase, the mechanism is transcriptional
and it also suggests that SR-A may participate in the signal transduction
directly.
Key words scavenger receptor；U937 cell line；genistein；ox-LDL
*Corresponding author：Tel,86-25-6662888；Fax,86-25-6508690；e-mail,[email protected]