Class A macrophage scavenger receptor gene expression levels in peripheral blood mononuclear cells specifically increase in patients with acute coronary syndrome.
OBJECTIVE
Morbidity and mortality rates are still high among patients with acute coronary syndrome (ACS); moreover, it is clinically difficult to determine precisely which patients will progress satisfactorily. Unstable plaque is characterized by an increased number of activated inflammatory cells, including macrophages and lymphocytes, and an increased release of numerous inflammatory mediators and proteolytic enzymes. Mononuclear cells consist of monocytes/macrophages and lymphocytes and are able to be experimentally isolated. We searched for a specific risk factor for ACS in the peripheral blood mononuclear cells (PBMCs).


RESULTS
We examined the expression of 12,625 genes in PBMCs utilizing a gene chip microarray system in ACS patients in acute and chronic stable phases. The gene expression profiles revealed that class A macrophage scavenger receptors (SR-A), among the immune response factors and the receptor activity markers, were the most strongly increased in the acute phase. We examined SR-A gene expression levels of PBMCs using real time RT-PCR in 122 consecutive patients: 32 ACS patients; 41 stable angina patients; and, 49 control subjects. The SR-A gene expression levels of the PBMCs were highest in the ACS patients (p<0.0001). The occurrence of a reattack of a cardiovascular event was significantly lower in the low SR-A group than in the high SR-A group (p<0.001).


CONCLUSIONS
SR-A gene expression level in the PBMCs specifically increases in patients with ACS, and provides a predictive marker for a reattack of a cardiovascular event.
Nakayama
Masafumi
M
Department of Cardiovascular Medicine, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto City 860-8556, Japan. nakama@kumamoto-u.ac.jp
Kudoh
Takashi
T
Kaikita
Koichi
K
Yoshimura
Michihiro
M
Oshima
Shuichi
S
Miyamoto
Yoshihiro
Y
Takeya
Motohiro
M
Ogawa
Hisao
H
D054058:Acute Coronary Syndrome / Q000097:blood* / Q000175:diagnosis*; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D015870:Gene Expression; D020869:Gene Expression Profiling; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000097:blood; D012008:Recurrence; D012044:Regression Analysis; D012307:Risk Factors; D051117:Scavenger Receptors, Class A / Q000235:genetics*
C495139:MSR1 protein, human; D012333:RNA, Messenger; D051117:Scavenger Receptors, Class A