[Cardiac valve MCSF-1 and its receptor expression changes in Staphylococcus aureus induced infective endocarditis].
OBJECTIVE
To explore the cellular immunology mechanism of infective endocarditis (IE), we investigated the effects of Staphylococcus aureus (S. aureus) on MCSF-1 and its receptor (c-fms) gene expression in cardiac valves.


METHODS
Thirty-two rabbits were divided into 4 groups: mitral or tricuspid valve artificial lesions with 5 x 10(4) CFU or 5 x 10(6) CFU S. aureus injection. Control rabbits (n = 7) received 5 x 10(6) CFU S. aureus injection. IE after operation were confirmed by naked eyes and electron microscope observations. MCSF-1, c-fms in mitral and tricuspid valves were detected by RT-PCR.


RESULTS
Twenty-six rabbits survived the operation and 14 rabbits developed IE (2 with 5 x 10(4) CFU and 12 with 5 x 10(6) CFU S. aureus injection) one day post operation. S. aureus injection alone did not induce IE. Compared to control rabbits, MCSF-1 mRNA was significantly upregulated and c-fms mRNA significantly downregulated after 5 x 10(4) CFU S. aureus injection with heart valve artificial lesion in mitral valves or tricuspid valves. MCSF-1 expression in mitral valves was further increased while remained unchanged in tricuspid valve after 5 x 10(6) CFU S. aureus injection compared to that in 5 x 10(4) CFU S. aureus injection group.


CONCLUSIONS
High dose bacterial invasion and heart valves lesion were the main factors for inducing infective endocarditis. Development of infective endocarditis was associated with valve MCSF-1/c-fms expression changes in this rabbit model.
Zhao
Bo
B
Department of Tharocardiosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China. zhaobo0115@yahoo.com.cn
Wu
Liang
L
Sun
Wei
W
Fu
Xiang-Ning
XN
Li
Jun
J
Pan
Tie-Cheng
TC
D000818:Animals; D004697:Endocarditis, Bacterial / Q000378:metabolism* / Q000382:microbiology; D016173:Macrophage Colony-Stimulating Factor / Q000096:biosynthesis* / Q000235:genetics; D008943:Mitral Valve / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D011817:Rabbits; D016186:Receptor, Macrophage Colony-Stimulating Factor / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013203:Staphylococcal Infections / Q000378:metabolism* / Q000382:microbiology; D013211:Staphylococcus aureus
D012333:RNA, Messenger; D016173:Macrophage Colony-Stimulating Factor; D016186:Receptor, Macrophage Colony-Stimulating Factor