[Dynamic changes of peripheral blood monocyte subsets after myocardial ischemia/reperfusion in rats].
OBJECTIVE
To investigate the dynamic changes of monocyte subsets after myocardial ischemia/reperfusion (I/R) in rats and their correlations with myocardial repair after I/R injury.


METHODS
Sixteen male Wistar rats were randomly divided into two groups: I/R group and sham group. Myocardial I/R was induced by left anterior descending coronary artery ligation for 45 min followed by permanent reperfusion. Peripheral blood was harvested from the tail vein to evaluate the dynamics of CD172a(+);CD43(low); and CD172a(+);CD43(high); monocyte subsets by flow cytometry at baseline and on day 1, 3, 5, 7 and 14 after I/R injury. Survival rats were sacrificed on day 30, and the hearts were prepared for the evaluation of collagen deposition (Masson's trichrome staining) and myocardial hypertrophy (wheat-germ agglutinin staining).


RESULTS
In I/R group, there was a significant increase of CD172a(+);CD43(low); monocytes on day 1 compared with the baseline (P<0.05), followed by an increasing trend, which peaked on day 3 (P<0.01), and then underwent a gradual decreasing trend to the baseline on day 7. In sham group, a similar increasing trend of CD172a(+);CD43(low); monocytes was observed on day 1 (P<0.05) compared with the baseline, whereas this trend declined rapidly to the baseline level on day 3. The proportion of CD172a(+);CD43(low); in I/R group on day 3 was much higher than that in the sham group (P<0.01). There were no significant differences between the two groups at any other time points. A reciprocal change of CD172a(+);CD43(high); monocytes was observed during investigation. Cardiac pathological evaluation revealed that there was a significant reparative fibrosis in the infarct area (P<0.05) along with a significant myocardial hypertrophy in non-infarct area (P<0.01) in I/R group. Correlation analysis showed that the proportion of CD172a(+);CD43(low); monocytes on day 3, but not CD172a(+);CD43(high); monocytes, was positively correlated with the level of collagen deposition in the infarct area (r=0.86, P<0.05).


CONCLUSIONS
The study demonstrates the dynamic profile of circulating monocyte subsets following myocardial I/R injury in rats, which indicates that the proinflammatory CD172a(+);CD43(low); monocytes might be a therapeutic target to attenuate myocardial I/R injury.
School of Graduates, Tianjin Medical University, Tianjin 300070; Institute of Cardiovascular Diseases and Heart Center, Pingjin Hospital, Logistics University of Chinese People's Armed Police Forces, Tianjin 300162, China.
Ruiyi
R
Lu
Institute of Cardiovascular Diseases and Heart Center, Pingjin Hospital, Logistics University of Chinese People's Armed Police Forces, Tianjin 300162, China.
Xin
X
Zhou
Department of Respiratory and Critical Care Medicine, Pingjin Hospital, Logistics University of Chinese People's Armed Police Forces, Tianjin 300162, China.
Wenjie
W
Ji
Institute of Cardiovascular Diseases and Heart Center, Pingjin Hospital, Logistics University of Chinese People's Armed Police Forces, Tianjin 300162, China.
Yuechen
Y
Luo
Institute of Cardiovascular Diseases and Heart Center, Pingjin Hospital, Logistics University of Chinese People's Armed Police Forces, Tianjin 300162, China.
Guohong
G
Yang
Institute of Cardiovascular Diseases and Heart Center, Pingjin Hospital, Logistics University of Chinese People's Armed Police Forces, Tianjin 300162, China.
Haiying
H
Sun
Institute of Cardiovascular Diseases and Heart Center, Pingjin Hospital, Logistics University of Chinese People's Armed Police Forces, Tianjin 300162, China.
Lan
L
Ge
Institute of Cardiovascular Diseases and Heart Center, Pingjin Hospital, Logistics University of Chinese People's Armed Police Forces, Tianjin 300162, China.
Tiemin
T
Jiang
Institute of Cardiovascular Diseases and Heart Center, Pingjin Hospital, Logistics University of Chinese People's Armed Police Forces, Tianjin 300162, China.
Yuming
Y
Li
D000818:Animals; D051917:Leukosialin / Q000378:metabolism; D008297:Male; D009000:Monocytes / Q000378:metabolism*; D017202:Myocardial Ischemia / Q000150:complications*; D009206:Myocardium / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000097:blood* / Q000150:complications* / Q000473:pathology; D013997:Time Factors
D051917:Leukosialin