Spleen associated immune-response mediates brain-heart interaction after intracerebral hemorrhage.
BACKGROUND AND PURPOSE
Intracerebral hemorrhage (ICH) patients frequently encounter cardiovascular complications which may contribute to increased mortality and poor long term outcome. ICH induces systemic oxidative stress and activates peripheral immune responses which are involved in the pathological cascade leading to cardiac dysfunction and heart failure after ICH. We have previously reported that ICH induces progressive cardiac dysfunction in mice without primary cardiac diseases. In this study, we have investigated the role of immune response in mediating cardiac dysfunction post ICH in mice.


METHODS
Adult male C57BL/6 J mice were randomly assigned to the following groups (n = 8/group): 1) sham control; 2) ICH; 3) splenectomy with ICH (ICH + Spx); 4) splenectomy alone (Spx). Echocardiography was performed at 7 and 28 days after ICH. A battery of neurological and cognitive tests were performed. Flow cytometry, western blot and immunostaining were used to test mechanisms of ICH induced cardiac dysfunction.


RESULTS
Compared to sham control mice, Spx alone does not induce acute (7 day) or chronic (28 day) cardiac dysfunction. ICH induces significant neurological and cognitive deficits, as well as acute and chronic cardiac dysfunction compared to sham control mice. Mice subjected to ICH + Spx exhibit significantly improved neurological and cognitive function compared to ICH mice. Mice with ICH + Spx also exhibit significantly improved acute and chronic cardiac function compared to ICH mice indicated by increased left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS), decreased cardiac fibrosis, decreased cardiomyocyte hypertrophy, decreased cardiac infiltration of immune cells and decreased expression of inflammatory factor and oxidative stress in the heart.


CONCLUSIONS
Our study demonstrates that splenectomy attenuates ICH-induced neurological and cognitive impairment as well as ICH-induced cardiac dysfunction in mice. Inflammatory cell infiltration into heart and immune responses mediated by the spleen may contribute to ICH-induce acute and chronic cardiac dysfunction and pathological cardiac remodeling.
['Li|Wei|W|', 'Li|Linlin|L|', 'Li|Wenkui|W|', 'Chopp|Michael|M|', 'Venkat|Poornima|P|', 'Zacharek|Alex|A|', 'Chen|Zhili|Z|', 'Landschoot-Ward|Julie|J|', 'Chen|Jieli|J|']
D000818:Animals D001921:Brain D002543:Cerebral Hemorrhage D003071:Cognition D004195:Disease Models, Animal D006321:Heart D008297:Male D051379:Mice D009206:Myocardium D018384:Oxidative Stress D013154:Spleen D013156:Splenectomy
Intracerebral hemorrhage Oxidative stress Cardiac dysfunction Splenectomy Brain-heart axis Neurological recovery