http://circ.ahajournals.org/content/early/2015/10/27/CIRCULATIONAHA.115.016540.abstract
- Nirav Dhanesha1;
- Ajmal Ahmad1;
- Prem Prakash1;
- Prakash Doddapattar1;
- Steven R. Lentz1;
- Anil K. Chauhan1*
+ Author Affiliations
- ↵* Department of Internal Medicine, University of Iowa, 3120 Medical Labs, Iowa City, IA 52242 anil-chauhan@uiowa.edu
Abstract
Background—The
fibronectin splicing variant containing extra domain A (Fn-EDA) is
present in negligible amounts in the plasma of healthy
humans, but markedly elevated in patients with
comorbid conditions including diabetes and hypercholesterolemia, which
are
risk factors for stroke. It remains unknown,
however, whether Fn-EDA worsens stroke outcomes in such conditions. We
determined
the role of Fn-EDA in stroke outcome in a model
of hypercholesterolemia, the apolipoprotein E-deficient (Apoe-/-) mouse.
Methods and Results—In a transient cerebral ischemia/reperfusion injury model, Apoe-/- mice expressing Fn deficient in EDA (Fn-EDA-/-Apoe-/- mice) exhibited smaller infarcts and improved neurological outcomes at days 1 and 8 (P<0.05 vs. Apoe-/-
mice). Concomitantly, intracerebral thrombosis (assessed by fibrin
(ogen) deposition) and postischemic inflammation (phospho-NF-κB
p65, phospho IKKα/β, IL1-β and TNFα) within
lesions of Fn-EDA-/-Apoe-/- mice were markedly decreased (P<0.05 vs. Apoe-/- mice). In a FeCl3 injury-induced carotid artery thrombosis model, thrombus growth rate and the time to occlusion were prolonged in Fn-EDA-/-Apoe-/- mice (P<0.05 vs. Apoe-/- mice). Genetic ablation of TLR4 improved stroke outcome in Apoe-/- mice (P<0.05) but had no effect on stroke outcome in Fn-EDA-/-Apoe-/- mice. Bone marrow transplantation experiments revealed that non-hematopoietic cell-derived Fn-EDA exacerbates stroke through
TLR4 expressed on hematopoietic cells. Infusion of a specific inhibitor of Fn-EDA into Apoe-/- mouse 15 minutes after reperfusion significantly improved stroke outcome.
Conclusions—Hypercholesterolemic
mice deficient in Fn-EDA exhibit reduced cerebral thrombosis and less
inflammatory response after ischemia/reperfusion
injury. These findings suggest that targeting
Fn-EDA could be an effective therapeutic strategy in stroke associated
with
hypercholesterolemia.
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