Identifying novel endogenous ligands that promote thrombosis and inflammatory processes in pathological settings, such as, diabetes, hypercholesterolemia and vascular hypertension may lead to new therapies that improve outcomes in patients at high risk for stroke. A variant of fibronectin (FN) containing the alternatively-spliced extra domain A (EDA+-FN), which is absent in the arteries or circulation of healthy humans and mice, is specifically expressed in the endothelium of atherosclerotic arteries and elevated in circulation during pathological settings, such as diabetes, atherosclerosis and vascular hypertension, most likely due to endothelial dysfunction. Recently, we have discovered that EDA+-FN promotes thrombosis and inflammatory processes. The underlying mechanisms by which EDA+-FN contributes to thrombosis and inflammation are not well understood. EDA+-FN is known to activate the toll-like- receptor 4 (TLR4) signaling pathway. Additionally, EDA is a ligand for integrin ?9?1, which is expressed on inflammatory cells, such as, neutrophils and macrophages. Hypercholesterolemia is one of the major risk factors for acute stroke in humans. Therefore, in hypercholesterolemic apolipoprotein E-deficient (ApoE-/-, atherosclerosis prone) mice, we propose to test the central hypothesis that EDA+-FN contributes to ischemia/reperfusion (I/R) brain injury in pathological setting, and that it does so by enhancing thrombosis and inflammatory processes via parallel ?9?1and TLR4-mediated pathways.
In Aim1, we will define the role of TLR4 in EDA+-FN-mediated thrombosis and inflammatory I/R brain injury.
In Aim 2, we will determine the role of integrin ?9?1 in EDA+-FN -mediated thrombosis and inflammatory I/R brain injury.
In Aim 3, we will define the role of plasma versus endothelial cell EDA+-FN in I/R brain injury. Furthermore, we will determine the source of EDA+-FN in the plasma of the aforementioned pathological conditions. As a translational approach, we will test the hypothesis that blocking EDA+-FN with specific monoclonal antibodies will reduce stroke injury in the context of hypercholesterolemia. To achieve our specific experimental goals, we have developed novel genetically modified mice strains and reagents that we will share with other researchers in the field. The contribution of th proposed studies is highly clinically significant as it determine the mechanistic insights by which EDA+-FN promotes thrombosis and inflammatory brain injury in disease context of atherosclerosis. The proposal has future translational potential, as it may have significant impact on the diagnosis and treatment of common thrombo-inflammatory diseases including acute stroke.
Despite advances in therapy during last 20 years, stroke still continues to be 4th most common threat to life and health in the United States and worldwide, and accounts for rising health costs. The proposed studies are expected to yield important mechanistic insights by which fibronectin containing alternatively spliced extra domain A promotes thrombosis and ischemia/reperfusion brain injury in disease context of atherosclerosis. When this work is completed, it is conceivable that the resulting knowledge will reveal a novel pathway that may translate into improved diagnosis and therapies, thus limiting stroke injury in pathological settings, such as diabetes, hypertension and atherosclerosis.
|Prakash, Prem; Nayak, Manasa K; Chauhan, Anil K (2016) P-selectin can promote thrombus propagation independently of both von Willebrand factor and thrombospondin1 in mice. J Thromb Haemost :|
|Dhanesha, Nirav; Prakash, Prem; Doddapattar, Prakash et al. (2016) Endothelial Cell-Derived von Willebrand Factor Is the Major Determinant That Mediates von Willebrand Factor-Dependent Acute Ischemic Stroke by Promoting Postischemic Thrombo-Inflammation. Arterioscler Thromb Vasc Biol 36:1829-37|
|Gu, Sean X; Blokhin, Ilya O; Wilson, Katina M et al. (2016) Protein methionine oxidation augments reperfusion injury in acute ischemic stroke. JCI Insight 1:|
|Niki, Masaru; Nayak, Manasa K; Jin, Hong et al. (2016) Dok-1 negatively regulates platelet integrin Î±IIbÎ²3 outside-in signalling and inhibits thrombosis in mice. Thromb Haemost 115:969-78|
|Dhanesha, Nirav; Ahmad, Ajmal; Prakash, Prem et al. (2015) Genetic Ablation of Extra Domain A of Fibronectin in Hypercholesterolemic Mice Improves Stroke Outcome by Reducing Thrombo-Inflammation. Circulation 132:2237-47|
|Prakash, Prem; Kulkarni, Paresh P; Chauhan, Anil K (2015) Thrombospondin 1 requires von Willebrand factor to modulate arterial thrombosis in mice. Blood 125:399-406|
|Klutho, Paula J; Pennington, Steven M; Scott, Jason A et al. (2015) Deletion of Methionine Sulfoxide Reductase A Does Not Affect Atherothrombosis but Promotes Neointimal Hyperplasia and Extracellular Signal-Regulated Kinase 1/2 Signaling. Arterioscler Thromb Vasc Biol 35:2594-604|
|Doddapattar, Prakash; Gandhi, Chintan; Prakash, Prem et al. (2015) Fibronectin Splicing Variants Containing Extra Domain A Promote Atherosclerosis in Mice Through Toll-Like Receptor 4. Arterioscler Thromb Vasc Biol 35:2391-400|
|Prakash, Prem; Kulkarni, Paresh P; Lentz, Steven R et al. (2015) Cellular fibronectin containing extra domain A promotes arterial thrombosis in mice through platelet Toll-like receptor 4. Blood 125:3164-72|
|Jin, Hong; Gebska, Milena A; Blokhin, Ilya O et al. (2015) Endothelial PPAR-Î³ protects against vascular thrombosis by downregulating P-selectin expression. Arterioscler Thromb Vasc Biol 35:838-44|
Showing the most recent 10 out of 11 publications