The goal of this project is to understandthe mechanisms that drive downregulation of the transcription factor, CREB in pulmonary hypertension (PH) and the contribution of this event to pulmonary artery (PA) remodeling. We have previously shown that CREB levels are diminished in smooth muscle cells (SMCs) from remodeled, hypertensive PAs. Inhibition of CREB in SMCs increased their proliferation, migration, and collagen and elastin production. Loss of CREB in SMCs is stimulated by PDGF, which induces proteasomal degradation of CREB. Finally, rosiglitazone (ROSI) prevents remodeling of the PA wall in response to chronic hypoxia. New preliminary data links these observations into a coherent model for the regulation of SMC phenotype. First, PDGF-induced CREB depletion in SMCs is mediated by casein kinase 2 (CK2). Second, ROSI prevents CREB depletion by blocking PDGF induction of CK2. Third, PA remodeling is associated with the appearance macrophages in the PA adventitia. The accumulation of these cells is blocked by ROSI, which also attenuate PA remodeling in response to chronic hypoxia. Fourth, depletion of CREB augments the expression of adhesion molecules and cytokines linked to the accumulation of macrophages in systemic arteries. Therefore we hypothesize the existence of a regulatory cascade in which PDGF elicits the depletion of CREB via increased expression of CK2. Loss of CREB in SMCs results in SMC proliferation, collagen and elastin synthesis, and decreased SMC marker expression. Loss of CREB also promotes the recruitment of macrophages to the PA wall, which exacerbates PA remodeling. ROSI inhibits this cascade by preventing PDGF-induced CK2 expression.
Four specific aims will test these hypotheses.
Aim 1 will test whether SMC loss of CREB is mechanistically linked to the development of PH in animals.
Aim 2 will examine whether ROSI regulates CREB and CK2 in SMCs via the nuclear receptor, PPARy.
Aim 3 will determine whether downregulation of CK2 and upregulation of CREB mediate the protective effects of ROSI on SMC phenotype. Finally, Aim 4 will examine the ability of ROSI or macrophage depletion to suppress PA remodeling and the development of PH in SMC CREB loss-of-funotion mice.
(Seeinstructions): Despite major advances in the treatment of cardiopulmonary conditions, hypoxia-induced pulmonary hypertension (PH) remains a deadly disease that is largely unresponsive to current treatments. In order to generate innovative treatments it is critical to understand the mechanisms that lead to disease progression. This project will identify novel pathways and their contributions to the pathogenesis of PH.
|Jiang, Xinguo; Nicolls, Mark R; Tian, Wen et al. (2018) Lymphatic Dysfunction, Leukotrienes, and Lymphedema. Annu Rev Physiol 80:49-70|
|Schäfer, Michal; Humphries, Stephen; Stenmark, Kurt R et al. (2018) 4D-flow cardiac magnetic resonance-derived vorticity is sensitive marker of left ventricular diastolic dysfunction in patients with mild-to-moderate chronic obstructive pulmonary disease. Eur Heart J Cardiovasc Imaging 19:415-424|
|D'Alessandro, Angelo; El Kasmi, Karim C; Plecitá-Hlavatá, Lydie et al. (2018) Hallmarks of Pulmonary Hypertension: Mesenchymal and Inflammatory Cell Metabolic Reprogramming. Antioxid Redox Signal 28:230-250|
|Karoor, Vijaya; Fini, Mehdi A; Loomis, Zoe et al. (2018) Sustained Activation of Rho GTPases Promotes a Synthetic Pulmonary Artery Smooth Muscle Cell Phenotype in Neprilysin Null Mice. Arterioscler Thromb Vasc Biol 38:154-163|
|Stenmark, Kurt R; Graham, Brian B (2018) Urocortin 2: will a drug targeting both the vasculature and the right ventricle be the future of pulmonary hypertension therapy? Cardiovasc Res 114:1057-1059|
|Madhavan, Krishna; Frid, Maria G; Hunter, Kendall et al. (2018) Development of an electrospun biomimetic polyurea scaffold suitable for vascular grafting. J Biomed Mater Res B Appl Biomater 106:278-290|
|Stenmark, Kurt R; Frid, Maria G; Graham, Brian B et al. (2018) Dynamic and diverse changes in the functional properties of vascular smooth muscle cells in pulmonary hypertension. Cardiovasc Res 114:551-564|
|Schäfer, Michal; Kheyfets, Vitaly O; Barker, Alex J et al. (2018) Reduced shear stress and associated aortic deformation in the thoracic aorta of patients with chronic obstructive pulmonary disease. J Vasc Surg 68:246-253|
|Graham, Brian B; Kumar, Rahul; Mickael, Claudia et al. (2018) Vascular Adaptation of the Right Ventricle in Experimental Pulmonary Hypertension. Am J Respir Cell Mol Biol 59:479-489|
|Wick, Marilee J; Harral, Julie W; Loomis, Zoe L et al. (2018) An Optimized Evans Blue Protocol to Assess Vascular Leak in the Mouse. J Vis Exp :|
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