Abnormal pulmonary vascular relaxation and increased reactivity, early manifestations of pulmonary vascular disease, are responsible for significant morbidity in infants and children with common congenital heart defects that cause increased pulmonary blood flow. Beginning immediately after birth, the pulmonary vasculature in these patients is subjected to pathologic mechanical forces, including chronically increased shear stress, which results in early functional abnormalities of the vascular endothelium. Importantly, these functional abnormalities, which are thought to include decreases in bioavailable nitric oxide (NO) and increases in oxidative stress, occur prior to the development of well-described vascular remodeling. Unfortunately, little is known about the molecular mechanisms that mediate this process, particularly those that transduce the abnormal shear forces associated with increased pulmonary blood flow into abnormal vascular function and reactivity. Peroxisome proliferator-activated receptors (PPARs), members of a nuclear hormone receptor superfamily, are emerging as integral mediators of a wide array of disease processes, including vascular disorders. In fact, a recent study found that PPAR?, a member of the PPAR family, is decreased in patients with severe pulmonary hypertension and that shear stress decreases endothelial cell PPAR? expression. Interestingly, Kruppel-like Factor 2 (KLF2), a zinc finger protein transcriptional factor, was recently shown to be uniquely induced by flow in human lung endothelial cells, and to be a potent inhibitor of PPAR? expression in adipose tissues. However, the mechanisms by which PPAR3 and KLF2 may affect the development of pulmonary vascular disease are not understood. Utilizing our ovine model of a congenital heart defect with increased pulmonary blood flow, created by the in utero placement of an aorto-pulmonary vascular graft, we have generated preliminary data to support our overall hypothesis that disruption of PPAR? signaling secondary to a H2O2-induced, flow-mediated activation of LKLF2, results in increased ROS and decreased bioavailable NO, and thereby fundamentally participates in the development of pulmonary vascular disease under conditions of increased pulmonary blood flow. In this proposal, a series of studies that integrate anatomic, biochemical, cellular, and molecular techniques, will be undertaken in order to investigate this hypothesis. With a clinically relevant large animal model as a foundation, the data generated from this proposal could translate readily into novel and efficacious clinical therapies for patients suffering from pulmonary vascular disease.

Public Health Relevance

Infants and children afflicted with congenital heart defects with increased pulmonary blood flow, suffer morbidity and mortality from the development of pulmonary vascular disease with abnormal pulmonary vascular reactivity. Understanding the controlling mechanisms of this pathology might improve the clinical outcome, that is the quality of life and survival, of this vulnerable population. In this proposal, we will study the novel potential role of LKLF2 and PPAR? in this pathology. With a clinically relevant large animal model as a foundation, the data generated from this proposal could translate readily into novel and efficacious clinical therapies for patients suffering from pulmonary vascular disease.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL061284-11
Application #
7665384
Study Section
Respiratory Integrative Biology and Translational Research Study Section (RIBT)
Program Officer
Blaisdell, Carol J
Project Start
1999-07-01
Project End
2012-04-30
Budget Start
2009-05-01
Budget End
2010-04-30
Support Year
11
Fiscal Year
2009
Total Cost
$572,543
Indirect Cost
Name
University of California San Francisco
Department
Pediatrics
Type
Schools of Medicine
DUNS #
094878337
City
San Francisco
State
CA
Country
United States
Zip Code
94143
Morris, Catherine J; Kameny, Rebecca J; Boehme, Jason et al. (2018) KLF2-mediated disruption of PPAR-? signaling in lymphatic endothelial cells exposed to chronically increased pulmonary lymph flow. Am J Physiol Heart Circ Physiol 315:H173-H181
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Black, Stephen M; Field-Ridley, Aida; Sharma, Shruti et al. (2017) Altered Carnitine Homeostasis in Children With Increased Pulmonary Blood Flow Due to Ventricular Septal Defects. Pediatr Crit Care Med 18:931-934
Rafikova, Olga; Meadows, Mary L; Kinchen, Jason M et al. (2016) Metabolic Changes Precede the Development of Pulmonary Hypertension in the Monocrotaline Exposed Rat Lung. PLoS One 11:e0150480
Datar, Sanjeev A; Gong, Wenhui; He, Youping et al. (2016) Disrupted NOS signaling in lymphatic endothelial cells exposed to chronically increased pulmonary lymph flow. Am J Physiol Heart Circ Physiol 311:H137-45
Oishi, Peter; Fineman, Jeffrey R (2016) Pulmonary Hypertension. Pediatr Crit Care Med 17:S140-5
Kameny, Rebecca Johnson; Fineman, Jeffrey R (2016) The Prescient Prognosticator? Hepatoma-derived Growth Factor in Pulmonary Hypertension. Am J Respir Crit Care Med 194:1186-1187
Boehme, Jason; Sun, Xutong; Tormos, Kathryn V et al. (2016) Pulmonary artery smooth muscle cell hyperproliferation and metabolic shift triggered by pulmonary overcirculation. Am J Physiol Heart Circ Physiol 311:H944-H957
Sun, Xutong; Kellner, Manuela; Desai, Ankit A et al. (2016) Asymmetric Dimethylarginine Stimulates Akt1 Phosphorylation via Heat Shock Protein 70-Facilitated Carboxyl-Terminal Modulator Protein Degradation in Pulmonary Arterial Endothelial Cells. Am J Respir Cell Mol Biol 55:275-87
Bertero, Thomas; Cottrill, Katherine A; Lu, Yu et al. (2015) Matrix Remodeling Promotes Pulmonary Hypertension through Feedback Mechanoactivation of the YAP/TAZ-miR-130/301 Circuit. Cell Rep 13:1016-32

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