NADPH oxidase (NOX) appears to play a role in the development of myocardial hypertrophy and subsequent progression of heart failure. However, the signaling mechanisms of NOX in cardiac myocytes is unknown. The long-term goal of this research is to understand the signaling mechnisms of NOX in the development of myocardial hypertrophy and heart failure induced by excessive adrenergic stimulation and hemodynamic pressure overload. Our prelminary data indicate that p67phox, the major cytosolic subunit of NOX, mediates the development of myocardial hypertrophy through a novel reactive oxygen species (ROS) - independent mechanism. Based on these data, we hypothesize that NOX/p67phox mediates myocardial hypertrophy that is induced by hypertrophic stimuli including 11-AR-stimulation and hemodynamic pressure overload, and its signaling function involve a novel ROS-independent mechanism. To test this hypothesis, we proposed the following three Specific Aims:
In Specific Aim 1, we will determine whether NOX/p67phox mediates 11-adrenergic receptor (11-AR)- stimulated myocardial hypertrophy and whether this involves a novel ROS-independent signaling mechanism in vitro. Dominant negative (DN) mutants and wild type (WT) contstructs of two NOX cytosolic subunits, p67phox and p47phox. Mutants or WT constructs will be overexpressed in cultured adult rat ventricular myocytes (ARVM). The effects of these mutants or WT constructs on 11-AR stimulation-induced hypertrophy and NOX enzyme activity will be determined. The potential protein-protein interaction between p67phox and MEK-ERK cascade will also be determined in this aim.
In Specific Aim 2, we will test if p67phox mediates 11-AR-stimulated cardiac hypertrophy in vivo. We will use the newly generated heterozygous DN-p67 transgenic (TG) mice with cardiac-specific overexpression of the DN p67phox mutant to generate homozygous DN-p67 TG mice. Since the commercially available TG mice with cardiac-specific overexpression of a constitutively activated mutant of 11B-AR (CAM-11B-AR) develop cardiac hypertrophy, we will crossbreed these two TG lines (DN-p67 and CAM-11B-AR) to study the effect of overexperssion of DN p67phox mutant protein in the heart on 11B-AR-induced myocardial hypertrophy in vivo.
In Specific Aim 3, we will test the role of myocardial p67phox in mediating hemodynamic overload- induced myocardial hypertrophy in vivo. The homozygous DN-p67 TG mice and age- and gender-matched WT control mice will be subjected to chronic pressure overload caused by ascending aorta constriction (AAC). The cardiac phenotypes and function of these TG and WT mice with AAC or sham operation will be studied to determine the role of p67phox in mediating chronic pressure overload-induced myocardial hypertrophy in vivo. Our studies will provide new understanding of the role and novel mechanisms of NOX/p67phox in the development of cardiac hypertrophy that should lead to novel treatments for congestive heart failure.

Public Health Relevance

Our studies will provide new understanding of the novel pathological mechanisms of p67phox and NADPH oxidase in the development of hypertrophy in the heart, which could lead to the major cardiovascular disease, heart failure. Therefore, our research will have direct relevance to a common cause of heart failure, which has a high mortality and disability rate and is a major threat to the public health.

National Institute of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Research Project (R01)
Project #
Application #
Study Section
Myocardial Ischemia and Metabolism Study Section (MIM)
Program Officer
Schwartz, Lisa
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Illinois at Chicago
Internal Medicine/Medicine
Schools of Medicine
United States
Zip Code
Ranjan, R; Lee, Y G; Karpurapu, M et al. (2015) p47phox and reactive oxygen species production modulate expression of microRNA-451 in macrophages. Free Radic Res 49:25-34
Liu, Y; Lou, Y Q; Liu, K et al. (2014) Role of leptin receptor gene polymorphisms in susceptibility to the development of essential hypertension: a case-control association study in a Northern Han Chinese population. J Hum Hypertens 28:551-6
DeSantiago, Jaime; Bare, Dan J; Xiao, Lei et al. (2014) p21-Activated kinase1 (Pak1) is a negative regulator of NADPH-oxidase 2 in ventricular myocytes. J Mol Cell Cardiol 67:77-85
Zhao, Guiqing; Yu, Rui; Deng, Jing et al. (2013) Pivotal role of reactive oxygen species in differential regulation of lipopolysaccharide-induced prostaglandins production in macrophages. Mol Pharmacol 83:167-78
Yu, Rui; Zhao, Guiqing; Christman, John W et al. (2013) Method development and validation for ultra-high pressure liquid chromatography/tandem mass spectrometry determination of multiple prostanoids in biological samples. J AOAC Int 96:67-76
Sovari, Ali A; Rutledge, Cody A; Jeong, Euy-Myoung et al. (2013) Mitochondria oxidative stress, connexin43 remodeling, and sudden arrhythmic death. Circ Arrhythm Electrophysiol 6:623-31
Kim, Kyun Ha; Sadikot, Ruxana T; Xiao, Lei et al. (2013) Nrf2 is essential for the expression of lipocalin-prostaglandin D synthase induced by prostaglandin D2. Free Radic Biol Med 65:1134-1142
Xiao, Lei; Ornatowska, Magdalena; Zhao, Guiqing et al. (2012) Lipopolysaccharide-induced expression of microsomal prostaglandin E synthase-1 mediates late-phase PGE2 production in bone marrow derived macrophages. PLoS One 7:e50244
Yu, Rui; Xiao, Lei; Zhao, Guiqing et al. (2011) Competitive enzymatic interactions determine the relative amounts of prostaglandins E2 and D2. J Pharmacol Exp Ther 339:716-25