LOX-1 abrogation reduces cardiac hypertrophy and collagen accumulation following chronic ischemia in the mouse
LOX-1 abrogation reduces cardiac hypertrophy and collagen accumulation following chronic ischemia in the mouse
We hypothesized that lectin-like oxidized LDL receptor-1 (LOX-1) deletion may inhibit oxidative stress signals, reduce collagen accumulation and attenuate cardiac remodeling after chronic ischemia. Activation of LOX-1 plays a significant role in the development of inflammation, apoptosis and collagen signals during acute ischemia. Wild-type and LOX-1 knockout (KO) mice were subjected to occlusion of left coronary artery for 3 weeks. Markers of cardiac hypertrophy, fibrosis-related signals (collagen IV, collagen-1 and fibronectin) and oxidant load (nicotinamide adenine dinucleotide phosphate oxidase expression, activity of mitogen-activated protein kinases and left ventricular (LV) tissue thiobarbituric acid reactive substances) were analyzed. In in vitro experiments, HL-1 cardiomyocytes were transfected with angiotensin II (Ang II) type 1 receptor (AT1R) or type 2 receptor (AT2R) genes to determine their role in the cardiomyocyte hypertrophy. LOX-1 KO mice had 25% improvement in survival over the 3-week period of chronic ischemia. LOX-1 deletion reduced collagen deposition and cardiomyocyte hypertrophy (∼75%) in association with a decrease in oxidant load and AT1R upregulation (all P<0.05). The LOX-1 KO mice hearts exhibited a disintegrin and metalloproteinase 10 (ADAM10) and a disintegrin and metalloproteinase 17 (ADAM17) expression and matrix metalloproteinase 2 activity, and increased AT2R expression (P<0.05). Attenuation of cardiac remodeling was associated with improved cardiac hemodynamics (LV ±dp/dt and cardiac ejection fraction). In vitro studies showed that it is AT1R, and not AT2R overexpression that induces cardiomyocyte hypertrophy. We demonstrate for the first time that LOX-1 deletion reduces oxidative stress and related intracellular signaling, which leads to attenuation of the positive feedback loop involving AT1R and LOX-1. This results in reduced chronic cardiac remodeling.
- Central Arkansas Veterans Healthcare System United States
- University of Arkansas for Medical Sciences United States
Male, Mice, Knockout, Ventricular Remodeling, Myocardial Ischemia, Cardiomegaly, Scavenger Receptors, Class E, Mice, Oxidative Stress, Coronary Occlusion, Animals, Collagen, Adaptor Proteins, Signal Transducing, Signal Transduction
Male, Mice, Knockout, Ventricular Remodeling, Myocardial Ischemia, Cardiomegaly, Scavenger Receptors, Class E, Mice, Oxidative Stress, Coronary Occlusion, Animals, Collagen, Adaptor Proteins, Signal Transducing, Signal Transduction
3 Research products, page 1 of 1
- 2017IsRelatedTo
citations This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).54 popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.Top 10% influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).Top 10% impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.Top 10%
