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Li Q.,Institute of Genetics | Li Q.,Cardiovascular Research Laboratories | Ling Y.,Institute of Genetics | Yu L.,Institute of Genetics
Journal of Cancer Research and Clinical Oncology | Year: 2012

Purpose The aim of this study is to investigate whether GDF3 is related to the progression of human breast cancer and the effects of GDF3 on breast cancer cells. Methods The expression of GDF3 in 24 breast cancer specimens paired with corresponding neighboring nontumorous tissue was studied by Western blot. Breast cancer cells were treated with different concentrations of recombinant human GDF3 protein. Using lentivirus containing sh-RNA, we knocked down the expression of GDF3. Soft agar assay was performed to explore the effects of GDF3 on colony formation. Different anti-tumor drugs dealt with MCF-7 cells stably expressing GDF3. Results We found that GDF3 expression level was significantly down-regulated in breast cancer tissues compared to the surrounding nontumorous tissues. GDF3 proteins could inhibit the proliferation of MCF-7 and T47D cells. We also found that the knockdown of GDF3 resulted in the promotion of colony formation and enhanced the ability of anchorage-independent cell growth in soft agar. Furthermore, overexpression of GDF3 could promote the apoptosis induced by Taxol. Conclusions Our data indicated that GDF3 expression is significantly decreased in human breast cancer tissues, and reconstitution of GDF3 in breast cancer may be a potential therapeutic approach to inhibit aggressive growth of breast cancer. © Springer-Verlag 2012.


Huang Y.,Shanghai JiaoTong University | Zhou M.,Shanghai JiaoTong University | Sun H.,Shanghai JiaoTong University | Sun H.,Cardiovascular Research Laboratories | And 2 more authors.
Cardiovascular Research | Year: 2011

Metabolic remodelling is an integral part of the pathogenesis of heart failure. Although much progress has been made in our current understanding of the metabolic impairment involving carbohydrates and fatty acids in failing hearts, relatively little is known about the changes and potential impact of amino acid metabolism in the onset of heart diseases. Although most amino acid catabolic activities are found in the liver, branched-chain amino acid (BCAA) catabolism requires activity in several non-hepatic tissues, including cardiac muscle, diaphragm, brain and kidney. In this review, the new insights into the regulation of cardiac BCAA catabolism and functional impact on cardiac development and physiology will be discussed along with the potential contribution of impairment in BCAA catabolism to heart diseases. A particular focus will be the new information obtained from recently developed genetic models with BCAA catabolic defects and metabolomic studies in human and animal models. These studies have revealed the potential role of BCAA catabolism in cardiac pathophysiology and have helped to distinguish BCAA metabolic defects as an under-appreciated culprit in cardiac diseases rather than an epiphenomenon associated with metabolic remodelling in the failing heart. © 2010 The Author.


Lu G.,University of California at Los Angeles | Ota A.,University of California at Los Angeles | Ren S.,University of California at Los Angeles | Franklin S.,University of California at Los Angeles | And 10 more authors.
Molecular Metabolism | Year: 2013

The protein phosphatase 1-like gene ( PPM1l) was identified as causal gene for obesity and metabolic abnormalities in mice. However, the underlying mechanisms were unknown. In this report, we find PPM1l encodes an endoplasmic reticulum (ER) membrane targeted protein phosphatase (PP2Ce) and has specific activity to basal and ER stress induced auto-phosphorylation of Inositol-REquiring protein-1 (IRE1). PP2Ce inactivation resulted in elevated IRE1 phosphorylation and higher expression of XBP-1, CHOP, and BiP at basal. However, ER stress stimulated XBP-1 and BiP induction was blunted while CHOP induction was further enhanced in PP2Ce null cells. PP2Ce protein levels are significantly induced during adipogenesis in vitro and are necessary for normal adipocyte maturation. Finally, we provide evidence that common genetic variation of PPM11 gene is significantly associated with human lipid profile. Therefore, PPM1l mediated IRE1 regulation and downstream ER stress signaling is a plausible molecular basis for its role in metabolic regulation and disorder. © 2013 The Authors.


Gao C.,Molecular Biology Institute | Gao C.,Cardiovascular Research Laboratories | Ren S.,Cardiovascular Research Laboratories | Lee J.-H.,Molecular Biology Institute | And 20 more authors.
Journal of Clinical Investigation | Year: 2016

RNA splicing is a major contributor to total transcriptome complexity; however, the functional role and regulation of splicing in heart failure remain poorly understood. Here, we used a total transcriptome profiling and bioinformatic analysis approach and identified a muscle-specific isoform of an RNA splicing regulator, RBFox1 (also known as A2BP1), as a prominent regulator of alternative RNA splicing during heart failure. Evaluation of developing murine and zebrafish hearts revealed that RBFox1 is induced during postnatal cardiac maturation. However, we found that RBFox1 is markedly diminished in failing human and mouse hearts. In a mouse model, RBFox1 deficiency in the heart promoted pressure overload-induced heart failure. We determined that RBFox1 is a potent regulator of RNA splicing and is required for a conserved splicing process of transcription factor MEF2 family members that yields different MEF2 isoforms with differential effects on cardiac hypertrophic gene expression. Finally, induction of RBFox1 expression in murine pressure overload models substantially attenuated cardiac hypertrophy and pathological manifestations. Together, this study identifies regulation of RNA splicing by RBFox1 as an important player in transcriptome reprogramming during heart failure that influence pathogenesis of the disease.


PubMed | Cardiovascular Research Laboratories and University of California at Los Angeles
Type: Journal Article | Journal: The Journal of biological chemistry | Year: 2014

Oxidative stress has been implicated in cardiac arrhythmia, although a causal relationship remains undefined. We have recently demonstrated a marked up-regulation of NADPH oxidase isoform 4 (NOX4) in patients with atrial fibrillation, which is accompanied by overproduction of reactive oxygen species (ROS). In this study, we investigated the impact on the cardiac phenotype of NOX4 overexpression in zebrafish. One-cell stage embryos were injected with NOX4 RNA prior to video recording of a GFP-labeled (myl7:GFP zebrafish line) beating heart in real time at 24-31 h post-fertilization. Intriguingly, NOX4 embryos developed cardiac arrhythmia that is characterized by irregular heartbeats. When quantitatively analyzed by an established LQ-1 program, the NOX4 embryos displayed much more variable beat-to-beat intervals (mean S.D. of beat-to-beat intervals was 0.027 s/beat in control embryos versus 0.038 s/beat in NOX4 embryos). Both the phenotype and the increased ROS in NOX4 embryos were attenuated by NOX4 morpholino co-injection, treatments of the embryos with polyethylene glycol-conjugated superoxide dismutase, or NOX4 inhibitors fulvene-5, 6-dimethylamino-fulvene, and proton sponge blue. Injection of NOX4-P437H mutant RNA had no effect on the cardiac phenotype or ROS production. In addition, phosphorylation of calcium/calmodulin-dependent protein kinase II was increased in NOX4 embryos but diminished by polyethylene glycol-conjugated superoxide dismutase, whereas its inhibitor KN93 or AIP abolished the arrhythmic phenotype. Taken together, our data for the first time uncover a novel pathway that underlies the development of cardiac arrhythmia, namely NOX4 activation, subsequent NOX4-specific NADPH-driven ROS production, and redox-sensitive CaMKII activation. These findings may ultimately lead to novel therapeutics targeting cardiac arrhythmia.


Wu J.,Vanderbilt University | Saleh M.A.,Vanderbilt University | Saleh M.A.,Mansoura University | Kirabo A.,Vanderbilt University | And 16 more authors.
Journal of Clinical Investigation | Year: 2016

Vascular oxidative injury accompanies many common conditions associated with hypertension. In the present study, we employed mouse models with excessive vascular production of ROS (tgsm/p22phox mice, which overexpress the NADPH oxidase subunit p22phox in smooth muscle, and mice with vascular-specific deletion of extracellular SOD) and have shown that these animals develop vascular collagen deposition, aortic stiffening, renal dysfunction, and hypertension with age. T cells from tgsm/p22phox mice produced high levels of IL-17A and IFN-γ. Crossing tgsm/p22phox mice with lymphocyte-deficient Rag1-/- mice eliminated vascular inflammation, aortic stiffening, renal dysfunction, and hypertension; however, adoptive transfer of T cells restored these processes. Isoketal-protein adducts, which are immunogenic, were increased in aortas, DCs, and macrophages of tgsm/p22phox mice. Autologous pulsing with tgsm/p22phox aortic homogenates promoted DCs of tgsm/p22phox mice to stimulate T cell proliferation and production of IFN-γ, IL-17A, and TNF-α. Treatment with the superoxide scavenger tempol or the isoketal scavenger 2-hydroxybenzylamine (2-HOBA) normalized blood pressure; prevented vascular inflammation, aortic stiffening, and hypertension; and prevented DC and T cell activation. Moreover, in human aortas, the aortic content of isoketal adducts correlated with fibrosis and inflammation severity. Together, these results define a pathway linking vascular oxidant stress to immune activation and aortic stiffening and provide insight into the systemic inflammation encountered in common vascular diseases.

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