Abstract 151: A Novel Role for DDiT4L in Regulation of mTOR and Autophagy in the Heart

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Bridget Simonson ◽  
Hannabeth Franchino ◽  
Ashley Knight ◽  
Anthony Rosenzweig ◽  
Saumya Das
Keyword(s):  
Heart Failure ◽  
Protein Expression ◽  
Glucose Deprivation ◽  
Mtor Signaling ◽  
Confocal Imaging ◽  
Negative Regulator ◽  
Neonatal Rat ◽  
Pathological Hypertrophy ◽  
Gene And Protein Expression ◽  
Physiological Hypertrophy

Introduction: DDiT4L is a known negative regulator of mTOR signaling in skeletal muscle; however its role in the heart is unknown. We have recently showed increased DDiT4L mRNA in a murine transgenic model of pathological but not physiological hypertrophy. Here we test the hypothesis that DDiT4L is a regulator of mTOR signaling in the heart and may play a role in pathological hypertrophy and heart failure. Methods: We investigated the regulation of DDiT4L in murine models of hypertrophy and in cultured neonatal rat ventricular cardiomyocytes (NRVMs). Loss and gain of function of DDiT4L in mTOR regulation and autophagy was investigated using confocal imaging, immunoblotting, and qRT-PCR in NRVMs. Results: DDiT4L gene and protein expression was increased four-fold in pressure overload hypertrophy (n = 4-6, p<0.001), but not in a swim model of physiological hypertrophy. DDiT4L gene expression also significantly increased in a genetic model of dilated cardiomyopathy model (n = 4, p<0.001). In NRVMs, DDiT4L was induced by cardiac stressors such as pathological stretch, hypoxia, and glucose deprivation (n = 3-5 in duplicate, p<0.05-0.01). Increased DDiT4L expression correlated with inhibition of mTOR signaling, and an increase in autophagy markers. siRNA ablation of DDiT4L revealed that inhibition of mTOR signaling by DDiT4L was necessary for glucose deprivation induced autophagy, as determined by imaging of GFP-LC3 autophagosomes (n = 3 in duplicate, p<0.01), and immunoblotting of autophagy markers. Conversely, adenoviral-driven overexpression of DDiT4L inhibited mTOR signaling and significantly increased basal autophagy (n = 3 in duplicate, p<0.05). In TAC mice, the increase in DDiT4L protein expression correlated to inhibition of mTOR signaling, increases in autophagy markers (p<0.01), and preceded the transition to LV dilation and HF. Conclusion: Our data suggests that DDiT4L expression is altered in diverse models of pathological hypertrophy and precedes the development of LV dilatation and overt heart failure. DDiT4L inhibition of mTOR and modulation of autophagy may play a role in the progression to heart failure. DDiT4L may represent a novel therapeutic target to prevent this transition.

scholarly journals VEGF Regulation of Angiogenic Factors via Inflammatory Signaling in Myeloproliferative Neoplasms

2021 ◽  
Vol 22 (13) ◽  
pp. 6671
Author(s):  
Tijana Subotički ◽  
Olivera Mitrović Ajtić ◽  
Emilija Živković ◽  
Miloš Diklić ◽  
Dragoslava Đikić ◽  
...  
Keyword(s):  
Protein Expression ◽  
Chronic Inflammation ◽  
Myeloproliferative Neoplasms ◽  
Myeloproliferative Neoplasm ◽  
Angiogenic Factors ◽  
Mtor Signaling ◽  
Angiogenic Factor ◽  
Inflammatory Signaling ◽  
Gene And Protein Expression ◽  
Hel Cells

Background: Chronic inflammation has been recognized in neoplastic disorders, including myeloproliferative neoplasm (MPN), as an important regulator of angiogenesis. Aims: We investigated the influence of vascular endothelial growth factor (VEGF) and pro-inflammatory interleukin-6 (IL-6) on the expression of angiogenic factors, as well as inflammation-related signaling in mononuclear cells (MNC) of patients with MPN and JAK2V617F positive human erythroleukemic (HEL) cells. Results: We found that IL-6 did not change the expression of angiogenic factors in the MNC of patients with MPN and HEL cells. However, IL-6 and the JAK1/2 inhibitor Ruxolitinib significantly increased angiogenic factors—endothelial nitric oxide synthase (eNOS), VEGF, and hypoxia-inducible factor-1 alpha (HIF-1α)—in patients with polycythemia vera (PV). Furthermore, VEGF significantly increased the expression of HIF-1α and eNOS genes, the latter inversely regulated by PI3K and mTOR signaling in the MNC of primary myelofibrosis (PMF). VEGF and inhibitors of inflammatory JAK1/2, PI3K, and mTOR signaling reduced the eNOS protein expression in HEL cells. VEGF also decreased the expression of eNOS and HIF-1α proteins in the MNC of PMF. In contrast, VEGF increased eNOS and HIF-1α protein expression in the MNC of patients with PV, which was mediated by the inflammatory signaling. VEGF increased the level of IL-6 immunopositive MNC of MPN. In summary, VEGF conversely regulated gene and protein expression of angiogenic factors in the MNC of PMF, while VEGF increased angiogenic factor expression in PV mediated by the inflammation-related signaling. Conclusion: The angiogenic VEGF induction of IL-6 supports chronic inflammation that, through positive feedback, further promotes angiogenesis with concomitant JAK1/2 inhibition.

Abstract 208: Mitochondrial-targeted Grk2 Increases Superoxide Formation And Impairs Cardiomyocyte Respiratory Reserve Capacity

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Priscila Y Sato ◽  
J K Chuprun ◽  
Jessica Ibetti ◽  
John W Elrod ◽  
Walter J Koch
Keyword(s):  
Heart Failure ◽  
Ventricular Myocytes ◽  
Permeability Transition ◽  
Fold Increase ◽  
Confocal Imaging ◽  
Neonatal Rat ◽  
Redox Stress ◽  
Mitochondrial Oxidative Stress ◽  
Neonatal Rat Ventricular Myocytes ◽  
Cellular Dysfunction

β-adrenergic receptors (βARs) are powerful regulators of cardiovascular function and are impaired in heart failure (HF). Signal transduction of βARs is canonically shut down by phosphorylation via G protein-coupled receptor kinase 2 (GRK2) and the subsequent binding of β-arrestins. This process of receptor desensitization is enhanced in HF via the up-regulation of GRK2 and contributes to disease progression. We have recently reported non-canonical actions of GRK2, which contribute to the development of HF independent of βAR desensitization. We have previously shown that GRK2 can act as a pro-death kinase in cardiomyocytes bytranslocating to mitochondria and activating mitochondria permeability transition. This study was designed to gain more understanding of the mitochondrial function of GRK2. We isolated adult cardiomyocytes from cardiac-specific transgenic mice overexpressing GRK2 at levels found in human HF (TgGRK2), and examined superoxide production using the redox sensitive reporter MitoSox Red. Confocal imaging revealed a 4.6 fold increase in superoxide levels in cardiomyocytes overexpressing Grk2 as compared to non-transgenic (NLC) cardiomyocytes (corrected total cell fluorescence 11.59±1.06, TgGRK2 (n= 3 hearts, 88 cells) vs 2.54±0.02 NLC (n=3 hearts, 52 cells), (p<0.001). This indicates that the chronic elevation of GRK2 induces mitochondrial oxidative stress priming the myocyte for enhanced injury. To further explore the mitochondrial actions of GRK2 and consequences of redox stress we examined oxidative phosphorylation by performing oxygen consumption measurements in neonatal rat ventricular myocytes overexpressing GRK2 or GFP-expressing control myocytes. Seahorse analysis showed that cells overexpressing GRK2 have a significant decrease in spare respiratory capacity indicating that cells with elevated GRK2 levels have an impaired capacity to generated ATP during times of stress. Further studies with mutants that limit GRK2 kinase activity or mitochondrial localization demonstrate that mitochondrial GRK2 may be a significant contributor to cellular dysfunction as seen in heart failure.

scholarly journals Dissociation between gene and protein expression of metabolic enzymes in a rodent model of heart failure

2006 ◽  
Vol 8 (7) ◽  
pp. 687-693 ◽  
Author(s):  
Eric E. Morgan ◽  
Margaret P. Chandler ◽  
Martin E. Young ◽  
Tracy A. McElfresh ◽  
Theodore A. Kung ◽  
...  
Keyword(s):  
Heart Failure ◽  
Protein Expression ◽  
Metabolic Enzymes ◽  
Rodent Model ◽  
Gene And Protein Expression

mTOR signaling-related microRNAs as cardiac hypertrophy modulators in high‐volume endurance training

2021 ◽  
Author(s):  
Bruno R.A. Pelozin ◽  
Ursula Paula Reno Soci ◽  
João L. P. Gomes ◽  
Edilamar Menezes Oliveira ◽  
Tiago Fernandes
Keyword(s):  
Protein Expression ◽  
Molecular Mechanisms ◽  
High Volume ◽  
Left Ventricular ◽  
Mtor Signaling ◽  
Neonatal Rat ◽  
Cardiomyocyte Hypertrophy ◽  
Peak Exercise ◽  
Dependent Manner ◽  
Rat Cardiomyocytes

Aerobic exercise training (ET) promotes cardiovascular adaptations, including physiological left ventricular hypertrophy (LVH). However, the molecular mechanisms that underlying these changes are unclear. The study aimed to elucidate specific miRNAs and target genes involved with the Akt/mTOR signaling in high-volume ET-induced LVH. Eight-week-old female Wistar rats were assigned to three groups: sedentary control (SC), trained protocol 1 (P1), and trained protocol 2 (P2). P1 consisted of 60 minutes/day of swimming, 5x/week, for 10 weeks. P2 consisted of the same protocol as P1 until the 8th week; in the 9th week, rats trained 2x/day, and in the 10th week, trained 3x/day. Subsequently, structure and molecular parameters were evaluated in the heart. Trained groups demonstrate higher values to VO2 peak, exercise tolerance, and LVH in a volume-dependent manner. The miRNA-26a-5p levels were higher in P1 and P2 compared to SC group (150±15%, d=1.8; 148±16%, d=1.7; and 100±7%, respectively, P < 0.05). In contrast, miRNA-16-5p levels were lower in P1 and P2 compared to SC group (69±5%, d=2.3, P < 0.01; 37±4%, d=5.6, P < 0.001 and 100±6%, respectively). Additionally, miRNA-16-5p knockdown and miRNA-26a-5p overexpression significantly promoted cardiomyocyte hypertrophy in neonatal rat cardiomyocytes. Both miRNAs were selected, using Diana Tolls bioinformatics website, for acting in the mTOR signaling pathway. The protein expression of Akt, mTOR, p70S6k, and 4E-BP1 were greater in P1 and even more pronounced in P2. Nonetheless, GSK3β protein expression was lower in trained groups. Together, these molecular changes may contribute to a pronounced physiological LVH observed in high-volume aerobic training.

CXCR4 Is a Regulator Of Disease Involvement Of Extramedullary Myeloma Confirmed By a Novel Mouse Model For Extramedullary Disease

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 5320-5320 ◽  
Author(s):  
Yuji Mishima ◽  
Michele Moschetta ◽  
Michaela R Reagan ◽  
Yong Zhang ◽  
Ilyas Sahin ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Protein Expression ◽  
Cell Lines ◽  
Chemokine Receptors ◽  
Research Funding ◽  
Advisory Board ◽  
Confocal Imaging ◽  
Extramedullary Disease ◽  
Gene And Protein Expression

Abstract Background Extramedullary disease (EMD) in patients with multiple myeloma occurs mostly in advanced disease or relapse. EMD seems to have a different pathogenesis from medullary myeloma and is often characterized by a more aggressive clinical course. To date molecular mechanisms of development of EMD have not been fully understood. Methods: Human MM cell lines, IM-9 and MM1S were serially selected in immune-deficient mice. IM-9 and MM1S cells were inoculated intravenously and harvested from the tumors developed in the bone marrow (BM) and liver (site of extramedullary disease), aiming to establish BM-prone and liver-prone clones. Tumor progression was periodically checked by bioluminescence (BLI) and in vivo live confocal imaging. After three rounds of in vivo selections, the cells of both BM- and liver-prone were characterized by gene and protein expression and cellular functional assays. Results: We obtained three liver-prone sub-clones in both IM-9 and MM1S after serial in vivo selections. These cells had equal proliferation rates in vitro compared to the original or BM-prone cells, but exhibited more aggressive phenotype in vivo. Liver-prone clones had significantly higher migration ability than BM-prone clones (11.6% vs 6.1% migration, respectively p=0.018). Gene and protein expression analysis revealed that each liver-prone clone had a higher expression of sets of chemokine receptors specifically CXCR4. Using thein vivo metastatic model CXCR4-over expressing myeloma cells exhibited higher metastatic property to the extramedullary organs whereas CXCR4-knockdown cells has less tumor metastasis to the liver. Discussion: We established EMD-prone human multiple myeloma cell lines that reproducibly developed liverinvolvement consistent with human extramedullary disease. These cells exhibited higher migratory ability and increased expression of several chemokine receptors, specifically CXCR4. We validated the effect of CXCR4 on developing extramedullary myeloma using our established in vivo mode. Further studies to determine the role of CXCR4 for therapeutic targeting of extramedullary disease in MM are ongoing. Disclosures: Ghobrial: Sanofi: Research Funding; Noxxon: Research Funding; BMS: Advisory board, Advisory board Other, Research Funding; Onyx: Advisoryboard Other.

Alterations in apoptosis regulatory factors during hypertrophy and heart failure

2004 ◽  
Vol 287 (1) ◽  
pp. H72-H80 ◽  
Author(s):  
Peter M. Kang ◽  
Patrick Yue ◽  
Zhilin Liu ◽  
Oleg Tarnavski ◽  
Natalya Bodyak ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Hypertrophy ◽  
Primary Cultures ◽  
High Salt ◽  
Terminal Deoxynucleotidyl Transferase ◽  
High Salt Diet ◽  
Salt Diet ◽  
Pathological Hypertrophy ◽  
Increased Sensitivity ◽  
Physiological Hypertrophy

Cardiac hypertrophy from pathological stimuli often proceeds to heart failure, whereas cardiac hypertrophy from physiological stimuli does not. In this study, physiological hypertrophy was created by a daily exercise regimen and pathological hypertrophy was created from a high-salt diet in Dahl salt-sensitive rats. The rats continued on a high-salt diet progressed to heart failure associated with an increased rate of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive cardiomyocytes. We analyzed primary cultures of these hearts and found that only cardiomyocytes made hypertrophic by a pathological stimulus show increased sensitivity to apoptosis. Examination of the molecular changes associated with these distinct types of hypertrophy revealed changes in Bcl-2 family members and caspases favoring survival during physiological hypertrophy. However, in pathological hypertrophy, there were more diffuse proapoptotic changes, including changes in Fas, the Bcl-2 protein family, and caspases. Therefore, we speculate that this increased sensitivity to apoptotic stimulation along with proapoptotic changes in the apoptosis program may contribute to the development of heart failure seen in pathological cardiac hypertrophy.

Genetic expression profiles during physiological and pathological cardiac hypertrophy and heart failure in rats

2005 ◽  
Vol 21 (1) ◽  
pp. 34-42 ◽  
Author(s):  
Sek Won Kong ◽  
Natalya Bodyak ◽  
Patrick Yue ◽  
Zhilin Liu ◽  
Jeffrey Brown ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Hypertrophy ◽  
Protein Biosynthesis ◽  
Expression Profiles ◽  
Gene Clusters ◽  
Growth Factor Signaling ◽  
Gene Score ◽  
Apoptosis Pathway ◽  
Pathological Hypertrophy ◽  
Physiological Hypertrophy

Cardiac hypertrophy is a complex and nonhomogenous response to various stimuli. In this study, we used high-density oligonucleotide microarray to examine gene expression profiles during physiological hypertrophy, pathological hypertrophy, and heart failure in Dahl salt-sensitive rats. There were changes in 404/3,160 and 874/3,160 genes between physiological and pathological hypertrophy and the transition from hypertrophy to heart failure, respectively. There were increases in stress response genes (e.g., heat shock proteins) and inflammation-related genes (e.g., pancreatitis-associated protein and arachidonate 12-lipoxygenase) in pathological processes but not in physiological hypertrophy. Furthermore, atrial natriuretic factor and brain natriuretic protein showed distinctive changes that are very specific to different conditions. In addition, we used a resampling-based gene score-calculating method to define significantly altered gene clusters, based on Gene Ontology classification. It revealed significant alterations in genes involved in the apoptosis pathway during pathological hypertrophy, suggesting that the apoptosis pathway may play a role during the transition to heart failure. In addition, there were significant changes in glucose/insulin signaling, protein biosynthesis, and epidermal growth factor signaling during physiological hypertrophy but not during pathological hypertrophy.

Abstract 319: Mir-222 is Required for Physiological Hypertrophy but Inhibits Pathological Hypertrophy and Heart Failure

2018 ◽  
Vol 123 (Suppl_1) ◽  
Author(s):  
Xiaojun Liu ◽  
Haobo Li ◽  
Chunyang Xiao ◽  
Federico Damilano ◽  
Colin Platt ◽  
...  
Keyword(s):  
Heart Failure ◽  
Pathological Hypertrophy ◽  
Physiological Hypertrophy

Changes in Expressions of HSP27, HSP70 and Soluble Glycoprotein in Heart Failure Rats Complicated with Pulmonary Edema and Correlations with Cardiopulmonary Functions Running title: Expressions of HSP27, HSP70 and Soluble Glycoprotein in Heart Failure

2021 ◽  
Vol 7 (5) ◽  
pp. 4286-4295
Author(s):  
Yan Tan ◽  
Bo Gao ◽  
Dongming Gu ◽  
Shuyun Wang ◽  
Zhinua Wang
Keyword(s):  
Heart Failure ◽  
Protein Expression ◽  
Pulmonary Edema ◽  
Airway Resistance ◽  
Lung Compliance ◽  
Left Ventricular ◽  
Normal Group ◽  
Model Group ◽  
Expression Levels ◽  
Gene And Protein Expression

Objective: The study aimed to investigate the changes in expressions of heat shock protein 27 (HSP27), HSP70 and soluble glycoprotein (SGP) in heart failure (HF) rats complicated with pulmonary edema, and explore their potential correlations with cardiopulmonary functions. Methods: The rat model of HF was established, and the rats were divided into HF model group (model group, n=15) and normal group (n=15). After successful modeling, MRI and ECG were applied to detect the cardiac function indexes of the rats. The myocardial function indexes were determined, the injury of myocardial tissues was observed via hematoxylin and eosin (HE) staining, and the content of myeloperoxidase (MPO), matrix metalloproteinase-9 (MMP-9) and tumor necrosis factor-alpha (TNF-a) in the blood was measured. The partial pressure of oxygen (Pa02) and oxygenation index (01) were observed, and the airway resistance and lung compliance were examined. Moreover, quantitative polymerase chain reaction (qPCR) and Western blotting assay were performed to detect the gene and protein expression levels of HSP27, HSP70 and SGP130. Results: The levels of serum creatine kinase (CK), creatine (Cr) and blood urea nitrogen (BUN) were increased markedly in model group (p<0.05). Model group had notably decreased fractional shortening (FS) and ejection fraction (EF) compared with normal group (p<0.05), while the opposite results of left ventricular end-diastolic diameter (LVEDD) and left ventricular end-systolic diameter (LVESD) were detected. In model group, the content of serum MPO, MMP-9 and TNF-a was raised remarkably (p<0.05), 01 and Pa02were reduced notably (p<0.05), the airway resistance was increased (p<0.05), and the lung compliance was decreased (p<0.05). Obviously elevated gene and protein expression levels of HSP27, HSP70 and SGP130 were detected in model group (p<0.05). Conclusion: The expressions of HSP27, HSP70 and SGP130 are increased in HF rats complicated with pulmonary edema, seriously affecting the cardiopulmonary functions of the rats.

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