9 results on '"Sommer, Natascha"'
Search Results
2. Metabolic Reprogramming in Congenital Cyanotic Heart Disease: Another Fight in Puberty?
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Sommer, Natascha, Weissmann, Norbert, and Ghofrani, Hossein-Ardeschir
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CONGENITAL heart disease , *TYPE 2 diabetes , *PRECOCIOUS puberty , *PUBERTY , *SODIUM-glucose cotransporters , *PYRUVATE dehydrogenase kinase , *CARDIOVASCULAR diseases , *RESEARCH , *RESEARCH methodology , *MEDICAL cooperation , *EVALUATION research , *COMPARATIVE studies , *CYANOSIS - Abstract
Congenital heart disease, hypoxia, metabolism, puberty, pulmonary heart disease, pulmonary hypertension HIF-1 indicates hypoxia-inducible factor-1 ; HOX, hypoxia; incl., including; LV, left ventricle; and RV, right ventricle. Keywords: congenital heart disease; hypoxia; metabolism; puberty; pulmonary heart disease; pulmonary hypertension EN congenital heart disease hypoxia metabolism puberty pulmonary heart disease pulmonary hypertension 2273 2276 4 06/10/21 20210608 NES 210608 B Article, see p 2254 b Congenital heart diseases are complex anatomic malformations that lead to molecular and structural adaptations to compensate for the resulting hemodynamic disturbances. [Extracted from the article]
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- 2021
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3. Mitochondrial Complex IV Subunit 4 Isoform 2 Is Essential for Acute Pulmonary Oxygen Sensing.
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Sommer, Natascha, Hüttemann, Maik, Pak, Oleg, Scheibe, Susan, Knoepp, Fenja, Sinkler, Christopher, Malczyk, Monika, Gierhardt, Mareike, Esfandiary, Azadeh, Kraut, Simone, Jonas, Felix, Veith, Christine, Aras, Siddhesh, Sydykov, Akylbek, Alebrahimdehkordi, Nasim, Giehl, Klaudia, Hecker, Matthias, Brandes, Ralf P., Seeger, Werner, and Grimminger, Friedrich
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- 2017
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4. Letter by Hüttemann et al Regarding Article, "Ndufs2, a Core Subunit of Mitochondrial Complex I, Is Essential for Acute Oxygen-Sensing and Hypoxic Pulmonary Vasoconstriction".
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Hüttemann, Maik, Sommer, Natascha, Weissmann, Norbert, and Grossman, Lawrence I.
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- 2019
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5. Validation of the Tricuspid Annular Plane Systolic Excursion/Systolic Pulmonary Artery Pressure Ratio for the Assessment of Right Ventricular-Arterial Coupling in Severe Pulmonary Hypertension.
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Tello, Khodr, Wan, Jun, Dalmer, Antonia, Vanderpool, Rebecca, Ghofrani, Hossein A., Naeije, Robert, Roller, Fritz, Mohajerani, Emad, Seeger, Werner, Herberg, Ulrike, Sommer, Natascha, Gall, Henning, and Richter, Manuel J.
- Abstract
Supplemental Digital Content is available in the text. Background: The ratios of tricuspid annular plane systolic excursion (TAPSE)/echocardiographically measured systolic pulmonary artery pressure (PASP), fractional area change/invasively measured mean pulmonary artery pressure, right ventricular (RV) area change/end-systolic area, TAPSE/pulmonary artery acceleration time, and stroke volume/end-systolic area have been proposed as surrogates of RV-arterial coupling. The relationship of these surrogates with the gold standard measure of RV-arterial coupling (invasive pressure-volume loop-derived end-systolic/arterial elastance [Ees/Ea] ratio) and RV diastolic stiffness (end-diastolic elastance) in pulmonary hypertension remains incompletely understood. We evaluated the relationship of these surrogates with invasive pressure-volume loop-derived Ees/Ea and end-diastolic elastance in pulmonary hypertension. Methods: We performed right heart echocardiography and cardiac magnetic resonance imaging 1 day before invasive measurement of pulmonary hemodynamics and single-beat RV pressure-volume loops in 52 patients with pulmonary arterial hypertension or chronic thromboembolic pulmonary hypertension. The relationships of the proposed surrogates with Ees/Ea and end-diastolic elastance were evaluated by Spearman correlation, multivariate logistic regression, and receiver operating characteristic analyses. Associations with prognosis were evaluated by Kaplan-Meier analysis. Results: TAPSE/PASP, fractional area change/mean pulmonary artery pressure, RV area change/end-systolic area, and stroke volume/end-systolic area but not TAPSE/pulmonary artery acceleration time were correlated with Ees/Ea and end-diastolic elastance. Of the surrogates, only TAPSE/PASP emerged as an independent predictor of Ees/Ea (multivariate odds ratio: 18.6; 95% CI, 0.8–96.1; P =0.08). In receiver operating characteristic analysis, a TAPSE/PASP cutoff of 0.31 mm/mm Hg (sensitivity: 87.5% and specificity: 75.9%) discriminated RV-arterial uncoupling (Ees/Ea <0.805). Patients with TAPSE/PASP <0.31 mm/mm Hg had a significantly worse prognosis than those with higher TAPSE/PASP. Conclusions: Echocardiographically determined TAPSE/PASP is a straightforward noninvasive measure of RV-arterial coupling and is affected by RV diastolic stiffness in severe pulmonary hypertension. Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03403868. [ABSTRACT FROM AUTHOR]
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- 2019
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6. Reserve of Right Ventricular-Arterial Coupling in the Setting of Chronic Overload.
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Tello, Khodr, Dalmer, Antonia, Axmann, Jens, Vanderpool, Rebecca, Ghofrani, Hossein A., Naeije, Robert, Roller, Fritz, Seeger, Werner, Sommer, Natascha, Wilhelm, Jochen, Gall, Henning, and Richter, Manuel J.
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Supplemental Digital Content is available in the text. Background: Right ventricular (RV) maladaptation and failure determine outcome in pulmonary hypertension. The adaptation of RV function to loading (RV-pulmonary arterial coupling) is defined by a ratio of end-systolic to arterial elastances (Ees/Ea). How RV-pulmonary arterial coupling relates to pulmonary hypertension severity and onset of RV failure (defined by excessive volume increase and ejection fraction [EF] decrease) is not exactly known. Methods and Results: We performed cardiac magnetic resonance (CMR) imaging within 24 hours of a diagnostic right heart catheterization and invasive measurement of RV pressure-volume loops in 42 patients with pulmonary hypertension. Median (interquartile range) Ees and Ea were 0.49 (0.35–0.74) and 0.74 (0.45–1.04) mm Hg/mL, respectively; Ees/Ea was 0.73 (0.47–1.07). End-diastolic elastance (Eed) was 0.14 (0.06–0.24) mm Hg/mL. RV EF was 39±13%. End-systolic volume and end-diastolic volume/body surface area (BSA) were 62 (45–101) and 104 (83–143) mL/m
2 , respectively. Ees/Ea decreased with increasing RV end-diastolic volume/BSA, mass/BSA, and pulmonary arterial stiffness, and with decreasing EF, from 0.89 to 1.09 in the least impaired tertiles to 0.55 to 0.61 in the most impaired tertiles. Eed increased with increasing RV mass/BSA, end-diastolic volume/BSA, and T1 mapping and with decreasing EF. Receiver operating characteristic analysis identified an Ees/Ea cutoff of 0.805 associated with onset of RV failure defined by increased RV volumes with EF <35%. Conclusions: RV-pulmonary arterial coupling (Ees/Ea) has considerable reserve, from normal values of 1.5–2 to <0.8, and has the ability to detect pending RV failure in patients with pulmonary hypertension. Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03403868. [ABSTRACT FROM AUTHOR]- Published
- 2019
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7. Respiratory and Metabolic Responses of CD4 + T Cells to Acute Exercise and their Association with Cardiorespiratory Fitness.
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Gebhardt K, Hebecker A, Honekamp C, Nolte S, Barthkuhn M, Wilhelm J, Klatt S, Weyh C, Sommer N, and Krüger K
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Introduction: The study aimed to investigate to what extent acute endurance exercise, especially eccentric exercise and cardiorespiratory fitness affect the metabolic profile of CD4 + cells., Methods: 15 male, healthy adults aged between 20 and 33 years with a maximal oxygen uptake (VO 2max ) between 44 and 63 ml/kg/min performed a downhill run (DR) and a level run (LR) for 45 minutes at 70% of their VO 2max on a treadmill in a cross-over design. Blood samples were taken before (T0), directly after (T1), 3 hours after (T3), and 24 hours (T24) after each exercise for analyzing leukocyte numbers and cytokine levels. Isolated CD4 + cells were incubated for 4 hours in autologous resting versus 3 hours after exercise serum (T3 DR and T3 LR), and subsequently, cellular respiration, transcriptomic, and metabolomics profiles were measured., Results: The systemic immune inflammation index increased significantly after DR and LR at T1 and T3 (p < .001). In contrast, the transcriptomic and metabolic profile of CD4 + cells showed no significant alterations after incubation in T3 exercise serum. However, cardiorespiratory fitness positively correlated with the maximal mitochondrial respiration in CD4 + cells after incubation with T3 LR serum (r = .617, p = .033) and with gene expression of oxidative phosphorylation and levels of different metabolites. Similarly, VO 2max was associated with an anti-inflammatory profile on RNA level. Lower lactate, methylmalonic acid, and D-gluconic acid levels were found in CD4 + cells of participants with a high VO 2max (p < .001)., Conclusions: Acute exercise leads to a mild pro-inflammatory milieu with only small changes in the metabolic homeostasis of CD4 + cells. High cardiorespiratory fitness is associated with a metabolic shift to oxidative phosphorylation in CD4 + cells. Functional relevance of this metabolic shift needs to be further investigated., Competing Interests: Conflict of Interest and Funding Source: No conflicts of interest are declared., (Copyright © 2024 by the American College of Sports Medicine.)
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- 2024
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8. SPARC, a Novel Regulator of Vascular Cell Function in Pulmonary Hypertension.
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Veith C, Vartürk-Özcan I, Wujak M, Hadzic S, Wu CY, Knoepp F, Kraut S, Petrovic A, Gredic M, Pak O, Brosien M, Heimbrodt M, Wilhelm J, Weisel FC, Malkmus K, Schäfer K, Gall H, Tello K, Kosanovic D, Sydykov A, Sarybaev A, Günther A, Brandes RP, Seeger W, Grimminger F, Ghofrani HA, Schermuly RT, Kwapiszewska G, Sommer N, and Weissmann N
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- Animals, Cell Proliferation, Cells, Cultured, Endothelial Cells metabolism, Familial Primary Pulmonary Hypertension metabolism, Humans, Hypoxia metabolism, Mice, Mice, Inbred C57BL, Myocytes, Smooth Muscle metabolism, Osteonectin genetics, Pulmonary Artery, Vascular Remodeling genetics, Hypertension, Pulmonary pathology
- Abstract
Background: Pulmonary hypertension (PH) is a life-threatening disease, characterized by excessive pulmonary vascular remodeling, leading to elevated pulmonary arterial pressure and right heart hypertrophy. PH can be caused by chronic hypoxia, leading to hyper-proliferation of pulmonary arterial smooth muscle cells (PASMCs) and apoptosis-resistant pulmonary microvascular endothelial cells (PMVECs). On reexposure to normoxia, chronic hypoxia-induced PH in mice is reversible. In this study, the authors aim to identify novel candidate genes involved in pulmonary vascular remodeling specifically in the pulmonary vasculature., Methods: After microarray analysis, the authors assessed the role of SPARC (secreted protein acidic and rich in cysteine) in PH using lung tissue from idiopathic pulmonary arterial hypertension (IPAH) patients, as well as from chronically hypoxic mice. In vitro studies were conducted in primary human PASMCs and PMVECs. In vivo function of SPARC was proven in chronic hypoxia-induced PH in mice by using an adeno-associated virus-mediated Sparc knockdown approach., Results: C57BL/6J mice were exposed to normoxia, chronic hypoxia, or chronic hypoxia with subsequent reexposure to normoxia for different time points. Microarray analysis of the pulmonary vascular compartment after laser microdissection identified Sparc as one of the genes downregulated at all reoxygenation time points investigated. Intriguingly, SPARC was vice versa upregulated in lungs during development of hypoxia-induced PH in mice as well as in IPAH, although SPARC plasma levels were not elevated in PH. TGF-β1 (transforming growth factor β1) or HIF2A (hypoxia-inducible factor 2A) signaling pathways induced SPARC expression in human PASMCs. In loss of function studies, SPARC silencing enhanced apoptosis and reduced proliferation. In gain of function studies, elevated SPARC levels induced PASMCs, but not PMVECs, proliferation. Coculture and conditioned medium experiments revealed that PMVECs-secreted SPARC acts as a paracrine factor triggering PASMCs proliferation. Contrary to the authors' expectations, in vivo congenital Sparc knockout mice were not protected from hypoxia-induced PH, most probably because of counter-regulatory proproliferative signaling. However, adeno-associated virus-mediated Sparc knockdown in adult mice significantly improved hemodynamic and cardiac function in PH mice., Conclusions: This study provides evidence for the involvement of SPARC in the pathogenesis of human PH and chronic hypoxia-induced PH in mice, most likely by affecting vascular cell function.
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- 2022
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9. Epigenetic Regulation by Suv4-20h1 in Cardiopulmonary Progenitor Cells Is Required to Prevent Pulmonary Hypertension and Chronic Obstructive Pulmonary Disease.
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Qi H, Liu H, Pullamsetti SS, Günther S, Kuenne C, Atzberger A, Sommer N, Hadzic S, Günther A, Weissmann N, Zhou Y, Yuan X, and Braun T
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- Animals, Humans, Mice, Mice, Knockout, Epigenesis, Genetic genetics, Histone-Lysine N-Methyltransferase metabolism, Hypertension, Pulmonary genetics, Pulmonary Disease, Chronic Obstructive genetics, Stem Cells metabolism
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Background: The pathogenesis of life-threatening cardiopulmonary diseases such as pulmonary hypertension (PH) and chronic obstructive pulmonary disease (COPD) originates from a complex interplay of environmental factors and genetic predispositions that is not fully understood. Likewise, little is known about developmental abnormalities or epigenetic dysregulations that might predispose for PH or COPD in adult individuals., Methods: To identify pathology-associated epigenetic alteration in diseased lung tissues, we screened a cohort of human patients with PH and COPD for changes of histone modifications by immunofluorescence staining. To analyze the function of H4K20me2/3 in lung pathogenesis, we developed a series of Suv4-20h1 knockout mouse lines targeting cardiopulmonary progenitor cells and different heart and lung cell types, followed by hemodynamic studies and morphometric assessment of tissue samples. Molecular, cellular, and biochemical techniques were applied to analyze the function of Suv4-20h1-dependent epigenetic processes in cardiopulmonary progenitor cells and their derivatives., Results: We discovered a strong reduction of the histone modifications of H4K20me2/3 in human patients with COPD but not patients with PH that depend on the activity of the H4K20 di-methyltransferase SUV4-20H1. Loss of Suv4-20h1 in cardiopulmonary progenitor cells caused a COPD-like/PH phenotype in mice including the formation of perivascular tertiary lymphoid tissue and goblet cell hyperplasia, hyperproliferation of smooth muscle cells/myofibroblasts, impaired alveolarization and maturation defects of the microvasculature leading to massive right ventricular dilatation and premature death. Mechanistically, SUV4-20H1 binds directly to the 5'-upstream regulatory element of the superoxide dismutase 3 ( Sod3 ) gene to repress its expression. Increased levels of the extracellular SOD3 enzyme in Suv4-20h1 mutants increases hydrogen peroxide concentrations, causing vascular defects and impairing alveolarization., Conclusions: Our findings reveal a pivotal role of the histone modifier SUV4-20H1 in cardiopulmonary codevelopment and uncover the developmental origins of cardiopulmonary diseases. We assume that the study will facilitate the understanding of pathogenic events causing PH and COPD and aid the development of epigenetic drugs for the treatment of cardiopulmonary diseases.
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- 2021
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