scholarly journals Corticotropin releasing hormone receptor 2 exacerbates chronic cardiac dysfunction

2017 ◽  
Vol 214 (7) ◽  
pp. 1877-1888 ◽  
Author(s):  
Takuma Tsuda ◽  
Mikito Takefuji ◽  
Nina Wettschureck ◽  
Kazuhiko Kotani ◽  
Ryota Morimoto ◽  
...  

Heart failure occurs when the heart is unable to effectively pump blood and maintain tissue perfusion. Despite numerous therapeutic advancements over previous decades, the prognosis of patients with chronic heart failure remains poor, emphasizing the need to identify additional pathophysiological factors. Here, we show that corticotropin releasing hormone receptor 2 (Crhr2) is a G protein–coupled receptor highly expressed in cardiomyocytes and continuous infusion of the Crhr2 agonist, urocortin 2 (Ucn2), reduced left ventricular ejection fraction in mice. Moreover, plasma Ucn2 levels were 7.5-fold higher in patients with heart failure compared to those in healthy controls. Additionally, cardiomyocyte-specific deletion of Crhr2 protected mice from pressure overload-induced cardiac dysfunction. Mice treated with a Crhr2 antagonist lost maladaptive 3′-5′-cyclic adenosine monophosphate (cAMP)–dependent signaling and did not develop heart failure in response to overload. Collectively, our results indicate that constitutive Crhr2 activation causes cardiac dysfunction and suggests that Crhr2 blockade is a promising therapeutic strategy for patients with chronic heart failure.

2020 ◽  
Vol 90 (1-2) ◽  
pp. 49-58 ◽  
Author(s):  
Wang Chunbin ◽  
Wang Han ◽  
Cai Lin

Abstract. Vitamin D deficiency commonly occurs in chronic heart failure. Whether additional vitamin D supplementation can be beneficial to adults with chronic heart failure remains unclear. We conducted a meta-analysis to derive a more precise estimation. PubMed, Embase, and Cochrane databases were searched on September 8, 2016. Seven randomized controlled trials that investigated the effects of vitamin D on cardiovascular outcomes in adults with chronic heart failure, and comprised 592 patients, were included in the analysis. Compared to placebo, vitamin D, at doses ranging from 2,000 IU/day to 50,000 IU/week, could not improve left ventricular ejection fraction (Weighted mean difference, WMD = 3.31, 95% confidence interval, CL = −0.93 to 7.55, P < 0.001, I2 = 92.1%); it also exerts no beneficial effects on the 6 minute walk distance (WMD = 18.84, 95% CL = −24.85 to 62.52, P = 0.276, I2 = 22.4%) and natriuretic peptide (Standardized mean difference, SMD = −0.39, 95% confidence interval CL = −0.48 to 0.69, P < 0.001, I2 = 92.4%). However, a dose-response analysis from two studies demonstrated an improved left ventricular ejection fraction with vitamin D at a dose of 4,000 IU/day (WMD = 6.58, 95% confidence interval CL = −4.04 to 9.13, P = 0.134, I2 = 55.4%). The results showed that high dose vitamin D treatment could potentially benefit adults with chronic heart failure, but more randomized controlled trials are required to confirm this result.


Author(s):  
С.А. Крыжановский ◽  
И.Б. Цорин ◽  
Е.О. Ионова ◽  
В.Н. Столярук ◽  
М.Б. Вититнова ◽  
...  

Цель исследования - разработка трансляционной модели хронической сердечной недостаточности (ХСН) у крыс, позволяющей, с одной стороны, изучить тонкие механизмы, лежащие в основе данной патологии, а с другой стороны, выявить новые биомишени для поиска и изучения механизма действия инновационных лекарственных средств. Методика. Использован комплекс эхокардиографических, морфологических, биохимических и молекулярно-биологических исследований, позволяющий оценивать и дифференцировать этапы формирования ХСН. Результаты. Динамические эхокардиографические исследования показали, что ХСН формируется через 90 дней после воспроизведения переднего трансмурального инфаркта миокарда. К этому времени у животных основной группы отмечается статистически значимое по сравнению со 2-ми сут. после воспроизведения экспериментального инфаркта миокарда снижение ФВ левого желудочка сердца (соответственно 55,9 ± 1,4 и 63,9 ± 1,6%, р = 0,0008). Снижение насосной функции сердца (на 13% по сравнению со 2-ми сут. после операции и на ~40% по сравнению с интактными животными) сопровождается увеличением КСР и КДР (соответственно с 2,49 ± 0,08 до 3,91 ± 0,17 мм, р = 0,0002, и с 3,56 ± 0,11 до 5,20 ± 0,19 мм, р = 0,0001), то есть к этому сроку развивается сердечная недостаточность. Результаты эхокардиографических исследований подтверждены данными морфометрии миокарда, продемонстрировавшими дилатацию правого и левого желудочков сердца. Параллельно проведенные гистологические исследования свидетельствуют о наличии патогномоничных для данной патологии изменений миокарда (постинфарктный кардиосклероз, компенсаторная гипертрофия кардиомиоцитов, очаги исчезновения поперечной исчерченности мышечных волокон и т.д.) и признаков венозного застоя в легких и печени. Биохимические исследования выявили значимое увеличение концентрации в плазме крови биохимического маркера ХСН - мозгового натрийуретического пептида. Данные молекулярно-биологических исследований позволяют говорить о наличии гиперактивности ренин-ангиотензин-альдостероновой и симпатоадреналовой систем, играющих ключевую роль в патогенезе ХСН. Заключение. Разработана трансляционная модель ХСН у крыс, воспроизводящая основные клинико-диагностические критерии этого заболевания. Показано наличие корреляции между морфометрическими, гистологическими, биохимическими и молекулярными маркерами прогрессирующей ХСН и эхокардиографическими диагностическими признаками, что позволяет использовать неинвазивный метод эхокардиографии, характеризующий состояние внутрисердечной гемодинамики, в качестве основного критерия оценки наличия/отсутствия данной патологии. Aim. Development of a translational model for chronic heart failure (CHF) in rats to identify new biotargets for finding and studying mechanisms of innovative drug effect in this disease. Methods. A set of echocardiographic, morphological, biochemical, and molecular methods was used to evaluate and differentiate stages of CHF development. Results. Dynamic echocardiographic studies showed that CHF developed in 90 days after anterior transmural myocardial infarction. By that time, left ventricular ejection fraction was significantly decreased in animals of the main group compared with rats studied on day 2 after experimental myocardial infarction (55.9 ± 1.4% vs . 63.9 ± 1.6%, respectively, p<0.0008). The decrease in heart’s pumping function (by 13% compared with day 2 after infarction and by approximately 40% compared to intact animals) was associated with increased ESD and EDD (from 2.49 ± 0.08 to 3.91 ± 0.17 mm, p = 0.0002, and from 3.56 ± 0.11 to 5.20 ± 0.19 mm, respectively, p = 0.0001); therefore, heart failure developed by that time. The results of echocardiographic studies were confirmed by myocardial morphometry, which demonstrated dilatation of both right and left ventricles. Paralleled histological studies indicated presence of the changes pathognomonic for this myocardial pathology (postinfarction cardiosclerosis, compensatory hypertrophy of cardiomyocytes, foci of disappeared transverse striation of muscle fibers, etc.) and signs of venous congestion in lungs and liver. Biochemical studies demonstrated a significant increase in plasma concentration of brain natriuretic peptide, a biochemical marker of CHF. Results of molecular studies suggested hyperactivity of the renin-angiotensin-aldosterone and sympathoadrenal systems, which play a key role in the pathogenesis of CHF. Conclusions. A translational model of CHF in rats was developed, which reproduced major clinical and diagnostic criteria for this disease. Morphometric, histological, biochemical, and molecular markers for progressive CHF were correlated with echocardiographic diagnostic signs, which allows using this echocardiographic, noninvasive method characterizing the intracardiac hemodynamics as a major criterion for the presence / absence of this pathology.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Satoshi Okumura ◽  
Yunzhe Bai ◽  
Meihua Jin ◽  
Sayaka Suzuki ◽  
Akiko Kuwae ◽  
...  

The sympathetic nervous system and proinflammatory cytokines are believed to play independent roles in the pathophysiology of heart failure. However, the recent identification of Epac (exchange protein activated by cyclic AMP), a new cyclic AMP-binding protein that directly activates Rap1, have implicated that there may be a potential cross talk between the sympathetic and cytokine signals. In order to examine the role of Epac in cytokine signal to regulate cardiac function, we have generated transgenic mice expressing the human Epac1 gene under the control of alpha-cardiac myosin heavy chain promoter (Epac1-TG), and examined their response in lipopolysaccharide (LPS)-induced cardiac dysfunction, a well established model for sepsis-induced cardiac dysfunction. Sepsis-induced cardiac dysfunction results from the production of proinflammatory cytokines. At baseline, left ventricular ejection fraction (LVEF) was similar (TG vs. NTG, 67±1.7 vs. 69±2.1%, n =7–9). The degree of cardiac hypertrophy (LV(mg)/tibia(mm)) was also similar at 3 months old (TG vs. NTG 4.0±0.1 vs. 4.2±0.1, n =5–6), but it became slightly but significantly greater in Epac1-TG at 5 month old (TG vs. NTG 4.9±0.1 vs. 4.4±0.1, p< 0.05, n =5–7). LPS (5mg/kg) elicited a significant and robust reduction of LVEF in both Epac1-TG and NTG, but the magnitude of this decrease was much less in Epac1-TG at 6 hr after injection (TG vs. NTG 48±2.4 vs. 57±1.8%, p< 0.01, n =6–9). At 24 hr after injection, cardiac function was restored to the baseline in both Epac1-TG and NTG. We also examined the activation of JAK-STAT pathway at 24 hr after injection. The tyrosine phosphorylation of STAT1 (Tyr701) and STAT3 (Tyr705) in LV, which is an indicator of STAT activation, was reduced to a greater degree in Epac1-TG by 31±8.8% ( p< 0.05, n =4) and 29±5.9% ( p< 0.05, n =7), respectively, relative to that in NTG. Taken together, Epac1 protects the heart from the cytokine-induced cardiac dysfunction, at least in part, through the inhibition of the JAK-STAT pathway, suggesting the beneficial role played by sympathetic signal to antagonize proinflammatory cytokine signal in heart failure.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Marcus Sandri ◽  
Stephan Gielen ◽  
Norman Mangner ◽  
Volker Adams ◽  
Sandra Erbs ◽  
...  

Background: The concept of ventricular-arterial coupling implies that LV-function is determined by the three factors left ventricular diastolic, left ventricular systolic and arterial elastance. We have previously documented an improvement in endothelial function and systolic LV-function in patients with chronic heart failure (CHF) after 6 months of exercise training (ET). It remains, however, unclear, how shorter ET periods may affect endothelial, systolic and diastolic ventricular function as echocardiographic parameters related to ventricular arterial coupling in patients with CHF. METHODS: In this ongoing study we randomised 43 patients with stable CHF (age 60.3 ± 2.9 years, EF 27.4 ± 1.7%, VO 2 max 14.7 ± 4.3ml/kg*min) to a training or a control group (C). Patients in the training group exercised 4 times daily at 70% of the individual heart rate reserve for 4 weeks under supervision. At baseline and after 4 weeks the E/A ratio and septal/lateral E’/A’ velocities were determined by echocardiography with tissue Doppler. Exercise capacity was measured by ergospirometry and flow-mediated dilatation (FMD) was assessed by high-resolution radial ultrasound. RESULTS: After only 4 weeks of ET oxygen uptake at peak exercise increased from 14.9 ± 3.3 to 18.1 ± 4.7 ml/min/kg, (p<0.01 vs. C) in training subjects. Left ventricular ejection fraction improved from 26.8 ± 4.6 to 33.1 ± 5.5% (p<0.05 vs. C) in patients of the training group while it remained unchanged in the control group. E/A-ratio mended from 0.63 ± 0.12 to 0.81 ± 0.22 (p<0.01 vs. C) in training patients. Septal E’ velocities increased from 5.5 ± 0.5 to 7.8 ± 1.4 cm/s in training patients (p<0.05 vs. C). FMD of the radial artery improved from 8.2 ± 2.1 to 15.2 ± 3.8% (p<0.01 vs. C) as a result of ET. CONCLUSIONS: Only 4 weeks of endurance training are highly effective with significantly improved FMD accompanied by an emended systolic and diastolic LV-function. We hypothesise that the improvement in LV-EF in training patients may be caused by a corrected ventricular-arterial coupling: ventricular diastolic relaxation and effective endothelial function are ameliorated resulting in an augmentation of stroke volume.


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