scholarly journals The mechanism of BAF60c in myocardial metabolism through the PGC1α/PPARα/mTOR signaling pathway in rats with heart failure

Author(s):  
Qiang Chen ◽  
Lizhu Chen ◽  
Jianguo Jian ◽  
Junping Li ◽  
Xiaomiao Zhang

BRM-associated factor (BAF) 60c promotes muscle glycolysis and improves glucose homeostasis. This study explored the mechanism of BAF60c in heart failure (HF). Fetal/adult rat models of HF were established, and the levels of cardiac contractile proteins and energy metabolism-, oxidative metabolism- and glycolysis-related factors were detected. Overexpression/siRNA BAF60c plasmids were injected into adult HF rats to estimate myocardial glucose uptake, high-energy phosphate contents, mitochondrial function, and cell proliferation and apoptosis. The overexpression/siRNA BAF60c plasmids were transfected into cardiac hypertrophic H9C2 cells to explore the in vitro effects. The interaction of BAF60c and PGC1α was detected. The results suggested that adult HF rats presented increased levels of fetal proteins (ssTnI and fTnT), BAF60c and glycolysis-related factors, and reduced levels of cardiac contractile proteins, PGC1α, PPARα, and oxidative metabolism-related factors. BAF60c knockdown improved glucose uptake, maintained the oxidative metabolism/glycolysis balance, promoted H9C2 cell proliferation, and inhibited apoptosis. PGC1α interacted with BAF60c. Knocking down BAF60c also activated the PGC1α/PPARα/mTOR pathway. Overexpression of PGC1α decreased the damage to H9C2 cells caused by BAF60c. Altogether, BAF60c downregulation activated the PGC1α/PPARα/mTOR pathway, maintained the oxidative metabolism/glycolysis balance and improved mitochondrial function in rat models of HF. This study may offer novel insights into HF treatment.

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
J Borger ◽  
D Scheiber ◽  
P Horn ◽  
D Pesta ◽  
U Boeken ◽  
...  

Abstract Background Alterations of mitochondrial function have been identified to play a role in Heart Failure (HF) pathophysiology. Oxidative phosphorylation (OXPHOS) capacity of the myocardium was shown to be reduced in the failing heart. Ineffective mitochondrial function promotes formation of reactive oxygen species (ROS) that may affect remodelling in ischemia. Thus far, human mitochondrial function comparing dilated cardiomyopathy (DCM) and ischemic cardiomyopathy (ICM) resembling the main aetiologies of heart failure with reduced ejection fraction (HFrEF) has not been investigated. Purpose We hypothesised that 1. ROS production is elevated in left ventricular myocardial tissue specimens of ICM patients compared to DCM. 2. Mitochondrial OXPHOS capacity is higher in left ventricular myocardial tissue specimens of DCM compared to ICM patients. Methods Myocardial tissue was obtained from the left ventricular apex from 63 patients (38 ICM, 25 DCM) with advanced HFrEF requiring implantation of a Left Ventricular Assist Device (LVAD). We performed high-resolution respirometry (HRR, OROBOROS Oxygraph-2k) in saponine-permeabilised myocardial fibres and measured ROS production fluoroscopically via the Amplex Red method. Statistical analysis was conducted using GraphPad Prism 7 and IBM SPSS v26.0. Results Groups were of comparable age (61.5±1.2 vs. 59.3±2.4 years, p=n.s.), sex (87% vs 85% male, p=n.s.), diabetic status (32% vs 38.4% type 2 diabetes mellitus, p=n.s.), and body mass index (28.1±0.8 vs. 26.3±1.1 kg/m2, p=n.s.). We detected reduced myocardial mitochondrial OXPHOS capacity in ICM under state 3 conditions by about 15% (68.7±34.0 vs. 80.9±30.5 pmol/(s*mg), p<0.05), after addition of Glutamate by 25% (78.9±38.7 vs. 104.8±41.2 pmol/(s*mg), p<0.01) as well as after Succinate (115.5±65.5 vs. 155±62.0 pmol/(s*mg), p<0.01), uncoupling agent FCCP (114.1±56.8 vs. 150.5±47.3 pmol/(s*mg), p<0.01), and by about 40% after addition of Complex I inhibitor Rotenone (55.5±25.9 vs. 96.9±28.0 pmol/(s*mg), p<0.001). We detected no difference in ROS production between ICM and DCM (0.6±0.05 vs. 0.76±0.08 pmol/(s*ml), p=n.s.). Conclusion This is the first human study deciphering distinct alterations in mitochondrial function (OXPHOS capacity) in ventricular myocardium of HFrEF patients. Future studies may address how distinct metabolic patterns at the time of implantation may relate to long-term outcome of HFrEF in terms of remodelling and recovery. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): DFG (German Research Foundation)


Author(s):  
Majid Jafari Khorchani ◽  
Mohammad Samare-Najaf ◽  
Ali Abbasi ◽  
Sina Vakili ◽  
Fatemeh Zal

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 53
Author(s):  
Jung Joo Yoon ◽  
Chan Ok Son ◽  
Hye Yoom Kim ◽  
Byung Hyuk Han ◽  
Yun Jung Lee ◽  
...  

Cardiac hypertrophy is a major risk factor for heart failure and leads to cardiovascular morbidity and mortality. Doxorubicin (DOX) is regarded as one of the most potent anthracycline antibiotic agents; however, its clinical usage has some limitations because it has serious cardiotoxic side effects such as dilated cardiomyopathy and congestive heart failure. Betulinic acid (BA) is a pentacyclic-cyclic lupane-type triterpene that has been reported to have anti-bacterial, anti-inflammatory, anti-vascular neogenesis, and anti-fibrotic effects. However, there is no study about its direct effect on DOX induced cardiac hypertrophy and apoptosis. The present study aims to investigate the effect of BA on DOX-induced cardiomyocyte hypertrophy and apoptosis in vitro in H9c2 cells. The H9c2 cells were stimulated with DOX (1 µM) in the presence or absence of BA (0.1–1 μM) and incubated for 24 h. The results of the present study indicated that DOX induces the increase cell surface area and the upregulation of hypertrophy markers including atrial natriuretic peptide (ANP), B-type natriuretic peptide (BNP), beta-myosin heavy chain (β-MHC), and Myosin Light Chain-2 (MLC2) in H9c2 cells. However, the pathological hypertrophic responses were downregulated after BA treatment. Moreover, phosphorylation of JNK, ERK, and p38 in DOX treated H9c2 cells was blocked by BA. As a result of measuring the change in ROS generation using DCF-DA, BA significantly inhibited DOX-induced the production of intracellular reactive oxygen species (ROS) when BA was treated at a concentration of over 0.1 µM. DOX-induced activation of GATA-4 and calcineurin/NFAT-3 signaling pathway were remarkably improved by pre-treating of BA to H9c2 cells. In addition, BA treatment significantly reduced DOX-induced cell apoptosis and protein expression levels of Bax and cleaved caspase-3/-9, while the expression of Bcl-2 was increased by BA. Therefore, BA can be a potential treatment for cardiomyocyte hypertrophy and apoptosis that lead to sudden heart failure.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
M Zaleska-Kociecka ◽  
K Witczak ◽  
K Bartolik ◽  
D Was ◽  
A Kleinork ◽  
...  

Abstract Background High mortality risk in heart failure (HF) is related to repeat HF hospitalizations but also individual patient characteristics. Purpose To evaluate the impact of HF re-/hospitalizations and patient-related factors (sex, HF etiology, age, comorbidity) on all-cause mortality. Methods Our study represents one of the most extensive retrospective cohort analyses consisting of 1,686,861 adult Polish HF patients who presented into public health system in years 2013–2018. It is a part of a nationwide National Health Fund registry covering out- and in-patient data for the entire Polish population (38,495,659 in 2013) since 2009. HF hospitalizations were extracted using ICD-10 coding, whereas the comorbidity was evaluated by means of Charlson Comorbidity Index (CCI). Results In years 2013–2018 the absolute number of HF hospitalizations in Poland grew by 33% to 264,808 in 2018, whereas the number of rehospitalizations increased 1.5-fold to reach 137,708 in 2018. In fact, nearly half of HF patients (n=817,432; 48.5%) experienced at least one hospitalization, while 15.4% (n=259,868) were rehospitalized during the study period. After initial hospitalization the readmission rate due to HF/all circulatory diseases at 30, 60, 180, 360, and 720 days was 10.4%/15.1%, 21.2%/28.3%, 43.9%/52.8%, 62%/70.4%, and 81%/87%, respectively. As compared to patients who were hospitalized just once, those who underwent at least one rehospitalization were more often female (p<0.001), slightly older (p<0.001), and with higher burden of comorbidities based on CCI (p<0.001). Patient survival was highly dependent on hospitalization frequency (Fig. 1). Mean survival rate at day 720 was 66.4%, 59.8%, 54.9%, 51%, and 43.9% for 1st, 2nd, 3rd, 4th, and ≥5th hospitalization, respectively. After adjusting for age, sex, etiology (ischemic/non-ischemic) and CCI using a multivariate stratified Cox regression model, the estimated hazard ratios (HR) for all-cause mortality amounted to 1.22 (95% CI: 1.21–1.23, p<0.001) for 2nd, 1.4 (95% CI: 1.39–1.42, p<0.001) for 3rd, 1.58 (95% CI: 1.56–1.6, p<0.001) for 4th, and 1.97 (95% CI: 1.95–1.98 p<0.001) for 5th and subsequent hospitalizations, as compared to the first hospitalization. Conclusions Hospitalization rate in Poland is alarmingly high. Repeat HF hospitalizations strongly predict mortality rate for HF patients even after adjustment for age, sex, etiology, and comorbidity burden. Figure 1. Kaplan-Meier for survival post hosp. Funding Acknowledgement Type of funding source: Public grant(s) – EU funding. Main funding source(s): The project is co-financed by the European Union from the European Social Fund under the Operational Programme Knowledge Education Development and it is being carried out by the Analyses and Strategies Department of the Polish Ministry of Health.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Yoichi Sunagawa ◽  
Miho Suzuki ◽  
Masafumi Funamoto ◽  
Yasufumi Katanasaka ◽  
Hidetoshi Suzuki ◽  
...  

Introduction: Heart failure is associated with pathological growth and mitochondrial dysfunction of constituent cardiomyocytes. To achieve effective oral pharmacological therapy for heart failure, we screened compounds isolated from natural products and found that auraptene derived from the peel of Citrus Hassaku may be applicable to pharmacological therapy for heart failure. Hypothesis: We assessed the hypothesis that auraptene could improve the deterioration of mitochondrial function and the development of heart failure in rats with myocardial infarction (MI). Methods and Results: In cultured cardiomyocytes, auraptene (2.5-10 μM) dose-dependently repressed phenylephrine-induced hypertrophic responses such as increase in cell size and ANF and ET-1 promoter activations. Auraptene also activated mitochondrial- and lipid metabolism-related gene transcriptions, such as PGC1α, PPARα/γ, mCPT1, UCP3, and PDK4. One week after operation, 22 rats with a moderate size of MI (Fractional shortening (FS) < 40%) were then randomly assigned to vehicle (n=8), auraptene low-dose (5 mg/kg/day, n=7), or high-dose (50 mg/kg/day, n=7). Oral daily treatments with these agents were continued for 6 weeks. There were no differences in left ventricle (LV) geometric and functional data among the 3 MI groups before treatment. After treatment, LVFS was significantly higher in the auraptene low-dose (21%, p < 0.0001) and high-dose (26%, p < 0.0001) groups than the vehicle group (16%). LV wall thickness in the remote non-infarct area was significantly thinner in the auraptene low-dose (1.4 mm, p < 0.01) and high-dose (1.2 mm, p < 0.0001) groups than the vehicle group (2.5 mm). Histological analysis demonstrated that auraptene treatment significantly suppressed MI-induced increases in myocardial cell diameter and perivascular fibrosis compared with vehicle treatment. Moreover, auraptene also prevented the activations of ANF and MCP-1 mRNA levels and up-regulated mitochondrial- and lipid metabolism-related gene transcriptions in LV. Conclusions: Auraptene treatment prevents the worsening of LV systolic function and represses hypertrophy after MI in adult rats. A natural compound, auraptene is expected as a novel useful agent for heart failure therapy in humans.


Endocrinology ◽  
2021 ◽  
Author(s):  
Yuanzhong Wang ◽  
Shiuan Chen

Abstract Estrogen and estrogen receptor (ER) play a fundamental role in breast cancer. To adapt the rapid proliferation of ER+ breast cancer cells, estrogen increases glucose uptake and reprograms glucose metabolism. Meanwhile, estrogen/ER activates the anticipatory unfolded protein response (UPR) preparing cancer cells for the increased protein production required for subsequent cell proliferation. Here, we report that thioredoxin-interacting protein (TXNIP) is an important regulator of glucose metabolism in ER+ breast cancer cells, and estrogen/ER increases glucose uptake and reprograms glucose metabolism via activating anticipatory unfolded protein response (UPR) and subsequently repressing TXNIP expression. By using two widely used ER+ breast cancer cell lines MCF7 and T47D, we showed that MCF7 cells express high TXNIP levels and exhibit mitochondrial oxidative phosphorylation (OXPHOS) phenotype, while T47D cells express low TXNIP levels and display aerobic glycolysis (Warburg effect) phenotype. Knockdown of TXNIP promoted glucose uptake and Warburg effect, while forced overexpression of TXNIP inhibited glucose uptake and Warburg effect. We further showed that estrogen represses TXNIP expression and activates UPR sensor inositol-requiring enzyme 1 (IRE1) via ER in the breast cancer cells, and IRE1 activity is required for estrogen suppression of TXNIP expression and estrogen-induced cell proliferation. Together, our study suggests that TXNIP is involved in estrogen-induced glucose uptake and metabolic reprogramming in ER+ breast cancer cells, and links anticipatory UPR to estrogen reprogramming glucose metabolism.


2019 ◽  
Vol 316 (3) ◽  
pp. C299-C311 ◽  
Author(s):  
Jing Luo ◽  
Zhong-Zhou Si ◽  
Ting Li ◽  
Jie-Qun Li ◽  
Zhong-Qiang Zhang ◽  
...  

Hepatocellular carcinoma (HCC) is known for its high mortality rate worldwide. Based on intensive studies, microRNA (miRNA) expression functions in tumor suppression. Therefore, we aimed to evaluate the contribution of miR-146a-5p to radiosensitivity in HCC through the activation of the DNA damage repair pathway by binding to replication protein A3 (RPA3). First, the limma package of R was performed to differentially analyze HCC expression chip, and regulative miRNA of RPA3 was predicted. Expression of miR-146a-5p, RPA3, and DNA damage repair pathway-related factors in tissues and cells was determined. The effects of radiotherapy on the expression of miR-146a-5p and RPA3 as well as on cell radiosensitivity, proliferation, cell cycle, and apoptosis were also assessed. The results showed that there exists a close correlation between miR-146a and the radiotherapy effect on HCC progression through regulation of RPA3 and the DNA repair pathway. The positive rate of ATM, pCHK2, and Rad51 in HCC tissues was higher when compared with that of the paracancerous tissues. SMMC-7721 and HepG2 cell proliferation were significantly inhibited following 8 Gy 6Mv dose. MiR-146a-5p restrained the expression of RPA3 and promoted the expression of relative genes associated with the DNA repair pathway. In addition, miR-146a-5p overexpression suppresses cell proliferation and enhances radiosensitivity and cell apoptosis in HCC cells. In conclusion, the present study revealed that miR-146a-5p could lead to the restriction of proliferation and the promotion of radiosensitivity and apoptosis in HCC cells through activation of DNA repair pathway and inhibition of RPA3.


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