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Objective: To observe the changes of short-chain acyl-CoA dehydrogenase (SCAD) expression on human umbilical vein endothelial cell (HUVEC) apoptosis and investigate its relationship with apoptosis., Methods: The HUVEC was cultured normally for 2-3 days. The apoptotic model of HUVEC was established by tert-butyl hydrogen peroxide (tBHP). The HUVEC was treated by different concentrations of tBHP (0, 10, 20, 30, 40, 50 μmol/L) for 12 hours and different time (0, 3, 6, 9, 12 hours) with 50 μmol/L tBHP to establish the apoptotic model of HUVEC. The cell viability was detected by methyl thiazolyl tetrazolium (MTT), the mRNA expression of SCAD was determined by real-time polymerase chain reaction (PCR), the protein expression of SCAD was achieved by Western Blot. The best concentrate and time were determined to interfere the HUVEC to achieve the apoptotic model of HUVEC. The SCAD gene of HUVEC was knocked down by RNA interference sequence (siRNA274, siRNA414, siRNA679). The mRNA expression of SCAD, the protein expression of SCAD and the activity of SCAD enzyme were detected to achieve the best RNA interference sequence. The HUVEC was intervened by the best RNA interference sequence and tBHP. The cell activity and apoptosis rate, the enzyme activity of SCAD, the mRNA and protein expression of SCAD, the contents of reactive oxygen species (ROS), aderosine triphosphate (ATP) and free fatty acid (FFA) were detected to observe the effect of SCAD on apoptosis of HUVEC., Results: (1) The cell viability, the mRNA expression and the protein expression of SCAD were decreased gradually in a concentration and time dependent manner with the increase of tBHP concentration and the prolongation of intervention time. The decline was most significant in the group of the 50 μmol/L tBHP to interfere HUVEC for 12 hours. (2) The siRNA679 transfection was the most significant in reducing SCAD mRNA and protein expressions among the three interference sequences (siRNA274, siRNA414, siRNA679). (3) Compare with blank control group, the cell viability was significantly decreased in the siRNA679 group (A value: 0.48±0.09 vs. 1.00±0.09, P < 0.01), the apoptotic rate of HUVEC was significantly increased [(29.96±2.09)% vs. (2.90±1.90)%, P < 0.01], the expression of SCAD mRNA and SCAD protein, the activity of SCAD enzyme and the content of ATP were significantly decreased [SCAD mRNA (2 -ΔΔCt ): 0.50±0.16 vs. 1.34±0.12, SCAD/α-Tubulin: 0.67±0.11 vs. 1.00±0.06, the activity of SCAD enzyme (kU/g): 0.38±0.04 vs. 0.53±0.04, the content of ATP (μmol/g): 0.14±0.02 vs. 0.19±0.01, all P < 0.05], the contents of FFA and ROS were significantly increased [FFA (nmol/g): 0.84±0.07 vs. 0.47±0.04, ROS (average fluorescence intensity): 647.5±23.7 vs. 434.2±46.5, both P < 0.01]. Meanwhile, SCAD siRNA treatment triggered the same apoptosis as HUVEC treated with tBHP., Conclusions: Down-regulation of SCAD may play an important role in HUVEC apoptosis. Increase in the expression of SCAD may become an important part in intervening HUVEC apoptosis.

Objective: To Study the changes of short-chain acyl-CoA dehydrogenase (SCAD) in heart failure (HF) after myocardial infarction (MI), and the effect of aerobic exercise on SCAD., Methods: Healthy male Sprague-Dawley (SD) rats were divided into sham operation group (Sham group), sham operation swimming group (Sham+swim group), HF model group (LAD group) and HF swimming group (LAD+swim group) by random number table method, with 9 rats in each group. The left anterior descending branch of coronary artery (LAD) was ligated to establish a rat model of HF after MI. In Sham group, only one loose knot was threaded under the left coronary artery, and the rest operations were the same as those in LAD group. Rats in Sham+swim group and LAD+swim group were given swimming test for 1 week after operation (from 15 minutes on the 1st day to 60 minutes on the 5th day). Then they were given swimming endurance training (from the 2nd week onwards, 60 minutes daily, 6 times weekly, 10 weeks in a row). Tail artery systolic pressure (SBP) was measured before swimming endurance training and every 2 weeks until the end of the 10th week. Ten weeks after swimming training, echocardiography was performed to measure cardiac output (CO), stroke volume (SV), left ventricular ejection fraction (LVEF), shortening fraction (FS), left ventricular end-systolic diameter (LVESD), left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic volume (LVESV), and left ventricular end-diastolic volume (LVEDV). Morphological changes of heart were observed by Masson staining. Apoptosis of myocardial cells was detected by transferase-mediated deoxyuridine triphosphate-biotin nick end labeling stain (TUNEL) and apoptosis index (AI) was calculated. Reverse transcription-polymerase chain reaction (RT-PCR) and Western Blot were used to detect the mRNA and protein expression of myocardial SCAD respectively. In addition, the enzyme activity of SCAD, the content of adenosine triphosphate (ATP) and free fatty acid (FFA) in serum and myocardium were detected according to the kit instruction steps., Results: Compared with Sham group, Sham+swim group showed SBP did not change significantly, with obvious eccentric hypertrophy and increased myocardial contractility, and LAD group showed persistent hypotension, obvious MI, thinning of left ventricle, and decreased myocardial systolic/diastolic function. Compared with LAD group, SBP, systolic/diastolic function and MI in LAD+swim group were significantly improved [SBP (mmHg, 1 mmHg = 0.133 kPa): 119.5±4.4 vs. 113.2±4.5 at 4 weeks, 120.3±4.0 vs. 106.5±3.7 at 6 weeks, 117.4±1.3 vs. 111.0±2.3 at 8 weeks, 126.1±1.6 vs. 119.4±1.9 at 10 weeks; CO (mL/min): 59.10±6.31 vs. 33.19±4.76, SV (μL): 139.42±17.32 vs. 84.02±14.26, LVEF: 0.523±0.039 vs. 0.309±0.011, FS: (28.17±2.57)% vs. (15.93±3.64)%, LVEDD (mm): 8.80±0.19 vs. 9.35±0.30, LVESD (mm): 5.90±0.77 vs. 7.97±0.60, LVEDV (μL): 426.57±20.84 vs. 476.24±25.18, LVESV (μL): 209.50±25.18 vs. 318.60±16.10; AI: (20.4±1.4)% vs. (31.2±4.6)%; all P < 0.05]. Compared with Sham group, the mRNA and protein expression of myocardium SCAD, the activity of SCAD in Sham+swim group were significantly increased, the content of ATP was slightly increased, the content of serum FFA was significantly decreased, and the content of myocardial FFA was slightly decreased; conversely, the mRNA and protein expression of myocardium SCAD, the activity of SCAD and the content of ATP in LAD group were significantly decreased, the content of serum and myocardial FFA were significantly increased. Compared with LAD group, the mRNA and protein expression of myocardium SCAD, the content of ATP were significantly increased in LAD+swim group [SCAD mRNA (2 -ΔΔCt ): 0.52±0.16 vs. 0.15±0.01, SCAD/GAPDH (fold increase from Sham group): 0.94±0.08 vs. 0.60±0.11, ATP content (μmol/g): 52.8±10.1 vs. 14.7±6.1, all P < 0.05], the content of serum and myocardial FFA were significantly decreased [serum FFA (nmol/L): 0.11±0.03 vs. 0.29±0.04, myocardial FFA (nmol/g): 32.7±8.2 vs. 59.7±10.7, both P < 0.05], and the activity of SCAD was slightly increased (kU/g: 12.3±4.3 vs. 8.9±5.8, P > 0.05)., Conclusions: The expression of SCAD in HF was significantly down-regulated, and the expression was significantly up-regulated after aerobic exercise intervention, indicating that swimming may improve the severity of HF by up-regulating the expression of SCAD.

Short-chain acyl-CoA dehydrogenase (SCAD), a key enzyme of fatty acid β-oxidation, plays an important role in cardiac hypertrophy. However, its effect on the cardiomyocyte apoptosis remains unknown. We aimed to determine the role of SCAD in tert-butyl hydroperoxide (tBHP)-induced cardiomyocyte apoptosis. The mRNA and protein expression of SCAD were significantly down-regulated in the cardiomyocyte apoptosis model. Inhibition of SCAD with siRNA-1186 significantly decreased SCAD expression, enzyme activity and ATP content, but obviously increased the content of free fatty acids. Meanwhile, SCAD siRNA treatment triggered the same apoptosis as cardiomyocytes treated with tBHP, such as the increase in cell apoptotic rate, the activation of caspase3 and the decrease in the Bcl-2/Bax ratio, which showed that SCAD may play an important role in primary cardiomyocyte apoptosis. The changes of phosphonate AMP-activated protein kinase α (p-AMPKα) and Peroxisome proliferator-activated receptor α (PPARα) in cardiomyocyte apoptosis were consistent with that of SCAD. Furthermore, PPARα activator fenofibrate and AMPKα activator AICAR treatment significantly increased the expression of SCAD and inhibited cardiomyocyte apoptosis. In conclusion, for the first time our findings directly demonstrated that SCAD may be as a new target to prevent cardiomyocyte apoptosis through the AMPK/PPARα/SCAD signal pathways., (© 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Aims: Short-chain acyl-CoA dehydrogenase (SCAD) is a key enzyme in fatty acid oxidation. In the present study we aim to investigate the changes in SCAD between pathological and physiological cardiomyocyte hypertrophy. We also explore the different signaling pathways of pathological and physiological cardiomyocyte hypertrophy., Main Methods: After neonatal rat cardiomyocytes were treated as setups, cell surface area, expression of SCAD, PPARα, phospho-ERK1/2, activity of SCAD, free fatty acid content and ATP content in the cardiomyocytes were measured., Key Findings: Neonatal rat cardiomyocytes treated by PE showed an increased cell surface area and free fatty acid content, increased ERK1/2 phosphorylation, decreased expression of PPARα, decreased expression and activity of SCAD and decreased levels of ATP. Neonatal rat cardiomyocytes treated by IGF-1 showed the reverse effects except for the cell surface area. PPARα inhibitor GW6471 and PPARα activator Fenofibrate treatments abrogated the effects induced by IGF-1 and PE in cardiomyocytes respectively, as well as ERK1/2 activator EGF and ERK1/2 inhibitor PD98059., Significance: SCAD has different changes between pathological and physiological cardiomyocyte hypertrophy. The ERK1/2/PPARα/SCAD signaling pathways play different roles in pathological and physiological cardiomyocyte hypertrophy. SCAD may be used as a new target to prevent the development of pathological cardiac hypertrophy., (Copyright © 2015 Elsevier Inc. All rights reserved.)