Background The angiotensin‐receptor neprilysin inhibitor (ARNI) sacubitril/valsartan was shown to be superior to the angiotensin‐converting enzyme inhibitor enalapril in terms of reducing cardiovascular mortality in the PARADIGM‐HF (Prospective Comparison of ARNI with angiotensin‐converting enzyme inhibitor to Determine Impact on Global Mortality and Morbidity in Heart Failure) study. However, the impact of ARNI on cardiac reverse remodeling (CRR) has not been established. Methods and Results We conducted a meta‐analysis to compare the effects of ARNI versus angiotensin‐converting enzyme inhibitors or angiotensin receptor blockers on CRR indices. We searched databases for studies published between 2010 and 2019 that reported CRR indices following ARNI administration. Effect size was expressed as mean difference (MD) with 95% CIs. Twenty studies enrolling 10 175 patients were included. ARNI improved functional capacity in patients with heart failure (HF) and a reduced ejection fraction (EF), including increasing New York Heart Association functional class (MD −0.79, 95% CI −0.86, −0.71) and 6‐minute walking distance (MD 27.62 m, 95% CI 15.76, 39.48). ARNI outperformed angiotensin‐converting enzyme inhibitors/angiotensin receptor blockers in terms of CRR indices, with striking changes in left ventricular EF, diameter, and volume. However, there were no significant improvements in indices except left ventricular mass index (MD −3.25 g/m 2 , 95% CI −3.78, −2.72) and left atrial volume (MD −7.20 mL, 95% CI −14.11, −0.29) in HF patients with preserved EF treated with ARNI. Improvements in CRR indices were observed at 3 months and became more significant with longer follow‐up to 12 months. The regression equation for the relationship between left ventricular EF and end‐diastolic dimension was y=0.041+0.071x+0.045x 2 +0.006x 3 . Conclusions ARNI distinctly improved left ventricular size and hypertrophy compared with angiotensin‐converting enzyme inhibitors/angiotensin receptor blockers in HF with reduced EF patients, even after short‐term follow‐up. Patients appeared to benefit more in terms of CRR treated with ARNI as early as possible and for at least 3 months. Further large sample trials are required to determine the effects of ARNI on CRR in HF with preserved EF patients.

Luteolin has long been used in traditional Chinese medicine for treatment of various diseases. Recent studies have suggested that administration of luteolin yields cardioprotective effects during ischemia/reperfusion (I/R) in rats. However, the precise mechanisms of this action remain unclear. The aim of this study is to confirm that luteolin-mediated extracellular signal regulated kinase (ERK1/2) and c-Jun N-terminal kinase (JNK) pathways are responsible for their cardioprotective effects during I/R. Wistar rats were divided into the following groups: (i) DMSO group (DMSO); (ii) I/R group (I/R); (iii) luteolin+I/R group (Lut+I/R); (iv) ERK1/2 inhibitor PD98059+I/R group (PD+I/R); (v) PD98059+luteolin+I/R group (PD+Lut+I/R); and (vi) JNK inhibitor SP600125+I/R group (SP+I/R). The following properties were measured: contractile function of isolated heart and cardiomyocytes; infarct size; the release of lactate dehydrogenase (LDH); the percentage of apoptotic cells; the expression levels of Bcl-2 and Bax; and phosphorylation status of ERK1/2, JNK, type 1 protein phosphatase (PP1a), phospholamban (PLB) and sarcoplasmic reticulum Ca2+-ATPase (SERCA2a). Our data showed that pretreatment with luteolin or SP600125 significantly improved the contraction of the isolated heart and cardiomyocytes, reduced infarct size and LDH activity, decreased the rate of apoptosis and increased the Bcl-2/Bax ratio. However, pretreatment with PD98059 alone before I/R had no effect on the above indexes. Further, these consequences of luteolin pretreatment were abrogated by co-administration of PD98059. We also found that pretreatment with PD98059 caused a significant increase in JNK expression, and SP600125 could cause ERK1/2 activation during I/R. In addition, we are the first to demonstrate that luteolin affects PP1a expression, which results in the up-regulation of the PLB, thereby relieving its inhibition of SERCA2a. These results showed that luteolin improves cardiomyocyte contractile function after I/R injury by an ERK1/2-PP1a-PLB-SERCA2a-mediated mechanism independent of JNK signaling pathway.

Myocardial ischemia often results in damaged heart structure and function, which can be restored through ischemia/reperfusion (I/R) in most cases. However, I/R can exacerbate myocardial ischemia reperfusion injury (IRI). Luteolin, a widely distributed flavonoid, a member of a group of naturally occurring polyphenolic compounds found in many fruits, vegetables and medicinal herbs, has been reported to exhibit anti-inflammatory, antioxidant and anti-carcinogenic activities. In recent years, luteolin has been shown to play an important role in the cardioprotection of IRI. However, its role and mechanism in cardioprotection against IRI has not been clearly elucidated with respect to the apoptosis pathway. The purpose of this paper is to review luteolin’s anti-apoptotic role and mechanism following I/R in rats, and indicate luteolin as a potential candidate for preventing and treating cardiovascular diseases.

BackgroundLuteolin (LUT), a kind of flavonoid which is extracted from a variety of diets, has been reported to convey protective effects of various diseases. Recent researches have suggested that LUT can carry out cardioprotective effects during ischemia/reperfusion (I/R). However, there have no reports on whether LUT can exert protective effects against myocardial I/R injury through the actions of specific microRNAs (miRs). The purpose of this study was to determine which miRs and target genes LUT exerted such function through.MethodsExpression of various miRs in perfused rat hearts was detected using a gene chip. Target genes were predicted with TargetScan, MiRDB and MiRanda. Anoxia/reoxygenation was used to simulate I/R. Cells were transfected by miR-208b-3p mimic, inhibitor and small interfering RNA of Ets1 (avian erythroblastosis virus E26 (v ets) oncogene homolog 1). MiR-208b-3p and Ets1 mRNA were quantified by real-time quantitative polymerase chain reaction. The percentage of apoptotic cells was detected by annexin V-fluorescein isothiocyanate/propidium iodide dyeing and flow cytometry. The protein expression levels of cleaved caspase-3, Bcl-2, Bax, and Ets1 were examined by western blot analysis. A luciferase reporter assay was used to verify the combination between miR-208b-3p and the 3’-untranslated region of Ets1.ResultsLUT pretreatment reduced miR-208b-3p expression in myocardial tissue, as compared to the I/R group. And LUT decreased miR-208b-3p expression and apoptosis caused by I/R. However, overexpression of miR-208b-3p further aggravated the changes caused by I/R and blocked all the effects of LUT. Knockdown of miR-208b-3p expression also attenuated apoptosis, while knockdown of Ets1 promoted apoptosis. Further, the luciferase reporter assay showed that miR-208b-3p could inhibit Ets1 expression.ConclusionLUT pretreatment conveys anti-apoptotic effects after myocardial I/R injury by decreasing miR-208b-3p and increasing Ets1 expression levels.

Background/Aims: A major challenge for current therapeutic strategies against ischemia/reperfusion (I/R) is the lack of effective drugs. Considering luteolin enhances the activity of sarcoplasmic reticulum Ca²⁺-ATPase (SERCA2a) to improve the systolic/diastolic function of rat hearts and cardiomyocytes during the I/R process, we studied the regulatory function of the p38 MAPK pathway in this protective mechanism. Methods: Isolated cardiomyocytes and perfused hearts were separately divided into five groups and used to investigate I/R. The phosphorylation of p38 and phospholamban (p-PLB), the levels and activity of SERCA2a and the levels of proteins related to apoptosis were measured. Apoptotic cells were assessed using the TUNEL assay. Single-cell shortening, Ca²⁺ transients, and the decay of the mitochondrial membrane potential (Δψm) were detected. Results: The p38 MAPK pathway was activated during the I/R process, and inhibiting it with SB203580 promoted p-PLB, which enhanced the activity of SERCA2a and relieved the calcium overload to promote the recovery of the Δψm and reduce cardiomyocyte apoptosis in I/R. Luteolin also suppressed the activation of the p38 MAPK pathway and showed cardioprotective effects during I/R injury. Conclusions: We conclude that luteolin enhances SERCA2a activity to improve systolic/diastolic function during I/R in rat hearts and cardiomyocytes by attenuating the inhibitive effects of the p38 pathway on p-PLB.

The purpose of this study was to observe the effects of salvianolic acid A (SAA) pretreatment on the myocardium during ischemia/reperfusion (I/R) and to illuminate the interrelationships among dual specificity protein phosphatase (DUSP) 2/4/16, ERK1/2 and JNK pathways during myocardial I/R, with the ultimate goal of elucidating how SAA exerts cardioprotection against I/R injury (IRI). Wistar rats were divided into the following six groups: control group (CON), I/R group, SAA+I/R group, ERK1/2 inhibitor PD098059+I/R group (PD+I/R), PD+SAA+I/R group, and JNK inhibitor SP600125+I/R group (SP+I/R). The cardioprotective effects of SAA on the myocardium during I/R were investigated with a Langendorff device. Heart rate (HR), left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), maximum rate of ventricular pressure rise and fall (±dp/dtmax), myocardial infarction areas (MIA), lactate dehydrogenase (LDH), and cardiomyocytes apoptosis were monitored. To determine the crosstalk betwee JNK and ERK1/2 via DUSP2/4/16 with SAA pretreatment, siRNA-DUSP2/4/16 were performed. The expression levels of Bcl-2, Bax, caspase 3, p-JNK, p-ERK1/2 and DUSP2/4/16 in cardiomyocytes were assayed by Western blot. Our results showed that LDH, MIA and cell apoptosis were decreased, and various parameters of heart function were improved by SAA pretreatment and SP application. In the I/R group, the expression levels of p-ERK1/2 and DUSP4/16 were not significantly different compared with the CON group, however, the protein expression levels of p-ERK1/2, Bcl-2 and DUSP4/16 were higher, while p-JNK, Bax, caspase 3 and DUSP2 levels were reduced among the SAA+I/R, PD+SAA+I/R and SP+I/R groups. The above indices were not significantly different between the SAA+I/R and SP+I/R groups. Compared with the SAA+I/R group, p-ERK1/2 was increased and p-JNK was decreased in the SAA+si-DUSP2+I/R, however, p-ERK was downregulated and p-JNK was upregulated in SAA+si-DUSP4+I/R group. SAA exerts an anti-apoptotic role against myocardial IRI by inhibiting DUSP2-mediated JNK dephosphorylation and activating DUSP4/16-mediated ERK1/2 phosphorylation.

We previously found that luteolin (Lut) appeared to improve the contractility of cardiomyocytes during ischemia/reperfusion in rats. The enhancement was associated with the alteration in sarcoplasmic reticulum Ca 2+ -ATPase 2a (SERCA2a). This finding prompted us to consider if the mechanism worked in heart failure (HF). We studied the regulation of SERCA2a by Lut in failing cardiomyocytes and intact heart of rats. Improvement of contractility and the mechanisms centered on SERCA2a were studied in isolated cardiomyocytes and intact heart. We found that Lut significantly improved contractility and Ca 2+ transients, ameliorated expression, activity and stability of SERCA2a and upregulated expression of small ubiquitin-related modifier (SUMO) 1, which is a newfound SERCA2a regulator. Lut also increased phosphorylation of protein kinase B (Akt), phospholaban (PLB) and sumoylation of SERCA2a, specificity protein 1 (Sp1). Transcriptions of SUMO1 and SERCA2a were concurrently increased. Inhibition of posphatidylinositol 3 kinase/Akt (PI3K/Akt) pathway and SERCA2a activity both markedly abolished Lut-induced benefits in vitro and in vivo. Lut upregulated the expression ratio of Bcl-2/Bax, caspase-3/cleaved-Caspase3. Meanwhile, Lut ameliorated the myocardium fibrosis of HF. These discoveries provide an important potential therapeutic strategy that Lut targeted SERCA2a SUMOylation related to PI3K/Akt-mediated regulations on rescuing the dysfunction of HF.Heart failure (HF) is a complex syndrome that results from the deterioration of the cardiac structure and function, characterized by the impaired ability of the ventricle to fill with or eject blood 1 . It is an ultimate common pathway that begins with diverse etiologies, such as hypertension, ischemia, tachycardia, infection, metabolic disorder, and cardiomyopathy, and develops with continual activation of the renin-angiotensin and sympathetic nervous systems. The incidence, prevalence and economic burden of HF are now steadily increasing due to the aging of the population and transition of acute cardiac problems into chronic disorders.Abnormality Ca 2+ homeostasis is a universal characteristic of human and experimental HF 2 . Ca 2+ homeostasis is directly modulated by four proteins: L-type Ca 2+ channel and Na + /Ca 2+ exchanger (NCX) in cell membrane, Ca 2+ -ATPase and ryanodine receptor type 2 in sarcoplasmic reticulum (SR) 3 . Any abnormality of the expression or activity of the Ca 2+ handling proteins mentioned above leads to alterations in cardiac contractility. Sarcoplasmic reticulum Ca 2+ -ATPase 2a (SERCA2a), a principal cardiac form of SERCA, is important in controlling excitation/contraction coupling. SERCA2a's role in HF has been extensively studied in animal models and human, which have shown that SERCA expression and activity are reduced in failing myocardium 4 . Genetic treatments show that reduction in SERCA2a level results in impaired intracellular Ca 2+ homeostasis and reduces both systolic and diastolic function 5,6 . These results indicate that modul...

Salvianolic acid A (Sal A), the water-soluble component from the root of the Salvia miltiorrhiza plant, possesses antioxidant, antiproliferative, and antiplatelet properties. However, whether it plays a role in the protection against ischemia-reperfusion (I/R) injury in rat hearts has yet to be elucidated. In the present study, we tested cell viability, shortening amplitude, necrosis, apoptosis, and the expression levels of Akt, phosphorylated Akt, Bcl-2, Bax, and caspase-3 after 3-hour simulated ischemia and 2- or 6-hour simulated reperfusion in cardiomyocytes. We further observed the contractile function and infarct size in isolated hearts after they were subjected to global 30-minute ischemia and 120-minute reperfusion. Pretreatment with Sal A markedly increased cell viability and shortening amplitude while reducing evidence of necrosis and apoptosis in the cells. In addition, the expression of Bcl-2 was upregulated and Bax was downregulated, thereby increasing the Bcl-2/Bax ratio. Sal A inhibited the activation of caspase-3 as well. The results also showed that Sal A significantly increased phosphorylation of Akt and that this phosphorylation can be partially inhibited by phosphoinositide 3-kinase/Akt inhibitor. Furthermore, Sal A improved I/R-induced myocardial contractile function and reduced infarct size. In summary, our results showed that Sal A prevents I/R-induced myocardial damage by reducing necrosis and apoptosis in isolated rat hearts and cardiomyocytes.