Ruscogenin Alleviates Myocardial Ischemia via Myosin IIA-Dependent Mitochondrial Fusion and Fission Balance

Ruscogenin (RUS), a major effective steroidal sapogenin derived from Ophiopogon japonicas, has been reported to alleviate myocardial ischemia (MI), but its cardioprotective mechanism is still not completely clear. In this study, we observed that RUS markedly reduced MI-induced myocardial injury, as evidenced by notable reductions in infarct size, improvement in biochemical markers, alleviation of cardiac pathology, amelioration of mitochondrial damage, and inhibition of myocardial apoptosis. Moreover, RUS notably suppressed oxygen-glucose deprivation (OGD)-triggered cell injury and apoptosis. Notably, RUS demonstrated a considerable decrease of the interaction between myosin IIA and F-actin, along with the restoration of mitochondrial fusion and fission balance. We further confirmed that the effects of RUS on MI were mediated by myosin IIA using siRNA and overexpression techniques. The inhibition of myosin IIA resulted in a significant improvement of mitochondrial fusion and fission imbalance, while simultaneously counteracting the beneficial effects of RUS. By contrast, overexpression of myosin IIA aggravated the imbalance between mitochondrial fusion and fission and partially weakened the protection of RUS. These findings suggest that myosin IIA is essential or even a key functional protein in the cardioprotection of RUS. Overall, our results have elucidated an undiscovered mechanism involving myosin IIA-dependent mitochondrial fusion and fission balance for treating MI. Furthermore, our study has uncovered a novel mechanism underlying the protective effects of RUS.

Association between dietary intake of anthocyanidins and heart failure among American adults: NHANES (2007–2010 and 2017–2018)

Background

Despite anthocyanidins have anti-inflammatory and antioxidant properties, no studies have researched association between dietary intake of anthocyanidins and heart failure.

Methods

We enrolled 15,869 participants from the National Health and Nutrition Examination Survey (NHANES) (2007–2010 and 2017–2018) in this cross-sectional study. We examined baseline data and prevalence of heart failure in different quartile groups of anthocyanin intake (Q1-4). Three models were established through logistic regression to evaluate the protective effect of Q4 (highest anthocyanidins intake) on heart failure. The protective effect of high anthocyanidins intake on heart failure was further evaluated in different subgroups.

Results

Participants with the highest anthocyanidins intake (Q4) had the lowest prevalence of heart failure (Q1:2.54%, Q2:2.33%, Q3:2.43%, Q4:1.57%, p = 0.02). After adjusting for possible confounding factors, compared with the Q1 group, the highest anthocyanidins intake (Q4) was independently related to lower presence of heart failure (Q4: OR 0.469, 95%CI [0.289, 0.732], p = 0.003). And this association was still stable in subgroups of female, ≥45 years, smoker, non-Hispanic White or without diabetes, stroke and renal failure.

Conclusion

Dietary intake of anthocyanidins had negative association with the presence of heart failure.

Paeonol attenuates heart failure induced by transverse aortic constriction via ERK1/2 signalling

CONTEXT

Paeonol (PAE) is the main phytochemical from Cortex Moutan. Its main pharmacological effects are anti-inflammatory and antioxidant, but its cardioprotective effect is unclear.

OBJECTIVE

The study investigates the effects and underlying mechanisms of PAE on transverse aortic constriction (TAC)-induced heart failure (HF) in mice.

MATERIALS AND METHODS

C57BL/6 mice were randomly divided into five groups: sham, TAC, PAE10 (TAC + PAE 10 mg/kg), PAE20 (TAC + PAE 20 mg/kg) and PAE 50 (TAC + PAE 50 mg/kg). Paeonol was intragastrically administered to mice for 4 weeks. Mice were anaesthetized with pentobarbital sodium and underwent cardiac echocardiography using echocardiography system. Serum levels of atrial natriuretic peptide (ANP), tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were measured by enzyme-linked immunosorbent assay (ELISA). Myocardial apoptosis was detected with terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling (TUNEL) staining. Haematoxylin-eosin (H&E) and Masson's staining were used for histopathological evaluation. Western and quantitative real-time PCR (qRT-PCR) were performed to detect levels of apoptosis and fibrosis-related proteins.

RESULTS

Echocardiography showed PAE improved cardiac function (LVEF: TAC, 52.3±6.8%; PAE20, 65.8±3.6%; PAE50, 71.4±2.5%) and H&E staining showed PAE alleviated myocardial injury (TAC: 1170.3 ± 134.6 μm²; PAE50: 576.0 ± 53.5 μm²). Western and qRT-PCR results showed that PAE down-regulated the levels of ANP, BNP and α-MHC. In addition, TUNEL and western results showed PAE significantly inhibited apoptosis. Masson and western results showed PAE inhibited cardiac hypertrophy. Western results showed the ERK1/2/JNK pathway could be inhibited by PAE.

DISCUSSION AND CONCLUSIONS

Paeonol regulates ERK1/2/JNK to improve cardiac function, which provides theoretical support for the extensive clinical treatment of HF.

Inhibition of Myocardial Cell Apoptosis Is Important Mechanism for Ginsenoside in the Limitation of Myocardial Ischemia/Reperfusion Injury

Ischemic heart disease has a high mortality, and the recommended therapy is reperfusion. Nevertheless, the restoration of blood flow to ischemic tissue leads to further damage, namely, myocardial ischemia/reperfusion injury (MIRI). Apoptosis is an essential pathogenic factor in MIRI, and ginsenosides are effective in inhibiting apoptosis and alleviating MIRI. Here, we reviewed published studies on the anti-apoptotic effects of ginsenosides and their mechanisms of action in improving MIRI. Each ginsenoside can regulate multiple pathways to protect the myocardium. Overall, the involved apoptotic pathways include the death receptor signaling pathway, mitochondria signaling pathway, PI3K/Akt signaling pathway, NF-κB signaling pathway, and MAPK signaling pathway. Ginsenosides, with diverse chemical structures, regulate different apoptotic pathways to relieve MIRI. Summarizing the effects and mechanisms of ginsenosides contributes to further mechanism research studies and structure–function relationship research studies, which can help the development of new drugs. Therefore, we expect that this review will highlight the importance of ginsenosides in improving MIRI via anti-apoptosis and provide references and suggestions for further research in this field.

How Birds During Migration Maintain (Oxidative) Balance

Animals dynamically adjust their physiology and behavior to survive in changing environments, and seasonal migration is one life stage that demonstrates these dynamic adjustments. As birds migrate between breeding and wintering areas, they incur physiological demands that challenge their antioxidant system. Migrating birds presumably respond to these oxidative challenges by up-regulating protective endogenous systems or accumulating dietary antioxidants at stopover sites, although our understanding of the pre-migration preparations and mid-migration responses of birds to such oxidative challenges is as yet incomplete. Here we review evidence from field and captive-bird studies that address the following questions: (1) Do migratory birds build antioxidant capacity as they build fat stores in preparation for long flights? (2) Is oxidative damage an inevitable consequence of oxidative challenges such as flight, and, if so, how is the extent of damage affected by factors such as the response of the antioxidant system, the level of energetic challenge, and the availability of dietary antioxidants? (3) Do migratory birds ‘recover’ from the oxidative damage accrued during long-duration flights, and, if so, does the pace of this rebalancing of oxidative status depend on the quality of the stopover site? The answer to all these questions is a qualified ‘yes’ although ecological factors (e.g., diet and habitat quality, geographic barriers to migration, and weather) affect how the antioxidant system responds. Furthermore, the pace of this dynamic physiological response remains an open question, despite its potential importance for shaping outcomes on timescales ranging from single flights to migratory journeys. In sum, the antioxidant system of birds during migration is impressively dynamic and responsive to environmental conditions, and thus provides ample opportunities to study how the physiology of migratory birds responds to a changing and challenging world.

Pharmacology of Catechins in Ischemia-Reperfusion Injury of the Heart

Catechins represent a group of polyphenols that possesses various beneficial effects in the cardiovascular system, including protective effects in cardiac ischemia-reperfusion (I/R) injury, a major pathophysiology associated with ischemic heart disease, myocardial infarction, as well as with cardioplegic arrest during heart surgery. In particular, catechin, (−)-epicatechin, and epigallocatechin gallate (EGCG) have been reported to prevent cardiac myocytes from I/R-induced cell damage and I/R-associated molecular changes, finally, resulting in improved cell viability, reduced infarct size, and improved recovery of cardiac function after ischemic insult, which has been widely documented in experimental animal studies and cardiac-derived cell lines. Cardioprotective effects of catechins in I/R injury were mediated via multiple molecular mechanisms, including inhibition of apoptosis; activation of cardioprotective pathways, such as PI3K/Akt (RISK) pathway; and inhibition of stress-associated pathways, including JNK/p38-MAPK; preserving mitochondrial function; and/or modulating autophagy. Moreover, regulatory roles of several microRNAs, including miR-145, miR-384-5p, miR-30a, miR-92a, as well as lncRNA MIAT, were documented in effects of catechins in cardiac I/R. On the other hand, the majority of results come from cell-based experiments and healthy small animals, while studies in large animals and studies including comorbidities or co-medications are rare. Human studies are lacking completely. The dosages of compounds also vary in a broad scale, thus, pharmacological aspects of catechins usage in cardiac I/R are inconclusive so far. Therefore, the aim of this focused review is to summarize the most recent knowledge on the effects of catechins in cardiac I/R injury and bring deep insight into the molecular mechanisms involved and dosage-dependency of these effects, as well as to outline potential gaps for translation of catechin-based treatments into clinical practice.

[8]-Gingerol exerts anti-myocardial ischemic effects in rats via modulation of the MAPK signaling pathway and L-type Ca2+ channels

Myocardial ischemia (MI) remains the leading cause of mortality worldwide. Therefore, it is urgent to seek the treatment to protect the heart. [8]‐Gingerol (8‐Gin), one of the most active ingredients in ginger, has antioxidant, cardiotonic, and cardiovascular protective properties. The present study elucidated the cardioprotection effects and underlying mechanisms of 8‐Gin in isoproterenol (ISO)‐induced MI. ISO (85 mg/kg/d) was subcutaneously injected for 2 consecutive days to induce acute MI model in rats. Electrocardiography, oxidative stress levels, calcium concentrations, and apoptosis degree were observed. The effects of 8‐Gin on L‐type Ca²⁺ current (I_Ca‐L), contraction, and Ca²⁺ transients were monitored in rat myocytes via patch‐clamp and IonOptix detection systems. 8‐Gin decreased J‐point elevation and heart rate and improved pathological heart damage. Moreover, 8‐Gin reduced the levels of CK, LDH, and MDA, ROS production, and calcium concentrations in myocardial tissue, while increased the activities of SOD, CAT, and GSH. In addition, 8‐Gin down‐regulated Caspase‐3 and Bax expressions, while up‐regulated Bcl‐2 expression. 8‐Gin produced a marked decrease in the expression of p38, JNK, and ERK1/2 proteins. 8‐Gin inhibited I_Ca‐L, cell contraction, and Ca²⁺ transients in isolated rat myocytes. The results indicate that 8‐Gin could exert anti‐myocardial ischemic effects, which may be associated with oxidative stress reduction, cardiomyocytes apoptosis inhibition through MAPK signaling pathway, and Ca²⁺ homeostasis regulation via I_Ca‐L modulation.

Starch based hydrogel NPs loaded by anthocyanins might treat glycogen storage at cardiomyopathy in animal fibrotic model

Many reports have been published recently confirmed the limitation of cargo molecules delivered into the heart. This failure is mostly associated with lymphatic or vascular channels washing or to the immune system recognition. Delivery of anthocyanins by encapsulation may augment it retention in the heart at early time points as the capsules are too large to wash out by lymphatic or venous channels and the physical structure of the capsule may shield the anthocyanins from immunoglobulins and cellular components of the immune system. In the current study, the cardiac dysfunction was induced by using carbon tetrachloride and then animal were treated orally by using anthocyanins incorporated into hydrogel NPs twice time /week for 4 weeks. The results showed anthocyanin loaded hydrogel NPs has ability to re-maintain the glycogen content in the liver and heart tissues of fibrotic group (13 ± 1.4 and 5 ± 0.7 μmol glucose/g tissue). Additionally, MDA and hydroxyproline were significantly reduced. PAS stain showed depletion of glycogen granules from heart tissue. It is concluded that starch based hydrogel loaded by anthocyanins can improve histological cardiac functions after their injury .

Anthocyanin Protects Cardiac Function and Cardiac Fibroblasts From High-Glucose Induced Inflammation and Myocardial Fibrosis by Inhibiting IL-17

Diabetic cardiomyopathy (DCM) is one of the major causes of death in diabetic patients. Its pathogenesis involves inflammation and fibrosis that damages the heart tissue and impairs cardiac function. Interleukin (IL)-17, a pro-inflammatory cytokine that plays an important role in a variety of chronic inflammatory processes can serve as an attractive therapeutic target. Anthocyanin, a water-soluble natural pigment, possesses impressive anti-inflammatory activity. However, its role in DCM is unclear. Hence, we investigated the protective effect of anthocyanin on the cardiovascular complications of diabetes using a mouse type 1 diabetes mellitus model induced by streptozotocin. Cardiac function and structural alterations in diabetic mice were tested by echocardiography, hematoxylin and eosin staining, and Masson trichrome staining. Immunohistochemistry was performed to evaluate the distribution and deposition of IL-17 and collagen I and III from the left ventricular tissues of diabetic mice. Cell viability was measured using the methyl thiazolyl tetrazolium assay. Protein levels of IL-17, tumor necrosis factor α, IL-1β, and IL-6 were determined using enzyme-linked immunosorbent assay. IL-17 and collagen I and III were detected by western blotting and immunofluorescence, and their mRNA levels were quantified using quantitative reverse transcription PCR. We observed that anthocyanin lowered blood glucose, improved cardiac function, and alleviated inflammation and fibrosis in the heart tissue of diabetic mice. Meanwhile, anthocyanin reduced the expression of IL-17 in high-glucose-treated cardiac fibroblasts and exhibited an anti-inflammatory effect. Deposition of collagen I and III was also decreased by anthocyanin, suggesting that anthocyanin contributes to alleviating myocardial fibrosis. In summary, anthocyanin could protect cardiac function and inhibit IL-17-related inflammation and fibrosis, which indicates its therapeutic potential in the treatment of diabetes mellitus-related complications.

Oxidative Stress in Ischemic Heart Disease

One of the novel interesting topics in the study of cardiovascular disease is the role of the oxidation system, since inflammation and oxidative stress are known to lead to cardiovascular diseases, their progression and complications. During decades of research, many complex interactions between agents of oxidative stress, oxidation, and antioxidant systems have been elucidated, and numerous important pathophysiological links to na number of disorders and diseases have been established. This review article will present the most relevant knowledge linking oxidative stress to vascular dysfunction and disease. The review will focus on the role of oxidative stress in endotheleial dysfunction, atherosclerosis, and other pathogenetic processes and mechanisms that contribute to the development of ischemic heart disease.

[miR-133b inhibits myocardial ischemia-reperfusion-induced cardiomyocyte apoptosis and accumulation of reactive oxygen species in rats by targeting YES1]

OBJECTIVE

To investigate the effect of miR-133b on cardiomyocyte apoptosis induced by myocardial ischemia-reperfusion (I/R) and explore the mechanism.

METHODS

Thirty-six adult SD rats were randomized into sham-operated group, I/R group, AdmiR-NC group and AdmiR-133b group, and rat models of myocardial I/R were established in the latter 3 groups with myocardial injections of saline or recombinant adenoviruses in the left ventricle. The expression of MiR-133b was detected using RT-qPCR, and cardiac function of the rats was determined using FDP 1 HRV and BRS analysis system. Serum CK-MB and cTnI levels were determined by ELISA, myocardial injury was evaluated with HE staining, cardiomocyte apoptosis was detected by flow cytometry, and ROS content was determined using a DCFH-DA probe. In the in vitro experiment, H9C2 myocardial cells with hypoxia/reoxygenation (H/R) treatment were transfected with Mir-NC or MiR-133b mimic, and the cellular expression of MiR-133b, cell apoptosis, and ROS content were determined. Dual luciferase reporter assay was performed to verify the targeting relationship between miR-133b and YES1. The effects of pc-YES1 or miR-133b mimic transfection on YES1 expression, apoptosis, and ROS content in H9C2 cells were evaluated.

RESULTS

Compared with those in I/R group, miR-133b expression was obviously up-regulated, LVEDP, cTnI and CK-MB levels were significantly decreased, and LVSP, +dp/dt, -dp/dt, HR and CF levels were increased in admiR-133b group (P < 0.01). The rats in admiR-133b group showed obviously reduced pathological damage, cell apoptosis and ROS content compared with those in I/ R group (P < 0.01). In H9C2 cells exposed to H/R, transfection with miR-133b mimic significantly up-regulated miR-133b expression and decreased cell apoptosis and ROS content (P < 0.01). The results of dual luciferase reporter assay suggested a direct targeting relationship between miR-133b and YES1, and MiR-133b mimic transfection significantly down-regulated YES1 protein expression in cells with H/R exposure (P < 0.01). Co-transfection with pc-YES1 reversed the effect of miR-133b overexpression on myocardial cell apoptosis and ROS accumulation.

CONCLUSIONS

miR-133b can inhibit I/R-induced myocardial cell apoptosis and ROS accumulation by targeting YES1 to reduce myocardial I/R injury in rats.