AKT signalling in the failing heart

Aging in Heart Failure: Embracing Biology Over Chronology: JACC Family Series

Age is among the most potent risk factors for developing heart failure and is strongly associated with adverse outcomes. As the global population continues to age and the prevalence of heart failure rises, understanding the role of aging in the development and progression of this chronic disease is essential. Although chronologic age is on a fixed course, biological aging is more variable and potentially modifiable in patients with heart failure. This review describes the current knowledge on mechanisms of biological aging that contribute to the pathogenesis of heart failure. The discussion focuses on 3 hallmarks of aging-impaired proteostasis, mitochondrial dysfunction, and deregulated nutrient sensing-that are currently being targeted in therapeutic development for older adults with heart failure. In assessing existing and emerging therapeutic strategies, the review also enumerates the importance of incorporating geriatric conditions into the management of older adults with heart failure and in ongoing clinical trials.

Polo-like kinase 4 promotes tumorigenesis and glucose metabolism in glioma by activating AKT1 signaling

Glioblastoma (GBM) is an extremely aggressive tumor associated with a poor prognosis that impacts the central nervous system. Increasing evidence suggests an inherent association between glucose metabolism dysregulation and the aggression of GBM. Polo-like kinase 4 (PLK4), a highly conserved serine/threonine protein kinase, was found to relate to glioma progression and unfavorable prognosis. As revealed by the integration of proteomics and phosphoproteomics, PLK4 was found to be involved in governing metabolic processes and the PI3K/AKT/mTOR pathway. For the first time, this study supports evidence demonstrating that PLK4 activated PI3K/AKT/mTOR signaling through direct binding to AKT1 and subsequent phosphorylating AKT1 at S124, T308, and S473 to promote tumorigenesis and glucose metabolism in glioma. In addition, PLK4-mediated phosphorylation of AKT1 S124 significantly augmented the phosphorylation of AKT1 S473. Therefore, PLK4 exerted an influence on glucose metabolism by stimulating PI3K/AKT/mTOR signaling. Additionally, the expression of PLK4 protein exhibited a positive correlation with AKT1 phosphorylation in glioma patient tissues. These findings highlight the pivotal role of PLK4-mediated phosphorylation of AKT1 in glioma tumorigenesis and dysregulation of glucose metabolism.

Systematic elucidation of the multi-target pharmacological mechanism of Terminalia arjuna against congestive cardiac failure via network pharmacology and molecular modelling approaches

Congestive cardiac failure (CCF) is a pathophysiologic state when the heart is not able to maintain its cardiac output to meet the demand of metabolising tissues. CCF is responsible for approximately 2.9 million deaths worldwide. The heterogeneous nature of CCF draws the attention of researchers to find more enthralling and promising diagnostic and treatment options. Terminalia arjuna (Arjuna) is an evergreen, deciduous tree exhibited various astringent, anti-bacterial, and anti-microbial properties. T. arjuna is being used in various regions for anginal pain, hypertension, congestive heart failure, and dyslipidemia. Although previous in vitro studies have demonstrated the therapeutic potential of T. arjuna, the exact molecular mechanism underlying its protective effect on the heart remains unclear. In this study, a network pharmacology technique was used to explore the active ingredients, potential targets in T. arjuna for the treatment of CCF. In the framework of this study, we explored the active ingredient-target-pathway network and figured out that oleanolic acid, arjunolic acid, luteolin, kaempferol, cholesterol, ellagic acid 4-O-xylopyranoside 3,3'-dimethyl ether, and cyclohexyl (2,4-dimethyl phenyl) methanone contributed significantly to the development of CCF by affecting AKT1, MAPK14, TNF, IL6, ESR1, and HSP90AA1 genes. Molecular docking analysis further validated the activities of these compounds against potential targets. To sum up, integrated network pharmacology and docking analysis revealed that T. arjuna exerts its cardioprotective effect by acting on various signalling pathways, including the thyroid hormone, VEGF signalling pathway, AGE-RAGE signalling pathway in diabetic complications, HIF signalling pathway, sphingolipid signalling pathway, and oestrogen signalling pathways. Overall, this study provides valuable insights into the molecular mechanism of T. arjuna in CCF and highlights its potential as a promising preventive treatment for this condition.

Non-neuronal cholinergic system delays cardiac remodelling in type 1 diabetes

Aims

Type 1 diabetes mellitus (T1DM) is associated with increased risk of cardiovascular disease (CVD) and mortality. The underlying mechanisms for T1DM-induced heart disease still remains unclear. In this study, we aimed to investigate the effects of cardiac non-neuronal cholinergic system (cNNCS) activation on T1DM-induced cardiac remodelling.

Methods

T1DM was induced in C57Bl6 mice using low-dose streptozotocin. Western blot analysis was used to measure the expression of cNNCS components at different time points (4, 8, 12, and 16 weeks after T1DM induction). To assess the potential benefits of cNNCS activation, T1DM was induced in mice with cardiomyocyte-specific overexpression of choline acetyltransferase (ChAT), the enzyme required for acetylcholine (Ac) synthesis. We evaluated the effects of ChAT overexpression on cNNCS components, vascular and cardiac remodelling, and cardiac function.

Key findings

Western blot analysis revealed dysregulation of cNNCS components in hearts of T1DM mice. Intracardiac ACh levels were also reduced in T1DM. Activation of ChAT significantly increased intracardiac ACh levels and prevented diabetes-induced dysregulation of cNNCS components. This was associated with preserved microvessel density, reduced apoptosis and fibrosis, and improved cardiac function.

Significance

Our study suggests that cNNCS dysregulation may contribute to T1DM-induced cardiac remodelling, and that increasing ACh levels may be a potential therapeutic strategy to prevent or delay T1DM-induced heart disease.

HDAC Inhibitors Alleviate Uric Acid-Induced Vascular Endothelial Cell Injury by Way of the HDAC6/FGF21/PI3K/AKT Pathway

ABSTRACT

Uric acid (UA) accumulation triggers endothelial dysfunction, oxidative stress, and inflammation. Histone deacetylase (HDAC) plays a vital role in regulating the pathological processes of various diseases. However, the influence of HDAC inhibitor on UA-induced vascular endothelial cell injury (VECI) remains undefined. Hence, this study aimed to investigate the effect of HDACs inhibition on UA-induced vascular endothelial cell dysfunction and its detailed mechanism. UA was used to induce human umbilical vein endothelial cell (HUVEC) injury. Meanwhile, potassium oxonate-induced and hypoxanthine-induced hyperuricemia mouse models were also constructed. A broad-spectrum HDAC inhibitor trichostatin A (TSA) or selective HDAC6 inhibitor TubastatinA (TubA) was given to HUVECs or mice to determine whether HDACs can affect UA-induced VECI. The results showed pretreatment of HUVECs with TSA or HDAC6 knockdown-attenuated UA-induced VECI and increased FGF21 expression and phosphorylation of AKT, eNOS, and FoxO3a. These effects could be reversed by FGF21 knockdown. In vivo, both TSA and TubA reduced inflammation and tissue injury while increased FGF21 expression and phosphorylation of AKT, eNOS, and FoxO3a in the aortic and renal tissues of hyperuricemia mice. Therefore, HDACs, especially HDAC6 inhibitor, alleviated UA-induced VECI through upregulating FGF21 expression and then activating the PI3K/AKT pathway. This suggests that HDAC6 may serve as a novel therapeutic target for treating UA-induced endothelial dysfunction.

Progress on the role of traditional Chinese medicine in therapeutic angiogenesis of heart failure

ETHNOPHARMACOLOGICAL RELEVANCE

Cardiovascular diseases are still the leading cause of death worldwide. Heart failure (HF), as the terminal stage of many cardiovascular diseases, has brought a heavy burden to the global medical system. Microvascular rarefaction (decreased myocardial capillary density) with reduced coronary flow reserve is a hallmark of HF and therapeutic myocardial angiogenesis is now emerging as a promising approach for the prevention and treatment in HF. Traditional Chinese medicine (TCM) has made remarkable achievements in the treatment of many cardiovascular diseases. Growing evidence have shown that their protective effect in HF is closely related to therapeutic angiogenesis.

AIM OF THE STUDY

This review is to enlighten the therapeutic effect and pro-angiogenic mechanism of TCM in HF, and provide valuable hints for the development of pro-angiogenic drugs for the treatment of HF.

MATERIALS AND METHODS

The relevant information about cardioprotective TCM was collected from electronic scientific databases such as PubMed, Web of Science, ScienceDirect, and China National Knowledge Infrastructure (CNKI).

RESULTS

The studies showed that TCM formulas, extracts, and compounds from herbal medicines can provide therapeutic effect in HF with their pro-angiogenic activity. Their actions are achieved mainly by regulating the key angiogenesis factors particularly VEGF, as well as related regulators including signal molecules and pathways, non-coding miRNAs and stem cells.

CONCLUSION

TCM and their active components might be promising in therapeutic angiogenesis for the treatment of HF.

Endothelial cell-specific mineralocorticoid receptor activation promotes diastolic dysfunction in diet-induced obese male mice

Widespread consumption of diets high in fat and fructose (Western diet, WD) has led to increased prevalence of obesity and diastolic dysfunction (DD). DD is a prominent feature of heart failure with preserved ejection fraction (HFpEF). However, the underlying mechanisms of DD are poorly understood, and treatment options are still limited. We have previously shown that deletion of the cell-specific mineralocorticoid receptor in endothelial cells (ECMR) abrogates DD induced by WD feeding in female mice. However, the specific role of ECMR activation in the pathogenesis of DD in male mice has not been clarified. Therefore, we fed 4-wk-old ECMR knockout (ECMRKO) male mice and littermates (LM) with either a WD or chow diet (CD) for 16 wk. WD feeding resulted in DD characterized by increased left ventricle (LV) filling pressure (E/e') and diastolic stiffness [E/e'/LV inner diameter at end diastole (LVIDd)]. Compared with CD, WD in LM resulted in increased myocardial macrophage infiltration, oxidative stress, and increased myocardial phosphorylation of Akt, in concert with decreased phospholamban phosphorylation. WD also resulted in focal cardiomyocyte remodeling, characterized by areas of sarcomeric disorganization, loss of mitochondrial electron density, and mitochondrial fragmentation. Conversely, WD-induced DD and associated biochemical and structural abnormalities were prevented by ECMR deletion. In contrast with our previously reported observations in females, WD-fed male mice exhibited enhanced Akt signaling and a lower magnitude of cardiac injury. Collectively, our data support a critical role for ECMR in obesity-induced DD and suggest critical mechanistic differences in the genesis of DD between males and females.

LCZ696 protects against doxorubicin-induced cardiotoxicity by inhibiting ferroptosis via AKT/SIRT3/SOD2 signaling pathway activation

Doxorubicin (DOX) is an effective and widely used anticancer drug but has limited clinical applicability because of its cardiotoxicity. Ferroptosis plays a key role in DOX-induced cardiac damage and cardiomyocyte cell death. The inhibition of ferroptosis reverses DOX-induced cardiotoxicity (DIC). LCZ696, a first-in-class angiotensin receptor neprilysin inhibitor, protects against DIC. However, the mechanism of action of LCZ696, especially its effect on ferroptosis, is incompletely understood. This study investigates the cardioprotective effects of LCZ696 on DIC in vivo and in vitro.Cardiotoxicity was induced in Wistar rats by tail intravenous injection of 2.5 mg/kg DOX once a week for six weeks. Rats and H9c2 cells were treated with or without LCZ696 to determine the cardioprotective role and underlying mechanisms of LCZ696 against DIC. To assess the role of SIRT3 and correlated pathways in ferroptosis, SIRT3 knockout was performed using lentiviral vectors, and AKT was inhibited with LY294002. LCZ696 significantly attenuated DIC by decreasing the concentrations of lipid reactive oxygen species and malondialdehyde and increasing the levels of glutathione peroxidase-4 and reduced glutathione in cells and heart tissues. Moreover, LCZ696 remodeled myocardial structures and improved heart ventricular function in DOX-treated rats. LCZ696 treatment increased SIRT3 expression and deacetylated its target gene SOD2, and these changes were mediated by AKT activation. SIRT3 knockdown and AKT inhibition induced lipid peroxidation and reduced the protective effect of LCZ696 in H9c2 cells. Collectively,LCZ696 prevents DIC by inhibiting ferroptosis via AKT/SIRT3/SOD2 signaling pathway activation. Thus, LZC696 is a potential therapeutic strategy for DIC.

Dietary Nε-(carboxymethyl) lysine affects cardiac glucose metabolism and myocardial remodeling in mice

BACKGROUND

Myocardial remodeling is a key factor in the progression of cardiovascular disease to the end stage. In addition to myocardial infarction or stress overload, dietary factors have recently been considered associated with myocardial remodeling. N^ε-(carboxymethyl)lysine (CML) is a representative foodborne toxic product, which can be ingested via daily diet. Therefore, there is a marked need to explore the effects of dietary CML on the myocardium.

AIM

To explore the effects of dietary CML (dCML) on the heart.

METHODS

C57 BL/6 mice were divided into a control group and a dCML group. The control group and the dCML group were respectively fed a normal diet or diet supplemented with CML for 20 wk. Body weight and blood glucose were recorded every 4 wk. ¹⁸F-fluorodeoxyglucose (FDG) was used to trace the glucose uptake in mouse myocardium, followed by visualizing with micro-positron emission tomography (PET). Myocardial remodeling and glucose metabolism were also detected. In vitro, H9C2 cardiomyocytes were added to exogenous CML and cultured for 24 h. The effects of exogenous CML on glucose metabolism, collagen I expression, hypertrophy, and apoptosis of cardiomyocytes were analyzed.

RESULTS

Our results suggest that the levels of fasting blood glucose, fasting insulin, and serum CML were significantly increased after 20 wk of dCML. Micro-PET showed that ¹⁸F-FDG accumulated more in the myocardium of the dCML group than in the control group. Histological staining revealed that dCML could lead to myocardial fibrosis and hypertrophy. The indexes of myocardial fibrosis, apoptosis, and hypertrophy were also increased in the dCML group, whereas the activities of glucose metabolism-related pathways and citrate synthase (CS) were significantly inhibited. In cardiomyocytes, collagen I expression and cellular size were significantly increased after the addition of exogenous CML. CML significantly promoted cellular hypertrophy and apoptosis, while pathways involved in glucose metabolism and level of Cs mRNA were significantly inhibited.

CONCLUSION

This study reveals that dCML alters myocardial glucose metabolism and promotes myocardial remodeling.

The sodium-glucose co-transporter-2 inhibitor ertugliflozin modifies the signature of cardiac substrate metabolism and reduces cardiac mTOR signalling, endoplasmic reticulum stress and apoptosis

AIM

To investigate cardiac signalling pathways connecting substrate utilization with left ventricular remodelling in a murine pressure overload model.

METHODS

Cardiac hypertrophy was induced by transverse aortic constriction surgery in 20-week-old C57BL/6J mice treated with or without the sodium-glucose co-transporter 2 (SGLT2) inhibitor ertugliflozin (225 mg kg^-1 chow diet) for 10 weeks.

RESULTS

Ertugliflozin improved left ventricular function and reduced myocardial fibrosis. This occurred simultaneously with a fasting-like response characterized by improved glucose tolerance and increased ketone body concentrations. While cardiac insulin signalling was reduced in response to SGLT2 inhibition, AMP-activated protein kinase (AMPK) signalling was increased with induction of the fatty acid transporter cluster of differentiation 36 and phosphorylation of acetyl-CoA carboxylase (ACC). Further, enzymes responsible for ketone body catabolism (β-hydroxybutyrate dehydrogenase, succinyl-CoA:3-oxoacid-CoA transferase and acetyl-CoA acetyltransferase 1) were induced by SGLT2 inhibition. Ertugliflozin led to more cardiac abundance of fatty acids, tricarboxylic acid cycle metabolites and ATP. Downstream mechanistic target of rapamycin (mTOR) pathway, relevant for protein synthesis, cardiac hypertrophy and adverse cardiac remodelling, was reduced by SGLT2 inhibition, with alleviation of endoplasmic reticulum (ER) stress and unfolded protein response (UPR) providing a potential mechanism for abundant reduced left ventricular apoptosis and fibrosis.

CONCLUSION

SGLT2 inhibition reduced left ventricular fibrosis in a murine model of cardiac hypertrophy. Mechanistically, this was associated with reduced cardiac insulin and increased AMPK signalling as a potential mechanism for less cardiac mTOR activation with alleviation of downstream ER stress, UPR and apoptosis.

Deficiency of ataxia-telangiectasia mutated kinase attenuates Western-type diet-induced cardiac dysfunction in female mice

Chronic consumption of Western-type diet (WD) induces cardiac structural and functional abnormalities. Previously, we have shown that WD consumption in male ATM (ataxia-telangiectasia mutated kinase) deficient mice associates with accelerated body weight (BW) gain, cardiac systolic dysfunction with increased preload, and exacerbation of hypertrophy, apoptosis, and inflammation. This study investigated the role of ATM deficiency in WD-induced changes in functional and biochemical parameters of the heart in female mice. Six-week-old wild-type (WT) and ATM heterozygous knockout (hKO) female mice were placed on WD or NC (normal chow) for 14 weeks. BW gain, fat accumulation, and cardiac functional and biochemical parameters were measured 14 weeks post-WD. WD-induced subcutaneous and total fat contents normalized to body weight were higher in WT-WD versus hKO-WD. Heart function measured using echocardiography revealed decreased percent fractional shortening and ejection fraction, and increased LV end systolic diameter and volume in WT-WD versus WT-NC. These functional parameters remained unchanged in hKO-WD versus hKO-NC. Myocardial fibrosis, myocyte hypertrophy, and apoptosis were higher in WT-WD versus WT-NC. However, apoptosis was significantly lower and hypertrophy was significantly higher in hKO-WD versus WT-WD. MMP-9 and Bax expression, and Akt activation were higher in WT-WD versus WT-NC. PARP-1 (full-length) expression and mTOR activation were lower in WT-WD versus hKO-WD. Thus, ATM deficiency in female mice attenuates fat weight gain, preserves heart function, and associates with decreased cardiac cell apoptosis in response to WD.

Using human induced pluripotent stem cell-derived cardiomyocytes to understand the mechanisms driving cardiomyocyte maturation

Cardiovascular diseases are the leading cause of mortality and reduced quality of life globally. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) provide a personalized platform to study inherited heart diseases, drug-induced cardiac toxicity, and cardiac regenerative therapy. However, the immaturity of CMs obtained by current strategies is a major hurdle in utilizing hiPSC-CMs at their fullest potential. Here, the major findings and limitations of current maturation methodologies to enhance the utility of hiPSC-CMs in the battle against a major source of morbidity and mortality are reviewed. The most recent knowledge of the potential signaling pathways involved in the transition of fetal to adult CMs are assimilated. In particular, we take a deeper look on role of nutrient sensing signaling pathways and the potential role of cap-independent translation mediated by the modulation of mTOR pathway in the regulation of cardiac gap junctions and other yet to be identified aspects of CM maturation. Moreover, a relatively unexplored perspective on how our knowledge on the effects of preterm birth on cardiovascular development can be actually utilized to enhance the current understanding of CM maturation is examined. Furthermore, the interaction between the evolving neonatal human heart and brown adipose tissue as the major source of neonatal thermogenesis and its endocrine function on CM development is another discussed topic which is worthy of future investigation. Finally, the current knowledge regarding transcriptional mediators of CM maturation is still limited. The recent studies have produced the groundwork to better understand CM maturation in terms of providing some of the key factors involved in maturation and development of metrics for assessment of maturation which proves essential for future studies on in vitro PSC-CMs maturation.

Doxorubicin-induced cardiotoxicity is mediated by neutrophils through release of neutrophil elastase

The mechanisms by which Doxorubicin (Dox) causes acute and late cardiotoxicity are not completely understood. One understudied area is the innate immune response, and in particular the role of neutrophils in Dox-induced cardiotoxicity. Here, using echocardiography, flow cytometry and immunofluorescence staining, we demonstrated increased infiltration of neutrophils that correlated with decreased heart function, disruption of vascular structures and increased collagen deposition in the heart after Dox treatment. Depleting neutrophils protected the heart from Dox-induced cardiotoxicity and changes in vascular structure. Furthermore, our data using neutrophil elastase (NE) knock-out mice and the NE inhibitor AZD9668 suggest that neutrophils cause this damage by releasing NE and that inhibiting NE can prevent Dox-induced cardiotoxicity. This work shows the role of neutrophils and NE in Doxorubicin-induced cardiotoxicity for the first time and suggests a new possible therapeutic intervention.

Hyperactivation of mTOR and AKT in a cardiac hypertrophy animal model of Friedreich ataxia

Cardiomyopathy is a primary cause of death in Friedreich ataxia (FRDA) patients with defective iron-sulfur cluster (ISC) biogenesis due to loss of functional frataxin and in rare patients with functional loss of other ISC biogenesis factors. The mechanistic target of rapamycin (mTOR) and AKT signaling cascades that coordinate eukaryotic cell growth and metabolism with environmental inputs, including nutrients and growth factors, are crucial regulators of cardiovascular growth and homeostasis. We observed increased phosphorylation of AKT and dysregulation of multiple downstream effectors of mTORC1, including S6K1, S6, ULK1 and 4EBP1, in a cardiac/skeletal muscle specific FRDA conditional knockout (cKO) mouse model and in human cell lines depleted of ISC biogenesis factors. Knockdown of several mitochondrial metabolic proteins that are downstream targets of ISC biogenesis, including lipoyl synthase and subunit B of succinate dehydrogenase, also resulted in activation of mTOR and AKT signaling, suggesting that mTOR and AKT hyperactivations are part of the metabolic stress response to ISC deficiencies. Administration of rapamycin, a specific inhibitor of mTOR signaling, enhanced the survival of the Fxn cKO mice, providing proof of concept for the potential of mTOR inhibition to ameliorate cardiac disease in patients with defective ISC biogenesis. However, AKT phosphorylation remained high in rapamycin-treated Fxn cKO hearts, suggesting that parallel mTOR and AKT inhibition might be necessary to further improve the lifespan and healthspan of ISC deficient individuals.

The focal adhesion protein β-parvin controls cardiomyocyte shape and sarcomere assembly in response to mechanical load

Physiological and pathological cardiac stress induced by exercise and hypertension, respectively, increase the hemodynamic load for the heart and trigger specific hypertrophic signals in cardiomyocytes leading to adaptive or maladaptive cardiac hypertrophy responses involving a mechanosensitive remodeling of the contractile cytoskeleton. Integrins sense load and have been implicated in cardiac hypertrophy, but how they discriminate between the two types of cardiac stress and translate mechanical loads into specific cytoskeletal signaling pathways is not clear. Here, we report that the focal adhesion protein β-parvin is highly expressed in cardiomyocytes and facilitates the formation of cell protrusions, the serial assembly of newly synthesized sarcomeres, and the hypertrophic growth of neonatal rat ventricular cardiomyocytes (NRVCs) in vitro. In addition, physiological mechanical loading of NRVCs by either the application of cyclic, uni-axial stretch, or culture on physiologically stiff substrates promotes NRVC elongation in a β-parvin-dependent manner, which is achieved by binding of β-parvin to α/β-PIX, which in turn activates Rac1. Importantly, loss-of-function studies in mice also revealed that β-parvin is essential for the exercise-induced cardiac hypertrophy response in vivo. Our results identify β-parvin as a novel mechano-responsive signaling hub in hypertrophic cardiomyocytes that drives cell elongation in response to physiological mechanical loads.

Insight into the Role of the PI3K/Akt Pathway in Ischemic Injury and Post-Infarct Left Ventricular Remodeling in Normal and Diabetic Heart

Despite the significant decline in mortality, cardiovascular diseases are still the leading cause of death worldwide. Among them, myocardial infarction (MI) seems to be the most important. A further decline in the death rate may be achieved by the introduction of molecularly targeted drugs. It seems that the components of the PI3K/Akt signaling pathway are good candidates for this. The PI3K/Akt pathway plays a key role in the regulation of the growth and survival of cells, such as cardiomyocytes. In addition, it has been shown that the activation of the PI3K/Akt pathway results in the alleviation of the negative post-infarct changes in the myocardium and is impaired in the state of diabetes. In this article, the role of this pathway was described in each step of ischemia and subsequent left ventricular remodeling. In addition, we point out the most promising substances which need more investigation before introduction into clinical practice. Moreover, we present the impact of diabetes and widely used cardiac and antidiabetic drugs on the PI3K/Akt pathway and discuss the molecular mechanism of its effects on myocardial ischemia and left ventricular remodeling.

Major vault protein attenuates cardiomyocyte injury in doxorubicin-induced cardiomyopathy through activating AKT

Background

Doxorubicin (DOX) has limited chemotherapy application for malignancies due to cardiotoxicity. The pathogenesis of DOX-induced cardiomyopathy (DiCM) is yet to be elucidated. Increasing studies proved that activation of AKT prevented cardiomyocyte apoptosis and cardiac dysfunction in response to DOX insult. Our previous studies indicated that major vault protein (MVP) deficiency was accompanied by suppressed phosphorylation of AKT in metabolic diseases. This study aimed to investigate the role and underlying mechanism of MVP on cardiomyocyte apoptosis in DiCM.

Methods

Mice were intraperitoneally injected with DOX 5 mg/kg, once a week for 5 weeks, the total cumulative dose was 25 mg/kg. Cardiomyocyte-specific MVP overexpression was achieved using an adeno-associated virus system under the cTnT promoter after the fourth DOX injection. Cardiac function was examined by echocardiography followed by euthanasia. Tissue and serum were collected for morphology analysis and biochemical examination.

Results

Herein, we found that MVP expression was upregulated in DOX-treated murine hearts. Cardiac-specific MVP overexpression alleviated DOX-induced cardiac dysfunction, oxidative stress and fibrosis. Mechanistically, MVP overexpression activated AKT signaling and decreased cardiomyocyte apoptosis in DiCM.

Conclusions

Based on these findings, we supposed that MVP was a potential therapeutic agent against DiCM.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02517-9.

The Research Progress of Trastuzumab-Induced Cardiotoxicity in HER-2-Positive Breast Cancer Treatment

In recent years, the incidence of breast cancer has been increasing on an annual basis. Human epidermal growth factor receptor-2 (HER-2) is overexpressed in 15-20% human breast cancers, which is associated with poor prognosis and a high recurrence rate. Trastuzumab is the first humanized monoclonal antibody against HER-2. The most significant adverse effect of trastuzumab is cardiotoxicity, which has become an important factor in limiting the safe use of the drug. Unfortunately, the mechanism causing this cardiotoxicity is still not completely understood, and the use of preventive interventions remains controversial. This article focuses on trastuzumab-induced cardiotoxicity, reviewing the clinical application, potential cardiotoxicity, mechanism and discussing the potential interventions through summarizing related researches over the past tens of years.

Capillaries as a Therapeutic Target for Heart Failure

Prognosis of heart failure remains poor, and it is urgent to find new therapies for this critical condition. Oxygen and metabolites are delivered through capillaries; therefore, they have critical roles in the maintenance of cardiac function. With aging or age-related disorders, capillary density is reduced in the heart, and the mechanisms involved in these processes were reported to suppress capillarization in this organ. Studies with rodents showed capillary rarefaction has causal roles for promoting pathologies in failing hearts. Drugs used as first-line therapies for heart failure were also shown to enhance the capillary network in the heart. Recently, the approach with senolysis is attracting enthusiasm in aging research. Genetic or pharmacological approaches concluded that the specific depletion of senescent cells, senolysis, led to reverse aging phenotype. Reagents mediating senolysis are described to be senolytics, and these compounds were shown to ameliorate cardiac dysfunction together with enhancement of capillarization in heart failure models. Studies indicate maintenance of the capillary network as critical for inhibition of pathologies in heart failure.

The Potential of Gamma Secretase as a Therapeutic Target for Cardiac Diseases

Heart diseases are some of the most common and pressing threats to human health worldwide. The American Heart Association and the National Institute of Health jointly work to annually update data on cardiac diseases. In 2018, 126.9 million Americans were reported as having some form of cardiac disorder, with an estimated direct and indirect total cost of USD 363.4 billion. This necessitates developing therapeutic interventions for heart diseases to improve human life expectancy and economic relief. In this review, we look into gamma-secretase as a potential therapeutic target for cardiac diseases. Gamma-secretase, an aspartyl protease enzyme, is responsible for the cleavage and activation of a number of substrates that are relevant to normal cardiac development and function as found in mutation studies. Some of these substrates are involved in downstream signaling processes and crosstalk with pathways relevant to heart diseases. Most of the substrates and signaling events we explored were found to be potentially beneficial to maintain cardiac function in diseased conditions. This review presents an updated overview of the current knowledge on gamma-secretase processing of cardiac-relevant substrates and seeks to understand if the modulation of gamma-secretase activity would be beneficial to combat cardiac diseases.

SGLT2 Inhibition for Cardiovascular Diseases, Chronic Kidney Disease, and NAFLD

Sodium glucose cotransporter 2 (SGLT-2) inhibitors are the latest class of antidiabetic medications. They prevent glucose reabsorption in the proximal convoluted tubule to decrease blood sugar. Several animal studies revealed that SGLT-2 is profoundly involved in the inflammatory response, fibrogenesis, and regulation of numerous intracellular signaling pathways. Likewise, SGLT-2 inhibitors markedly attenuated inflammation and fibrogenesis and improved the function of damaged organ in animal studies, observational studies, and clinical trials. SGLT-2 inhibitors can decrease blood pressure and ameliorate hypertriglyceridemia and obesity. Likewise, they improve the outcome of cardiovascular diseases such as heart failure, arrhythmias, and ischemic heart disease. SGLT-2 inhibitors are associated with lower cardiovascular and all-cause mortality as well. Meanwhile, they protect against nonalcoholic fatty liver disease (NAFLD), chronic kidney disease, acute kidney injury, and improve micro- and macroalbuminuria. SGLT-2 inhibitors can reprogram numerous signaling pathways to improve NAFLD, cardiovascular diseases, and renal diseases. For instance, they enhance lipolysis, ketogenesis, mitochondrial biogenesis, and autophagy while they attenuate the renin-angiotensin-aldosterone system, lipogenesis, endoplasmic reticulum stress, oxidative stress, apoptosis, and fibrogenesis. This review explains the beneficial effects of SGLT-2 inhibitors on NAFLD and cardiovascular and renal diseases and dissects the underlying molecular mechanisms in detail. This narrative review explains the beneficial effects of SGLT-2 inhibitors on NAFLD and cardiovascular and renal diseases using the results of latest observational studies, clinical trials, and meta-analyses. Thereafter, it dissects the underlying molecular mechanisms involved in the clinical effects of SGLT-2 inhibitors on these diseases.

Zerumbone prevents pressure overload-induced left ventricular systolic dysfunction by inhibiting cardiac hypertrophy and fibrosis

BACKGROUND

Cardiac hypertrophy and fibrosis are hallmarks of cardiac remodeling and are involved functionally in the development of heart failure (HF). However, it is unknown whether Zerumbone (Zer) prevents left ventricular (LV) systolic dysfunction by inhibiting cardiac hypertrophy and fibrosis.

PURPOSE

This study investigated the effect of Zer on cardiac hypertrophy and fibrosis in vitro and in vivo.

STUDY DESIGN/METHODS

In primary cultured cardiac cells from neonatal rats, the effect of Zer on phenylephrine (PE)-induced hypertrophic responses and transforming growth factor beta (TGF-β)-induced fibrotic responses was observed. To determine whether Zer prevents the development of pressure overload-induced HF in vivo, a transverse aortic constriction (TAC) mouse model was utilized. Cardiac function was evaluated by echocardiography. The changes of cardiomyocyte surface area were observed using immunofluorescence staining and histological analysis (HE and WGA staining). Collagen synthesis and fibrosis formation were measured by scintillation counter and picrosirius staining, respectively. The total mRNA levels of genes associated with hypertrophy (ANF and BNP) and fibrosis (Postn and α-SMA) were measured by qRT-PCR. The protein expressions (Akt and α-SMA) were assessed by western blotting.

RESULTS

Zer significantly suppressed PE-induced increase in cell size, mRNA levels of ANF and BNP, and Akt phosphorylation in cardiomyocytes. The TGF-β-induced increase in proline incorporation, mRNA levels of Postn and α-SMA, and protein expression of α-SMA were decreased by Zer in cultured cardiac fibroblasts. In the TAC male C57BL/6 mice, echocardiography results demonstrated that Zer improved cardiac function by increasing LV fractional shortening and reducing LV wall thickness compared with the vehicle group. ZER significantly reduced the level of phosphorylated Akt both in cultured cardiomyocytes treated with PE and in the hearts of TAC. Finally, Zer inhibited the pressure overload-induced cardiac hypertrophy and cardiac fibrosis.

CONCLUSION

Zer ameliorates pressure overload-induced LV dysfunction, at least in part by suppressing both cardiac hypertrophy and fibrosis.

Alpha Mangostin Derived from Garcinia magostana Linn Ameliorates Cardiomyocyte Hypertrophy and Fibroblast Phenotypes in Vitro

Cardiac hypertrophy and fibrosis are significant risk factors for chronic heart failure (HF). Since pharmacotherapy agents targeting these processes have not been established, we investigated the effect of alpha-magostin (α-man) on cardiomyocyte hypertrophy and fibrosis in vitro. Primary cultured cardiomyocytes and cardiac fibroblasts were prepared from neonatal rats. After α-man treatment, phenylephrine (PE) and transforming growth factor-beta (TGF-β) were added to the cardiomyocytes and cardiac fibroblasts to induce hypertrophic and fibrotic responses, respectively. Hypertrophic responses were assessed by measuring the cardiomyocyte surface area and hypertrophic gene expression levels. PE-induced phosphorylation of Akt, extracellular signal-regulated kinase (ERK)1/2, and p38 was examined by Western blotting. Fibrotic responses were assessed by measuring collagen synthesis, fibrotic gene expression levels, and myofibroblast differentiation. In addition, TGF-β-induced reactive oxygen species (ROS) production was investigated. In cultured cardiomyocytes, α-man significantly suppressed PE-induced increases in the cardiomyocyte surface area, and the mRNA levels (atrial natriuretic factor (ANF) and brain natriuretic peptide (BNP)). Treatment with α-man significantly suppressed PE-induced Akt phosphorylation, but not ERK and p38 phosphorylation. In cultured cardiac fibroblasts, α-man significantly suppressed TGF-β-induced increases in L-proline incorporation, mRNA levels (POSTN and alpha-smooth muscle actin (α-SMA)), and myofibroblast differentiation. Additionally, it significantly inhibited TGF-β-induced reduced nicotinamide adenine dinucleotide phosphate oxidase4 (NOX4) expression and ROS production in cardiac fibroblasts. Treatment with α-man significantly ameliorates hypertrophy by inhibiting Akt phosphorylation in cardiomyocytes and fibrosis by inhibiting NOX4-generating ROS in fibroblasts. These findings suggest that α-man is a possible natural product for the prevention of cardiac hypertrophy and fibrosis.

Chronic colitis upregulates microRNAs suppressing brain-derived neurotrophic factor in the adult heart

Ulcerative colitis and Crohn's disease are classified as chronic inflammatory bowel diseases (IBD) with known extraintestinal manifestations. The interplay between heart and gut in IBD has previously been noted, but the mechanisms remain elusive. Our objective was to identify microRNAs mediating molecular remodeling and resulting cardiac impairment in a rat model of colitis. To induce chronic colitis, dextran sodium sulfate (DSS) was given to adult rats for 5 days followed by 9 days with normal drinking water for 4 cycles over 8 weeks. Echocardiography was performed to evaluate heart function. DSS-induced colitis led to a significant decrease in ejection fraction, increased left ventricular mass and size, and elevated B-type natriuretic protein. MicroRNA profiling showed a total of 56 miRNAs significantly increased in the heart by colitis, 8 of which are predicted to target brain-derived neurotrophic factor (BDNF). RT-qPCR validated the increases of miR-1b, Let-7d, and miR-155. Transient transfection revealed that miR-155 significantly suppresses BDNF in H9c2 cells. Importantly, DSS colitis markedly decreased BDNF in both myocardium and serum. Levels of various proteins critical to cardiac homeostasis were also altered. Functional studies showed that BDNF increases cell viability and mitigates H2O2-induced oxidative damage in H9c2 cells, demonstrating its protective role in the adult heart. Mechanistically, cellular experiments identified IL-1β as the inflammatory mediator upregulating cardiac miR-155; this effect was confirmed in adult rats. Furthermore, IL-1β neutralizing antibody ameliorated the DSS-induced increase in miR-155 and concurrent decrease in BDNF in the adult heart, showing therapeutic potential. Our findings indicate that chronic colitis impairs heart function through an IL-1β→miR-155→BDNF signaling axis.

Role of PI3K/AKT/mTOR Pathway Associated Oxidative Stress and Cardiac Dysfunction in Takotsubo Syndrome

INTRODUCTION

Takotsubo syndrome (TTS) is a stress-induced cardiomyopathy, but the accurate cause of this syndrome is still unknown.

METHODS

β-adrenergic agonist isoproterenol (ISO) is used to establish the TTS rats model. TTS rats were treated with or without LY294002 or Rapamycin. The rat cardiomyoblast cell line H9C2 was subjected to infect with constitutively active Akt (myr-Akt) or dominant-negative mutant Akt (dn-Akt) and then, treated with ISO. Cell apoptosis was assessed using the Bax/ Bcl-2 ratio. In addition, reactive oxygen species (ROS) levels were measured using dihydroethidium (DHE). Mitochondrial superoxide generation and membrane potential were assayed by MitoSOX and JC-1 fluorescence intensity.

RESULTS

ISO might induce the erratic acute cardiac dysfunction and overexpression of PI3K/AKT/mTOR. Moreover, it also increased the oxidative stress and apoptosis in TTS rats. The Akt inhibitor significantly reversed the cardiac injury effect, which triggered by ISO treatment. In H9C2 cells, the inhibition of Akt provides a protective role against ISO-induced injury by reducing oxidative stress, apoptosis and mitochondrial dysfunction.

CONCLUSION

This study provided new insight into the protective effects of myocardial dysfunction in TTS rats via chronic inhibition of the PI3K/AKT/mTOR expression, which could reduce mitochondrial ROS and oxidative stress-induced apoptosis. PI3K/AKT/mTOR inhibitor could be a therapeutic target to treat cardiovascular dysfunction induced by stress cardiomyopathy.

The mechanism of myocardial fibrosis is ameliorated by myocardial infarction-associated transcript through the PI3K/Akt signaling pathway to relieve heart failure

OBJECTIVE

This study aimed to investigate the role of long noncoding RNA (LncRNA) myocardial infarction-associated transcript (MIAT) in a heart failure (HF) model in vivo and in vitro by regulating the PI3K/Akt signaling pathway.

METHODS

We established HF models in vivo and in vitro and evaluated the collagen content of these models and other factors.

RESULTS

We found that when LncRNA MIAT was silenced, vascular endothelial growth factor, phosphorylated protein kinase B (Akt), and phosphorylated phosphoinositide 3-kinase (PI3K) mRNA and protein levels were significantly downregulated, which suggested that MIAT activated the PI3K/Akt signaling pathway. Akt and PI3K expression was not significantly changed. We also found that when LncRNA MIAT was silenced, collagen expression was significantly downregulated. This finding suggested that MIAT promoted myocardial fibrosis during the development of HF. The levels of inflammatory factors were also significantly reduced with silencing of LncRNA MIAT. This finding suggested that MIAT promoted the expression of inflammatory factors in myocardial fibrosis by activating the PI3K/Akt signaling pathway.

CONCLUSION

This study indicates that silencing LncRNA MIAT may improve myocardial fibrosis and alleviate HF through the PI3K/Akt signaling pathway, which may be helpful for patients with HF to obtain a better therapeutic effect.

Soluble receptor for advanced glycation end-products promotes angiogenesis through activation of STAT3 in myocardial ischemia/reperfusion injury

Soluble receptor for advanced glycation end-products (sRAGE), which exerts cardioprotective effect through inhibiting cardiomyocyte apoptosis and autophagy during ischemia/reperfusion (I/R) injury, is also known to enhance angiogenesis in post-ischemic reperfusion injury-critical limb ischemia (PIRI-CLI) mice. However, whether sRAGE protects the heart from myocardial I/R injury via promoting angiogenesis remains unclear. Myocardial model of I/R injury was conducted by left anterior descending (LAD) ligation for 30 min and reperfusion for 2 weeks in C57BL/6 mice. And I/R injury in cardiac microvascular endothelial cells (CMECs) was duplicated by oxygen and glucose deprivation. The results showed that I/R-induced cardiac dysfunction, inflammation and myocardial fibrosis were all reversed by sRAGE. CD31 immunohistochemistry staining showed that sRAGE increased the density of vessels after I/R injury. The results from cultured CMECs showed that sRAGE inhibited apoptosis and increased proliferation, migration, angiogenesis after exposure to I/R. These effects were dependent on signal transducer and activator of transcription 3 (STAT3) pathway. Together, the present study demonstrated that activation of STAT3 contributed to the protective effects of sRAGE on myocardial I/R injury via promoting angiogenesis.

Extracellular matrix remodeling in animal models of anthracycline-induced cardiomyopathy: a meta-analysis

As in other cardiomyopathies, extracellular matrix (ECM) remodeling plays an important role in anthracycline-induced cardiomyopathy. To understand the pattern and timing of ECM remodeling pathways, we conducted a systematic review in which we describe protein and mRNA markers for ECM remodeling that are differentially expressed in the hearts of animals with anthracycline-induced cardiomyopathy. We included 68 studies in mice, rats, rabbits, and pigs with follow-up of 0.1-8.2 human equivalent years after anthracycline administration. Using meta-analysis, we found 29 proteins and 11 mRNAs that were differentially expressed in anthracycline-induced cardiomyopathy compared to controls. Collagens, matrix metalloproteinases (MMPs), inflammation markers, transforming growth factor ß signaling markers, and markers for cardiac hypertrophy were upregulated, whereas the protein kinase B (AKT) pro-survival pathway was downregulated. Their expression patterns over time from single time point studies were studied with meta-regression using human equivalent years as the time scale. Connective tissue growth factor showed an early peak in expression but remained upregulated at all studied time points. Brain natriuretic peptide (BNP) and MMP9 protein levels increased in studies with longer follow-up. Significant associations were found for higher atrial natriuretic peptide with interstitial fibrosis and for higher BNP and MMP2 protein levels with left ventricular systolic function.

The Prominin-1-Derived Peptide Improves Cardiac Function Following Ischemia

Myocardial infarction (MI) remains the leading cause of death in the western world. Despite advancements in interventional revascularization technologies, many patients are not candidates for them due to comorbidities or lack of local resources. Non-invasive approaches to accelerate revascularization within ischemic tissues through angiogenesis by providing Vascular Endothelial Growth Factor (VEGF) in protein or gene form has been effective in animal models but not in humans likely due to its short half-life and systemic toxicity. Here, we tested the hypothesis that PR1P, a small VEGF binding peptide that we developed, which stabilizes and upregulates endogenous VEGF, could be used to improve outcome from MI in rodents. To test this hypothesis, we induced MI in mice and rats via left coronary artery ligation and then treated animals with every other day intraperitoneal PR1P or scrambled peptide for 14 days. Hemodynamic monitoring and echocardiography in mice and echocardiography in rats at 14 days showed PR1P significantly improved multiple functional markers of heart function, including stroke volume and cardiac output. Furthermore, molecular biology and histological analyses of tissue samples showed that systemic PR1P targeted, stabilized and upregulated endogenous VEGF within ischemic myocardium. We conclude that PR1P is a potential non-invasive candidate therapeutic for MI.

The traditional Chinese medicine formula Fufang-Zhenzhu-Tiaozhi protects myocardia from injury in diabetic minipigs with coronary heart disease

BACKGROUND AND PURPOSE

Diabetes mellitus (DM) is a major risk factor for coronary heart disease (CHD). Previous research has reported that the Fufang-Zhenzhu-Tiaozhi (FTZ) formula has obvious effects on the treatment of dyslipidemia and hyperglycemia. In the present study, we intended to establish a convenient DM-CHD model in minipigs and investigated the protective effect of FTZ against myocardial injury and its mechanism.

METHODS

The DM-CHD model was established by a high-fat/high-sucrose/high-cholesterol diet (HFSCD) combined with balloon injury in the coronary artery. Subsequently, sixteen Wuzhishan minipigs were assigned to three groups: control group, model group, and FTZ group. The model group and FTZ group were given a HFSCD, while the control group was given a normal diet (ND). FTZ was given with meals in the FTZ group. During this time, biochemical parameters, such as total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein (HDL-C), and fasting blood glucose (FBG), were measured by using testing kits. Insulin (INS) was determined by ELISA, and the homeostasis model assessment index of insulin resistance (HOMA-IR) was calculated to evaluate insulin resistance levels. After FTZ administration, the plasma levels of lactate dehydrogenase (LDH), creatine kinase isoenzyme MB (CK-MB), and cardiac troponin I (cTnI) were measured by using ELISA kits to evaluate myocardial injury. Coronary artery stenosis was analyzed by angiographic and HE staining. Myocardial ischemia was assayed with electrocardiogram (ECG). Moreover, cytokines, including interleukin-6 (IL-6), hypersensitive C-reactive protein (hs-CRP), and tumor necrosis factor-alpha (TNF-α), were measured by ELISA kits to assess inflammation. The myocardial tissue was collected, and the pathological morphology was observed by transmission electron microscopy (TEM), HE staining, and Masson staining. Western blots were used to detect the expression of PI3K, AKT, p-AKT, p-NF-κB, and NF-κB.

RESULTS

A DM-CHD model in minipigs with glucose-lipid metabolism disorder, coronary artery incrassation and myocardial damage was successfully established through balloon injury in the coronary artery combined with HFSCD. FTZ effectively inhibited coronary artery incrassation and protected the myocardium against injury in DM-CHD minipigs. FTZ decreased proinflammatory cytokine levels and upregulated the protein expression of the PI3K/Akt pathway in the myocardium.

CONCLUSIONS

A novel DM-CHD model in minipigs was successfully established through balloon injury in the coronary artery combined with HFSCD. FTZ has a protective effect against myocardial injury in DM-CHD by inhibiting inflammation and activating the PI3K/AKT signaling pathway.

Hypoxic Jumbo Squid Activate Neuronal Apoptosis but Not MAPK or Antioxidant Enzymes during Oxidative Stress

AbstractThe limitations that hypoxia imparts on mitochondrial oxygen supply are circumvented by the activation of anaerobic metabolism and prosurvival mechanisms in hypoxia-tolerant animals. To deal with the hypoxia that jumbo squid (Dosidicus gigas) experience in the ocean's depth, they depress their metabolic rate by up to 52% relative to normoxic conditions. This is coupled with molecular reorganization to facilitate their daily descents into the ocean's oxygen minimum zone, where they face not only low oxygen levels but also higher pressures and colder frigid waters. Our current study explores the tissue-specific hypoxia responses of three central processes: (1) antioxidant enzymes responsible for defending against oxidative stress, (2) early apoptotic machinery that signals the activation of cell death, and (3) mitogen-activated protein kinases (MAPKs) that act as central regulators of numerous cellular processes. Luminex xMAP technology was used to assess protein levels and phosphorylation states under normoxic and hypoxic conditions in brains, branchial hearts, and mantle muscles. Hypoxic brains were found to activate apoptosis via upregulation of phospho-p38, phospho-p53, activated caspase 8, and activated caspase 9, whereas branchial hearts were the only tissue to show an increase in antioxidant enzyme levels. Hypoxic muscles seemed the least affected by hypoxia. Our results suggest that hypoxic squid do not undergo large dynamic changes in the phosphorylation states of key apoptotic and central MAPK factors, except for brains, suggesting that these mechanisms are involved in squid hypometabolic responses.

Deficiency of ataxia-telangiectasia mutated kinase modulates functional and biochemical parameters of the heart in response to Western-type diet

Ataxia-telangiectasia mutated (ATM) kinase deficiency exacerbates heart dysfunction late after myocardial infarction. Here, we hypothesized that ATM deficiency modulates Western-type diet (WD)-induced cardiac remodeling with an emphasis on functional and biochemical parameters of the heart. Weight gain was assessed in male wild-type (WT) and ATM heterozygous knockout (hKO) mice on weekly basis, whereas cardiac functional and biochemical parameters were measured 14 wk post-WD. hKO-WD mice exhibited rapid body weight gain at weeks 5, 6, 7, 8, and 10 versus WT-WD. WD decreased percent fractional shortening and ejection fraction, and increased end-systolic volumes and diameters to a similar extent in both genotypes. However, WD decreased stroke volume, cardiac output, peak velocity of early ventricular filling, and aortic ejection time and increased isovolumetric relaxation time (IVRT) and Tei index versus WT-NC (normal chow). Conversely, IVRT, isovolumetric contraction time, and Tei index were lower in hKO-WD versus hKO-NC and WT-WD. Myocyte apoptosis and hypertrophy were higher in hKO-WD versus WT-WD. WD increased fibrosis and expression of collagen-1α1, matrix metalloproteinase (MMP)-2, and MMP-9 in WT. WD enhanced AMPK activation, while decreasing mTOR activation in hKO. Akt and IKK-α/β activation, and Bax, PARP-1, and Glut-4 expression were higher in WT-WD versus WT-NC, whereas NF-κB activation and Glut-4 expression were lower in hKO-WD versus hKO-NC. Circulating concentrations of IL-12(p70), eotaxin, IFN-γ, macrophage inflammatory protein (MIP)-1α, and MIP-1β were higher in hKO-WD versus WT-WD. Thus, ATM deficiency accelerates weight gain, induces systolic dysfunction with increased preload, and associates with increased apoptosis, hypertrophy, and inflammation in response to WD.NEW & NOTEWORTHY Ataxia-telangiectasia mutated (ATM) kinase deficiency in humans associates with enhanced susceptibility to ischemic heart disease. Here, we provide evidence that ATM deficiency accelerates body weight gain and associates with increased cardiac preload, hypertrophy, and apoptosis in mice fed with Western-type diet (WD). Further investigations of the role of ATM deficiency in WD-induced alterations in function and biochemical parameters of the heart may provide clinically applicable information on treatment and/or nutritional counseling for patients with ATM deficiency.

Cardiovascular toxicity of PI3Kα inhibitors

The phosphoinositide 3-kinases (PI3Ks) are a family of intracellular lipid kinases that phosphorylate the 3'-hydroxyl group of inositol membrane lipids, resulting in the production of phosphatidylinositol 3,4,5-trisphosphate from phosphatidylinositol 4,5-bisphosphate. This results in downstream effects, including cell growth, proliferation, and migration. The heart expresses three PI3K class I enzyme isoforms (α, β, and γ), and these enzymes play a role in cardiac cellular survival, myocardial hypertrophy, myocardial contractility, excitation, and mechanotransduction. The PI3K pathway is associated with various disease processes but is particularly important to human cancers since many gain-of-function mutations in this pathway occur in various cancers. Despite the development, testing, and regulatory approval of PI3K inhibitors in recent years, there are still significant challenges when creating and utilizing these drugs, including concerns of adverse effects on the heart. There is a growing body of evidence from preclinical studies revealing that PI3Ks play a crucial cardioprotective role, and thus inhibition of this pathway could lead to cardiac dysfunction, electrical remodeling, vascular damage, and ultimately, cardiovascular disease. This review will focus on PI3Kα, including the mechanisms underlying the adverse cardiovascular effects resulting from PI3Kα inhibition and the potential clinical implications of treating patients with these drugs, such as increased arrhythmia burden, biventricular cardiac dysfunction, and impaired recovery from cardiotoxicity. Recommendations for future directions for preclinical and clinical work are made, highlighting the possible role of PI3Kα inhibition in the progression of cancer-related cachexia and female sex and pre-existing comorbidities as independent risk factors for cardiac abnormalities after cancer treatment.

Aged Monkeys Fed a High-Fat/High-Sugar Diet Recapitulate Metabolic Disorders and Cardiac Contractile Dysfunction

Aged nonhuman primate (NHP) models are of great value for studying the pathology of metabolic heart diseases and developing therapeutic strategies. In this study, aged male cynomolgus monkeys were fed a regular diet or a high-fat/high-sugar diet (HFSD) for 8 months. Metabolic disorders were diagnosed by ¹H-NMR and serum biochemistry, and cardiac function was evaluated by echocardiography. Our results showed that serum metabolic profiles were altered in aged monkeys fed a HFSD, in line with aortic tissue damage, cardiac remodeling, and contractile dysfunction. This aged monkey model significantly increased expression of proinflammatory cytokines and altered expression and phosphorylation of intracellular signaling proteins in the heart, as compared to aged monkeys on a regular diet. Furthermore, the animals demonstrated increased phosphorylation of cardiac myofilament proteins which are causatively associated with decreased myofilament contractility. We conclude that the aged monkey model fed a HFSD exhibits metabolic disorders and cardiac contractile dysfunction.

Upregulated hepatokine fetuin B aggravates myocardial ischemia/reperfusion injury through inhibiting insulin signaling in diabetic mice

Patients with type 2 diabetes mellitus (T2DM) are more susceptible to acute myocardial ischemia/reperfusion (MI/R) injury. However, the mechanism remains largely elusive. Clinical observation showed that high levels of hepatokine fetuin-B (FetB) in plasma are significantly associated with both diabetes and coronary artery diseases. This study was aimed to determine whether FetB mostly derived from liver exacerbates MI/R-induced injury and the underlying mechanisms in T2DM. Mice were given high-fat diet and streptozotocin to induce T2DM model and subjected to 30 min MI followed by reperfusion. Diabetes caused increased hepatic FetB expression and greater myocardial injury as evidenced by increased apoptosis and myocardial enzymes release following MI/R. In T2DM hearts, insulin-induced phosphorylations of insulin receptor substrate 1 at Tyr608 site and Akt at Ser473 site and glucose transporter 4 membrane translocation were markedly reduced. Interaction between FetB and insulin receptor-β subunit (IRβ) was enhanced assessed by immunoprecipitation analysis. More importantly, FetB knockdown via AAV9 alleviated MI/R injury and improved cardiac insulin-induced signaling in T2DM mice. Conversely, upregulation of FetB in normal mice caused exacerbated MI/R injury and impairment of insulin-mediated signaling. In cultured neonatal mouse cardiomyocytes, incubation of FetB significantly reduced tyrosine kinase activity of IR and insulin-induced glucose uptake, and increased hypoxia/reoxygenation-induced apoptosis. Furthermore, FoxO1 knockdown by siRNA suppressed FetB expressions in hepatocytes treated with palmitic acid. In conclusion, upregulated FetB in diabetic liver contributes to increased MI/R injury and cardiac dysfunction via directly interacting with IRβ and consequently impairing cardiac insulin signaling.

BGP-15 Protects against Heart Failure by Enhanced Mitochondrial Biogenesis and Decreased Fibrotic Remodelling in Spontaneously Hypertensive Rats

Heart failure (HF) is a complex clinical syndrome with poor clinical outcomes despite the growing number of therapeutic approaches. It is characterized by interstitial fibrosis, cardiomyocyte hypertrophy, activation of various intracellular signalling pathways, and damage of the mitochondrial network. Mitochondria are responsible for supplying the energy demand of cardiomyocytes; therefore, the damage of the mitochondrial network causes cellular dysfunction and finally leads to cell death. BGP-15, a hydroxylamine derivative, is an insulin-sensitizer molecule and has a wide range of cytoprotective effects in animal as well as in human studies. Our recent work was aimed at examining the effects of BGP-15 in a chronic hypertension-induced heart failure model. 15-month-old male SHRs were used in our experiment. The SHR-Baseline group represented the starting point (n = 7). Animals received BGP-15 (SHR-B, n = 7) or placebo (SHR-C, n = 7) for 18 weeks. WKY rats were used as age-matched normotensive controls (n = 7). The heart function was monitored by echocardiography. Histological preparations were made from cardiac tissue. The levels of signalling proteins were determined by Western blot. At the end of the study, systolic and diastolic cardiac function was preserved in the BGP-treated animals. BGP-15 decreased the interstitial collagen deposition via decreasing the activity of TGFβ/Smad signalling factors and prevented the cardiomyocyte hypertrophy in hypertensive animals. BGP-15 enhanced the prosurvival signalling pathways (Akt/Gsk3β). The treatment increased the activity of MKP1 and decreased the activity of p38 and JNK signalling routes. The mitochondrial mass of cardiomyocytes was also increased in BGP-15-treated SHR animals due to the activation of mitochondrial biogenesis. The mitigation of remodelling processes and the preserved systolic cardiac function in hypertension-induced heart failure can be a result-at least partly-of the enhanced mitochondrial biogenesis caused by BGP-15.

Neutrophil Elastase Deficiency Ameliorates Myocardial Injury Post Myocardial Infarction in Mice

Neutrophils are recruited into the heart at an early stage following a myocardial infarction (MI). These secrete several proteases, one of them being neutrophil elastase (NE), which promotes inflammatory responses in several disease models. It has been shown that there is an increase in NE activity in patients with MI; however, the role of NE in MI remains unclear. Therefore, the present study aimed to investigate the role of NE in the pathogenesis of MI in mice. NE expression peaked on day 1 in the infarcted hearts. In addition, NE deficiency improved survival and cardiac function post-MI, limiting fibrosis in the noninfarcted myocardium. Sivelestat, an NE inhibitor, also improved survival and cardiac function post-MI. Flow cytometric analysis showed that the numbers of heart-infiltrating neutrophils and inflammatory macrophages (CD11b⁺F4/80⁺CD206^low cells) were significantly lower in NE-deficient mice than in wild-type (WT) mice. At the border zone between intact and necrotic areas, the number of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive apoptotic cells was lower in NE-deficient mice than in WT mice. Western blot analyses revealed that the expression levels of insulin receptor substrate 1 and phosphorylation of Akt were significantly upregulated in NE-knockout mouse hearts, indicating that NE deficiency might improve cardiac survival by upregulating insulin/Akt signaling post-MI. Thus, NE may enhance myocardial injury by inducing an excessive inflammatory response and suppressing Akt signaling in cardiomyocytes. Inhibition of NE might serve as a novel therapeutic target in the treatment of MI.

Maternal obesity persistently alters cardiac progenitor gene expression and programs adult-onset heart disease susceptibility

Objective

Heart disease risk can be programmed by intrauterine exposure to obesity. Dysregulating key transcription factors in cardiac progenitors can cause subsequent adult-onset heart disease. In this study, we investigated the transcriptional pathways that are altered in the embryonic heart and linked to heart disease risk in offspring exposed to obesity during pregnancy.

Methods

Female mice were fed an obesogenic diet and mated with males fed a control diet. Heart function and genome-wide gene expression were analyzed in adult offspring born to obese and lean mice at baseline and in response to stress. Cross-referencing with genes dysregulated genome-wide in cardiac progenitors from embryos of obese mice and human fetal hearts revealed the transcriptional events associated with adult-onset heart disease susceptibility.

Results

We found that adult mice born to obese mothers develop mild heart dysfunction consistent with early stages of disease. Accordingly, hearts of these mice dysregulated genes controlling extracellular matrix remodeling, metabolism, and TGF-β signaling, known to control heart disease progression. These pathways were already dysregulated in cardiac progenitors in embryos of obese mice. Moreover, in response to cardiovascular stress, the heart of adults born to obese dams developed exacerbated myocardial remodeling and excessively activated regulators of cell-extracellular matrix interactions but failed to activate metabolic regulators. Expression of developmentally regulated genes was altered in cardiac progenitors of embryos of obese mice and human hearts of fetuses of obese donors. Accordingly, the levels of Nkx2-5, a key regulator of heart development, inversely correlated with maternal body weight in mice. Furthermore, Nkx2-5 target genes were dysregulated in cardiac progenitors and persistently in adult hearts born to obese mice and human hearts from pregnancies affected by obesity.

Conclusions

Obesity during pregnancy alters Nkx2-5-controlled transcription in differentiating cardiac progenitors and persistently in the adult heart, making the adult heart vulnerable to dysregulated stress responses.

•

Maternal obesity programs progressive heart dysfunction in adult offspring.

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Offspring of obese dams are prone to dysregulated stress responses in the heart.

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Nkx2-5-controlled transcription is dysregulated in hearts exposed to obesity in utero.

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Obesity during pregnancy broadly affects gene expression in the embryonic heart.

Poly(I:C) preconditioning protects the heart against myocardial ischemia/reperfusion injury through TLR3/PI3K/Akt-dependent pathway

Emerging evidence suggests that Toll-like receptors (TLRs) ligands pretreatment may play a vital role in the progress of myocardial ischemia/reperfusion (I/R) injury. As the ligand of TLR3, polyinosinic-polycytidylic acid (poly(I:C)), a synthetic double-stranded RNA, whether its preconditioning can exhibit a cardioprotective phenotype remains unknown. Here, we report the protective effect of poly(I:C) pretreatment in acute myocardial I/R injury by activating TLR3/PI3K/Akt signaling pathway. Poly(I:C) pretreatment leads to a significant reduction of infarct size, improvement of cardiac function, and downregulation of inflammatory cytokines and apoptotic molecules compared with controls. Subsequently, our data demonstrate that phosphorylation of TLR3 tyrosine residue and its interaction with PI3K is enhanced, and protein levels of phospho-PI3K and phospho-Akt are both increased after poly(I:C) pretreatment, while knock out of TLR3 suppresses the cardioprotection of poly(I:C) preconditioning through a decreased activation of PI3K/Akt signaling. Moreover, inhibition of p85 PI3K by the administration of LY294002 in vivo and knockdown of Akt by siRNA in vitro significantly abolish poly(I:C) preconditioning-induced cardioprotective effect. In conclusion, our results reveal that poly(I:C) preconditioning exhibits essential protection in myocardial I/R injury via its modulation of TLR3, and the downstream PI3K/Akt signaling, which may provide a potential pharmacologic target for perioperative cardioprotection.

Topoisomerase 2B Decrease Results in Diastolic Dysfunction via p53 and Akt: A Novel Pathway

Diastolic dysfunction is condition of a stiff ventricle and a function of aging. It causes significant cardiovascular mortality and morbidity, and in fact, three million Americans are currently suffering from this condition. To date, all the pharmacological clinical trials have been negative. The lack of success in attenuating/ameliorating diastolic dysfunction stems from lack of duplication of myriads of clinical manifestation in pre-clinical settings. Here we report, a novel genetically engineered mice which may represents a preclinical model of human diastolic dysfunction to some extent. Topoisomerase 2 beta (Top2b) is an important enzyme in transcriptional activation of some inducible genes through transient double-stranded DNA breakage events around promoter regions. We created a conditional, tissue-specific, inducible Top2b knockout mice in the heart. Serendipitously, echocardiographic parameters and more invasive analysis of left ventricular function with pressure–volume loops show features of diastolic dysfunction. This was also confirmed histologically. At the cellular level, the Top2b knockdown showed morphological changes and molecular signaling akin to human diastolic dysfunction. Reverse phase protein analysis showed activation of p53 and inhibition of, Akt, as the possible mediators of diastolic dysfunction. Finally, activation of p53 and inhibition of Akt were confirmed in myocardial biopsy samples obtained from human diastolic dysfunctional hearts. Thus, we report for the first time, a Top2b downregulated preclinical mice model for diastolic dysfunction which demonstrates that Akt and p53 are the possible mediators of the pathology, hence representing novel and viable targets for future therapeutic interventions in diastolic dysfunction.

Cross-Sectional Transcriptional Analysis of the Aging Murine Heart

Cardiovascular disease accounts for millions of deaths each year and is currently the leading cause of mortality worldwide. The aging process is clearly linked to cardiovascular disease, however, the exact relationship between aging and heart function is not fully understood. Furthermore, a holistic view of cardiac aging, linking features of early life development to changes observed in old age, has not been synthesized. Here, we re-purpose RNA-sequencing data previously-collected by our group, investigating gene expression differences between wild-type mice of different age groups that represent key developmental milestones in the murine lifespan. DESeq2's generalized linear model was applied with two hypothesis testing approaches to identify differentially-expressed (DE) genes, both between pairs of age groups and across mice of all ages. Pairwise comparisons identified genes associated with specific age transitions, while comparisons across all age groups identified a large set of genes associated with the aging process more broadly. An unsupervised machine learning approach was then applied to extract common expression patterns from this set of age-associated genes. Sets of genes with both linear and non-linear expression trajectories were identified, suggesting that aging not only involves the activation of gene expression programs unique to different age groups, but also the re-activation of gene expression programs from earlier ages. Overall, we present a comprehensive transcriptomic analysis of cardiac gene expression patterns across the entirety of the murine lifespan.

THRIL mediates endothelial progenitor cells autophagy via AKT pathway and FUS

Background

This study focused on the roles of lncRNA THRIL in coronary atherosclerotic heart disease (CAD) through regulating AKT signaling pathway and directly interacting with FUS.

Methods

QRT-PCR was conducted to detect the expression of THRIL in CAD blood samples and endothelial progenitor cells (EPCs). Cell autophagy of EPCs was examined through Cyto-ID Autophagy Detection Kit. CCK-8 assay and flow cytometry were carried out to assess cell viability and apoptosis under various interference conditions. Western blotting was conducted to detect the expression of interest proteins. The expression levels of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) were measured by qRT-PCR. The direct interactions between HCG18 and FUS was confirmed through RNA electrophoretic mobility shift assay (RNA EMSA) and RNA immunoprecipitation (RIP) assay.

Results

THRIL was upregulated in CAD blood samples and EPCs. Knockdown of THRIL in EPCs promoted cell viability, inhibited cell autophagy and further suppressed the development of CAD. Over-expression of THRIL induced inactivation of AKT pathway, while knockdown of THRIL played reversed effects. THRIL directly interacted with FUS protein and knockdown of FUS reversed the over-expressing effect of THRIL on cell proliferation, autophagy and the status of AKT pathway.

Conclusion

THRIL inhibits the proliferation and mediates autophagy of endothelial progenitor cells via AKT pathway and FUS.

Carnosic acid protects against pressure overload-induced cardiac remodelling by inhibiting the AKT/GSK3β/NOX4 signalling pathway

Oxidative stress and apoptosis serve an important role in the development of pressure overload-induced cardiac remodelling. Carnosic acid (CA) has been found to exert antioxidant and anti-apoptotic effects. The present study investigated the underlying mechanism of CA protection and whether this effect was exerted against pressure overload-induced cardiac remodelling. Aortic banding (AB) surgery was performed to induce cardiac remodelling. Mice were randomly divided into four groups (n=15/group): i) Sham + vehicle; ii) sham + CA; iii) AB + vehicle; and iv) AB + CA. After 2 days of AB, 50 mg kg CA was administered orally for 12 days. Echocardiography, histological analysis and molecular biochemistry techniques were performed to evaluate the roles of CA. CA treatment decreased cardiac hypertrophy, fibrosis, oxidative stress and apoptosis in mice challenged with pressure overload. CA also decreased the cross-sectional area of cardiomyocytes and the mRNA and protein expression levels of hypertrophic markers. Furthermore, CA treatment decreased collagen deposition, α-smooth muscle actin expression and the mRNA and protein expression of various fibrotic markers. Additionally, CA reversed the AB-mediated increase in NAPDH oxidase (NOX) 2, NOX4 and 4-hydroxynonenal levels. The number of apoptotic cells was decreased following CA treatment following under conditions of pressure overload. CA also suppressed the activation of AKT and glycogen synthase kinase 3 β (GSK3β) in mice challenged with AB. The present results suggested that CA could inhibit pressure overload-induced cardiac hypertrophy and fibrosis by suppressing the AKT/GSK3β/NOX4 signalling pathway. Therefore, CA may be a promising therapy for cardiac remodelling.

The Hypoxia Tolerance of the Goldfish (Carassius auratus) Heart: The NOS/NO System and Beyond

The extraordinary capacity of the goldfish (Carassius auratus) to increase its cardiac performance under acute hypoxia is crucial in ensuring adequate oxygen supply to tissues and organs. However, the underlying physiological mechanisms are not yet completely elucidated. By employing an ex vivo working heart preparation, we observed that the time-dependent enhancement of contractility, distinctive of the hypoxic goldfish heart, is abolished by the Nitric Oxide Synthase (NOS) antagonist L-NMMA, the Nitric Oxide (NO) scavenger PTIO, as well as by the PI3-kinase (PI3-K) and sarco/endoplasmic reticulum Ca²⁺-ATPase 2a (SERCA2a) pumps’ inhibition by Wortmannin and Thapsigargin, respectively. In goldfish hearts exposed to hypoxia, an ELISA test revealed no changes in cGMP levels, while Western Blotting analysis showed an enhanced expression of the phosphorylated protein kinase B (pAkt) and of the NADPH oxidase catalytic subunit Nox2 (gp91phox). A significant decrease of protein S-nitrosylation was observed by Biotin Switch assay in hypoxic hearts. Results suggest a role for a PI3-K/Akt-mediated activation of the NOS-dependent NO production, and SERCA2a pumps in the mechanisms conferring benefits to the goldfish heart under hypoxia. They also propose protein denitrosylation, and the possibility of nitration, as parallel intracellular events.

Dietary Fat and Sugar Differentially Affect β-Adrenergic Stimulation of Cardiac ERK and AKT Pathways in C57BL/6 Male Mice Subjected to High-Calorie Feeding

BACKGROUND

High dietary fat and sugar promote cardiac hypertrophy independently from an increase in blood pressure. The respective contribution that each macronutrient exerts on cardiac growth signaling pathways remains unclear.

OBJECTIVE

The goal of this study was to investigate the mechanisms by which high amounts of dietary fat and sugar affect cardiac growth regulatory pathways.

METHODS

Male C57BL/6 mice (9 wk old; n = 20/group) were fed a standard rodent diet (STD; kcal% protein-fat-carbohydrate, 29-17-54), a high-fat diet (HFD; 20-60-20), a high-fat and high-sugar Western diet (WD; 20-45-35), a high-sugar diet with mixed carbohydrates (HCD; 20-10-70), or a high-sucrose diet (HSD; 20-10-70). Body composition was assessed weekly by EchoMRI. Whole-body glucose utilization was assessed with an intraperitoneal glucose tolerance test. After 6 wk on diets, mice were treated with saline or 20 mg/kg isoproterenol (ISO), and the activity of cardiac growth regulatory pathways was analyzed by immunoblotting. Data were analyzed by ANOVA with data from the STD group included for references only.

RESULTS

Compared with HCD and HSD, WD and HFD increased body fat mass 2.7- to 3.8-fold (P < 0.001), induced glucose intolerance (P < 0.001), and increased insulin concentrations >1.5-fold (P < 0.05), thereby enhancing basal and ISO-stimulated AKT phosphorylation at both threonine 308 and serine 473 residues (+25-63%; P < 0.05). Compared with HFD, the high-sugar diets potentiated ISO-mediated stimulation of the glucose-sensitive kinases PYK2 (>47%; P < 0.05 for HCD and HSD) and ERK (>34%; P < 0.05 for WD, HCD, and HSD), thereby leading to increased phosphorylation of protein synthesis regulator S6K1 at threonine 389 residue (>64%; P < 0.05 for WD, HCD, and HSD).

CONCLUSIONS

Dietary fat and sugar affect cardiac growth signaling pathways in C57BL/6 mice through distinct and additive mechanisms. The findings may provide new insights into the role of overnutrition in pathological cardiac remodeling.

Stimulation of TRPA1 attenuates ischemia-induced cardiomyocyte cell death through an eNOS-mediated mechanism

The functional expression of transient receptor potential cation channel of the ankyrin-1 subtype (TRPA1) has recently been identified in adult mouse cardiac tissue where stimulation of this ion channel leads to increases in adult mouse ventricular cardiomyocyte (CM) contractile function via a Ca²⁺-Calmodulin-dependent kinase (CaMKII) pathway. However, the extent to which TRPA1 induces nitric oxide (NO) production in CMs, and whether this signaling cascade mediates physiological or pathophysiological events in cardiac tissue remains elusive. Freshly isolated CMs from wild-type (WT) or TRPA1 knockout (TRPA1^-/-) mouse hearts were treated with AITC (100 µM) and prepared for immunoblot, NO detection or ischemia protocols. Our findings demonstrate that TRPA1 stimulation with AITC results in phosphorylation of protein kinase B (Akt) and endothelial NOS (eNOS) concomitantly with NO production in a concentration- and time-dependent manner. Additionally, we found that TRPA1 induced increases in CM [Ca²⁺]_i and contractility occur independently of Akt and eNOS activation mechanisms. Further analysis revealed that the presence and activation of TRPA1 promotes CM survival and viability following ischemic insult via a mechanism partially dependent upon eNOS. Therefore, activation of the TRPA1/Akt/eNOS pathway attenuates ischemia-induced CM cell death.

Cardiac Contractility Modulation Attenuates Chronic Heart Failure in a Rabbit Model via the PI3K/AKT Pathway

The Akt plays an important role in regulating cardiac growth, myocardial angiogenesis, and cell death in cardiac myocytes. However, there are few studies to focus on the responses of the Akt pathway to cardiac contractility modulation (CCM) in a chronic heart failure (HF) model. In this study, the effects of CCM on the treatment of HF in a rabbit model were investigated. Thirty six-month-old rabbits were randomly separated into control, HF, and CCM groups. The rabbits in HF and CCM groups were pressure uploaded, which can cause an aortic constriction. Then, CCM was gradually injected to the myocardium of rabbits in the CCM group, and this process lasted for four weeks with six hours per day. Rabbit body weight, heart weight, and heart beating rates were recorded during the experiment. To assess the CCM impacts, rabbit myocardial histology was examined as well. Additionally, western blot analysis was employed to measure the protein levels of Akt, FOXO3, Beclin, Pi3k, mTOR, GSK-3β, and TORC2 in the myocardial histology of rabbits. Results showed that the body and heart weight of rabbits decreased significantly after suffering HF when compared with those in the control group. However, they gradually recovered after CCM application. The CCM significantly decreased collagen volume fraction in myocardial histology of HF rabbits, indicating that CCM therapy attenuated myocardial fibrosis and collagen deposition. The levels of Akt, FOXO3, Beclin, mTOR, GSK-3β, and TORC2 were significantly downregulated, but Pi3k concentration was greatly upregulated after CCM utilization. Based on these findings, it was concluded that CCM could elicit positive effects on HF therapy, which was potentially due to the variation in the Pi3k/Akt signaling pathway.