Therapeutic targeting of autophagy in cardiovascular disease

SGLT2 inhibitors: how do they affect the cardiac cells

The first sodium-glucose cotransporter-2 inhibitor (SGLT2I), canagliflozin, was approved by the U.S. Food and Drug Administration for the treatment of type 2 diabetes in 2013. Since then, other members of this drug class (such as dapagliflozin, empagliflozin, and ertugliflozin) have become widely used. Unlike classical antidiabetic agents, these drugs do not interfere with insulin secretion or action, but instead promote renal glucose excretion. Since their approval, many preclinical and clinical studies have been conducted to investigate the diverse effects of SGLT2Is. While originally introduced as antidiabetic agents, the SGLT2Is are now recognized as pillars in the treatment of heart failure and chronic kidney disease, in patients with or without diabetes. The beneficial cardiac effects of this class have been attributed to several mechanisms. Among these, SGLT2Is inhibit fibrosis, hypertrophy, apoptosis, inflammation, and oxidative stress. They regulate mitochondrial function and ion transport, and stimulate autophagy through several underlying mechanisms. This review details the potential effects of SGLT2Is on cardiac cells.

Clinical safety and pharmacokinetics of a novel oral niclosamide formulation compared with marketed niclosamide chewing tablets in healthy volunteers: A three-part randomized, double-blind, placebo-controlled trial

AIM

Niclosamide is an established anthelmintic substance and a promising candidate for treating cancer, viral infections, and other diseases. However, its solubility in aqueous media is low, and the systemic bioavailability of the commercially available chewing tablet is poor, limiting the use of niclosamide for systemic treatment. A liquid oral formulation using polyethylene glycol 400 was developed and investigated in healthy volunteers to assess safety, tolerability, and pharmacokinetics in comparison to the marketed tablet. (ClinicalTrials.gov: NCT04644705).

METHODS

The study consisted of three parts: Part A was a double-blind placebo-controlled single ascending dose trial in three dose groups (200, 600, and 1600 mg) with four participants receiving either the investigational niclosamide formulation or placebo (3:1) under fasted and/or fed conditions. Part B was a crossover study comparing 1600 mg investigational niclosamide solution with the marketed 2000 mg chewing tablet in four healthy volunteers. Part C was a double-blind placebo-controlled multiple-dose trial comparing 1200 mg and 1600 mg (verum: placebo 4:2) in two dose groups with six subjects each, who received daily doses for seven days.

RESULTS

No serious or severe adverse events occurred. The most frequent adverse events were mild to moderate gastrointestinal reactions. There was also no apparent dependence between drug exposure levels (AUC, Cmax) and the severity and incidence of adverse events detectable. A relevant food effect was observed with a mean AUClast about 2-fold higher in fed condition compared to fasted condition. In Part B, dose-normalized Cmax and AUClast were similar for niclosamide solution and tablet. Absorption of niclosamide solution was highly variable. Some individuals showed high absorption (Cmax > 2µg/ml) whereas others did absorb only marginally. Importantly, there was no dose linearity in the range of 200 mg - 1600 mg. No signs of relevant systemic drug accumulation after multiple administrations were observed.

CONCLUSION

Overall safety and tolerability observed in healthy subjects were benign. This is also true for individuals with high absorption (Cmax > 2µg/ml), encouraging further research into niclosamide as a potential therapeutic agent. Galenic optimization, however, will remain challenging as evident from the observed exposure variability and non-linear PK. Non-linearity, if confirmed by additional data, might make niclosamide more suitable for multi-dose rather than high single dose regimens. The observed food effect should also be considered when further investigating systemic niclosamide exposures.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04644705.

Mir221- and Mir222-enriched adsc-exosomes mitigate PM exposure-exacerbated cardiac ischemia-reperfusion injury through the modulation of the BNIP3-MAP1LC3B-BBC3/PUMA pathway

Epidemiology has shown a strong relationship between fine particulate matter (PM) exposure and cardiovascular disease. However, it remains unknown whether PM aggravates myocardial ischemia-reperfusion (I/R) injury, and the related mechanisms are unclear. Our previous study has shown that adipose stem cell-derived exosomes (ADSC-Exos) contain high levels of Mir221 and Mir222. The present study investigated the effects of PM exposure on I/R-induced cardiac injury through mitophagy and apoptosis, as well as the potential role of Mir221 and Mir222 in ADSC-Exos. Wild-type, mir221- and mir222-knockout (KO), and Mir221- and Mir222-overexpressing transgenic (TG) mice were intratracheally injected with PM (10 mg/kg). After 24 h, mice underwent left coronary artery ligation for 30 min, followed by 3 h of reperfusion (I/R). H9c2 cardiomyocytes were cultured under 1% O2 for 6 h, then reoxygenated for 12 h (hypoxia-reoxygenation [H/R]). PM aggravated I/R (or H/R) cardiac injury by increasing ROS levels and causing mitochondrial dysfunction, which increased the expression of mitochondrial fission-related proteins (DNM1L/Drp1 and MFF) and mitophagy-related proteins (BNIP3 and MAP1LC3B/LC3B) in vivo and in vitro. Treatment with ADSC-Exos or Mir221- and Mir222-mimics significantly reduced PM+I/R-induced cardiac injury. Importantly, ADSC-Exos contain Mir221 and Mir222, which directly targets BNIP3, MAP1LC3B/LC3B, and BBC3/PUMA, decreasing their expression and ultimately reducing cardiomyocyte mitophagy and apoptosis. The present data showed that ADSC-Exos treatment regulated mitophagy and apoptosis through the Mir221 and Mir222-BNIP3-MAP1LC3B-BBC3/PUMA pathway and significantly reduced the cardiac damage caused by PM+I/R. The present study revealed the novel therapeutic potential of ADSC-Exos in alleviating PM-induced exacerbation of myocardial I/R injury.Abbreviation: ADSC-Exos: adipose-derived stem cell exosomes; AL: autolysosome; ATP: adenosine triphosphate; BBC3/PUMA: BCL2 binding component 3; BNIP3: BCL2/adenovirus E1B interacting protein 3; CASP3: caspase 3; CASP9: caspase 9; CDKN1B/p27: cyclin dependent kinase inhibitor 1B; CVD: cardiovascular disease; DCFH-DA: 2',7'-dichlorodihydrofluorescein diacetate; DHE: dihydroethidium; DNM1L/Drp1: dynamin 1-like; EF: ejection fraction; FS: fractional shortening; H/R: hypoxia-reoxygenation; I/R: ischemia-reperfusion; LDH: lactate dehydrogenase; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; MFF: mitochondrial fission factor; miRNA: microRNA; NAC: N-acetylcysteine; OCR: oxygen consumption rate; PIK3C3/Vps34: phosphatidylinositol 3-kinase catalytic subunit type 3; PM: particulate matter; PRKAA1/AMPK: protein kinase AMP-activated catalytic subunit alpha 1; ROS: reactive oxygen species; SQSTM1/p62: sequestosome 1; TEM: transmission electron microscopy; TRP53/p53: transformation related protein 53; TUNEL: terminal deoxynucleotidyl transferase dUTP nick end labeling.

Glycoprotein 130 Antagonism Counteracts Metabolic and Inflammatory Alterations to Enhance Right Ventricle Function in Pulmonary Artery Banded Pigs

Background

Right ventricular dysfunction (RVD) is a risk factor for death in multiple cardiovascular diseases, but RV-enhancing therapies are lacking. Inhibition of glycoprotein-130 (GP130) signaling with the small molecule SC144 improves RV function in rodent RVD via anti-inflammatory and metabolic mechanisms. However, SC144's efficacy and molecular effects in a translational large animal model of RVD are unknown.

Methods

4-week-old castrated male pigs underwent pulmonary artery banding (PAB). After 3 weeks, PAB pigs were randomized into 2 groups (daily injections of SC144 [2.2 mg/kg, PAB-SC144, n=5] or vehicle [PAB-Veh, n=5] for 3 weeks). Five age-matched pigs served as controls. Cardiac MRI quantified RV size/function. Right heart catheterization evaluated hemodynamics. Single-nucleus RNA sequencing delineated cell-type specific changes between experimental groups. Electron microscopy evaluated RV mitochondrial morphology. Phosphoproteomics identified dysregulated RV kinases. Lipidomics and metabolomics quantified lipid species and metabolites in RV tissue. Quantitative proteomics examined RV mitochondrial protein regulation.

Results

SC144 significantly improved RV ejection fraction (Control: 60±4%, PAB-Veh: 22±10%, PAB-SC144: 37±6%) despite similar RV afterload. Single-nucleus RNA sequencing demonstrated PAB-Veh pigs had lower cardiomyocyte and higher macrophage/lymphocyte/pericyte/endothelial cell abundances as compared to control, and many of these changes were blunted by SC144. SC144 combatted the downregulation of cardiomyocyte metabolic genes induced by PAB. Kinome enrichment analysis suggested SC144 counteracted RV mTORC1 activation. Correspondingly, SC144 rebalanced RV autophagy pathway proteins and improved mitochondrial morphology. Integrated lipidomics, metabolomics, and proteomics analyses revealed SC144 restored fatty acid metabolism. Finally, CellChat analysis revealed SC144 restored pericyte-endothelial cell cross-talk.

Conclusion

GP130 antagonism blunts elevated immune cell abundance, reduces pro-inflammatory gene transcription in macrophages and lymphocytes, rebalances autophagy and preserves fatty acid metabolism in cardiomyocytes, and restores endothelial cell and pericyte communication to improve RV function.

The Potential of Mesenchymal Stem Cell-Derived Exosomes in Cardiac Repair

Cardiovascular diseases (CVDs) are the leading cause of death worldwide, and effectively repairing the heart following myocardial injuries remains a significant challenge. Research has increasingly shown that exosomes derived from mesenchymal stem cells (MSC-Exo) can ameliorate myocardial injuries and improve outcomes after such injuries. The therapeutic benefits of MSC-Exo are largely due to their capacity to deliver specific cargo, including microRNAs and proteins. MSC-Exo can modulate various signaling pathways and provide several beneficial effects, including cytoprotection, inflammation modulation, and angiogenesis promotion to help repair the damaged myocardium. In this review, we summarize the cardioprotective effects of MSC-Exo in myocardial injury, the underlying molecular mechanism involved in the process, and various approaches studied to enhance their efficacy based on recent findings.

Microplastics and nanoplastics in cardiovascular disease-a narrative review with worrying links

With the widespread use of plastic products and the increase in waste, microplastics and nanoplastics (MNPs) have become an important issue in global environmental pollution. In recent years, an increasing number of studies have shown that MNPs may have negative impacts on human health. This review aimed to explore the association between MNPs and cardiovascular disease and provide an outlook for future research. Research has shown that there may be a link between MNPs exposure and cardiovascular disease. Laboratory studies have shown that animals exposed to MNPs often exhibit abnormalities in the cardiovascular system, such as increased blood pressure, vascular inflammation, and myocardial damage. Epidemiological surveys have also revealed that people exposed to MNPs are more likely to suffer from cardiovascular diseases, such as hypertension and myocardial infarction. Although the specific impact mechanism is not fully understood, there are several possible pathways of action, including the effects of toxic substances on MNPs and interference with the endocrine system. In summary, MNPs exposure may have a negative impact on cardiovascular health, but further research is needed to confirm its specific mechanism and extent of impact to guide relevant public health and environmental policies.

Quantitative analysis of the spatial distance between autophagy-related membrane structures and the endoplasmic reticulum in Saccharomyces cerevisiae

Macroautophagy/autophagy is the process by which cells degrade their cytoplasmic proteins or organelles in vacuoles to maintain cellular homeostasis under severe environmental conditions. In the yeast Saccharomyces cerevisiae, autophagy-related (Atg) proteins essential for autophagosome formation accumulate near the vacuole to form the dot-shaped phagophore assembly site/pre-autophagosomal structure (PAS). The PAS then generates the phagophore/isolation membrane (PG), which expands to become a closed double-membrane autophagosome. Hereinafter, we refer to the PAS, PG, and autophagosome as autophagy-related structures (ARSs). During autophagosome formation, Atg2 is responsible for tethering the ARS to the endoplasmic reticulum (ER) via ER exit sites (ERESs), and for transferring phospholipids from the ER to ARSs. Therefore, ARS and the ER are spatially close in the presence of Atg2 but are separated in its absence. Because the contact of an ARS with the ER must be established at the earliest stage of autophagosome formation, it is important to know whether the ARS is tethered to the ER. In this study, we developed a rapid and objective method to estimate tethering of the ARS to the ER by measuring the distance between the ARS and ERES under fluorescence microscopy, and found that tethering of the ARS to the ER was lost without Atg1. This method might be useful to predict the tethering activity of Atg2.Abbreviation: ARS, autophagy-related structure; Dautas, automated measurement of the distance between autophagy-related structures and ER exit sites analysis system; ERES, endoplasmic reticulum exit site; PAS, phagophore assembly site/pre-autophagosomal structure; PCR, polymerase chain reaction; PG, phagophore/isolation membrane; prApe1, precursor of vacuolar aminopeptidase I; Qautas, quantitative autophagy-related structure analysis system; SD/CA; synthetic dextrose plus casamino acid medium; WT, wild-type.

Amplification of Cardioprotective Response of Remote Ischemic Preconditioning in Rats by Quercetin: Potential Role of Activation of mTOR-dependent Autophagy and Nrf2

OBJECTIVES

Noninvasive remote ischemic preconditioning (RIPC) is a practical, acceptable, and feasible conditioning technique reported to provide cardioprotection in myocardial ischemia-reperfusion injury (MIRI). It has been well-reported that quercetin possesses antioxidant and anti-inflammatory properties. This study investigates the modification of the cardioprotective response of RIPC by quercetin.

METHODS

Adult Wistar rats were randomized into 12 groups of six animals each. MIRI was induced by subjecting the isolated hearts of Wistar rats to global ischemia for 30 min, succeeded by reperfusion of 120 min after mounting on the Langendorff PowerLab apparatus. Hind limb RIPC was applied in four alternate cycles of ischemia and reperfusion of 5 min each by tying the pressure cuff before isolation of hearts.

RESULTS

MIRI was reflected by significantly increased infarct size, LDH-1, and CK-MB, TNF-α, TBARS, and decreased GSH, catalase, and hemodynamic index, and modulated Nrf2. Pretreatment of quercetin (25 and 50 mg/kg; i.p.) significantly attenuated the MIRI-induced cardiac damage and potentiated the cardioprotective response of RIPC at the low dose. Pretreatment of ketamine (10 mg/kg; i.p.), an mTOR-dependent autophagy inhibitor, significantly abolished the cardioprotective effects of quercetin and RIPC.

CONCLUSIONS

The findings highlight the modification of the cardioprotective effect of RIPC by quercetin and that quercetin protects the heart against MIRI through multiple mechanisms, including mTOR-dependent activation of autophagy and Nrf-2 activation.

Nutrient-epigenome interactions: Implications for personalized nutrition against aging-associated diseases

Aging is a multifaceted process involving genetic and environmental interactions often resulting in epigenetic changes, potentially leading to aging-related diseases. Various strategies, like dietary interventions and calorie restrictions, have been employed to modify these epigenetic landscapes. A burgeoning field of interest focuses on the role of microbiota in human health, emphasizing system biology and computational approaches. These methods help decipher the intricate interplay between diet and gut microbiota, facilitating the creation of personalized nutrition strategies. In this review, we analysed the mechanisms related to nutritional interventions while highlighting the influence of dietary strategies, like calorie restriction and intermittent fasting, on microbial composition and function. We explore how gut microbiota affects the efficacy of interventions using tools like multi-omics data integration, network analysis, and machine learning. These tools enable us to pinpoint critical regulatory elements and generate individualized models for dietary responses. Lastly, we emphasize the need for a deeper comprehension of nutrient-epigenome interactions and the potential of personalized nutrition informed by individual genetic and epigenetic profiles. As knowledge and technology advance, dietary epigenetics stands on the cusp of reshaping our strategy against aging and related diseases.

Autophagy in Its (Proper) Context: Molecular Basis, Biological Relevance, Pharmacological Modulation, and Lifestyle Medicine

Autophagy plays a critical role in maintaining cellular homeostasis and responding to various stress conditions by the degradation of intracellular components. In this narrative review, we provide a comprehensive overview of autophagy's cellular and molecular basis, biological significance, pharmacological modulation, and its relevance in lifestyle medicine. We delve into the intricate molecular mechanisms that govern autophagy, including macroautophagy, microautophagy and chaperone-mediated autophagy. Moreover, we highlight the biological significance of autophagy in aging, immunity, metabolism, apoptosis, tissue differentiation and systemic diseases, such as neurodegenerative or cardiovascular diseases and cancer. We also discuss the latest advancements in pharmacological modulation of autophagy and their potential implications in clinical settings. Finally, we explore the intimate connection between lifestyle factors and autophagy, emphasizing how nutrition, exercise, sleep patterns and environmental factors can significantly impact the autophagic process. The integration of lifestyle medicine into autophagy research opens new avenues for promoting health and longevity through personalized interventions.

Harmony in Motion: Unraveling the Nexus of Sports, Plant-Based Nutrition, and Antioxidants for Peak Performance

The intricate interplay between plant-based nutrition, antioxidants, and their impact on athletic performance forms the cornerstone of this comprehensive review. Emphasizing the pivotal importance of dietary choices in the realm of sports, this paper sets the stage for an in-depth exploration of how stress and physical performance are interconnected through the lens of nutrition. The increasing interest among athletes in plant-based diets presents an opportunity with benefits for health, performance, and recovery. It is essential to investigate the connection between sports, plants, and antioxidants. Highlighting the impact of nutrition on recovery and well-being, this review emphasizes how antioxidants can help mitigate oxidative stress. Furthermore, it discusses the growing popularity of plant-based diets among athletes. It elaborates on the importance of antioxidants in combating radicals addressing stress levels while promoting cellular health. By identifying rich foods, it emphasizes the role of a balanced diet in ensuring sufficient intake of these beneficial compounds. Examining stress within the context of sports activities, this review provides insights into its mechanisms and its impact on athletic performance as well as recovery processes. This study explores the impact of plant-based diets on athletes including their types, potential advantages and challenges. It also addresses the drawbacks of relying on plant-based diets, concerns related to antioxidant supplementation and identifies areas where further research is needed. Furthermore, the review suggests directions for research and potential innovations in sports nutrition. Ultimately it brings together the aspects of sports, plant-based nutrition, and antioxidants to provide a perspective for athletes, researchers and practitioners. By consolidating existing knowledge, it offers insights that can pave the way for advancements in the ever-evolving field of sports nutrition.

Meteorin-like (METRNL) attenuates hypertensive induced cardiac hypertrophy by inhibiting autophagy via activating BRCA2

Hypertension, a prevalent cardiovascular ailment globally, can precipitate numerous complications, notably hypertensive cardiomyopathy. Meteorin-like (METRNL) is demonstrated to possess potential protective properties on cardiovascular diseases. However, its specific role and underlying mechanism in hypertensive myocardial hypertrophy remain elusive. Spontaneously hypertensive rats (SHRs) served as hypertensive models to explore the effects of METRNL on hypertension and its induced myocardial hypertrophy. The research results indicate that, in contrast to Wistar-Kyoto (WKY) rats, SHRs exhibit significant symptoms of hypertension and myocardial hypertrophy, but cardiac-specific overexpression (OE) of METRNL can partially ameliorate these symptoms. In H9c2 cardiomyocytes, METRNL suppresses Ang II-induced autophagy by controlling the BRCA2/Akt/mTOR signaling pathway. But when BRCA2 expression is knocked down, this effect will be suppressed. Collectively, METRNL emerges as a potential therapeutic target for hypertensive cardiomyopathy.

The role of exosomes in cancer-related programmed cell death

Cancer arises from the growth and division of uncontrolled erroneous cells. Programmed cell death (PCD), or regulated cell death (RCD), includes natural processes that eliminate damaged or abnormal cells. Dysregulation of PCD is a hallmark of cancer, as cancer cells often evade cell death and continue to proliferate. Exosomes nanoscale extracellular vesicles secreted by different types of cells carrying a variety of molecules, including nucleic acids, proteins, and lipids, to have indispensable role in the communication between cells, and can influence various cellular processes, including PCD. Exosomes have been shown to modulate PCD in cancer cells by transferring pro- or antideath molecules to neighboring cells. Additionally, exosomes can facilitate the spread of PCD to surrounding cancer cells, making them promising in the treatment of various cancers. The exosomes' diagnostic potential in cancer is also an active area of research. Exosomes can be isolated from a wide range of bodily fluids and tissues, such as blood and urine, and can provide a noninvasive way to monitor cancer progression and treatment response. Furthermore, exosomes have also been employed as a delivery system for therapeutic agents. By engineering exosomes to carry drugs or other therapeutic molecules, they can be targeted specifically to cancer cells, reducing toxicity to healthy tissues. Here, we discussed exosomes in the diagnosis and prevention of cancers, tumor immunotherapy, and drug delivery, as well as in different types of PCD.

The role of captopril in leukotriene deficient type 1 diabetic mice

T1D can be associated with metabolic disorders and several impaired pathways, including insulin signaling, and development of insulin resistance through the renin-angiotensin system (RAS). The main precursor of RAS is angiotensinogen (Agt) and this system is often linked to autophagy dysregulation. Dysregulated autophagy has been described in T1D and linked to impairments in both glucose metabolism, and leukotrienes (LTs) production. Here, we have investigated the role of RAS and LTs in both muscle and liver from T1D mice, and its effects on insulin and autophagy pathways. We have chemically induced T1D in 129sve and 129sve 5LO-/- mice (lacking LTs) with streptozotocin (STZ). To further inhibit ACE activity, mice were treated with captopril (Cap). In muscle of T1D mice, treatment with Cap increased the expression of RAS (angiotensinogen and angiotensin II receptor), insulin signaling, and autophagy markers, regardless of the genotype. In the liver of T1D mice, the treatment with Cap increased the expression of RAS and insulin signaling markers, mostly when LTs were absent. 5LO-/- T1D mice showed increased insulin sensitivity, and decreased NEFA, after the Cap treatment. Cap treatment impacted both insulin signaling and autophagy pathways at the mRNA levels in muscle and liver, indicating the potential role of ACE inhibition on insulin sensitivity and autophagy in T1D.

Herpud1 deficiency alleviates homocysteine-induced aortic valve calcification

OBJECTIVES

To evaluate the role and therapeutic value of homocysteine (hcy)-inducible endoplasmic reticulum stress (ERS) protein with ubiquitin like domain 1 (Herpud1) in hcy-induced calcific aortic valve disease (CAVD).

BACKGROUND

The morbidity and mortality rates of calcific aortic valve disease (CAVD) remain high while treatment options are limited.

METHODS

In vivo, we use the low-density lipoprotein receptor (LDLR) and Herpud1 double knockout (LDLR-/-/Herpud1-/-) mice and used high methionine diet (HMD) to assess of aortic valve calcification lesions, ERS activation, autophagy, and osteogenic differentiation of aortic valve interstitial cells (AVICs). In vitro, the role of Herpud1 in the Hcy-related osteogenic differentiation of AVICs was investigated by manipulating of Herpud1 expression.

RESULTS

Herpud1 was highly expressed in calcified human and mouse aortic valves as well as primary aortic valve interstitial cells (AVICs). Hcy increased Herpud1 expression through the ERS pathway and promoted CAVD progression. Herpud1 deficiency inhibited hcy-induced CAVD in vitro and in vivo. Herpud1 silencing activated cell autophagy, which subsequently inhibited hcy-induced osteogenic differentiation of AVICs. ERS inhibitor 4-phenyl butyric acid (4-PBA) significantly attenuated aortic valve calcification in HMD-fed low-density lipoprotein receptor-/- (LDLR-/-) mice by suppressing ERS and subsequent Herpud1 biosynthesis.

CONCLUSIONS

These findings identify a previously unknown mechanism of Herpud1 upregulation in Hcy-related CAVD, suggesting that Herpud1 silencing or inhibition is a viable therapeutic strategy for arresting CAVD progression.

HIGHLIGHTS

• Herpud1 is upregulated in the leaflets of Hcy-treated mice and patients with CAVD. • In mice, global knockout of Herpud1 alleviates aortic valve calcification and Herpud1 silencing activates cell autophagy, inhibiting osteogenic differentiation of AVICs induced by Hcy. • 4-PBA suppressed Herpud1 expression to alleviate AVIC calcification in Hcy treated AVICs and to mitigate aortic valve calcification in mice.

Current understanding of structural and molecular changes in diabetic cardiomyopathy

Diabetic Mellitus has been characterized as the most prevalent disease throughout the globe associated with the serious morbidity and mortality of vital organs. Cardiomyopathy is the major leading complication of diabetes and within this, myocardial dysfunction or failure is the leading cause of the emergency hospital admission. The review is aimed to comprehend the perspectives associated with diabetes-induced cardiovascular complications. The data was collected from several electronic databases such as Google Scholar, Science Direct, ACS publication, PubMed, Springer, etc. using the keywords such as diabetes and its associated complication, the prevalence of diabetes, the anatomical and physiological mechanism of diabetes-induced cardiomyopathy, the molecular mechanism of diabetes-induced cardiomyopathy, oxidative stress, and inflammatory stress, etc. The collected scientific data was screened by different experts based on the inclusion and exclusion criteria of the study. This review findings revealed that diabetes is associated with inefficient substrate utilization, inability to increase glucose metabolism and advanced glycation end products within the diabetic heart resulting in mitochondrial uncoupling, glucotoxicity, lipotoxicity, and initially subclinical cardiac dysfunction and finally in overt heart failure. Furthermore, several factors such as hypertension, overexpression of renin angiotensin system, hypertrophic obesity, etc. have been seen as majorly associated with cardiomyopathy. The molecular examination showed biochemical disability and generation of the varieties of free radicals and inflammatory cytokines and becomes are the substantial causes of cardiomyopathy. This review provides a better understanding of the involved pathophysiology and offers an open platform for discussing and targeting therapy in alleviating diabetes-induced early heart failure or cardiomyopathy.

Dissecting the Role of Autophagy-Related Proteins in Cancer Metabolism and Plasticity

Modulation of autophagy as an anticancer strategy has been widely studied and evaluated in several cell models. However, little attention has been paid to the metabolic changes that occur in a cancer cell when autophagy is inhibited or induced. In this review, we describe how the expression and regulation of various autophagy-related (ATGs) genes and proteins are associated with cancer progression and cancer plasticity. We present a comprehensive review of how deregulation of ATGs affects cancer cell metabolism, where inhibition of autophagy is mainly reflected in the enhancement of the Warburg effect. The importance of metabolic changes, which largely depend on the cancer type and form part of a cancer cell's escape strategy after autophagy modulation, is emphasized. Consequently, pharmacological strategies based on a dual inhibition of metabolic and autophagy pathways emerged and are reviewed critically here.

Assessment of Autophagy Markers Suggests Increased Activity Following LVAD Therapy

Left ventricular reverse remodeling in heart failure is associated with improved clinical outcomes. However, the molecular features that drive this process are poorly defined. Left ventricular assist devices (LVADs) are the therapy associated with the greatest reverse remodeling and lead to partial myocardial recovery in most patients. In this study, we examined whether autophagy may be implicated in post-LVAD reverse remodeling. We found expression of key autophagy factors increased post-LVAD, while autophagic substrates decreased. Autolysosome numbers increased post-LVAD, further indicating increased autophagy. These findings support the conclusion that mechanical unloading activates autophagy, which may underly the reverse remodeling observed.

Cardioprotective effect of epigallocatechin gallate in myocardial ischemia/reperfusion injury and myocardial infarction: a meta-analysis in preclinical animal studies

This meta-analysis aims to determine the efficacy of Epigallocatechin gallate (EGCG) in the treatment of myocardial ischemia-reperfusion injury (MIRI) and summarize the mechanisms involved. Literature from six databases including Web of Science, PubMed, Embase, China National Knowledge Infrastructure (CNKI), Wan-Fang database, and VIP database (VIP) were systematically searched. All the analysis were conducted by R. Twenty-five eligible studies involving 443 animals were included in this meta-analysis. The results indicated that compared to controls, EGCG exerts a cardioprotective effect by reducing myocardial infarct size (SMD = -4.06; 95% CI: -5.17, -2.94; P < 0.01; I2 = 77%). The funnel plot revealed publication bias. Moreover, EGCG significantly improves cardiac function, serum myocardial injury enzyme, and oxidative stress levels in MIRI animal models. This meta-analysis demonstrates that EGCG exhibits therapeutic promise in animal models of MIRI. However, further validation is still needed in large animal models and large clinical studies.

Restored autophagy is protective against PAK3-induced cardiac dysfunction

Despite the development of clinical treatments, heart failure remains the leading cause of mortality. We observed that p21-activated kinase 3 (PAK3) was augmented in failing human and mouse hearts. Furthermore, mice with cardiac-specific PAK3 overexpression exhibited exacerbated pathological remodeling and deteriorated cardiac function. Myocardium with PAK3 overexpression displayed hypertrophic growth, excessive fibrosis, and aggravated apoptosis following isoprenaline stimulation as early as two days. Mechanistically, using cultured cardiomyocytes and human-relevant samples under distinct stimulations, we, for the first time, demonstrated that PAK3 acts as a suppressor of autophagy through hyper-activation of the mechanistic target of rapamycin complex 1 (mTORC1). Defective autophagy in the myocardium contributes to the progression of heart failure. More importantly, PAK3-provoked cardiac dysfunction was mitigated by administering an autophagic inducer. Our study illustrates a unique role of PAK3 in autophagy regulation and the therapeutic potential of targeting this axis for heart failure.

Cardiovascular Protective Effects of NP-6A4, a Drug with the FDA Designation for Pediatric Cardiomyopathy, in Female Rats with Obesity and Pre-Diabetes

BACKGROUND

Obese and pre-diabetic women have a higher risk for cardiovascular death than age-matched men with the same symptoms, and there are no effective treatments. We reported that obese and pre-diabetic female Zucker Diabetic Fatty (ZDF-F) rats recapitulate metabolic and cardiac pathology of young obese and pre-diabetic women and exhibit suppression of cardio-reparative AT2R. Here, we investigated whether NP-6A4, a new AT2R agonist with the FDA designation for pediatric cardiomyopathy, mitigate heart disease in ZDF-F rats by restoring AT2R expression.

METHODS

ZDF-F rats on a high-fat diet (to induce hyperglycemia) were treated with saline, NP-6A4 (10 mg/kg/day), or NP-6A4 + PD123319 (AT2R-specific antagonist, 5 mg/kg/day) for 4 weeks (n = 21). Cardiac functions, structure, and signaling were assessed by echocardiography, histology, immunohistochemistry, immunoblotting, and cardiac proteome analysis.

RESULTS

NP-6A4 treatment attenuated cardiac dysfunction, microvascular damage (-625%) and cardiomyocyte hypertrophy (-263%), and increased capillary density (200%) and AT2R expression (240%) (p < 0.05). NP-6A4 activated a new 8-protein autophagy network and increased autophagy marker LC3-II but suppressed autophagy receptor p62 and autophagy inhibitor Rubicon. Co-treatment with AT2R antagonist PD123319 suppressed NP-6A4's protective effects, confirming that NP-6A4 acts through AT2R. NP-6A4-AT2R-induced cardioprotection was independent of changes in body weight, hyperglycemia, hyperinsulinemia, or blood pressure.

CONCLUSIONS

Cardiac autophagy impairment underlies heart disease induced by obesity and pre-diabetes, and there are no drugs to re-activate autophagy. We propose that NP-6A4 can be an effective drug to reactivate cardiac autophagy and treat obesity- and pre-diabetes-induced heart disease, particularly for young and obese women.

Autophagy, innate immunity, and cardiac disease

Autophagy is an evolutionarily conserved mechanism of cell adaptation to metabolic and environmental stress. It mediates the disposal of protein aggregates and dysfunctional organelles, although non-conventional features have recently emerged to broadly extend the pathophysiological relevance of autophagy. In baseline conditions, basal autophagy critically regulates cardiac homeostasis to preserve structural and functional integrity and protect against cell damage and genomic instability occurring with aging. Moreover, autophagy is stimulated by multiple cardiac injuries and contributes to mechanisms of response and remodeling following ischemia, pressure overload, and metabolic stress. Besides cardiac cells, autophagy orchestrates the maturation of neutrophils and other immune cells, influencing their function. In this review, we will discuss the evidence supporting the role of autophagy in cardiac homeostasis, aging, and cardioimmunological response to cardiac injury. Finally, we highlight possible translational perspectives of modulating autophagy for therapeutic purposes to improve the care of patients with acute and chronic cardiac disease.

Cardiomyocyte ZKSCAN3 regulates remodeling following pressure-overload

Autophagy is important for protein and organelle quality control. Growing evidence demonstrates that autophagy is tightly controlled by transcriptional mechanisms, including repression by zinc finger containing KRAB and SCAN domains 3 (ZKSCAN3). We hypothesize that cardiomyocyte-specific ZKSCAN3 knockout (Z3K) disrupts autophagy activation and repression balance and exacerbates cardiac pressure-overload-induced remodeling following transverse aortic constriction (TAC). Indeed, Z3K mice had an enhanced mortality compared to control (Con) mice following TAC. Z3K-TAC mice that survived exhibited a lower body weight compared to Z3K-Sham. Although both Con and Z3K mice exhibited cardiac hypertrophy after TAC, Z3K mice exhibited TAC-induced increase of left ventricular posterior wall thickness at end diastole (LVPWd). Conversely, Con-TAC mice exhibited decreases in PWT%, fractional shortening (FS%), and ejection fraction (EF%). Autophagy genes (Tfeb, Lc3b, and Ctsd) were decreased by the loss of ZKSCAN3. TAC suppressed Zkscan3, Tfeb, Lc3b, and Ctsd in Con mice, but not in Z3K. The Myh6/Myh7 ratio, which is related to cardiac remodeling, was decreased by the loss of ZKSCAN3. Although Ppargc1a mRNA and citrate synthase activities were decreased by TAC in both genotypes, mitochondrial electron transport chain activity did not change. Bi-variant analyses show that while in Con-Sham, the levels of autophagy and cardiac remodeling mRNAs form a strong correlation network, such was disrupted in Con-TAC, Z3K-Sham, and Z3K-TAC. Ppargc1a also forms different links in Con-sham, Con-TAC, Z3K-Sham, and Z3K-TAC. We conclude that ZKSCAN3 in cardiomyocytes reprograms autophagy and cardiac remodeling gene transcription, and their relationships with mitochondrial activities in response to TAC-induced pressure overload.

Synonymous Codon Variant Analysis for Autophagic Genes Dysregulated in Neurodegeneration

Neurodegenerative disorders are often a culmination of the accumulation of abnormally folded proteins and defective organelles. Autophagy is a process of removing these defective proteins, organelles, and harmful substances from the body, and it works to maintain homeostasis. If autophagic removal of defective proteins has interfered, it affects neuronal health. Some of the autophagic genes are specifically found to be associated with neurodegenerative phenotypes. Non-functional, mutated, or gene copies having silent mutations, often termed synonymous variants, might explain this. However, these synonymous variant which codes for exactly similar proteins have different translation rates, stability, and gene expression profiling. Hence, it would be interesting to study the pattern of synonymous variant usage. In the study, synonymous variant usage in various transcripts of autophagic genes ATG5, ATG7, ATG8A, ATG16, and ATG17/FIP200 reported to cause neurodegeneration (if dysregulated) is studied. These genes were analyzed for their synonymous variant usage; nucleotide composition; any possible nucleotide skew in a gene; physical properties of autophagic protein including GRAVY and AROMA; hydropathicity; instability index; and frequency of acidic, basic, neutral amino acids; and gene expression level. The study will help understand various evolutionary forces acting on these genes and the possible augmentation of a gene if showing unusual behavior.

Adenosine 2 receptor regulates autophagy and apoptosis to alleviate ischemia reperfusion injury in type 2 diabetes via IRE-1 signaling

PURPOSE

This study aimed to determine the effect and mechanism of action of adenosine 2 receptor (A2R) activation on myocardial ischemia reperfusion injury (MIRI) under diabetic conditions.

METHODS

MIRI type 2 diabetic rats and H9C2 cardiomyocytes were treated with A2R agonist and then subjected to hypoxia for 6 h and reoxygenation for 18 h. Myocardial damage, and infarct size were determined by cardiac ultrasound. Indicators of cardiomyocyte injury, creatine kinase-MB and cardiac troponin I were detected by Enzyme Linked Immunosorbent Assay. Endoplasmic reticulum stress (ERS) was determined through measuring the expression levels of ERS related genes GRP78, p-IRE1/IRE1, and p-JNKJNK. The mechanism of A2R cardio protection in MIRI through regulating ERS induced autophagy was determined by investigating the ER resident protein IRE-1. The ER-stress inducer Tunicamycin, and the IRE-1 inhibitor STF in combination with the A2R agonist NECA were used, and the cellular responses were assessed through autophagy proteins expression Beclin-1, p62, LC3 and apoptosis.

RESULTS

NECA improved left ventricular function post MIRI, limited myocardial infarct size, reduced myocardial damage, decreased cardiomyocytes apoptosis, and attenuated ERS induced autophagy through regulating the IRE-XBP1s-CHOP pathway. These actions resulted into overall protection of the myocardium against MIRI.

CONCLUSION

In summary, A2R activation by NECA prior to ischemia attenuates apoptosis, reduces ERS induced autophagy and restores left ventricular function. This protective effect occurs through regulating the IRE1-XBPs-CHOP related mechanisms. NECA is thus a potential target for the treatment of MIRI in patient with type 2 diabetes.

A Multi-omic and Multi-Species Analysis of Right Ventricular Failure

Right ventricular failure (RVF) is a leading cause of morbidity and mortality in multiple cardiovascular diseases, but there are no approved treatments for RVF as therapeutic targets are not clearly defined. Contemporary transcriptomic/proteomic evaluations of RVF are predominately conducted in small animal studies, and data from large animal models are sparse. Moreover, a comparison of the molecular mediators of RVF across species is lacking. Here, we used transcriptomics and proteomics analyses to define the molecular pathways associated with cardiac MRI-derived values of RV hypertrophy, dilation, and dysfunction in pulmonary artery banded (PAB) piglets. Publicly available data from rat monocrotaline-induced RVF and pulmonary arterial hypertension patients with preserved or impaired RV function were used to compare the three species. Transcriptomic and proteomic analyses identified multiple pathways that were associated with RV dysfunction and remodeling in PAB pigs. Surprisingly, disruptions in fatty acid oxidation (FAO) and electron transport chain (ETC) proteins were different across the three species. FAO and ETC proteins and transcripts were mostly downregulated in rats, but were predominately upregulated in PAB pigs, which more closely matched the human data. Thus, the pig PAB metabolic molecular signature was more similar to human RVF than rodents. These data suggest there may be divergent molecular responses of RVF across species, and that pigs more accurately recapitulate the metabolic aspects of human RVF.

Progranulin (PGRN) as a regulator of inflammation and a critical factor in the immunopathogenesis of cardiovascular diseases

Immune dysregulation has been identified as a critical cause of the most common types of cardiovascular diseases (CVDs). Notably, the innate and adaptive immune responses under physiological conditions are typically regulated with high sensitivity to avoid the exacerbation of inflammation, but any dysregulation can probably be associated with CVDs. In this respect, progranulin (PGRN) serves as one of the main components of the regulation of inflammatory processes, which significantly contributes to the immunopathogenesis of such disorders. PGRN has been introduced among the secreted growth factors as one related to wound healing, inflammation, and human embryonic development, as well as a wide variety of autoimmune diseases. The relationship between the serum PGRN and TNF-α ratio with the spontaneous bacterial peritonitis constitute one of the independent predictors of these conditions. The full-length PGRN can thus effectively reduce the calcification of valve interstitial cells, and the granulin precursor (GRN), among the degradation products of PGRN, can be beneficial. Moreover, it was observed that, PGRN protects the heart against ischemia-reperfusion injury. Above all, PGRN also provides protection in the initial phase following myocardial ischemia-reperfusion injury. The protective impact of PGRN on this may be associated with the early activation of the PI3K/Akt signaling pathway. PGRN also acts as a protective factor in hyperhomocysteinemia, probably by down-regulating the wingless-related integration site Wnt/β-catenin signaling pathway. Many studies have further demonstrated that SARS-CoV-2 (COVID-19) has dramatically increased the risks of CVDs due to inflammation, so PGRN has drawn much more attention among scholars. Lysosomes play a pivotal role in the inflammation process, and PGRN is one of the key regulators in their functioning, which contributes to the immunomodulatory mechanism in the pathogenesis of CVDs. Therefore, investigation of PGRN actions can help find new prospects in the treatment of CVDs. This review aims to summarize the role of PGRN in the immunopathogenesis of CVD, with an emphasis on its treatment.

Autophagy and pressure overload-induced cardiac hypertrophy

Autophagy plays an important role in the pathogenesis of cardiovascular diseases. Dysregulation of autophagy may have a huge effect on cardiac hypertrophy induced by overload pressure although reports on autophagy and cardiac hypertrophy have been contradictory. Some studies showed that autophagy activation attenuated cardiac hypertrophy. However, others suggested that inhibition of autophagy would be protective. Different research models or different pathways involved could be responsible for it. Cardiac hypertrophy may be alleviated through regulation of autophagy. This review aims to highlight the pathways and therapeutic targets identified in the prevention and treatment of cardiac hypertrophy by regulating autophagy.

Blocking Lipid Uptake Pathways Does not Prevent Toxicity in Adipose Triglyceride Lipase (ATGL) Deficiency

Lipid accumulation in nonadipose tissues can cause lipotoxicity, leading to cell death and severe organ dysfunction. Adipose triglyceride lipase (ATGL) deficiency causes human neutral lipid storage disease and leads to cardiomyopathy; ATGL deficiency has no current treatment. One possible approach to alleviate this disorder has been to alter the diet and reduce the supply of dietary lipids and, hence, myocardial lipid uptake. However, in this study, when we supplied cardiac Atgl KO mice a low- or high-fat diet, we found that heart lipid accumulation, heart dysfunction, and death were not altered. We next deleted lipid uptake pathways in the ATGL-deficient mice through the generation of double KO mice also deficient in either cardiac lipoprotein lipase or cluster of differentiation 36, which is involved in an lipoprotein lipase-independent pathway for FA uptake in the heart. We show that neither deletion ameliorated ATGL-deficient heart dysfunction. Similarly, we determined that non-lipid-containing media did not prevent lipid accumulation by cultured myocytes; rather, the cells switched to increased de novo FA synthesis. Thus, we conclude that pathological storage of lipids in ATGL deficiency cannot be corrected by reducing heart lipid uptake.

Autophagy in health and disease: From molecular mechanisms to therapeutic target

Macroautophagy/autophagy is an evolutionally conserved catabolic process in which cytosolic contents, such as aggregated proteins, dysfunctional organelle, or invading pathogens, are sequestered by the double-membrane structure termed autophagosome and delivered to lysosome for degradation. Over the past two decades, autophagy has been extensively studied, from the molecular mechanisms, biological functions, implications in various human diseases, to development of autophagy-related therapeutics. This review will focus on the latest development of autophagy research, covering molecular mechanisms in control of autophagosome biogenesis and autophagosome-lysosome fusion, and the upstream regulatory pathways including the AMPK and MTORC1 pathways. We will also provide a systematic discussion on the implication of autophagy in various human diseases, including cancer, neurodegenerative disorders (Alzheimer disease, Parkinson disease, Huntington's disease, and Amyotrophic lateral sclerosis), metabolic diseases (obesity and diabetes), viral infection especially SARS-Cov-2 and COVID-19, cardiovascular diseases (cardiac ischemia/reperfusion and cardiomyopathy), and aging. Finally, we will also summarize the development of pharmacological agents that have therapeutic potential for clinical applications via targeting the autophagy pathway. It is believed that decades of hard work on autophagy research is eventually to bring real and tangible benefits for improvement of human health and control of human diseases.

Recent Advances on Drug Development and Emerging Therapeutic Agents Through Targeting Cellular Homeostasis for Ageing and Cardiovascular Disease

Ageing is a progressive physiological process mediated by changes in biological pathways, resulting in a decline in tissue and cellular function. It is a driving factor in numerous age-related diseases including cardiovascular diseases (CVDs). Cardiomyopathies, hypertension, ischaemic heart disease, and heart failure are some of the age-related CVDs that are the leading causes of death worldwide. Although individual CVDs have distinct clinical and pathophysiological manifestations, a disturbance in cellular homeostasis underlies the majority of diseases which is further compounded with aging. Three key evolutionary conserved signalling pathways, namely, autophagy, mitophagy and the unfolded protein response (UPR) are involved in eliminating damaged and dysfunctional organelle, misfolded proteins, lipids and nucleic acids, together these molecular processes protect and preserve cellular homeostasis. However, amongst the numerous molecular changes during ageing, a decline in the signalling of these key molecular processes occurs. This decline also increases the susceptibility of damage following a stressful insult, promoting the development and pathogenesis of CVDs. In this review, we discuss the role of autophagy, mitophagy and UPR signalling with respect to ageing and cardiac disease. We also highlight potential therapeutic strategies aimed at restoring/rebalancing autophagy and UPR signalling to maintain cellular homeostasis, thus mitigating the pathological effects of ageing and CVDs. Finally, we highlight some limitations that are likely hindering scientific drug research in this field.

Activation of Autophagic Flux Maintains Mitochondrial Homeostasis during Cardiac Ischemia/Reperfusion Injury

Reperfusion injury after extended ischemia accounts for approximately 50% of myocardial infarct size, and there is no standard therapy. HDAC inhibition reduces infarct size and enhances cardiomyocyte autophagy and PGC1α-mediated mitochondrial biogenesis when administered at the time of reperfusion. Furthermore, a specific autophagy-inducing peptide, Tat-Beclin 1 (TB), reduces infarct size when administered at the time of reperfusion. However, since SAHA affects multiple pathways in addition to inducing autophagy, whether autophagic flux induced by TB maintains mitochondrial homeostasis during ischemia/reperfusion (I/R) injury is unknown. We tested whether the augmentation of autophagic flux by TB has cardioprotection by preserving mitochondrial homeostasis both in vitro and in vivo. Wild-type mice were randomized into two groups: Tat-Scrambled (TS) peptide as the control and TB as the experimental group. Mice were subjected to I/R surgery (45 min coronary ligation, 24 h reperfusion). Autophagic flux, mitochondrial DNA (mtDNA), mitochondrial morphology, and mitochondrial dynamic genes were assayed. Cultured neonatal rat ventricular myocytes (NRVMs) were treated with a simulated I/R injury to verify cardiomyocyte specificity. The essential autophagy gene, ATG7, conditional cardiomyocyte-specific knockout (ATG7 cKO) mice, and isolated adult mouse ventricular myocytes (AMVMs) were used to evaluate the dependency of autophagy in adult cardiomyocytes. In NRVMs subjected to I/R, TB increased autophagic flux, mtDNA content, mitochondrial function, reduced reactive oxygen species (ROS), and mtDNA damage. Similarly, in the infarct border zone of the mouse heart, TB induced autophagy, increased mitochondrial size and mtDNA content, and promoted the expression of PGC1α and mitochondrial dynamic genes. Conversely, loss of ATG7 in AMVMs and in the myocardium of ATG7 cKO mice abolished the beneficial effects of TB on mitochondrial homeostasis. Thus, autophagic flux is a sufficient and essential process to mitigate myocardial reperfusion injury by maintaining mitochondrial homeostasis and partly by inducing PGC1α-mediated mitochondrial biogenesis.

Direct Cardiac Actions of Sodium-Glucose Cotransporter 2 Inhibition Improve Mitochondrial Function and Attenuate Oxidative Stress in Pressure Overload-Induced Heart Failure

Clinical trials showed that sodium-glucose cotransporter 2 (SGLT2) inhibitors, a class of drugs developed for treating diabetes mellitus, improve prognosis of patients with heart failure (HF). However, the mechanisms for cardioprotection by SGLT2 inhibitors are still unclear. Mitochondrial dysfunction and oxidative stress play important roles in progression of HF. This study tested the hypothesis that empagliflozin (EMPA), a highly selective SGLT2 inhibitor, improves mitochondrial function and reduces reactive oxygen species (ROS) while enhancing cardiac performance through direct effects on the heart in a non-diabetic mouse model of HF induced by transverse aortic constriction (TAC). EMPA or vehicle was administered orally for 4 weeks starting 2 weeks post-TAC. EMPA treatment did not alter blood glucose or body weight but significantly attenuated TAC-induced cardiac dysfunction and ventricular remodeling. Impaired mitochondrial oxidative phosphorylation (OXPHOS) in failing hearts was significantly improved by EMPA. EMPA treatment also enhanced mitochondrial biogenesis and restored normal mitochondria morphology. Although TAC increased mitochondrial ROS and decreased endogenous antioxidants, EMPA markedly inhibited cardiac ROS production and upregulated expression of endogenous antioxidants. In addition, EMPA enhanced autophagy and decreased cardiac apoptosis in TAC-induced HF. Importantly, mitochondrial respiration significantly increased in ex vivo cardiac fibers after direct treatment with EMPA. Our results indicate that EMPA has direct effects on the heart, independently of reductions in blood glucose, to enhance mitochondrial function by upregulating mitochondrial biogenesis, enhancing OXPHOS, reducing ROS production, attenuating apoptosis, and increasing autophagy to improve overall cardiac function in a non-diabetic model of pressure overload-induced HF.

Cardiac Shockwave Therapy – A Novel Therapy for Ischemic Cardiomyopathy?

Over the past decades, shockwave therapy (SWT) has gained increasing interest as a therapeutic approach for regenerative medicine applications, such as healing of bone fractures and wounds. More recently, pre-clinical studies have elucidated potential mechanisms for the regenerative effects of SWT in myocardial ischemia. The mechanical stimulus of SWT may induce regenerative effects in ischemic tissue via growth factor release, modulation of inflammatory response, and angiogenesis. Activation of the innate immune system and stimulation of purinergic receptors by SWT appears to enhance vascularization and regeneration of injured tissue with functional improvement. Intriguingly, small single center studies suggest that SWT may improve angina, exercise tolerance, and hemodynamics in patients with ischemic heart disease. Thus, SWT may represent a promising technology to induce cardiac protection or repair in patients with ischemic heart disease.

Coenzyme Q10 Reduces Infarct Size in Animal Models of Myocardial Ischemia-Reperfusion Injury: A Meta-Analysis and Summary of Underlying Mechanisms

Objective

Effective interventions that might limit myocardial ischemia-reperfusion (I/R) injury are still lacking. Coenzyme Q₁₀ (CoQ₁₀) may exert cardioprotective actions that reduce myocardial I/R injury. We conducted this meta-analysis to assess the potential cardioprotective effect of CoQ₁₀ in animal models of myocardial I/R injury.

Methods

We searched PubMed and Embase databases from inception to February 2022 to identify animal studies that compared the effect of CoQ₁₀ with vehicle treatment or no treatment on myocardial infarct size in models of myocardial I/R injury. Means and standard deviations of the infarct size measurements were pooled as the weighted mean difference with 95% confidence interval (CI) using the random-effects model. Subgroup analyses were also conducted according to animals' species, models' type, and reperfusion time.

Results

Six animal studies (4 in vivo and 2 ex vivo) with 116 animals were included. Pooled analysis suggested that CoQ₁₀ significantly reduced myocardial infarct size by −11.36% (95% CI: −16.82, −5.90, p < 0.0001, I² = 94%) compared with the control group. The significance of the pooled effect estimate was maintained in rats, Hartley guinea pigs, and Yorkshire pigs. However, it became insignificant in the subgroup of rabbits −5.29% (95% CI: −27.83, 17.26; I² = 87%). Furthermore, CoQ₁₀ significantly reduced the myocardial infarct size regardless of model type (either in vivo or ex vivo) and reperfusion time (either ≤ 4 h or >4 h).

Conclusion

Coenzyme Q₁₀ significantly decreased myocardial infarct size by 11.36% compared with the control group in animal models of myocardial I/R injury. This beneficial action was retained regardless of model type and reperfusion time.

SS31 Ameliorates Oxidative Stress via the Restoration of Autophagic Flux to Protect Aged Mice From Hind Limb Ischemia

Background

Oxidative stress and impaired autophagic flux play important roles in the development of peripheral artery disease (PAD). SS31 is considered an important antioxidant peptide and autophagy regulator. We aimed to investigate the role of SS31 in PAD myopathy and its possible mechanism both in vivo and in vitro.

Methods

A hind limb ischemia (HLI) model was established with old C57BL/6 (14-month-old) mice. Mice in the SS31 group were intraperitoneally injected with SS31 (3 mg/kg) for 4 weeks. We examined skeletal muscle function and histomorphology, autophagy-related protein levels and reactive oxygen species (ROS) content. For the in vitro experiments, after C2C12 myotubes were treated with CoCl₂, SS31, and chloroquine (CQ) or rapamycin (RAPA), we measured ROS content, autophagy-related protein levels and antioxidant enzyme expression.

Results

SS31 treatment effectively enhanced the recovery of skeletal muscle function, alleviated skeletal muscle injury and suppressed mitochondrial ROS production in ischemic limbs. SS31 reduced apoptosis and oxidative stress, and SS31 restored impaired autophagic flux by inhibiting the AKT-mTOR pathway. In vitro studies showed that SS31 restored autophagic flux and improved oxidative stress in C2C12 cells. Moreover, phosphorylated AKT (p-AKT) and phosphorylated mTOR (p-mTOR) levels were reduced.

Conclusion

These experiments indicated that SS31 can inhibit oxidative stress by restoring autophagic flux to reverse hypoxia-induced injury in vivo and in vitro.

The ups and downs of caloric restriction and fasting: from molecular effects to clinical application

Age-associated diseases are rising to pandemic proportions, exposing the need for efficient and low-cost methods to tackle these maladies at symptomatic, behavioral, metabolic, and physiological levels. While nutrition and health are closely intertwined, our limited understanding of how diet precisely influences disease often precludes the medical use of specific dietary interventions. Caloric restriction (CR) has approached clinical application as a powerful, yet simple, dietary modulation that extends both life- and healthspan in model organisms and ameliorates various diseases. However, due to psychological and social-behavioral limitations, CR may be challenging to implement into real life. Thus, CR-mimicking interventions have been developed, including intermittent fasting, time-restricted eating, and macronutrient modulation. Nonetheless, possible side effects of CR and alternatives thereof must be carefully considered. We summarize key concepts and differences in these dietary interventions in humans, discuss their molecular effects, and shed light on advantages and disadvantages.

The Association Between Regular Physical Exercise, Sleep Patterns, Fasting, and Autophagy for Healthy Longevity and Well-Being: A Narrative Review

This narrative review of the literature assessed whether regular physical exercise and sleep patterns, fasting and autophagy, altogether can be an adequate strategy for achieving healthy longevity and well-being within different stage of life. There are a large number of studies dealing with well-being and healthy longevity; however, few of them have given us a specific formula for how to live long and healthy. Despite all the advances that have been made to create adequate physical exercise programs, sleep patterns or nutritional protocols, the relation between different types of fasting, nutritional supplementation as well as regular physical exercise and sleep patterns have not yet been satisfactorily resolved to cause the best effects of autophagy and, therefore, well-being and healthy longevity. In this way, future studies should clarify more efficiently the relationship between these variables to understand the association between regular physical exercise, sleep patterns, fasting and autophagy for healthy longevity and well-being.

Plantago asiatica L. seeds extract protects against cardiomyocyte injury in isoproterenol- induced cardiac hypertrophy by inhibiting excessive autophagy and apoptosis in mice

BACKGROUND

Cardiac hypertrophy is the early stage of many heart diseases, such as coronary heart disease, hypertension, valvular dysfunction and cardiomyopathy. Cardiomyocyte autophagy and apoptosis play an important role in the process of cardiac hypertrophic response. Plantago asiatica L. seeds extract (PASE) is prepared from a traditional herbal medicine in Asia with tremendous pharmacological activities. However, whether PASE could relieve cardiac hypertrophy has not been elucidated. The present study is aimed to investigate the effect of PASE on cardiac hypertrophy and explore its potential underlying mechanism.

METHODS

Cardiac hypertrophy was induced in C57BL/6 mice by subcutaneous injection of isoproterenol (ISO) for two weeks. Meanwhile, the mice were intraperitoneally injected with PASE at dosages of 20, 40 and 80 mg/kg/day. Cardiac hypertrophy was evaluated by echocardiographic examination, haematoxylin and eosin staining and quantitative real-time polymerase chain reaction. Expressions of proteins involved in autophagy and apoptosis such as Beclin1, p62, LC3II, Bax, Bcl-2 and Cleaved-caspase-3 were detected by western blot analysis. Western blot, transient transfection, acridine orange staining, TUNEL staining and autophagy inducer were used to observe the effect and explore the mechanism of PASE on cardiomyocyte and H9c2 cells with excessive autophagy and apoptosis induced by ISO.

RESULTS

ISO induction for two weeks disturbed the myocardial contractility and cardiac function of left ventricles of mice. PASE treated mice showed significantly improved cardiac function indexes, including EF, FS, SV and CO, compared with the ISO group. Treatment with PASE also decreased the heart weight/body weight ratio and cardiomyocyte size, and downregulated the mRNA and protein expressions of hypertrophic markers ANP, BNP, and β-MHC. Furthermore, the changes of autophagy and apoptosis markers, such as LC3II, Beclin1, p62, Bcl-2, Bax and Cleaved-caspase-3 induced by ISO were resumed by PASE treatment. Consistently, PASE demonstrated similar effects on ISO-induced H9c2 cells as it did in vivo. In addition, PASE could counteract the increased autophagy induced by the autophagy inducer, rapamycin.

CONCLUSION

PASE attenuated ISO-induced cardiac hypertrophy in mice by inhibiting excessive autophagy and apoptosis in cardiomyocytes. The novel findings may pave the way for the clinical usage of PASE for the prevention of heart diseases related with cardiac hypertrophy.

TFEB insufficiency promotes cardiac hypertrophy by blocking autophagic degradation of GATA4

Autophagosome-lysosome pathway (ALP) insufficiency has been suggested to play a critical role in the pathogenesis of cardiac hypertrophy. However, the mechanisms underlying ALP insufficiency remain largely unknown, and strategies to specifically manipulate ALP insufficiency for treating cardiac hypertrophy are lacking. Transcription factor EB (TFEB), as a master regulator of ALP, regulates the generation and function of autophagosomes and lysosomes. We found that TFEB was significantly decreased, whereas autophagosome markers were increased in phenylephrine (PE)-induced and transverse aortic constriction-induced cardiomyocyte hypertrophy and failing hearts from patients with dilated cardiomyopathy. Knocking down TFEB induced ALP insufficiency, as indicated by increased autophagosome markers, decreased light chain 3II flux, and cardiomyocyte hypertrophy manifested through increased levels of atrial natriuretic peptide and β-myosin heavy chain and enlarged cell size. The effects of TFEB knockdown were abolished by promoting autophagy. TFEB overexpression improved autophagic flux and attenuated PE-stimulated cardiomyocyte hypertrophy and transverse aortic constriction-induced hypertrophic remodeling, fibrosis, and cardiac dysfunction. Curcumin analog compound C1, a specific TFEB activator, similarly attenuated PE-induced ALP insufficiency and cardiomyocyte hypertrophy. TFEB knockdown increased the accumulation of GATA4, a transcription factor for several genes causing cardiac hypertrophy by blocking autophagic degradation of GATA4, whereas knocking down GATA4 attenuated TFEB downregulation-induced cardiomyocyte hypertrophy. Both TFEB overexpression and C1 promoted GATA4 autophagic degradation and alleviated PE-induced cardiomyocyte hypertrophy. In conclusion, TFEB downregulation plays a vital role in the development of pressure overload-induced cardiac hypertrophy by causing ALP insufficiency and blocking autophagic degradation. Activation of TFEB represents a potential therapeutic strategy for treating cardiac hypertrophy.

The potentials of distinct functions of autophagy to be targeted for attenuation of myocardial ischemia/reperfusion injury in preclinical studies: an up-to-date review

Despite remarkable advances in our knowledge about the function of autophagy in myocardial ischemia/reperfusion (I/R) injury, the debate continues over whether autophagy is protective or deleterious in cardiac I/R. Due to the complexity of autophagy signaling, autophagy can play a dual role in the pathological processes of myocardial I/R injury. Thus, more researches are needed to shed light on the complex roles of autophagy in cardioprotection for the future clinical development. Such researches can lead to the finding of new therapeutic strategies for improving cardiac I/R outcomes in patients. Several preclinical studies have targeted autophagy flux as a beneficial strategy against myocardial I/R injury. In this review, we aimed to discuss the complex contribution of autophagy in myocardial I/R injury, as well as the therapeutic agents that have been shown to be useful in reducing myocardial I/R injury by targeting autophagy. For this reason, we provided an updated summary of the data from in vivo, ex vivo, and in vitro experimental studies about the therapeutic agents that exert positive effects against myocardial I/R injury by modulating autophagy flux. By addressing these valuable studies, we try to provide a motivation for the promising hypothesis of "autophagy modulation as a therapeutic strategy against cardiac I/R" in the future clinical studies.

Activation of Autophagic Flux Blunts Cardiac Ischemia/Reperfusion Injury

[Figure: see text].

The Interplay Between Autophagy and Senescence in Anthracycline Cardiotoxicity

PURPOSE OF REVIEW

Doxorubicin (DOXO) is a highly effective chemotherapeutic drug employed for the treatment of a wide spectrum of cancers, spanning from solid tumours to haematopoietic malignancies. However, its clinical use is hampered by severe and dose-dependent cardiac side effects that ultimately lead to heart failure (HF).

RECENT FINDINGS

Mitochondrial dysfunction and oxidative stress are well-established mechanisms of DOXO-induced cardiotoxicity, although recent evidence suggests that deregulation of other biological processes, like autophagy, could be involved. It is increasingly recognized that autophagy deregulation is intimately interconnected with the initiation of detrimental cellular responses, including autosis and senescence, raising the possibility of using autophagy modulators as well as senolytics and senomorphics for preventing DOXO cardiotoxicity. This review aims at providing an overview of the signalling pathways that are common to autophagy and senescence, with a special focus on how the relationship between these two processes is deregulated in response to cardiotoxic treatments. Finally, we will discuss the potential therapeutic utility of drugs modulating autophagy and/or senescence for counteracting DOXO cardiotoxicity.

Beclin-1-Dependent Autophagy of Left Ventricular Cardiomyocytes in SHR and Wistar-Kyoto Rats with Type 1 Diabetes Mellitus

Autophagy is considered as a mechanism of progression of heart failure, but under certain conditions, it can also act as an adaptation mechanism. Beclin-1 plays the key role in autophagy. We studied the features of Beclin-1 expression in cardiomyocytes of the left ventricle in arterial hypertension, type 1 diabetes mellitus, and their combination. The experiment was performed on male 38-week-old Wistar Kyoto rats and SHR rats aged 38 and 57 weeks. Type 1 diabetes mellitus was modeled by a single parenteral administration of streptozotocin. Expression of Beclin-1 in cardiomyocytes of the left ventricle was evaluated by immunohistochemical analysis. In arterial hypertension, a decrease in the intensity of Beclin-1-dependent autophagy of cardiomyocytes was seen, while in combined pathology, we observed an opposite effect manifested as a significant increase in the expression of protein Beclin-1.

Significances of viable synergistic autophagy-associated cathepsin B and cathepsin D (CTSB/CTSD) as potential biomarkers for sudden cardiac death

Background

The Cathepsins family, including cathepsin B and cathepsin D, potentially affects the entire processes involved in atherosclerosis. Although coronary heart disease (CHD) has been widely studied as the basis of Sudden Cardiac Death (SCD), the relationship between CHD and CTSB/D remains unclear.

Methods

We screened for differentially expressed proteins (DEPs) associated with autophagy by limma package in R. For the genes corresponding to the DEPs after screening, we used various databases to carry out functional enrichment of related DEGs to explore their possible influence on a specific aspect of the disease. Functional enrichment analysis of DEGs was performed by DAVID, Metascape and GSEA. STRING and Cytoscape were obtained the hub genes, the analysis of interaction networks through the GENMANIA and Networkanalyst. Western Blot was used to validate the protein expression level of target genes. TF and miRNA prediction were performed using Networkanalyst and visualized using Cytoscape.

Results

The expression levels of members of the cathepsin family were up regulated in CHD tissues compared with the control. GO and KEGG revealed that cathepsin was markedly enriched in endopeptidase activities, immune responses, lysosome pathways, et al. The correlation analysis showed that in patients with CHD, the CTSB/CTSD expression were negatively correlated with ATG4D and BNIP3, but positively with BCL2L1, CAPNS1, and TP53. In the TF-mRNA-miRNA network, has-miR-24-3p and has-miR-128-3p had higher degrees, CTSB/CTSD could be targeted by them.

Conclusions

Our findings elucidated the expression and regulatory role of cathepsins in coronary heart disease induced SCD and might further explore the potential mechanisms of autophagy in CHD.

High Dietary Phosphate Exacerbates and Acts Independently of Low Autophagy Activity in Pathological Cardiac Remodeling and Dysfunction

High phosphate contributes to uremic cardiomyopathy. Abnormal autophagy is associated with the development and progression of heart disease. What is unknown is the effects of phosphate on autophagy and whether the ill effects of phosphate on cardiomyocytes are mediated by low autophagy. High (2.0% w/w)-phosphate diet reduced LC3 puncta in cardiomyocytes and ratio of LC3 II/I and increased p62 protein, indicating that autophagy activity was suppressed. Mice with cardiomyocyte-specific deletion of autophagy-related protein 5 (H-atg5-/-) had reduced autophagy only in the heart, developed cardiac dysfunction with hypertrophy and fibrosis, and had a short lifespan. When H-atg5-/- mice were fed a high-phosphate diet, they developed more apoptosis in cardiomyocytes, more severe cardiac remodeling, and shorter lifespan than normal phosphate-fed H-atg5-/- mice, indicating that cardiac phosphotoxicity is imparted independently of atg5. In conclusion, although high phosphate suppresses autophagy, high phosphate and low autophagy independently trigger and additionally amplify cardiac remodeling and dysfunction.

Functional role and molecular mechanisms underlying prohibitin 2 in platelet mitophagy and activation

Platelet mitophagy is a major pathway involved in the clearance of injured mitochondria during hemostasis and thrombosis. Prohibitin 2 (PHB2) has recently emerged as an inner mitochondrial membrane receptor involved in mitophagy. However, the mechanisms underlying PHB2-mediated platelet mitophagy and activation are not completely understood. PHB2 is a highly conserved inner mitochondrial membrane protein that regulates mitochondrial assembly and function due to its unique localization on the mitochondrial membrane. The present study aimed to investigate the role and mechanism underlying PHB2 in platelet mitophagy and activation. Phorbol-12-myristate-13-acetate (PMA) was used to induce MEG-01 cells maturation and differentiate into platelets following PHB2 knockdown. Cell Counting Kit-8 assays were performed to examine platelet viability. Flow cytometry was performed to assess platelet mitochondrial membrane potential. RT-qPCR and western blotting were conducted to measure mRNA and protein expression levels, respectively. Subsequently, platelets were exposed to CCCP and the role of PHB2 was assessed. The results of the present study identified a crucial role for PHB2 in platelet mitophagy and activation, suggesting that PHB2-mediated regulation of mitophagy may serve as a novel strategy for downregulating the expression of platelet activation genes. Although further research into mitophagy is required, the present study suggested that PHB2 may serve as a novel therapeutic target for thrombosis-related diseases due to its unique localization on the mitochondrial membrane.