Resveratrol as a new inhibitor of immunoproteasome prevents PTEN degradation and attenuates cardiac hypertrophy after pressure overload

Diet induced insulin resistance is due to induction of PTEN expression

Type 2 Diabetes (T2D) is a condition that is often associated with obesity and defined by reduced sensitivity of PI3K signaling to insulin (insulin resistance), hyperinsulinemia and hyperglycemia. Molecular causes and early signaling events underlying insulin resistance are not well understood. Insulin activation of PI3K signaling causes mTOR dependent induction of PTEN translation, a negative regulator of PI3K signaling. We speculated that insulin resistance is due to insulin dependent induction of PTEN protein that prevent further increases in PI3K signaling. Here we show that in a diet induced model of obesity and insulin resistance, PTEN levels are increased in fat, muscle and liver tissues. Onset of hyperinsulinemia and PTEN induction in tissue is followed by hyperglycemia, hepatic steatosis and severe glucose intolerance. Treatment with a PTEN phosphatase inhibitor prevents and reverses these phenotypes, whereas an mTORC1 kinase inhibitor reverses all but the hepatic steatosis. These data suggest that induction of PTEN by increasing levels of insulin elevates feedback inhibition of the pathway to a point where downstream PI3K signaling is reduced and hyperglycemia ensues. PTEN induction is thus necessary for insulin resistance and the type 2 diabetes phenotype and a potential therapeutic target.

The role of the immunoproteasome in cardiovascular disease

The ubiquitinproteasome system (UPS) is the main mechanism responsible for the intracellular degradation of misfolded or damaged proteins. Under inflammatory conditions, the immunoproteasome, an isoform of the proteasome, can be induced, enhancing the antigen-presenting function of the UPS. Furthermore, the immunoproteasome also serves nonimmune functions, such as maintaining protein homeostasis and regulating signalling pathways, and is involved in the pathophysiological processes of various cardiovascular diseases (CVDs). This review aims to provide a comprehensive summary of the current research on the involvement of the immunoproteasome in cardiovascular diseases, with the ultimate goal of identifying novel strategies for the treatment of these conditions.

Mapping the interplay of immunoproteasome and autophagy in different heart failure phenotypes

Proper protein degradation is required for cellular protein homeostasis and organ function. Particularly, in post-mitotic cells, such as cardiomyocytes, unbalanced proteolysis due to inflammatory stimuli and oxidative stress contributes to organ dysfunction. To ensure appropriate protein turnover, eukaryotic cells exert two main degradation systems, the ubiquitin-proteasome-system and the autophagy-lysosome-pathway. It has been shown that proteasome activity affects the development of cardiac dysfunction differently, depending on the type of heart failure. Studies analyzing the inducible subtype of the proteasome, the immunoproteasome (i20S), demonstrated that the i20S plays a double role in diseased hearts. While i20S subunits are increased in cardiac hypertrophy, atrial fibrillation and partly in myocarditis, the opposite applies to diabetic cardiomyopathy and ischemia/reperfusion injury. In addition, the i20S appears to play a role in autophagy modulation depending on heart failure phenotype. This review summarizes the current literature on the i20S in different heart failure phenotypes, emphasizing the two faces of i20S in injured hearts. A selection of established i20S inhibitors is introduced and signaling pathways linking the i20S to autophagy are highlighted. Mapping the interplay of the i20S and autophagy in different types of heart failure offers potential approaches for developing treatment strategies against heart failure.

Adaptive and maladaptive roles of different angiotensin receptors in the development of cardiac hypertrophy and heart failure

Angiotensin II (Ang II) is formed by the action of angiotensin-converting enzyme (ACE) in the renin-angiotensin system. This hormone is known to induce cardiac hypertrophy and heart failure and its actions are mediated by the interaction of both pro- and antihypertrophic Ang II receptors (AT1R and AT2R). Ang II is also metabolized by ACE 2 to Ang-(1-7), which elicits the activation of Mas receptors (MasR) for inducing antihypertrophic actions. Since heart failure under different pathophysiological situations is preceded by adaptive and maladaptive cardiac hypertrophy, we have reviewed the existing literature to gain some information regarding the roles of AT1R, AT2R, and MasR in both acute and chronic conditions of cardiac hypertrophy. It appears that the activation of AT1R may be involved in the development of adaptive and maladaptive cardiac hypertrophy as well as subsequent heart failure because both ACE inhibitors and AT1R antagonists exert beneficial effects. On the other hand, the activation of both AT2R and MasR may prevent the occurrence of maladaptive cardiac hypertrophy and delay the progression of heart failure, and thus therapy with different activators of these antihypertrophic receptors under chronic pathological stages may prove beneficial. Accordingly, it is suggested that a great deal of effort should be made to develop appropriate activators of both AT2R and MasR for the treatment of heart failure subjects.

Resveratrol protects against doxorubicin-induced cardiotoxicity by attenuating ferroptosis through modulating the MAPK signaling pathway

Doxorubicin (Dox) is a widely used antitumor agent with dose-dependent and cumulative cardiotoxic effects. Resveratrol (Res) is a natural non-flavonoid polyphenol that can potentially provide cardiovascular benefits. We aimed to estimate the protective effect of Res on Dox-induced cardiotoxicity (DIC) and explore whether it was related to attenuating ferroptosis. We established DIC models in C57BL/6 J mice, H9C2 cardiomyoblasts, and neonatal rat cardiomyocytes (NRCMs). We further treated H9C2 cells with RSL3, a ferroptosis agonist, to investigate whether Res exerted protective effects through inhibiting ferroptosis. Ferrostatin-1 (Fer-1) was applied to suppress ferroptosis. Dox treatment caused cardiac dysfunction and resulted in apparent ferroptotic damage in cardiac tissue, involving increased iron accumulation, glutathione depletion, increased expression of ferroptosis-related proteins, and decreased expression of glutathione peroxidase 4, which were alleviated by Fer-1 and Res administration. These findings were also confirmed in Dox-treated H9C2 cells and NRCMs, with Fer-1 and Res effectively attenuating Dox-induced cytotoxicity and ferroptosis. Furthermore, Res protected H9C2 cells from RSL3-induced ferroptotic cell death, and the protective effect was similar to that of Fer-1. Both Dox and RSL3 treatment increased the phosphorylation levels of mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated kinase, p38, and c-Jun N-terminal kinases; however, these changes were hindered by Res. This study demonstrates that Res effectively alleviates DIC by suppressing ferroptosis possibly through modulating the MAPK signaling pathway. Our results highlight that targeting ferroptosis can be a potential cardioprotective strategy for DIC.

Costunolide ameliorates angiotensin II-induced atrial inflammation and fibrosis by regulating mitochondrial function and oxidative stress in mice: A possible therapeutic approach for atrial fibrillation

Atrial fibrillation (AF) is a cardiac disease characterized by disordered atrial electrical activity. Atrial inflammation and fibrosis are involved in AF progression. Costunolide (COS) is a sesquiterpene lactone containing anti-inflammatory and anti-fibrotic activities. This study aims to explore the underlying mechanisms by which COS protects against AF. Male C57BL/6 mice (8- to 10-week-old) were infused with angiotensin (Ang) II for 3 weeks. Meanwhile, different doses of COS (COS-L: 10 mg/kg, COS-H: 20 mg/kg) were administered to mice by intragastric treatment. The results showed irregular and rapid heart rates in Ang II-treated mice. Moreover, the levels of inflammatory cytokines and fibrotic factors were elevated in mice. COS triggered a reduction of Ang II-induced inflammation and fibrosis, which conferred a protective effect. Mechanistically, mitochondrial dysfunction with mitochondrial respiration inhibition and aberrant ATP levels were observed after Ang II treatment. Moreover, Ang-II-induced excessive reactive oxygen species caused oxidative stress, which was further aggravated by inhibiting Nrf2 nuclear translocation. Importantly, COS diminished these Ang-II-mediated effects in mice. In conclusion, COS attenuated inflammation and fibrosis in Ang-II-treated mice by alleviating mitochondrial dysfunction and oxidative stress. Our findings represent a potential therapeutic option for AF treatment.

Dapagliflozin Attenuates Heart Failure With Preserved Ejection Fraction Remodeling and Dysfunction by Elevating β-Hydroxybutyrate-activated Citrate Synthase

ABSTRACT

Heart failure with preserved ejection fraction (HFpEF) is highly prevalent, accounting for 50% of all heart failure patients, and is associated with significant mortality. Sodium-glucose cotransporter subtype inhibitor (SGLT2i) is recommended in the AHA and ESC guidelines for the treatment of HFpEF, but the mechanism of SGLT2i to prevent and treat cardiac remodeling and dysfunction is currently unknown, hindering the understanding of the pathophysiology of HFpEF and the development of novel therapeutics. HFpEF model was induced by a high-fat diet (60% calories from lard) + N [w] -nitro- l -arginine methyl ester ( l -NAME-0.5 g/L) (2 Hit) in male Sprague Dawley rats to effectively recapture the myriad phenotype of HFpEF. This study's results showed that administration of dapagliflozin (DAPA, SGLT2 inhibitor) significantly limited the 2-Hit-induced cardiomyocyte hypertrophy, apoptosis, inflammation, oxidative stress, and fibrosis. It also improved cardiac diastolic and systolic dysfunction in a late-stage progression of HFpEF. Mechanistically, DAPA influences energy metabolism associated with fatty acid intake and mitochondrial dysfunction in HFpEF by increasing β-hydroxybutyric acid (β-OHB) levels, directing the activation of citrate synthase, reducing acetyl coenzyme A (acetyl-CoA) pools, modulating adenosine 5'-triphosphate production, and increasing the expression of mitochondrial oxidative phosphorylation system complexes I-V. In addition, following clinical DAPA therapy, the blood levels of β-OHB and citrate synthase increased and the levels of acetyl-CoA in the blood of HFpEF patients decreased. SGLT2i plays a beneficial role in the prevention and treatment of cardiac remodeling and dysfunction in HFpEF model by attenuating cardiometabolic dysregulation.

Searching for Effective Treatments in HFpEF: Implications for Modeling the Disease in Rodents

BACKGROUND

While the prevalence of heart failure with preserved ejection fraction (HFpEF) has increased over the last two decades, there still remains a lack of effective treatment. A key therapeutic challenge is posed by the absence of animal models that accurately replicate the complexities of HFpEF. The present review summarizes the effects of a wide spectrum of therapeutic agents on HF.

METHODS

Two online databases were searched for studies; in total, 194 experimental protocols were analyzed following the PRISMA protocol.

RESULTS

A diverse range of models has been proposed for studying therapeutic interventions for HFpEF, with most being based on pressure overload and systemic hypertension. They have been used to evaluate more than 150 different substances including ARNIs, ARBs, HMGR inhibitors, SGLT-2 inhibitors and incretins. Existing preclinical studies have primarily focused on LV diastolic performance, and this has been significantly improved by a wide spectrum of candidate therapeutic agents. Few experiments have investigated the normalization of pulmonary congestion, exercise capacity, animal mortality, or certain molecular hallmarks of heart disease.

CONCLUSIONS

The development of comprehensive preclinical HFpEF models, with multi-organ system phenotyping and physiologic stress-based functional testing, is needed for more successful translation of preclinical research to clinical trials.

Resveratrol inhibits ferroptosis and decelerates heart failure progression via Sirt1/p53 pathway activation

Resveratrol is an organic compound widely studied for its therapeutic uses. We investigated whether resveratrol exerts cardioprotective effects by inhibiting ferroptosis via the Sirt1/p53 pathway. A heart failure model was established by aortic coarctation in Sirt1 knockout mice. The superoxide dismutase (SOD), glutathione (GSH) levels and mitochondrial morphology in murine heart tissues were assessed at different time points to determine the role of ferroptosis in heart failure progression. The cardiac function of mice with heart failure was evaluated by determining the brain natriuretic peptide (BNP) and sST2 concentration and conducting echocardiography. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were transfected with the p53 K382R mutant and Sirt1 interference lentiviral vectors. Immunoprecipitation (IP) experiments were performed to investigate whether Sirt1 influences ferroptosis via p53 K382 acetylation and SLC7A11 expression modulation. Resveratrol improved cardiac function in mice and decelerated ferroptosis and fibrosis progression in heart failure. However, the ability of resveratrol to prevent ferroptosis and treat heart failure was lost after silencing Sirt1. Sirt1 reduced ferroptosis by diminishing the levels of p53 K382 acetylation, reducing the degradation of SLC7A11, and increasing the levels of GSH and glutathione peroxidase 4 (GPX4) in cells. In conclusion, by activating the Sirt1/p53 pathway in heart failure, resveratrol decreased the depletion of SLC7A11, inhibited ferroptosis, and improved cardiac function.

Resveratrol prevents Ang II-induced cardiac hypertrophy by inhibition of NF-κB signaling

BACKGROUND

Pathological cardiac hypertrophy is a hallmark of various cardiovascular diseases (CVD) including chronic heart failure (HF) and an important target for the treatment of these diseases. Aberrant activation of Angiotensin II (Ang II)/AT1R signaling pathway is one of the main triggers of cardiac hypertrophy, which further gives rise to excessive inflammation that is mediated by the key transcription factor NF-κB. Resveratrol (REV) is a natural polyphenol with multiple anti-inflammatory and anti-oxidative effects, however the ability of REV in preventing Ang II-induced cardiac hypertrophy in combination with NF-κB signaling activation remains unclear.

METHODS

Murine models of cardiac hypertrophy was conducted via implantation of Ang II osmotic pumps. Primary neonatal rat cardiomyocyte and heart tissues were examined to determine the effect and underlying mechanism of REV in preventing Ang II-induced cardiac hypertrophy.

RESULTS

Administrations of REV significantly prevented Ang II-induced cardiac hypertrophy, as well as robustly attenuated Ang II-induced cardiac fibrosis, and cardiac dysfunction. Furthermore, REV not only directly prevented Ang II/AT1R signal transductions, but also prevented Ang II-induced expressions of pro-inflammatory cytokines and activation of NF-κB signaling pathway.

CONCLUSIONS

Our study provides important new mechanistic insight into the cardioprotective effects of REV in preventing Ang II-induced cardiac hypertrophy via inhibiting adverse NF-κB signaling activation. Our findings further suggest the therapeutic potential of REV as a promising drug for the treatment of cardiac hypertrophy and heart failure.

Impact of polyphenols on heart failure and cardiac hypertrophy: clinical effects and molecular mechanisms

Polyphenols are abundant in regular diets and possess antioxidant, anti-inflammatory, anti-cancer, neuroprotective, and cardioprotective effects. Regarding the inadequacy of the current treatments in preventing cardiac remodeling following cardiovascular diseases, attention has been focused on improving cardiac function with potential alternatives such as polyphenols. The following online databases were searched for relevant orginial published from 2000 to 2023: EMBASE, MEDLINE, and Web of Science databases. The search strategy aimed to assess the effects of polyphenols on heart failure and keywords were "heart failure" and "polyphenols" and "cardiac hypertrophy" and "molecular mechanisms". Our results indicated polyphenols are repeatedly indicated to regulate various heart failure-related vital molecules and signaling pathways, such as inactivating fibrotic and hypertrophic factors, preventing mitochondrial dysfunction and free radical production, the underlying causes of apoptosis, and also improving lipid profile and cellular metabolism. In the current study, we aimed to review the most recent literature and investigations on the underlying mechanism of actions of different polyphenols subclasses in cardiac hypertrophy and heart failure to provide deep insight into novel mechanistic treatments and direct future studies in this context. Moreover, due to polyphenols' low bioavailability from conventional oral and intravenous administration routes, in this study, we have also investigated the currently accessible nano-drug delivery methods to optimize the treatment outcomes by providing sufficient drug delivery, targeted therapy, and less off-target effects, as desired by precision medicine standards.

Ursolic Acid Ameliorates Myocardial Ischaemia/Reperfusion Injury by Improving Mitochondrial Function via Immunoproteasome-PP2A-AMPK Signalling

Cardiac ischaemia/reperfusion (I/R) injury causes cardiomyocyte apoptosis and mitochondrial dysfunction. Ursolic acid (UA), as a pentacyclic triterpenoid carboxylic acid, exerts several bioactivities in animal models of different diseases, but the preventive role of UA in I/R-induced myocardial dysfunction remains largely unknown. Male wild-type mice were pre-administered with UA at a dosage of 80 mg/kg i.p. and then subjected to cardiac I/R injury for 24 h. Cardiac function and pathological changes were examined by echocardiography and histological staining. The protein and mRNA levels of the genes were determined using qPCR and immunoblotting analysis. Our results revealed that UA administration in mice significantly attenuated the I/R-induced decline in cardiac function, infarct size, myocyte apoptosis, and oxidative stress. Mechanistically, UA increased three immunoproteasome catalytic subunit expressions and activities, which promoted ubiquitinated PP2A degradation and activated AMPK-PGC1α signalling, leading to improved mitochondrial biosynthesis and dynamic balance. In vitro experiments confirmed that UA treatment prevented hypoxia/reperfusion (H/R)-induced cardiomyocyte apoptosis and mitochondrial dysfunction through activation of AMPK signalling. In summary, our findings identify UA as a new activator of the immunoproteasome that exerts a protective role in I/R-induced myocardial dysfunction and suggest that UA supplementation could be beneficial for the prevention of cardiac ischaemic disease.

Resveratrol alleviated 5-FU-induced cardiotoxicity by attenuating GPX4 dependent ferroptosis

The clinical use of 5-fluorouracil (5-FU), a potent antitumor agent, was limited by severe cardiotoxic effects. The present study was aimed to investigate the protective effects of resveratrol (Res) on 5-FU-induced cardiotoxicity and to explore its potential mechanisms.The cardiotoxicity model was intraperitoneal injection of 5-FU at the dose of 30 mg/kg for 7 consecutive days. Plasma enzymes activities, cardiac tissues were assessed after treatment with Res for 3 weeks. Ferrostatin-1 (Fer-1) was used as ferroptosis inhibitor. In H9c2 cardiomyocyte cells, cell viability, generation of reactive oxygen species (ROS), mitochondrial activity and cellular Fe²⁺ levels were measured. Western-blot assay was performed to evaluate the protein level of ferroptosis in vitro and in vivo. In the mice model, Res reduced 5-FU-induced cardiomyocyte injury (ferroptosis, myofibrillar loss and vacuolization). In addition, increased serum creatine kinase (CK), lactate dehydrogenase (LDH), malonaldehyde (MDA) and Fe²⁺ activity and decreased activities of glutathione (GSH) were observed in 5-FU group. These changes were prevented by treatment with Res. In H9c2 cardiomyocyte cells, Res increased the cell viability and attenuated cell ferroptosis as measured by DCFH-DA, TMRE and Calcein AM staining. In addition, 5-FU induced a reduction in GPX4, FTH1, Nrf2 and NQO1 and activation of TfR and P53 compared with the control group. However, Res effectively inhibited the changes in ferroptosis associated proteins in vitro and in vivo. Res possessed the cardioprotective potential against 5-FU induced cardiotoxicity. Moreover, Res attenuates 5-FU-induced cardiotoxicity via inhibiting GPX4 dependent ferroptosis.

Cardiomyocyte-specific Peli1 contributes to the pressure overload-induced cardiac fibrosis through miR-494-3p-dependent exosomal communication

Cardiac fibrosis is an essential pathological process in pressure overload (PO)-induced heart failure. Recently, myocyte-fibroblast communication is proven to be critical in heart failure, in which, pathological growth of cardiomyocytes (CMs) may promote fibrosis via miRNAs-containing exosomes (Exos). Peli1 regulates the activation of NF-κB and AP-1, which has been demonstrated to engage in miRNA transcription in cardiomyocytes. Therefore, we hypothesized that Peli1 in CMs regulates the activation of cardiac fibroblasts (CFs) through an exosomal miRNA-mediated paracrine mechanism, thereby promoting cardiac fibrosis. We found that CM-conditional deletion of Peli1 improved PO-induced cardiac fibrosis. Moreover, Exos from mechanical stretch (MS)-induced WT CMs (WT MS-Exos) promote activation of CFs, Peli1^-/- MS-Exos reversed it. Furthermore, miRNA microarray and qPCR analysis showed that miR-494-3p was increased in WT MS-Exos while being down regulated in Peli1^-/- MS-Exos. Mechanistically, Peli1 promoted miR-494-3p expression via NF-κB/AP-1 in CMs, and then miR-494-3p induced CFs activation by inhibiting PTEN and amplifying the phosphorylation of AKT, SMAD2/3, and ERK. Collectively, our study suggests that CMs Peli1 contributes to myocardial fibrosis via CMs-derived miR-494-3p-enriched exosomes under PO, and provides a potential exosomal miRNA-based therapy for cardiac fibrosis.

Extracellular vesicles DJ-1 derived from hypoxia-conditioned hMSCs alleviate cardiac hypertrophy by suppressing mitochondria dysfunction and preventing ATRAP degradation

BACKGROUND

As a pathological myocardial remodeling process in a variety of cardiovascular diseases, cardiac hypertrophy still has no effective treatment. Human mesenchymal stem cells (hMSCs) derived extracellular vesicles (EVs) has been recognized as a promising treatment strategy for cardiac disease.

METHODS

In this study, the inhibitory effects on cardiac hypertrophy are compared between normoxia-conditioned hMSC-derived EVs (Nor-EVs) and hypoxia-conditioned hMSC-derived EVs (Hypo-EVs) in neonatal rat cardiomyocytes (NRCMs) after angiotensin II (Ang II) stimulation and in a mouse model of transverse aortic constriction (TAC).

RESULTS

We demonstrate that Hypo-EVs exert an increased inhibitory effect on cardiac hypertrophy compared with Nor-EVs. Parkinson disease protein 7 (PARK7/DJ-1) is identify as a differential protein between Nor-EVs and Hypo-EVs by quantitative proteomics analysis. Results show that DJ-1, which is rich in Hypo-EVs, alleviates mitochondrial dysfunction and excessive mitochondrial reactive oxygen species (mtROS) production as an antioxidant. Mechanistic studies demonstrate for the first time that DJ-1 may suppress cardiac hypertrophy by inhibiting the activity of proteasome subunit beta type 10 (PSMB10) through a direct physical interaction. This interaction can inhibit angiotensin II type 1 receptor (AT1R)-mediated signaling pathways resulting in cardiac hypertrophy through alleviating ubiquitination degradation of AT1R-associated protein (ATRAP).

CONCLUSIONS

When taken together, our study suggests that Hypo-EVs have significant potential as a novel therapeutic agent for the treatment of cardiac hypertrophy.

Mitophagy: A Potential Target for Pressure Overload-Induced Cardiac Remodelling

The pathological mechanisms underlying cardiac remodelling and cardiac dysfunction caused by pressure overload are poorly understood. Mitochondrial damage and functional dysfunction, including mitochondrial bioenergetic disorder, oxidative stress, and mtDNA damage, contribute to heart injury caused by pressure overload. Mitophagy, an important regulator of mitochondrial homeostasis and function, is triggered by mitochondrial damage and participates in the pathological process of cardiovascular diseases. Recent studies indicate that mitophagy plays a critical role in the pressure overload model, but evidence on the causal relationship between mitophagy abnormality and pressure overload-induced heart injury is inconclusive. This review summarises the mechanism, role, and regulation of mitophagy in the pressure overload model. It also pays special attention to active compounds that may regulate mitophagy in pressure overload, which provide clues for possible clinical applications.

Role of resveratrol in inhibiting pathological cardiac remodeling

Cardiovascular disease is a group of diseases with high mortality in clinic, including hypertension, coronary heart disease, cardiomyopathy, heart valve disease, heart failure, to name a few. In the development of cardiovascular diseases, pathological cardiac remodeling is the most common cardiac pathological change, which often becomes a domino to accelerate the deterioration of the disease. Therefore, inhibiting pathological cardiac remodeling may delay the occurrence and development of cardiovascular diseases and provide patients with greater long-term benefits. Resveratrol is a non-flavonoid polyphenol compound. It mainly exists in grapes, berries, peanuts and red wine, and has cardiovascular protective effects, such as anti-oxidation, inhibiting inflammatory reaction, antithrombotic, dilating blood vessels, inhibiting apoptosis and delaying atherosclerosis. At present, the research of resveratrol has made rich progress. This review aims to summarize the possible mechanism of resveratrol against pathological cardiac remodeling, in order to provide some help for the in-depth exploration of the mechanism of inhibiting pathological cardiac remodeling and the development and research of drug targets.

MiR-155 Dysregulation Is Associated with the Augmentation of ROS/p53 Axis of Fibrosis in Thioacetamide-Induced Hepatotoxicity and Is Protected by Resveratrol

Liver fibrosis is a hallmark of thioacetamide (TAA) intoxications. MicroRNAs (miRs), such as miR-155, have been implied in the pathogenesis of liver disease, and regulated by the antioxidant and anti-inflammatory compound resveratrol (RES). The link between reactive oxygen species (ROS), tumour suppressor p53 (p53), and liver fibrosis-during the pathogenesis of TAA-induced liver injury-associated with miR-155 dysregulation with and without RES incorporation has not been previously studied. Therefore, one group of rats received TAA injections of 200 mg/kg; twice a week at the beginning of week 3 for 8 weeks (TAA group; or model group), whereas the protective group was pretreated daily with RES suspension (20 mg/kg; orally) for the first two weeks and subsequently sustained on receiving both RES and TAA until being sacrificed at the 10th week. Liver injuries developed in the model group were confirmed by a significant (p < 0.0001) elevation of hepatic tissue levels of miR-155, ROS, p53, and the profibrogenic biomarkers: tissue inhibitor of metalloproteinases-1 and α-smooth muscle actin, as well as collagen deposition (fibrosis). All these parameters were significantly (p ≤ 0.0234) protected by resveratrol (RES + TAA). In addition, we observed a significant (p < 0.0001) correlation between ROS/p53 axis mediated liver fibrosis and miR-155. Thus, TAA intoxication induced miR-155 imbalance and ROS/p53-mediated liver fibrosis, with resveratrol, conversely displaying beneficial hepatic pleiotropic effects for a period of 10 weeks.

Association of resveratrol with the suppression of TNF-α/NF-kB/iNOS/HIF-1α axis-mediated fibrosis and systemic hypertension in thioacetamide-induced liver injury

Chronic liver injury can lead to hepatic failure and the only available method of treatment would be liver transplantation. The link between inflammation (TNF-α), nuclear factor-kappa B (NF-kB), nitrosative stress (iNOS) and hypoxia-inducible factor-1α (HIF-1α) in thioacetamide (TAA) induced liver fibrosis, and hypertension with and without the incorporation of the anti-inflammatory and antioxidant resveratrol (RES) has not been investigated before. Consequently, we injected rats with either 200 mg/kg TAA for 8 weeks starting at week 2 (model group) or pretreated them before TAA injections with RES (20 mg/kg) for 2 weeks and continued them on RES and TAA until being culled at week 10 (protective group). In the model group, we documented the induction of hepatic fibrosis and upregulation of tumor necrosis factor-α (TNF-α), NF-kB, inducible nitric oxide synthase (iNOS), HIF-1α and the profibrotic biomarkers alpha-smooth muscle actin (α-SMA) and matrix metalloproteinase-9 (MMP-9) that was significantly (p ≤ 0.0014) ameliorated by RES. RES also significantly (p ≤ 0.0232) reduced triglycerides (TG), cholesterol (CHOL), very low-density lipoprotein (vLDL-C), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure, and heart rate (HR) induction by TAA. Also, a significant (p < 0.0001) positive correlation between TNF-α/NF-kB/iNOS/HIF-1α axis-mediated fibrosis and hypertension and liver injury biomarkers was observed. These findings suggest that in the hepatotoxic compound, TAA is associated with TNF-α/NF-kB/iNOS/HIF-1α-mediated fibrosis and hypertension, whilst being inhibited by RES.

Antioxidant Cardioprotection against Reperfusion Injury: Potential Therapeutic Roles of Resveratrol and Quercetin

Ischemia-reperfusion myocardial damage is a paradoxical tissue injury occurring during percutaneous coronary intervention (PCI) in acute myocardial infarction (AMI) patients. Although this damage could account for up to 50% of the final infarct size, there has been no available pharmacological treatment until now. Oxidative stress contributes to the underlying production mechanism, exerting the most marked injury during the early onset of reperfusion. So far, antioxidants have been shown to protect the AMI patients undergoing PCI to mitigate these detrimental effects; however, no clinical trials to date have shown any significant infarct size reduction. Therefore, it is worthwhile to consider multitarget antioxidant therapies targeting multifactorial AMI. Indeed, this clinical setting involves injurious effects derived from oxygen deprivation, intracellular pH changes and increased concentration of cytosolic Ca²⁺ and reactive oxygen species, among others. Thus, we will review a brief overview of the pathological cascades involved in ischemia-reperfusion injury and the potential therapeutic effects based on preclinical studies involving a combination of antioxidants, with particular reference to resveratrol and quercetin, which could contribute to cardioprotection against ischemia-reperfusion injury in myocardial tissue. We will also highlight the upcoming perspectives of these antioxidants for designing future studies.

Lingguizhugan decoction dynamically regulates MAPKs and AKT signaling pathways to retrogress the pathological progression of cardiac hypertrophy to heart failure

BACKGROUND

Heart failure (HF) is a grave health concern, with high morbidity and mortality, calling for the urgent need for new and alternative pharmacotherapies. Lingguizhugan decoction (LD) is a classic Chinese formula clinically used to treat HF. However, the underlying mechanisms involved are not fully elucidated.

PURPOSE

Based on that, this study aims to investigate the effects and underlying mechanisms of LD on HF.

METHODS

After confirming the therapeutic benefits of LD in transverse aortic constriction (TAC)-induced HF mice, network pharmacology and transcriptomic analyzes were utilized to predict the potential molecular targets and pathways of LD treatment in failing hearts, which were evaluated at 3 and 9 w after TAC. UHPLC-QE-MS analysis was utilized to detect bioactive ingredients from LD and plasma of LD-treated rats.

RESULTS

Our results showed that LD markedly alleviated cardiac dysfunction via down-regulating CH-related genes and proteins expression in TAC mice. Significantly, cardiac hypertrophy signaling, including AKT and MAPKs signaling pathways, were identified, suggesting the pathways as likely regulatory targets for LD treatment. LD inhibited p38 and ERK phosphorylated expression levels, with the latter effect likely dependent on regulation of AMPK. Interestingly, LD exerted a dual modulatory role in the AKT-GSK3β/mTOR/P70S6K signaling pathway's regulation, which was characterized by stimulatory activity at 3 w and inhibitory effects at 9 w. Finally, 15 bioactive compounds detected from plasma were predicted as the potential regulators of the AKT-GSK3β/mTOR and MAPKs signaling pathways.

CONCLUSION

Our study shows LD's therapeutic efficacy in failing hearts, signifies LD as HF medication that acts dynamically by balancing AKT-GSK3β/mTOR/P70S6K and MAPKs pathways, and reveals possible bioactive compounds responsible for LD effects on HF.

Overexpression of cytosolic long noncoding RNA cytb protects against pressure-overload-induced heart failure via sponging microRNA-103-3p

Long noncoding RNAs (lncRNAs) play crucial roles in cardiovascular diseases. To date, only limited studies have reported the role of mitochondria-derived lncRNAs in heart failure (HF). In the current study, recombinant adeno-associated virus 9 was used to manipulate lncRNA cytb (lnccytb) expression in vivo. Fluorescence in situ hybridization (FISH) assay was used to determine the location of lnccytb, while microRNA (miRNA) sequencing and bioinformatics analyses were applied to identify the downstream targets. The competitive endogenous RNA (ceRNA) function of lnccytb was evaluated by biotin-coupled miRNA pull-down assays and luciferase reporter assays. Results showed that lnccytb expression was decreased in the heart of mice with transverse aortic constriction (TAC), as well as in the heart and plasma of patients with HF. FISH assay and absolute RNA quantification via real-time reverse transcription PCR suggested that the reduction of the lnccytb transcripts mainly occurred in the cytosol. Upregulation of cytosolic lnccytb attenuated cardiac dysfunction in TAC mice. Moreover, overexpression of cytosolic lnccytb in cardiomyocytes alleviated isoprenaline-induced reactive oxidative species (ROS) production and hypertrophy. Mechanistically, lnccytb acted as a ceRNA via sponging miR-103-3p, ultimately mitigating the suppression of PTEN by miR-103-3p. In summary, we demonstrated that the overexpression of cytosolic lnccytb could ameliorate HF.

Natural AMPK Activators in Cardiovascular Disease Prevention

Cardiovascular diseases (CVD), as a life-threatening global disease, is receiving worldwide attention. Seeking novel therapeutic strategies and agents is of utmost importance to curb CVD. AMP-activated protein kinase (AMPK) activators derived from natural products are promising agents for cardiovascular drug development owning to regulatory effects on physiological processes and diverse cardiometabolic disorders. In the past decade, different therapeutic agents from natural products and herbal medicines have been explored as good templates of AMPK activators. Hereby, we overviewed the role of AMPK signaling in the cardiovascular system, as well as evidence implicating AMPK activators as potential therapeutic tools. In the present review, efforts have been made to compile and update relevant information from both preclinical and clinical studies, which investigated the role of natural products as AMPK activators in cardiovascular therapeutics.

Resveratrol protects against myocardial ischemia-reperfusion injury via attenuating ferroptosis

Resveratrol (Res) is a polyphenol with a variety of biological activities. However, whether Res can prevent myocardial ischemia-reperfusion (I/R) injury is not yet known. This study aimed to investigate the protective effect of Res on myocardial I/R injury and to explore its potential mechanism. H9c2 cells were used for the in vitro experiments and oxygen-glucose deprivation/reoxygenation (OGD/R) model was established. Rats were ligated and perfused by the left anterior descending branch with or without Res (50 mg/kg·bw) for 14 days.The higher level of oxidative stress and Fe²⁺ content was observed in OGD/R-induced H9c2 cells than that of normal cells. OGD/R-induced H9c2 cells showed increased ferroptosis, mainly by reducing the expression of glutathione peroxidase 4 (GPX4) and ferritin heavy chain 1 (FTH1), but enhancing the expression of transferrin receptor 1 (TfR1). Both in vivo and in vitro experiments indicated that Res reduced the level of oxidative stress and Fe2 + content. In addition, Res inhibited ferroptosis, decreased TfR1 expression, and increased the expressions of FTH1 and GPX4 in OGD/R-induced H9c2 cells and I/R rats. Moreover, we found that Res inhibited ferroptosis by the regulation of ubiquity specific peptidase 19 (USP19)-Beclin1 autophagy. Res protects against myocardial I/R injury via reducing oxidative stress and attenuating ferroptosis. Res could be a potential agent to the prevention of myocardial I/R injury.

The Effect of Resveratrol on the Cardiovascular System from Molecular Mechanisms to Clinical Results

Cardiovascular diseases are the leading causes of death worldwide. The cardioprotective effects of natural polyphenols such as resveratrol (3,5,4-trihydroxystilbene) have been extensively investigated throughout recent decades. Many studies of RES have focused on its favorable effects on pathological conditions related to cardiovascular diseases and their risk factors. The aim of this review was to summarize the wide beneficial effects of resveratrol on the cardiovascular system, including signal transduction pathways of cell longevity, energy metabolism of cardiomyocytes or cardiac remodeling, and its anti-inflammatory and antioxidant properties. In addition, this paper discusses the significant preclinical and human clinical trials of recent years with resveratrol on cardiovascular system. Finally, we present a short overview of antiviral and anti-inflammatory properties and possible future perspectives on RES against COVID-19 in cardiovascular diseases.

Resveratrol and endothelial function: A literature review

Endothelial dysfunction is a major contributing factor to diseases such as atherosclerosis, diabetes mellitus, obesity, hypertension, acute lung injury, preeclampsia, among others. Resveratrol (RSV) is a naturally occurring bioactive polyphenol found in grapes and red wine. According to experimental studies, RSV modulates several events involved in endothelial dysfunction such as impaired vasorelaxation, eNOS uncoupling, leukocyte adhesion, endothelial senescence, and endothelial mesenchymal transition. The endothelial protective effects of RSV are found to be mediated by numerous molecular targets (e.g. Silent Information Regulator 1 (SIRT1), 5' AMP-activated protein kinase (AMPK), endothelial nitric oxide synthase (eNOS), nuclear factor-erythroid-derived 2-related factor-2 (Nrf2), peroxisome proliferator-activated receptor (PPAR), Krüppel-like factor-2 (KLF2), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB)). Herein, we present an updated review addressing pharmacological effects and molecular targets of RSV in maintaining endothelial function, and the potential of this phytochemical for endothelial dysfunction-associated disorders.

PTEN mediates serum deprivation-induced cytotoxicity in H9c2 cells via the PI3K/AKT signaling pathway

The pathogenesis of acute myocardial infarction (AMI) is associated with cardiomyocyte necrosis and apoptosis. Numerous studies have determined the regulatory effects of Phosphatase and tensin homolog (PTEN) cell proliferation and apoptosis in other cell types. However, the potential role of PTEN in cardiomyocyte is unclear. In this study, we used H9c2 cells cultured under serum deprivation to simulate the apoptosis process of myocardial infarction. Small interference RNA (siRNA) of PTEN was used to knock down the expression of PTEN. Cell viability was determined by CCK-8. Cell proliferation was examined by Edu staining, and the protein expression was analyzed by Western blot. We also evaluated the generation of ROS, the degree of DNA damage, and cell apoptosis using immunofluorescence assay. As a result, we observed that serum deprivation in H9c2 cells increased PTEN expression. Functionally, the PTEN knockdown experiment using siRNA inhibited serum deprivation-induced cell apoptosis, ROS production, and DNA damage, whereas increased cell proliferation. All these effects could be reversed by phosphatidylinositol 3-kinase (PI3K) inhibitor, which indicated the PI3K/protein kinase B (AKT) might be the critical component of the PTEN effects during serum deficiency. In conclusion, our study indicated the role of the PTEN/PI3K/AKT pathway in serum deprivation-induced cytotoxicity in H9c2 cells.

VEGF-C/VEGFR-3 axis protects against pressure-overload induced cardiac dysfunction through regulation of lymphangiogenesis

Prolonged pressure overload triggers cardiac hypertrophy and frequently leads to heart failure (HF). Vascular endothelial growth factor-C (VEGF-C) and its receptor VEGFR-3 are components of the central pathway for lymphatic vessel growth (also known as lymphangiogenesis), which has crucial functions in the maintenance of tissue fluid balance and myocardial function after ischemic injury. However, the roles of this pathway in the development of cardiac hypertrophy and dysfunction during pressure overload remain largely unknown. Eight- to 10-week-old male wild-type (WT) mice, VEGFR-3 knockdown (VEGFR-3f/- ) mice, and their WT littermates (VEGFR-3f/f ) were subjected to pressure overload induced by transverse aortic constriction (TAC) for 1-6 weeks. We found that cardiac lymphangiogenesis and the protein expression of VEGF-C and VEGFR-3 were upregulated in the early stage of cardiac hypertrophy but were markedly reduced in failing hearts. Moreover, TAC for 6 weeks significantly reduced cardiac lymphangiogenesis by inhibiting activation of VEGFR-3-mediated signals (AKT/ERK1/2, calcineurin A/NFATc1/FOXc2, and CX43), leading to increased cardiac edema, hypertrophy, fibrosis, apoptosis, inflammation, and dysfunction. These effects were further aggravated in VEGFR-3f/- mice and were dose-dependently attenuated by delivery of recombinant VEGF-C156S in WT mice. VEGF-C156s administration also reversed pre-established cardiac dysfunction induced by sustained pressure overload. Thus, these results demonstrate, for the first time, that activation of the VEGF-C-VEGFR-3 axis exerts a protective effect during the transition from cardiac hypertrophy to HF and highlight selective stimulation of cardiac lymphangiogenesis as a potential new therapeutic approach for hypertrophic heart diseases.

Growth differentiation factor 11 mitigates cardiac radiotoxicity via activating AMPKα

Cardiac radiotoxicity largely impedes the therapeutic benefits of radiotherapy to malignancies. Growth differentiation factor 11 (GDF11) is implicated in the pathogenesis of cardiac diseases under different pathological conditions. This study aims to investigate the role and underlying mechanisms of GDF11 on cardiac radiotoxicity. Mice were injected with cardiotropic adeno-associated virus 9 carrying the full-length mouse GDF11 gene or negative control under a cTnT promoter from the tail vein, and then received a single dose of 20 Gray (Gy) whole-heart irradiation (WHI) for 16 weeks to imitate cardiac radiotoxicity. Compound C (CC, 20 mg/kg) was intraperitoneally injected every two days at 1 week before WHI stimulation to inhibit 5' AMP-activated protein kinase α (AMPKα). Cardiac GDF11 expression was significantly suppressed at both the protein and mRNA levels. GDF11 overexpression decreased oxidative stress, apoptosis, and fibrosis in radiated hearts, thereby mitigating cardiac radiotoxicity, and dysfunction. Further detection revealed that GDF11 activated AMPKα to reduce radiation-induced oxidative damage and that AMPKα inhibition by CC offset the cardioprotective effects by GDF11. GDF11 mitigates cardiac radiotoxicity via activating AMPKα and it is a promising candidate to treat cardiac radiotoxicity.

Resveratrol and cardiac fibrosis prevention and treatment

Cardiovascular diseases are some of the major causes of morbidity and mortality in developed or developing countries but in developed countries as well. Cardiac fibrosis is one of the most often pathological changes of heart tissues. It occurs as a result of extracellular matrix proteins accumulation at myocardia. Cardiac fibrosis results in impaired cardiac systolic and diastolic functions and is associated with other effects. Therapies with medicines have not been sufficiently successful in treating chronic diseases such as CVD. Therefore, the interest for therapeutic potential of natural compounds and medicinal plants has increased. Plants such as grapes, berries and peanuts contain a polyphenolic compound called "resveratrol" which has been reported to have various therapeutic properties for a variety of diseases. Studies on laboratory models that show that resveratrol has beneficial effects on cardiovascular diseases including myocardial infarction, high blood pressure cardiomyopathy, thrombosis, cardiac fibrosis, and atherosclerosis. In vitro animal models using resveratrol indicated protective effects on the heart by neutralizing reactive oxygen species, preventing inflammation, increasing neoangiogenesis, dilating blood vessels, suppressing apoptosis and delaying atherosclerosis. In this review, we are presenting experimental and clinical results of studies concerning resveratrol effects on cardiac fibrosis as a CVD outcome in humans.

Sestrin 2, a potential star of antioxidant stress in cardiovascular diseases

Physiological reactive oxygen species (ROS) play an important role in cellular signal transduction. However, excessive ROS is an important pathological mechanism in most cardiovascular diseases (CVDs), such as myocardial aging, cardiomyopathy, ischemia/reperfusion injury (e.g., myocardial infarction) and heart failure. Programmed cell death, hypertrophy and fibrosis may be due to oxidative stress. Sestrin 2 (Sesn2), a stress-inducible protein associated with various stress conditions, is a potential antioxidant. Sesn2 can suppress the process of heart damage caused by oxidative stress, promote cell survival and play a key role in a variety of CVDs. This review discusses the effect of Sesn2 on the redox signal, mainly via participation in the signaling pathway of nuclear factor erythroid 2-related factor 2, activation of adenosine monophosphate-activated protein kinase and inhibition of mammalian target of rapamycin complex 1. It also discusses the effect of Sesn2's antioxidant activity on different CVDs. We speculate that Sesn2 plays an important role in CVDs by stimulating the process of antioxidation and promoting the adaptation of cells to stress conditions and/or the environment, opening a new avenue for related therapeutic strategies.

The Heart of the Alzheimer's: A Mindful View of Heart Disease

Purpose of Review: This review summarizes the current evidence for the involvement of proteotoxicity and protein quality control systems defects in diseases of the central nervous and cardiovascular systems. Specifically, it presents the commonalities between the pathophysiology of protein misfolding diseases in the heart and the brain. Recent Findings: The involvement of protein homeostasis dysfunction has been for long time investigated and accepted as one of the leading pathophysiological causes of neurodegenerative diseases. In cardiovascular diseases instead the mechanistic focus had been on the primary role of Ca2+ dishomeostasis, myofilament dysfunction as well as extracellular fibrosis, whereas no attention was given to misfolding of proteins as a pathogenetic mechanism. Instead, in the recent years, several contributions have shown protein aggregates in failing hearts similar to the ones found in the brain and increasing evidence have highlighted the crucial importance that proteotoxicity exerts via pre-amyloidogenic species in cardiovascular diseases as well as the prominent role of the cellular response to misfolded protein accumulation. As a result, proteotoxicity, unfolding protein response (UPR), and ubiquitin-proteasome system (UPS) have recently been investigated as potential key pathogenic pathways and therapeutic targets for heart disease. Summary: Overall, the current knowledge summarized in this review describes how the misfolding process in the brain parallels in the heart. Understanding the folding and unfolding mechanisms involved early through studies in the heart will provide new knowledge for neurodegenerative proteinopathies and may prepare the stage for targeted and personalized interventions.

Xanthohumol attenuates isoprenaline-induced cardiac hypertrophy and fibrosis through regulating PTEN/AKT/mTOR pathway

Emerging evidence suggests the cardiovascular protective effects of Xanthohumol (Xn), a prenylated flavonoid isolated from the hops (Humulus lupulus L.). However, the cardioprotective effect of Xn remains unclear. Present study aimed to investigate the protective role of Xn against isoprenaline (ISO)-induced cardiac hypertrophy and fibrosis, and elucidate the underlying mechanism. The cardiac hypertrophy and fibrosis model were established via subcutaneously administration of ISO. ISO reduced the left ventricular contractile function and elevated myocardial enzyme levels, suggesting cardiac dysfunction. Moreover, the increased cardiac myocyte area, heart weight/body weight (HW/BW) ratio and ANP/BNP expressions indicated the ISO-induced hypertrophy, while the excessive collagen-deposition and up-regulation of fibrosis marker protein (α-SMA, Collagen-I/III) expression indicated the ISO-induced fibrosis. The ISO-induced cardiac dysfunction, hypertrophy and fibrosis were significantly attenuated by oral administrated with Xn. PTEN/AKT/mTOR pathway has been reported to involve in pathogenesis of cardiac hypertrophy and fibrosis. We found that Xn administration up-regulated PTEN expression and inhibited the phosphorylation of AKT/mTOR in ISO-treated mice. Moreover, treating with VO-ohpic, a specific PTEN inhibitor, abolished the cardioprotective effect of Xn. Collectively, these results suggested that Xn attenuated ISO-induced cardiac hypertrophy and fibrosis through regulating PTEN/AKT/mTOR pathway.

Long Noncoding RNA XIST/miR-17/PTEN Axis Modulates the Proliferation and Apoptosis of Vascular Smooth Muscle Cells to Affect Stanford Type A Aortic Dissection

Stanford type A aortic dissection (TAAD) is one of the most lethal cardiovascular diseases with an extremely high morbidity and mortality rate. LncRNA X-inactive specific transcript (XIST) is abundantly expressed in human thoracic aortic dissection, indicating it may play important roles in TAAD progression. However, the molecular mechanism of lncRNA XIST in TAAD is still in its infancy. Quantitative real-time PCR (qRT-PCR) was performed to detect the expression of XIST and miR-17 in the aortic wall tissues of TAAD patients and age-matched healthy volunteers. The relationships between XIST, miR-17, and PTEN were evaluated using dual-luciferase reporter, western blot, and qRT-PCR assays. The biological functions of XIST in rat aortic vascular smooth muscle cells (VSMCs) were explored with Cell Counting Kit 8 (CCK-8), qRT-PCR, and western blot assays. Results found that XIST was upregulated in aortic wall tissues of patients with TAAD and associated with the prognosis of patients with TAAD. Silence XIST facilitated VSMC proliferation and inhibited VSMC apoptosis, whereas restoration XIST displayed opposite effects. Moreover, mechanistic studies revealed that XIST contained binding sites for miR-17 and miR-17 downregulation reversed the elevation of cell proliferation and attenuation of cell apoptosis, which was induced by silence XIST. Further study revealed that XIST positively regulated PTEN expression through its competitive target miR-17. In conclusion, knockdown of lncRNA XIST might attenuate the progression of TAAD by sponging miR-17 and regulating the following downstream PTEN, which suggested a novel therapeutic target for TAAD treatment.

Resveratrol confers neuroprotection against high-fat diet in a mouse model of Alzheimer's disease via modulation of proteolytic mechanisms

Cumulative evidence indicates that excessive consumption of calories from saturated fat contributes to the development of Alzheimer's disease (AD). Here, we assess the triggering and progression of AD pathology induced by a high-fat diet (HFD), and the effects of resveratrol, a polyphenol found in common dietary sources with pleiotropic neuroprotective activities. Over 16 weeks, male wild type (WT) and AD transgenic 5XFAD mice were fed a control diet, HFD (60% kcal from fat), or HFD supplemented with 0.1% resveratrol. Resveratrol protected against HFD-induced memory loss in WT mice and prevented memory loss in 5XFAD mice. Resveratrol also reduced the amyloid burden aggravated by HFD in 5XFAD, and protected against HFD-induced tau pathology in both WT and 5XFAD strains. At the mechanistic level, resveratrol inhibited the HFD-increased amyloidogenic processing of the amyloid precursor protein in both strains; it also restored abnormal high levels in the proteolytic activity of the ubiquitin-proteasome system induced by HFD, suggesting the presence of a compensatory mechanism to counteract the accumulation of aberrant proteins. Thus, our data suggest that resveratrol can correct the harmful effects of HFD in the brain and may be a potential therapeutic agent against obesity-related disorders and AD pathology.

Gallic Acid Ameliorates Angiotensin II-Induced Atrial Fibrillation by Inhibiting Immunoproteasome- Mediated PTEN Degradation in Mice

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia and is a major cause of stroke and heart failure. We and others have found that gallic acid (GA) plays a beneficial role in cardiac hypertrophic remodeling and hypertension. However, the effect of GA on angiotensin II (Ang II)-induced AF and atrial remodeling as well as the underlying mechanisms remain unknown. AF was induced in mice by Ang II infusion (2000 ng/kg/min) for 3 weeks. Blood pressure was measured using the tail-cuff method. Atrial volume was evaluated by echocardiography. Atrial remodeling was studied using hematoxylin and eosin, Masson's trichrome, and immunohistochemical staining. Atrial oxidative stress was assessed by dihydroethidium staining. The gene expression of fibrotic and inflammatory markers and protein levels of signaling mediators were measured by quantitative real-time PCR and western blot analysis. In mice, GA administration significantly attenuated Ang II-induced elevation of blood pressure, AF incidence and duration, atrial dilation, fibrosis, inflammation, and oxidative stress compared with the vehicle control. Furthermore, GA downregulated Ang II-induced activity and expression of immunoproteasome subunits (β2i and β5i), which reduced PTEN degradation and led to the inactivation of AKT1 and downstream signaling mediators. Importantly, blocking PTEN activity by VO-Ohpic markedly reversed the GA-mediated protective effects on Ang II-induced AF and atrial remodeling. Therefore, our results provide novel evidence that GA exerts a cardioprotective role by inhibiting immunoproteasome activity, which attenuates PTEN degradation and activation of downstream signaling, and may represent a promising candidate for treating hypertensive AF.

Cell Clearing Systems as Targets of Polyphenols in Viral Infections: Potential Implications for COVID-19 Pathogenesis

The novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has generated the ongoing coronavirus disease-2019 (COVID-19) pandemic, still with an uncertain outcome. Besides pneumonia and acute lung injury (ALI) or acute respiratory distress syndrome (ARDS), other features became evident in the context of COVID-19. These includes endothelial and coagulation dysfunction with disseminated intravascular coagulation (DIC), and multiple organ dysfunction syndrome (MODS), along with the occurrence of neurological alterations. The multi-system nature of such viral infection is a witness to the exploitation and impairment of ubiquitous subcellular and metabolic pathways for the sake of its life-cycle, ranging from host cell invasion, replication, transmission, up to a cytopathic effect and overt systemic inflammation. In this frame, alterations in cell-clearing systems of the host are emerging as a hallmark in the pathogenesis of various respiratory viruses, including SARS-CoV-2. Indeed, exploitation of the autophagy and proteasome pathways might contribute not only to the replication of the virus at the site of infection but also to the spreading of either mature virions or inflammatory mediators at both cellular and multisystem levels. In this frame, besides a pharmacological therapy, many researchers are wondering if some non-pharmacological substances might counteract or positively modulate the course of the infection. The pharmacological properties of natural compounds have gained increasing attention in the field of alternative and adjunct therapeutic approaches to several diseases. In particular, several naturally-occurring herbal compounds (mostly polyphenols) are reported to produce widespread antiviral, anti-inflammatory, and anti-oxidant effects while acting as autophagy and (immuno)-proteasome modulators. This article attempts to bridge the perturbation of autophagy and proteasome pathways with the potentially beneficial effects of specific phytochemicals and flavonoids in viral infections, with a focus on the multisystem SARS-CoV-2 infection.

Caloric restriction mimetics for the treatment of cardiovascular diseases

Caloric restriction mimetics (CRMs) are emerging as potential therapeutic agents for the treatment of cardiovascular diseases. CRMs include natural and synthetic compounds able to inhibit protein acetyltransferases, to interfere with acetyl coenzyme A biosynthesis, or to activate (de)acetyltransferase proteins. These modifications mimic the effects of caloric restriction, which is associated with the activation of autophagy. Previous evidence demonstrated the ability of CRMs to ameliorate cardiac function and reduce cardiac hypertrophy and maladaptive remodelling in animal models of ageing, mechanical overload, chronic myocardial ischaemia, and in genetic and metabolic cardiomyopathies. In addition, CRMs were found to reduce acute ischaemia-reperfusion injury. In many cases, these beneficial effects of CRMs appeared to be mediated by autophagy activation. In the present review, we discuss the relevant literature about the role of different CRMs in animal models of cardiac diseases, emphasizing the molecular mechanisms underlying the beneficial effects of these compounds and their potential future clinical application.

Merging the Multi-Target Effects of Phytochemicals in Neurodegeneration: From Oxidative Stress to Protein Aggregation and Inflammation

Wide experimental evidence has been provided in the last decade concerning the neuroprotective effects of phytochemicals in a variety of neurodegenerative disorders. Generally, the neuroprotective effects of bioactive compounds belonging to different phytochemical classes are attributed to antioxidant, anti-aggregation, and anti-inflammatory activity along with the restoration of mitochondrial homeostasis and targeting alterations of cell-clearing systems. Far from being independent, these multi-target effects represent interconnected events that are commonly implicated in the pathogenesis of most neurodegenerative diseases, independently of etiology, nosography, and the specific misfolded proteins being involved. Nonetheless, the increasing amount of data applying to a variety of neurodegenerative disorders joined with the multiple effects exerted by the wide variety of plant-derived neuroprotective agents may rather confound the reader. The present review is an attempt to provide a general guideline about the most relevant mechanisms through which naturally occurring agents may counteract neurodegeneration. With such an aim, we focus on some popular phytochemical classes and bioactive compounds as representative examples to design a sort of main highway aimed at deciphering the most relevant protective mechanisms which make phytochemicals potentially useful in counteracting neurodegeneration. In this frame, we emphasize the potential role of the cell-clearing machinery as a kernel in the antioxidant, anti-aggregation, anti-inflammatory, and mitochondrial protecting effects of phytochemicals.

Gemcitabine potentiates anti-tumor effect of resveratrol on pancreatic cancer via down-regulation of VEGF-B

PURPOSE

In our previous study, we discovered that resveratrol (RSV) had potential tumor-promoting effect on pancreatic cancer (PaCa) via up-regulation of VEGF-B. Therefore, we assumed that a pharmacological inhibitor of VEGF-B should potentiate the anti-tumor effect of RSV on PaCa.

METHODS

Real-time PCR and western blotting were used to examine VEGF-B mRNA and protein levels. Cell viability and cell apoptosis were assessed by CCK-8 assay and flow cytometry analysis, respectively. PaCa cell-bearing nude mice were used to evaluate the anti-cancer effects of single treatment or co-administration of RSV and gemcitabine (GEM).

RESULTS

We found that treatment with GEM alone dramatically decreased VEGF-B expression in comparison with control group, indicating that GEM is a potential pharmacological inhibitor of VEGF-B in PaCa. The co-administration of RSV and GEM significantly lowered expression of VEGF-B and increased phosphorylation level of GSK3β at Ser9 when compared to RSV alone treatment either in vitro or in vivo. Combination of RSV and GEM significantly increased cell death and apoptosis of PaCa cells in vitro and inhibited tumor growth in vivo in comparison with RSV or GEM alone treatment. Furthermore, we found that the anti-tumor effect in combination group was dramatically weakened after VEGF-B overexpressed in PaCa cells.

CONCLUSION

These results suggest that VEGF-B signaling pathway plays an important role in the development of PaCa and combination of GEM and RSV would be a promising modality for clinical PaCa therapy.

Has resveratrol a potential for mucopolysaccharidosis treatment?

Mucopolysaccharidoses (MPS) represent a devastating group of lysosomal storage diseases (LSD) affecting approximately 1 in 25,000 individuals, where degradation of glycosaminoglycans (GAG) by lysosomal enzymes is impaired due to mutations causing defects in one of GAG-degrading enzymes. The most commonly used therapy for MPS is enzyme replacement therapy, consisting of application of an active form of the missing enzyme. However, supply of the missing enzyme is not enough in case of MPS types whose symptoms are expressed in central nervous system (CNS), as enzyme does not cross the blood-brain barrier. Moreover, even though enzyme replacement therapy for non-neuronopathic MPS IVA type is approved, it has a limited impact on bone abnormalities, that are one of main symptoms in the disease. Therefore, research into alternative therapeutic approaches for these types of MPS is highly desirable. One such alternative strategy is accelerated degradation of GAG by induction of autophagy. Autophagy is a process of lysosomal degradation of macromolecules that become abnormal or unnecessary for cells. One of the latest discoveries is that GAGs can also be such molecules. Potential drug should also cross blood-brain barrier and be safe in long-term therapy. It seems that one of the polyphenols, resveratrol, can meet the requirements. The mechanism of its action in autophagy stimulation is pleiotropic. Therefore, in this review, we will briefly discuss potential of resveratrol treatment for mucopolysaccharidosis through autophagy stimulation based on research in diseases with similar outcome.

A Re-Appraisal of Pathogenic Mechanisms Bridging Wet and Dry Age-Related Macular Degeneration Leads to Reconsider a Role for Phytochemicals

Which pathogenic mechanisms underlie age-related macular degeneration (AMD)? Are they different for dry and wet variants, or do they stem from common metabolic alterations? Where shall we look for altered metabolism? Is it the inner choroid, or is it rather the choroid–retinal border? Again, since cell-clearing pathways are crucial to degrade altered proteins, which metabolic system is likely to be the most implicated, and in which cell type? Here we describe the unique clearing activity of the retinal pigment epithelium (RPE) and the relevant role of its autophagy machinery in removing altered debris, thus centering the RPE in the pathogenesis of AMD. The cell-clearing systems within the RPE may act as a kernel to regulate the redox homeostasis and the traffic of multiple proteins and organelles toward either the choroid border or the outer segments of photoreceptors. This is expected to cope with the polarity of various domains within RPE cells, with each one owning a specific metabolic activity. A defective clearance machinery may trigger unconventional solutions to avoid intracellular substrates’ accumulation through unconventional secretions. These components may be deposited between the RPE and Bruch’s membrane, thus generating the drusen, which remains the classic hallmark of AMD. These deposits may rather represent a witness of an abnormal RPE metabolism than a real pathogenic component. The empowerment of cell clearance, antioxidant, anti-inflammatory, and anti-angiogenic activity of the RPE by specific phytochemicals is here discussed.

Gallic Acid Attenuates Angiotensin II-Induced Hypertension and Vascular Dysfunction by Inhibiting the Degradation of Endothelial Nitric Oxide Synthase

Hypertension is a major cause of heart attack and stroke. Our recent study revealed that gallic acid (GA) exerts protective effects on pressure overload-induced cardiac hypertrophy and dysfunction. However, the role of GA in angiotensin II (Ang II)-induced hypertension and vascular remodeling remains unknown. C57BL/6J mice were subjected to saline and Ang II infusion. Systolic blood pressure was measured using a tail-cuff system. Vascular remodeling and oxidative stress were examined by histopathological staining. Vasodilatory function was evaluated in the aortic ring. Our findings revealed that GA administration significantly ameliorated Ang II-induced hypertension, vascular inflammation, and fibrosis. GA also abolished vascular endothelial dysfunction and oxidative stress in Ang II-infused aortas. Mechanistically, GA treatment attenuated Ang II-induced upregulation of the immunoproteasome catalytic subunits β2i and β5i leading to reduction of the trypsin-like and chymotrypsin-like activity of the proteasome, which suppressed degradation of endothelial nitric oxide synthase (eNOS) and reduction of nitric oxide (NO) levels. Furthermore, blocking eNOS activity by using a specific inhibitor (_L-N^G-nitroarginine methyl ester) markedly abolished the GA-mediated beneficial effect. This study identifies GA as a novel immunoproteasome inhibitor that may be a potential therapeutic agent for hypertension and vascular dysfunction.

Poricoic acid A activates AMPK to attenuate fibroblast activation and abnormal extracellular matrix remodelling in renal fibrosis

BACKGROUND

In chronic kidney disease, although fibrosis prevention is beneficial, few interventions are available that specifically target fibrogenesis. Poricoic acid A (PAA) isolated from Poria cocos exhibits anti-fibrotic effects in the kidney, however the underlying mechanisms remain obscure.

PURPOSE

We isolated PAA and investigated its effects and the underlying mechanisms in renal fibrosis.

STUDY DESIGN

Unilateral ureteral obstruction (UUO) and 5/6 nephrectomy (Nx) animal models and TGF-β1-induced renal fibroblasts (NRK-49F) were used to investigate the anti-fibrotic activity of PAA and its underlying mechanisms.

METHODS

Western blots, qRT-PCR, immunofluorescence staining, co-immunoprecipitation and molecular docking methods were used. Knock-down and knock-in of adenosine monophosphate-activated protein kinase (AMPK) in the UUO model and cultured NRK-49F cells were employed to verify the mechanisms of action of PAA.

RESULTS

PAA improved renal function and alleviated fibrosis by stimulating AMPK and inhibiting Smad3 specifically in Nx and UUO models. Reduced AMPK activity was associated with Smad3 induction, fibroblast activation, and the accumulation and aberrant remodelling of extracellular matrix (ECM) in human renal puncture samples and cultured NRK-49F cells. PAA stimulated AMPK activity and decreased fibrosis in a dose-dependent manner, thus showing that AMPK was essential for PAA to exert its anti-fibrotic effects. AMPK deficiency reduced the anti-fibrotic effects of PAA, while AMPK overexpression enhanced its effect.

CONCLUSION

PAA activated AMPK and further inhibited Smad3 specifically to suppress fibrosis by preventing aberrant ECM accumulation and remodelling and facilitating the deactivation of fibroblasts.

Resveratrol attenuates angiotensin II-induced cellular hypertrophy through the inhibition of CYP1B1 and the cardiotoxic mid-chain HETE metabolites

Several reports demonstrated the direct contribution of cytochrome P450 1B1 (CYP1B1) enzyme and its associated cardiotoxic mid-chain, hydroxyeicosatetraenoic acid (HETEs) metabolites in the development of cardiac hypertrophy. Resveratrol is commercially available polyphenol that exerts beneficial effects in wide array of cardiovascular diseases including cardiac hypertrophy, myocardial infarction and heart failure. Nevertheless, the underlying mechanisms responsible for these effects are not fully elucidated. Since resveratrol is a well-known CYP1B1 inhibitor, the purpose of this study is to test whether resveratrol attenuates angiotensin II (Ang II)-induced cellular hypertrophy through inhibition of CYP1B1/mid-chain HETEs mechanism. RL-14 and H9c2 cells were treated with vehicle or 10 μM Ang II in the absence and presence of 2, 10 or 50 μM resveratrol for 24 h. Thereafter, the level of mid-chain HETEs was determined using liquid chromatography–mass spectrometry (LC/MS). Hypertrophic markers and CYP1B1 gene expression and protein levels were measured using real-time PCR and Western blot analysis, respectively. Our results demonstrated that resveratrol, at concentrations of 10 and 50 μM, was able to attenuate Ang-II-induced cellular hypertrophy as evidenced by substantial inhibition of hypertrophic markers, β-myosin heavy chain (MHC)/α-MHC and atrial natriuretic peptide. Ang II significantly induced the protein expression of CYP1B1 and increased the metabolite formation rate of its associated mid-chain HETEs. Interestingly, the protective effect of resveratrol was associated with a significant decrease of CYP1B1 protein expression and mid-chain HETEs. Our results provided the first evidence that resveratrol protects against Ang II-induced cellular hypertrophy, at least in part, through CYP1B1/mid-chain HETEs-dependent mechanism.

Selective Inhibition of the Immunoproteasome β5i Prevents PTEN Degradation and Attenuates Cardiac Hypertrophy

Cardiac hypertrophy without appropriate treatment eventually progresses to heart failure. Our recent data demonstrated that the immunoproteasome subunit β5i promotes cardiac hypertrophy. However, whether β5i is a promising therapeutic target for treating hypertrophic remodeling remains unknown. Here, we investigated the effects of PR-957, a β5i-specific inhibitor, on angiotensin II (Ang II)-induced hypertrophic remodeling in the murine heart. The infusion of Ang II increased immunoproteasome chymotrypsin-like activity and β5i catalytic subunit expression in the heart, whereas PR-957 treatment fully blocked the enhanced immunoproteasome activity caused by Ang II. Moreover, the administration of PR-957 significantly suppressed Ang II-induced cardiac hypertrophy, fibrosis, and inflammation. Mechanistically, PR-957 treatment inhibited phosphatase and tensin homolog on chromosome ten (PTEN) degradation, thereby inhibiting multiple signals including AKT/mTOR, ERK1/2, transforming growth factor-β, and IKB/NF-kB. Furthermore, PTEN blocking by its specific inhibitor VO-OHpic markedly attenuated the inhibitory effect of PR-957 on Ang II-induced cardiac hypertrophy in mice. We conclude that PR-957 blocks PTEN degradation and activates its downstream mediators, thereby attenuating Ang II-induced cardiac hypertrophy. These findings highlight that PR-957 may be a potential therapeutic agent for Ang II-induced hypertrophic remodeling.

Deficiency of the Immunoproteasome LMP10 Subunit Attenuates Angiotensin II-Induced Cardiac Hypertrophic Remodeling via Autophagic Degradation of gp130 and IGF1R

Background/Aim

Hypertensive cardiac hypertrophy is the leading cause of cardiac remodeling and heart failure. We recently demonstrated that the immunoproteasome, an inducible form of the constitutive proteasome, plays a critical role in regulating cardiovascular diseases. However, the role of the immunoproteasome LMP10 (β2i) catalytic subunit in the regulation of angiotensin II (Ang II)-induced cardiac hypertrophic remodeling remains unclear.

Methods

Wild-type (WT) and LMP10 knockout (KO) mice were infused with Ang II 1,000 ng/kg/min for 2 weeks. Blood pressure was measured using a tail-cuff system. Cardiac function and hypertrophic remodeling were examined by echocardiography and histological staining. The expression levels of genes and proteins were examined with quantitative real-time PCR and immunoblotting analysis, respectively.

Results

LMP10 mRNA and protein expression was significantly increased in Ang II-stimulated hearts and primary cardiomyocytes. Moreover, Ang II infusion for 2 weeks increased systolic blood pressure, abnormal cardiac function, hypertrophy, fibrosis, and inflammation in WT mice, which were significantly reversed in KO mice. Moreover, a marked reduction in the protein levels of insulin growth factor-1 receptor (IGF1R), glycoprotein 130 (gp130), and phosphorylated AKT, mTOR, STAT3, and ERK1/2 and an increase in the LC3II/I ratio were also observed in LMP10 KO mice compared with WT mice after Ang II infusion. In vitro culture experiments confirmed that LMP10 knockdown activated autophagy and increased IGF1R and gp130 degradation, leading to the inhibition of cardiomyocyte hypertrophy. However, inhibiting autophagy with chloroquine reversed this effect.

Conclusion

The results of this study indicate that LMP10 KO attenuates Ang II-induced cardiac hypertrophic remodeling via the autophagy-dependent degradation of IGF1R and gp130, and suggests that LMP10 may be a novel therapeutic target for hypertrophic heart diseases.

Resveratrol in Cancer Patients: From Bench to Bedside

Resveratrol (3,5,4'-trihydroxystilbene) is a natural phytoalexin that accumulates in several vegetables and fruits like nuts, grapes, apples, red fruits, black olives, capers, red rice as well as red wines. Being both an extremely reactive molecule and capable to interact with cytoplasmic and nuclear proteins in human cells, resveratrol has been studied over the years as complementary and alternative medicine (CAM) for the therapy of cancer, metabolic and cardiovascular diseases like myocardial ischemia, myocarditis, cardiac hypertrophy and heart failure. This review will describe the main biological targets, cardiovascular outcomes, physico-chemical and pharmacokinetic properties of resveratrol in preclinical and clinical models implementing its potential use in cancer patients.