Polydatin prevents hypertrophy in phenylephrine induced neonatal mouse cardiomyocytes and pressure-overload mouse models

Role of Cardiomyocyte-Derived Exosomal MicroRNA-146a-5p in Macrophage Polarization and Activation

Myocardial infarction arises from an excessive or prolonged inflammatory response, leading to ventricular remodeling or impaired cardiac function. Macrophages exhibit different polarization types associated with inflammation both at steady state and after myocardial infarction. Exosomal miR-146a-5p has been identified as an important molecule in the cardiovascular field in recent years. However, the effect of cardiomyocyte-derived exosomal miR-146a-5p on macrophages has not yet been elucidated. Initially, we found that exosomes with low expression of miR-146a-5p derived from myocardial infarction tissues modulated macrophage polarization. To determine whether cardiomyocyte-derived exosomal miR-146a-5p mediated macrophage polarization, we treated macrophages with exosomes rich in miR-146a-5p collected from neonatal mouse cardiomyocytes. The effects of exosomal miR-146a-5p on macrophage polarization were measured using RT-qPCR, transwell assays, and western blotting. The results showed that the increased expression of miR-146a-5p promoted M1 macrophage polarization, inhibited M2 macrophage polarization, and increased the expression of VEGFA. However, the decreased expression of exosomalmiR-146a-5p showed the opposite trends. Interestingly, in contrast to treatment with the solitary miR-146a-5p mimic, exosomal miR-146a-5p derived from neonatal mouse cardiomyocytes reduced TNFα and iNOS expression. In addition, when macrophages were activated by the miR-146a-5p mimic or exosomal miR-146a-5p, the expression of TNF receptor-associated factor 6 (TRAF6), a target gene of miR-146a-5p, was reduced significantly. Taken together, these findings indicate that exosomal miR-146a-5p derived from cardiomyocytes could stimulate M1 macrophage polarization to induce an inflammatory reaction, while targeting TRAF6, exerting an anti-inflammatory effect. Exosomal miR-146a-5p plays important roles in macrophages, illuminating a novel potential therapeutic target in myocardial infarction.

Mechanisms and Efficacy of Traditional Chinese Medicine in Heart Failure

Heart failure (HF) is one of the main public health problems at present. Although some breakthroughs have been made in the treatment of HF, the mortality rate remains very high. However, we should also pay attention to improving the quality of life of patients with HF. Traditional Chinese medicine (TCM) has a long history of being used to treat HF. To demonstrate the clinical effects and mechanisms of TCM, we searched published clinical trial studies and basic studies. The search results showed that adjuvant therapy with TCM might benefit patients with HF, and its mechanism may be related to microvascular circulation, myocardial energy metabolism, oxidative stress, and inflammation.

Old dog, new tricks: Polydatin as a multitarget agent for current diseases

Polydatin (PD) is a natural single-crystal product that is primarily extracted from the traditional plant Polygonum cuspidatum Sieb. et Zucc. Early research showed that PD exhibited a variety of biological activities. PD has attracted increasing research interest since 2014, but no review comprehensively summarized the new findings. A great gap between its biological activities and drug development remains. It is necessary to summarize new findings on the pharmacological effects of PD on current diseases. We propose that PD will most likely be used in cardiac and cerebral ischaemia/reperfusion-related diseases and atherosclerosis in the future. The present work classified these new findings according to diseases and summarized the main effects of PD via specific mechanisms of action. In summary, we found that PD played a therapeutic role in a variety of diseases, primarily via five mechanisms: antioxidative effects, antiinflammatory effects, regulation of autophagy and apoptosis, maintenance of mitochondrial function, and lipid regulation.

A Pivotal Role of the Nrf2 Signaling Pathway in Spinal Cord Injury: A Prospective Therapeutics Study

The nuclear erythroid 2-related factor 2 (Nrf2) signaling pathway has a main role against oxidative stress and inflammation. Spinal Cord Injury (SCI) leads to the high secretion of inflammatory cytokines and reactive oxygen species, which disturbs nervous system function and regeneration. Several studies have indicated that the activation of the Nrf2 signaling pathway may be effective against inflammation after SCI. The experimental studies have indicated that many chemical and natural agents act as Nrf2 inducer, which inhibits the SCI progression. Thus, the finding of novel Nrf2- inducer anti-inflammatory agents may be a valuable approach in drug discovery. In the present review, we discussed the Nrf2 signal pathway and crosstalk with the NF-κB pathway and also the impact of this pathway on inflammation in animal models of SCI. Furthermore, we discussed the regulation of Nrf2 by several phytochemicals and drugs, as well as their effects on the SCI inhibition. Therefore, the current study presented a new hypothesis of the development of anti-inflammatory agents that mediate the Nrf2 signaling pathway for treating the SCI outcomes.

Metabolic Interventions to Prevent Hypertrophy-Induced Alterations in Contractile Properties In Vitro

(1) Background: The exact mechanism(s) underlying pathological changes in a heart in transition to hypertrophy and failure are not yet fully understood. However, alterations in cardiac energy metabolism seem to be an important contributor. We characterized an in vitro model of adrenergic stimulation-induced cardiac hypertrophy for studying metabolic, structural, and functional changes over time. Accordingly, we investigated whether metabolic interventions prevent cardiac structural and functional changes; (2) Methods: Primary rat cardiomyocytes were treated with phenylephrine (PE) for 16 h, 24 h, or 48 h, whereafter hypertrophic marker expression, protein synthesis rate, glucose uptake, and contractile function were assessed; (3) Results: 24 h PE treatment increased expression of hypertrophic markers, phosphorylation of hypertrophy-related signaling kinases, protein synthesis, and glucose uptake. Importantly, the increased glucose uptake preceded structural and functional changes, suggesting a causal role for metabolism in the onset of PE-induced hypertrophy. Indeed, PE treatment in the presence of a PAN-Akt inhibitor or of a GLUT4 inhibitor dipyridamole prevented PE-induced increases in cellular glucose uptake and ameliorated PE-induced contractile alterations; (4) Conclusions: Pharmacological interventions, forcing substrate metabolism away from glucose utilization, improved contractile properties in PE-treated cardiomyocytes, suggesting that targeting glucose uptake, independent from protein synthesis, forms a promising strategy to prevent hypertrophy and hypertrophy-induced cardiac dysfunction.

Effect of Polydatin on Neurological Function and the Nrf2 Pathway during Intracerebral Hemorrhage

This study investigates the effect of polydatin on the neurological function of cerebral hemorrhage rats and on the Nrf2 pathway of the endogenous antioxidant system in tissues around cerebral hematoma. Further, the study also aims to provide solid insights for clinical diagnosis and treatment. A total of 54 SPF grade male Wistar rats were divided into three groups: the sham group, model group, and polydatin group. Various parameters such as neurological deficit score, brain water content, pathological morphology, oxidative stress index content, Nrf2, NQO1, HO-1 mRNA expression, and the expression of HO-1, Nrf2, and kelch-like epichlorohydrin-1 (Keap1) protein were observed. Compared with the sham group, the mNSS score and brain water content of rats in the model group increased significantly after dosing (P < 0.05). When compared with the model group, the mNSS score and brain water content of rats in the polydatin group decreased significantly after dosing (P < 0.05). Compared with the other group, the serum NSE content of rats in the polydatin group decreased (P < 0.05). An increase was observed in the contents of NO, SOD, MDA, GSSG, and GSH in the brain tissue of rats in the model group when compared with the sham group. Compared with the model group, the contents of NO and MDA in the brain tissue of rats in the polydatin group decreased, while the contents of SOD, GSSG, and GSH increased (P < 0.05). The relative expressions of Nrf2, NQO1, and HO-1mRNA in the brain tissue of rats in the polydatin group was relatively high compared with both groups (P < 0.05). Polydatin can improve the neurological function of ICH rats and reduce the oxidative stress response by regulating the Nrf2-ARE pathway and downstream gene expression. This study preliminarily discussed the relevant mechanism of polydatin in the treatment of ICH rats, thus providing a theoretical reference to ICH treatment.

Polydatin improves osteogenic differentiation of human bone mesenchymal stem cells by stimulating TAZ expression via BMP2-Wnt/β-catenin signaling pathway

OBJECTIVES

Polydatin (PD), extracted from Polygonum cuspidatum, has shown potential therapeutic applications due to its antiosteoporotic and anti-inflammatory activities. Our previous study suggested that PD promotes the osteogenesis of human bone marrow stromal cells (hBMSCs) via the BMP2-Wnt/β-catenin pathway. The aim of our present study was to further explore the role of PD-mediated regulation of Tafazzin (TAZ), a transcriptional coactivator with a PDZ-binding motif, in osteogenesis.

MATERIALS AND METHODS

hBMSCs were isolated and treated with PD at various concentrations. Alizarin red staining and RT-qPCR were performed to identify calcium complex deposition in hBMSCs as well as the expression of specific osteoblast-related markers, respectively, in each group. Next, TAZ-silenced hBMSCs were generated by lentivirus-produced TAZ shRNA. After treatment with PD, the osteogenic abilities of the TAZ-silenced and control hBMSCs were estimated by ALP activity assay, and expression of the TAZ protein was detected by Western blot analysis and immunofluorescence staining. In vitro, an ovariectomized (OVX) mouse model was established and used to evaluate the effect of PD on bone destruction by micro-CT, immunohistochemistry, and ELISA.

RESULTS

In vitro, 30 μM PD significantly improved the proliferation and calcium deposition of hBMSCs and markedly stimulated the expression of the mRNAs RUNX2, Osteopontin, DLX5, β-catenin, TAZ, and Osteocalcin (OCN). Osteogenic differentiation induced by PD was blocked by lentivirus-mediated TAZ shRNA. Furthermore, Noggin (a regulator of bone morphogenic protein 2 (BMP2)) and DKK1 (an inhibitor of the Wnt/β-catenin pathway) were found to inhibit the increase in TAZ expression induced by PD. In vivo, PD prevented estrogen deficiency-induced bone loss in the OVX mouse model.

CONCLUSION

Taken together, our findings suggest that PD improved the osteogenic differentiation of hBMSCs and maintained the bone matrix in the OVX mouse model through the activation of TAZ, a potential target gene of the BMP2-Wnt/β-catenin pathway.

Inhibition of Rho-associated protein kinase improves the survival of human induced pluripotent stem cell-derived cardiomyocytes after dissociation

Heart disease remains the leading cause of morbidity and mortality worldwide. Induced pluripotent stem cells (iPSCs) have the ability to differentiate into cardiomyocytes (CMs), rendering this cell type to be a promising pre-cursor of cardiomyocytes for cell-based cardiac regeneration. Obtaining CMs with a high yield and purity coupled with improved subsequent survival could prove to be invaluable for the future cell replacement therapeutic strategies. Rho-associated protein kinase (ROCK) is involved in a wide range of fundamental cellular functions and serves significant roles in cardiac physiology. In the present study, human (h)iPSC-CMs were generated from iPSCs by including glycogen synthase kinase 3β and Wnt inhibitors in the basal culture media. The possible effect of Y27632, a ROCK inhibitor, on hiPSC-CMs was then investigated. hiPSC-CMs of high purity were harvested with >96% of cells expressing cardiac troponin T. Additionally, treatment with 10 µM Y27632 significantly improved the viability of dissociated hiPSC-CMs. The effects of ROCK inhibitors Y27632 and fasudil, on the proliferation and apoptosis of hiPSC-CMs were also examined. Treatment with ROCK inhibitors markedly enhanced hiPSC-CM proliferation, by up to 2.5-fold, whilst Y27632 treatment reduced apoptosis in hiPSC-derived CMs under serum starvation and suspension by suppressing the expression of caspase-3. Taken together, data from the present study indicated that ROCK kinase inhibitors effectively improved the cultural system of hiPSC-derived CMs.

Polydatin attenuates spinal cord injury in rats by inhibiting oxidative stress and microglia apoptosis via Nrf2/HO-1 pathway

AIMS

Spinal cord injury (SCI) is one of the most devastating central lesions, resulting in serious locomotor deficit. Polydatin is a glucoside of resveratrol with proven anti-cardiovascular, anti-inflammatory and anti-oxidative properties. The main purpose of this study was to investigate whether polydatin could alleviate SCI in rats and explore the underlying mechanisms.

MATERIALS AND METHODS

SCI rats induced by a weight-drop device were treated with intraperitoneal injection of 20 or 40 mg/kg polydatin. Then the locomotor function of SCI rats was evaluated by the Basso, Beattie and Bresnahan locomotor rating scale, spinal cord edema was measured by the wet/dry weight method, oxidative stress markers were detected by commercial kits and cell apoptosis status was measured by TUNEL staining. In addition, reactive oxygen species (ROS) generation, lactate dehydrogenase (LDH) production and apoptosis status were detected in murine microglia BV2 cells treated with 100 ng/ml lipopolysaccharides (LPS) and 4.0 μM polydatin. The expression of apoptosis-related proteins involved in nuclear factor E2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway was measured by western blot.

KEY FINDINGS

Our data showed that polydatin treatment improved locomotor performance of SCI rats, as well as reduced oxidative stress and inhibited apoptosis by enhancing Nrf2/HO-1 signaling. In addition, polydatin was found to up-regulate Nrf2 activity and the inhibitory effects of polydatin on oxidative stress and apoptosis in LPS-stimulated BV2 microglia was neutralized by silencing Nrf2 using specific siRNA.

SIGNIFICANCE

We demonstrate that polydatin may protect the spinal cord from SCI by suppression of oxidative stress and apoptosis via improving Nrf2/HO-1 signaling in microglia.

Effects of Polyphenols on Oxidative Stress-Mediated Injury in Cardiomyocytes

Cardiovascular diseases are the main cause of mortality and morbidity in the world. Hypertension, ischemia/reperfusion, diabetes and anti-cancer drugs contribute to heart failure through oxidative and nitrosative stresses which cause cardiomyocytes nuclear and mitochondrial DNA damage, denaturation of intracellular proteins, lipid peroxidation and inflammation. Oxidative or nitrosative stress-mediated injury lead to cardiomyocytes apoptosis or necrosis. The reactive oxygen (ROS) and nitrogen species (RNS) concentration is dependent on their production and on the expression and activity of anti-oxidant enzymes. Polyphenols are a large group of natural compounds ubiquitously expressed in plants, and epidemiological studies have shown associations between a diet rich in polyphenols and the prevention of various ROS-mediated human diseases. Polyphenols reduce cardiomyocytes damage, necrosis, apoptosis, infarct size and improve cardiac function by decreasing oxidative stress-induced production of ROS or RNS. These effects are achieved by the ability of polyphenols to modulate the expression and activity of anti-oxidant enzymes and several signaling pathways involved in cells survival. This report reviews current knowledge on the potential anti-oxidative effects of polyphenols to control the cardiotoxicity induced by ROS and RNS stress.

Puerarin attenuates myocardial hypoxia/reoxygenation injury by inhibiting autophagy via the Akt signaling pathway

Puerarin (Pur), which is the major bioactive ingredient extracted from the root of Pueraria lobata (Willd.) Ohwi, has been demonstrated to relieve myocardial ischemia/reperfusion (I/R) injury. Macroautophagy, or autophagy, is an evolutionarily conserved cellular catabolic mechanism that is involved in myocardial I/R injury. The present study evaluated the involvement of autophagy in the protective mechanisms of Pur during myocardial hypoxia/reoxygenation (H/R). The results revealed that Pur and 3‑methyladenine pretreatment exerted a cardioprotective effect against H/R‑induced cell viability loss. Pur also decreased the ratio of light chain 3 (LC3) ‑II/LC3‑I and the degradation of p62 during H/R, which was accompanied by an increased level of phosphorylated‑protein kinase B (Akt). These findings suggested that autophagy during myocardial H/R was inhibited by Pur, and this was further confirmed by the results of transmission electron microscopy and adenovirus‑monomeric red fluorescent protein‑green fluorescent protein‑light chain 3 transfection. Furthermore, Pur inhibited the increased levels of autophagy induced by rapamycin, and the autophagy‑inhibiting effects of Pur during myocardial H/R were abolished by the Akt signaling inhibitor API‑2. Collectively, these data indicate that Pur pretreatment may attenuate myocardial H/R injury by inhibiting autophagy via the Akt signaling pathway.

trans-Polydatin protects the mouse heart against ischemia/reperfusion injury via inhibition of the renin–angiotensin system (RAS) and Rho kinase (ROCK) activity

Background: Recent studies highlighted the protective benefits of a Chinese herb extract frompolygonum cuspidatum,trans-polydatin, on cardiac disease.

Resveratrol

Cardiovascular disease (CVD) is the leading cause of death in both men and women and has largely been attributed to genetic makeup and lifestyle factors. However, genetic regulation does not fully explain the pathophysiology. Recently, epigenetic regulation, the regulation of the genetic code by modifications that affect the transcription and translation of target genes, has been shown to be important. Silent information regulator-2 proteins or sirtuins are an epigenetic regulator family of class III histone deacetylases (HDACs), unique in their dependency on coenzyme NAD+, that are postulated to mediate the beneficial effects of calorie restriction, thus promoting longevity by reducing the incidence of chronic diseases such as cancer, diabetes, and CVD. Emerging evidence shows that SIRT1 is ubiquitously expressed throughout the body. Resveratrol, a plant polyphenol, has cardioprotective effects and its mechanism of action is attributed to regulation of SIRT1. Incoproation of resveratrol into the diet may be a powerful therapeutic option for the prevention and treatment of CVD.

Polydatin post-treatment alleviates myocardial ischaemia/reperfusion injury by promoting autophagic flux

The present paper provides evidence that polydatin (PD) post-treatment alleviates myocardial ischaemia/reperfusion (I/R) injury by promoting autophagic flux to clear damaged mitochondria to reduce reactive oxygen species (ROS) and cell death.

Polydatin possesses notable anti‑osteoporotic activity via regulation of OPG, RANKL and β‑catenin

This study was designed to investigate the anti‑osteoporotic activity of polydatin and its possible underlying mechanism. Osteoporosis was induced in mice by ovariectomy (OVX) and the mice were divided into 5 groups: An OVX only group, polydatin groups (10, 20 and 40 mg/kg) and a sham group (n=10/group). After 12 weeks of treatment, body weight, uterine index and the dry weight of thigh‑bones were recorded. In addition, the serum calcium, serum phosphorus, alkaline phosphatase (ALP) and osteoprotegerin (OPG) levels were also determined. Western blot analysis was then conducted to investigate the possible mechanism underlying the effect of polydatin via determining the expression of OPG, receptor activators of nuclear factor‑κB ligand (RANKL) and β‑catenin in the ST2 cell line. The results indicated that intraperitoneal injection of polydatin (10, 20 and 40 mg/kg/day) decreased body weight, and increased uterine index and dry weights of thigh‑bones of ovariectomized mice (P<0.05), and polydatin also significantly increased the serum calcium, phosphorus, ALP and OPG of ovariectomized mice (P<0.05). Results of western blot analysis showed that polydatin upregulated the ratio of OPG/RANKL (P<0.05) and β‑catenin protein in ST2 cells. In conclusion, the results demonstrated that polydatin exhibits anti‑osteoporotic activity via regulating osteoprotegerin, RANKL and β‑catenin.

Polydatin-induced cell apoptosis and cell cycle arrest are potentiated by Janus kinase 2 inhibition in leukemia cells

Polydatin (PD), a natural precursor of resveratrol, has a variety of biological activities, including anti‑tumor effects. However, the underlying molecular mechanisms of the anti-cancer activity of PD has not been fully elucidated. The present study demonstrated that PD significantly inhibited the proliferation of the MOLT-4 leukemia cell line in a dose‑ and time-dependent manner by using Cell Counting Kit‑8 assay. PD also dose-dependently increased the apoptotic rate and caused cell cycle arrest in S phase in MOLT‑4 cells, as revealed by flow cytometry. In addition, PD dose-dependently decreased the mitochondrial membrane potential and led to the generation of reactive oxygen species in MOLT-4 cells. Western blot analysis revealed that the expression of anti‑apoptotic protein B-cell lymphoma 2 (Bcl-2) was decreased, whereas that of pro‑apoptotic protein Bcl‑2‑associated X was increased by PD. Furthermore, the expression of two cell cycle regulatory proteins, cyclin D1 and cyclin B1, was suppressed by PD. Of note, the pro‑apoptotic and cell cycle‑inhibitory effects of PD were potentiated by Janus kinase 2 (JAK2) inhibition. In conclusion, the results of the present study strongly suggested that PD is a promising therapeutic compound for the treatment of leukemia, particularly in combination with JAK inhibitors.

Polydatin Protects Bone Marrow Stem Cells against Oxidative Injury: Involvement of Nrf 2/ARE Pathways

Polydatin, a glucoside of resveratrol, has been reported to possess potent antioxidative effects. In the present study, we aimed to investigate the effects of polydatin in bone marrow-derived mesenchymal stem cells (BMSCs) death caused by hydrogen peroxide (H₂O₂), imitating the microenvironment surrounding transplanted cells in the injured spinal cord in vitro. In our study, MTT results showed that polydatin effectively prevented the decrease of cell viability caused by H₂O₂. Hochest 33258, Annexin V-PI, and Western blot assay showed H₂O₂-induced apoptosis in BMSCs, which was attenuated by polydatin. Further studies indicated that polydatin significantly protects BMSCs against apoptosis due to its antioxidative effects and the regulation of Nrf 2/ARE pathway. Taken together, our results indicate that polydatin could be used in combination with BMSCs for the treatment of spinal cord injury by improving the cell survival and oxidative stress microenvironments.

KMUP-1 Attenuates Endothelin-1-Induced Cardiomyocyte Hypertrophy through Activation of Heme Oxygenase-1 and Suppression of the Akt/GSK-3β, Calcineurin/NFATc4 and RhoA/ROCK Pathways

The signaling cascades of the mitogen activated protein kinase (MAPK) family, calcineurin/NFATc4, and PI3K/Akt/GSK3, are believed to participate in endothelin-1 (ET-1)-induced cardiac hypertrophy. The aim of this study was to investigate whether KMUP-1, a synthetic xanthine-based derivative, prevents cardiomyocyte hypertrophy induced by ET-1 and to elucidate the underlying mechanisms. We found that in H9c2 cardiomyocytes, stimulation with ET-1 (100 nM) for 4 days induced cell hypertrophy and enhanced expressions of hypertrophic markers, including atrial natriuretic peptide and brain natriuretic peptide, which were all inhibited by KMUP-1 in a dose-dependent manner. In addition, KMUP-1 prevented ET-1-induced intracellular reactive oxygen species generation determined by the DCFH-DA assay in cardiomyocytes. KMUP-1 also attenuated phosphorylation of ERK1/2 and Akt/GSK-3β, and activation of calcineurin/NFATc4 and RhoA/ROCK pathways induced by ET-1. Furthermore, we found that the expression of heme oxygenase-1 (HO-1), a stress-response enzyme implicated in cardio-protection, was up-regulated by KMUP-1. Finally, KMUP-1 attenuated ET-1-stimulated activator protein-1 DNA binding activity. In conclusion, KMUP-1 attenuates cardiomyocyte hypertrophy induced by ET-1 through inhibiting ERK1/2, calcineurin/NFATc4 and RhoA/ROCK pathways, with associated cardioprotective effects via HO-1 activation. Therefore, KMUP-1 may have a role in pharmacological therapy of cardiac hypertrophy.