Salidroside suppressing LPS-induced myocardial injury by inhibiting ROS-mediated PI3K/Akt/mTOR pathway in vitro and in vivo

Bacterial Quorum-Sensing Signal DSF Inhibits LPS-Induced Inflammations by Suppressing Toll-like Receptor Signaling and Preventing Lysosome-Mediated Apoptosis in Zebrafish

Bacteria and their eukaryotic hosts have co-evolved for millions of years, and the former can intercept eukaryotic signaling systems for the successful colonization of the host. The diffusible signal factor (DSF) family represents a type of quorum-sensing signals found in diverse Gram-negative bacterial pathogens. Recent evidence shows that the DSF is involved in interkingdom communications between the bacterial pathogen and the host plant. In this study, we explored the anti-inflammatory effect of the DSF and its underlying molecular mechanism in a zebrafish model. We found that the DSF treatment exhibited a strong protective effect on the inflammatory response of zebrafish induced by lipopolysaccharide (LPS). In the LPS-induced inflammation zebrafish model, the DSF could significantly ameliorate the intestinal pathological injury, reduce abnormal migration and the aggregation of inflammatory cells, inhibit the excessive production of inflammatory mediator reactive oxygen species (ROS) content, and prevent apoptosis. Through an RNA-Seq analysis, a total of 938 differentially expressed genes (DEGs) was screened between LPS and LPS + DSF treatment zebrafish embryos. A further bioinformatics analysis and validation revealed that the DSF might inhibit the LPS-induced zebrafish inflammatory response by preventing the activation of signaling in the Toll-like receptor pathway, attenuating the expression of pro-inflammatory cytokines and chemokines, and regulating the activation of the caspase cascade through restoring the expression of lysosomal cathepsins and apoptosis signaling. This study, for the first time, demonstrates the anti-inflammatory role and a potential pharmaceutical application of the bacterial signal DSF. These findings also suggest that the interkingdom communication between DSF-producing bacteria and zebrafish might occur in nature.

Salidroside Ameliorates Ischemia-Induced Neuronal Injury through AMPK Dependent and Independent Pathways to Maintain Mitochondrial Quality Control

Salidroside, an active ingredient in Rhodiola rosea, has potent protective activity against cerebral ischemia. However, the mechanisms underlying its pharmacological actions are poorly understood. In this study, we employed a mouse middle cerebral artery occlusion (MCAO) and cellular oxygen and glucose deprivation (OGD) models to test the hypothesis that salidroside may restore mitochondrial quality control in neurons by modulating the relevant signaling. The results indicated that salidroside mitigated almost 40% the ischemia-induced brain infarct volumes in mice and the OGD-decreased viability of neurons to ameliorate the mitochondrial functions. Furthermore, salidroside treatment alleviated the OGD- or ischemia-induced imbalance of mitochondrial fission and fusion, mitophagy and promoted mitochondrial biogenesis in neurons by attenuating the AMPK activity. Moreover, salidroside alleviated 50% the OGD-promoted mitochondrial calcium fluorescence intensity and 5% mitochondria-associated membrane (MAM) area by down-regulating GRP75 expression independent of the AMPK signaling. Finally, similar findings were achieved in primary mouse neurons. Collectively, these data indicate that salidroside effectively restores the mitochondria dynamics, facilitates mitochondrial biogenesis by attenuating the AMPK signaling, and maintains calcium homeostasis in neurons independent of the AMPK activity.

FOXO3a Alleviates the Inflammation and Oxidative Stress via Regulating TGF-β and HO-1 in Ankylosing Spondylitis

This study aimed to investigate whether Forkhead box O3a (FOXO3a) modulates inflammation and oxidative stress in ankylosing spondylitis (AS). We applied bioinformatics analysis, quantitative real-time polymerase chain reaction, immunoblotting, enzyme linked immunosorbent assay, chromatin immunoprecipitation, and dual-luciferase reporter assay. Gene overexpression and knockdown of FOXO3a were conducted via lentivirus and small interfering RNA, respectively. Downregulated FOXO3a expression was first confirmed in AS patients. Interleukin-8 (IL-8) and IL-17A were highly expressed and negatively related with FOXO3a in AS. Total antioxidant capacity (T-AOC) were markedly decreased and positively associated with FOXO3a in AS. Overexpression of FOXO3a inhibited the secretion of inflammatory cytokines and promoted the production of antioxidant enzymes in Jurkat cells. Transforming growth factor-β (TGF-β) and heme oxygenase 1 (HO-1), which had binding sites to FOXO3a based on bioinformatics analysis, were abnormally expressed and positively related with FOXO3a. Accordingly, FOXO3a obviously elevated the protein and transcription levels of TGF-β and HO-1 in Jurkat cells. The above results were verified by silencing FOXO3a. Moreover, FOXO3a directly interacted with and promoted the transcription of TGF-β and HO-1. In summary, the modulation of cellular inflammation and oxidative stress via FOXO3a-mediated TGF-β and HO-1 activation is partly involved in the pathogenesis of AS.

Hydroxytyrosol Alleviated Hypoxia-Mediated PC12 Cell Damage through Activating PI3K/AKT/mTOR-HIF-1α Signaling

Background

Hypoxia exerts pressure on cells and organisms, and this pressure can occur under both pathological and nonpathological conditions. There are many reports confirmed that hydroxytyrosol has good in vitro antioxidant activity, while the research about hydroxytyrosol on hypoxia-mediated cell damage is still unclear.

Purpose

The aim of this study was to investigate the effect and mechanism of hydroxytyrosol on hypoxia-mediated cell damage.

Methods

We studied the effects of hydroxytyrosol on the content of reactive oxygen species, the change of antioxidant enzymes activity of SOD, CAT, and GSH-Px and the content of oxidation products MDA and GSH, and the changes of cell membrane potential and effect on PI3K/AKT/mTOR-HIF-1α signaling pathway under hypoxia-mediated PC12 cell.

Results

PC12 cell treated with hydroxytyrosol abated the cell apoptosis and alleviated the oxidative stress through scavenging of reactive oxygen species, improving the enzyme activity and changing the content of oxidation products and alleviating mitochondria damage. Western blotting confirmed that the mechanism maybe related to the PI3K/AKT/mTOR-HIF-1α signaling pathway. The inhibition experiment confirmed that hydroxytyrosol takes part in the expression of protein PI3K and p-mTOR.

Conclusion

Hydroxytyrosol reduced the oxidative stress and resisted the inhibition of PI3K/AKT/mTOR-HIF-1α signaling pathway caused by hypoxia, improved cell apoptosis, and ameliorated the antihypoxia ability of PC12 cells under hypoxia.

Salidroside attenuates myocardial ischemia/reperfusion injury via AMPK-induced suppression of endoplasmic reticulum stress and mitochondrial fission

Ischemic heart disease (IHD) is the primary cause of death worldwide. Salidroside (Sal), the major active compound derived from Rhodiola rosea, is believed to have cardioprotective effects. AMP-activated protein kinase (AMPK), is a pivotal AMP-activated protein kinase in energy metabolism. Whether Sal plays an anti-endoplasmic reticulum stress/mitochondrial fission role through AMPK remains elusive. In this study, we established a myocardial ischemia/reperfusion (I/R) rat model. Rat hearts exposed to Sal with or without compound C were then subjected to I/R. Further, H9c2 cardiomyocytes were subjected to simulated ischemia/reperfusion (SIR) by hypoxia-reoxygenation. The rats and cardiomyocytes were pretreated with Sal, followed by Compound C and AMPK-siRNA to block AMPK activity. We found that Sal significantly ameliorated cardiac function, mitigated infarct size and serum content of lactate dehydrogenase and creatine kinase, improved mitochondrial function, and reduced mitochondrial fission and apoptosis. Furthermore, in cultured H9c2 cardiomyocytes, Sal increased the cell viability and inhibited SIR-induced myocardial apoptosis and mitochondrial fission. Furthermore, the translocation of Drp1 from the cytoplasm to mitochondria induced by salidroside was confirmed both in vivo and in vitro. However, the use of Compound C or AMPK siRNA to block AMPK activity leads to blockade of the protective effects of Sal. In summary, protects against myocardial I/R by activating the AMPK signaling pathway, inhibiting ER stress, and reducing mitochondrial fission and apoptosis.

Chrysophanol exerts a protective effect against sepsis-induced acute myocardial injury through modulating the microRNA-27b-3p/Peroxisomal proliferating-activated receptor gamma axis

Sepsis, a leading contributor to the death of inpatients, results in severe organ dysfunction as complications. The heart is one of the major organs attacked by sepsis, and the effective control of the inflammatory cascade reaction in sepsis is of great significance in alleviating sepsis-associated acute myocardial injury (S-AMI). Chrysophanol, a natural anthraquinone, has been discovered to carry anti-inflammatory effects. The aim of this paper is to probe the impact of Chrysophanol on S-AMI. An S-AMI model was engineered in rats via CLP. Pathological alterations in the myocardial tissues of rats were monitored. qRT-PCR, ELISA, and western blot measured the profiles of miR-27b-3p, Peroxisomal proliferating-activated receptor gamma (PPARG), inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-8), and inflammatory response proteins (NF-κB-p65, MAPK-p38, JNK1/2). Besides, miR-27b-3p mimics were transfected into cardiomyocytes, and the proliferation and apoptosis of cardiomyocytes were examined through MTT and flow cytometry. As evidenced by the experimental outcomes, chrysophanol suppressed sepsis-mediated acute myocardial injury and LPS-mediated apoptosis in myocardial cells and lessened the release of pro-inflammatory cytokines and inflammatory response proteins. Moreover, chrysophanol cramped miR-27b-3p expression and heightened PPARG expression. miR-27b-3p targeted PPARG and restrained its expression. On the other hand, the PPARG agonist (RGZ) partially eliminated the apoptosis and pro-inflammatory responses of myocardial cells elicited by LPS. Therefore, this study revealed that Chrysophanol guarded against sepsis-mediated acute myocardial injury through dampening inflammation and apoptosis via the miR-27b-3p-PPARG axis, adding to the references for treating sepsis-AMI.

Methylsulfonylmethane relieves cobalt chloride-induced hypoxic toxicity in C2C12 myoblasts

AIMS

In biology and medicine, hypoxia refers to reduced oxygen tension or oxygen starvation resulting from various environmental or pathological conditions. Prolonged hypoxia may lead to an imbalance in protein production and a loss of muscle mass in animals. The physiological response to hypoxia includes oxidative stress-induced activation of complex cell-signaling networks such as hypoxia-inducible factor (HIF), phosphoinositide 3-kinase (PI3K), and Janus kinase/signal transducer and activator of transcription (JAK-STAT). Methylsulfonylmethane (MSM) is a natural sulfur compound that regulates HIF-1α expression and provides cytoprotection from oxidative stress. In this study, we explored the anti-hypoxic activity and cytoprotective effect of MSM in cobalt chloride (CoCl₂)-induced hypoxic C2C12 mouse myoblast culture.

MATERIALS AND METHODS

We used western blotting, real time PCR, flow cytometry for molecular signaling studies and we also used MTT assay and ChIP assay along with comet assay for cellular processes.

KEY FINDINGS

MSM prevented the CoCl₂ induced cytotoxicity. Molecular markers of hypoxia, induced by CoCl₂, were normalized or reduced by MSM, which also inhibited the effect of CoCl₂-induced JAK2/STAT5b/Cyclin D1 and PI3K/AKT signaling. CoCl₂-induced oxidative stress results in activation of the NRF2/HO-1-mediated cell survival pathway and inhibition of DNA repair, both of which were prevented by MSM.

SIGNIFICANCE

We suggest MSM can be considered as a candidate drug for reducing the effects of hypoxia in both animals and humans.

LPS-pretreated MSC-conditioned medium optimized with 10-kDa filter attenuates the injury of H9c2 cardiomyocytes in a model of hypoxia/reoxygenation

Mesenchymal stem cell-derived conditioned medium (MSC-CM) improves cardiac function, which is partly attributed to released paracrine factors. Since such cardioprotection is moderate and transient, it's essential to optimize MSC-CM effective components to alleviate myocardial injury. To optimize MSC-CM, MSCs were treated with or without lipopolysaccharides (LPSs) for 48 h (serum-free), and the supernatant was collected. Then, LPS-CM (MSC stimulated by LPS) was further treated with LPS remover (LPS Re-CM) or was concentrated with a 10-kDa cutoff filter (10 kDa-CM). ELISA showed that all pretreatments increased levels of VEGF, HGF, and IGF except LPS remover; 10 kDa-CM was superior to other-CM. CCK-8 displayed that viability of injured H9c2 cells enhanced with the increase of MSC-CM concentration. We also found 10 kDa-CM significantly alleviated H9c2 hypoxia/reoxygenation (H/R) injury, as evidenced by increased Bcl-2/Bax ratio, decreased the levels of LDH and cTn. TEM, TUNEL, and H&E staining confirmed 10 kDa-CM inhibited H/R-induced H9c2 morphological changes. Proteomic analysis identified 41 differentially expressed proteins in 10 kDa-CM, among which anti-inflammation, pro-angiogenesis, and anti-apoptosis were related to cardiac protection. This study indicates that 10 kDa-CM protects H9c2 cardiomyocytes from H/R injury by preserving most of the protective factors, such as VEGF, HGF, and IGF, in MSC-CM.

miR-340-5p Alleviates Oxidative Stress Injury by Targeting MyD88 in Sepsis-Induced Cardiomyopathy

Background

Sepsis-induced cardiomyopathy (SIC) is a sort of severe disease in the intensive care unit. This research focuses on exploring the influence of miR-340-5p on SIC and its specific mechanism.

Methods

Mice were administered with lipopolysaccharide (LPS) to construct a SIC animal model. Mice were intramyocardially injected with Adenoassociated Virus- (AAV-) 9 containing the miR-340-5p precursor to make the miR-340-5p overexpression in the myocardium. The expression level of myocardial miR-340-5p was evaluated by qRT-PCR. The cardiac function was measured by echocardiography, the myocardial morphology was observed by hematoxylin-eosin (HE) staining, and the oxidative stress level was detected by 4-hydroxynonenal (4-HNE) immunohistochemical staining and malondialdehyde (MDA) assay in mice. The cells were pretreated with miR-340-5p mimic, mimic-NC, miR-340-5p inhibitor, inhibitor-NC, MyD88 siRNA, or si-NC and then administered with LPS or PBS. The cell viability was measured with the CCK-8 assay. The level of intracellular oxidative stress was evaluated using reactive oxygen species (ROS), MDA, and glutathione (GSH) detection. The MyD88 level was assessed via Western blotting analysis. The interaction of miR-340-5p with the MyD88 mRNA was confirmed via dual-luciferase reporter assay and RNA pull-down assay.

Results

The miR-340-5p overexpression partially alleviated the increase of the MyD88 level, impairment of cardiac function, and oxidative stress injury in the SIC animal model. In the SIC cell model, miR-340-5p mimic pretreatment partially relieved oxidative stress injury, while the miR-340-5p inhibitor had the opposite effect. Besides, the miR-340-5p mimic and inhibitor could reduce and further increase the MyD88 level in the SIC cell model, respectively. Dual-luciferase reporter and RNA pull-down experiments confirmed the interaction between the MyD88 mRNA and miR-340-5p. Finally, it was found that MyD88 siRNA pretreatment also partially alleviates the oxidative stress injury in the SIC cell model.

Conclusion

In sum, our study demonstrated that miR-340-5p can improve myocardial oxidative stress injury by targeting MyD88 in SIC.

Interplay between PI3K/AKT pathway and heart disorders

The PI3K/AKT signaling has crucial role in the regulation of numerous physiological functions through activation of downstream effectors and modulation of cell cycle transition, growth and proliferation. This pathway participates in the pathogenesis of several human disorders such as heart diseases through regulation of size and survival of cardiomyocytes, angiogenic processes as well as inflammatory responses. Moreover, PI3K/AKT pathway participates in the process of myocardial injury induced by a number of substances such as H₂O₂, Mercury, lipopolysaccharides, adriamycin, doxorubicin and epirubicin. In this review, we describe the contribution of this pathway in the pathoetiology of myocardial ischemia/reperfusion injury and myocardial infarction, heart failure, cardiac hypertrophy, cardiomyopathy and toxins-induced cardiac injury.

Puerarin protects against sepsis-induced myocardial injury through AMPK-mediated ferroptosis signaling

Objective: Research suggests that Puerarin may protect against sepsis-induced myocardial damage. However, the mechanisms responsible for Puerarin’s cardioprotective effect remain largely unclear. In this study, our objective is to investigate the role of Puerarin-induced AMPK-mediated ferroptosis signaling in protecting myocardial injury.

Methods: 48 male Sprague-Dawley rats were randomly divided into four groups: control group, LPS group, LPS + Pue group, LPS + Pue + Era (Erastin, ferroptosis activator) group, or LPS + Pue + CC (compound C, AMPK inhibitor) group. During the experiment, cardiac systolic function indexes and myocardial histopathological changes were monitored. The serum levels of myocardial injury marker enzyme, inflammatory response related marker enzyme, and oxidative stress related-marker enzyme were measured with ELISA. Apoptotic cardiomyocytes, the iron content in myocardial tissue, apoptosis-related proteins, AMPK, and ferroptosis-related proteins were determined.

Results: Puerarin inhibited the myocardial injury induced by LPS. The cardioprotective effects of Puerarin decreased after adding ferroptosis-activating compound Erastin. The protein expression levels of GPX4 and ferritin were down-regulated, whereas ACSL4, TFR, and heart iron content were up-regulated in LPS + Pue + Era group compared with LPS+Pue group. A significant difference was identified between LPS + Pue + Era group and LPS + Pue group in P-AMPK and T-AMPK levels. Meanwhile, after providing CC, P-AMPK/T-AMPK was significantly reduced, the protein expression levels of GPX4 and ferritin were down-regulated. ACSL4, TFR, and the heart iron content were up-regulated in LPS + Pue + CC group compared to LPS + Pue group.

Conclusions: Puerarin protected against sepsis-induced myocardial injury, and AMPK-mediated ferroptosis signaling played a crucial role in its cardioprotective effect.

The cardioprotective effects of perindopril in a model of polymicrobial sepsis: The role of radical oxygen species and the inflammation pathway

Mortality rates associated with myocardial dysfunction due to sepsis and septic shock are generally high across the world. The present study focused on the antioxidant and anti-inflammatory effects of perindopril (PER) for the purpose of preventing the adverse effects of sepsis on the myocardium and developing new alternatives in treatment. The control group received only saline solution via the oral route for 4 days. The second group underwent cecal ligation puncture (CLP), and the third underwent CLP and received PER (2 mg/kg). Rats in the third group received 2 mg/kg PER per oral (p.o.) from 4 days before induction of sepsis. Thiobarbituric acid reactive species (TBARS), total thiol (-SH), interleukin-1 beta (IL-1β), IL-6, 8-hydroxy-2'-deoxyguanosine (8-OHdG), and nuclear factor kappa B (NF-κB/p65) levels increased in the CLP groups. In contrast, PER (2 mg/kg) decreased the levels of biochemical parameters other than total-SH and decreased 8-OHdG, NF-κB/p65 immunopositivity in rat heart tissues. The data from this study show that impairment of the oxidant/antioxidant balance and inflammatory cytokine levels in favor of inflammation in heart tissue under septic conditions results in severe tissue damage. PER administration before sepsis was shown to exhibit antioxidant and anti-inflammatory properties by reducing these effects. This in turn increased the importance of PER as new evidence of its protective effects in heart tissue.

Acetyl-11-Keto-β-Boswellic Acid (AKBA) Prevents Lipopolysaccharide-Induced Inflammation and Cytotoxicity on H9C2 Cells

Acetyl-11-keto-beta-boswellic acid (AKBA), the major component of Boswellia serrata, exhibits anti-inflammatory activities. This in vitro study investigated the protective effects of AKBA against lipopolysaccharide (LPS)-induced cardiac dysfunction. In this study, the H9C2 cardiomyocytes were pretreated with AKBA (2.5, 5, and 10 μM for 24 h), and then cotreated with LPS for another 24 h. The MTT assay, ELISA test kits, and quantitative real-time PCR analysis assessed the cell viability, levels of proinflammatory factors (IL-β, IL-6, TNF- α, and PGE2), and the gene expression of IL-β, IL-6, TNF- α, iNOS, and COX-2, respectively. The nitric oxide (NO) and thiol levels were also measured using a biochemical assay. The results indicated that LPS exposure markedly reduced cell viability and total thiol content, but increased the inflammatory cytokines, NO metabolites, and gene expression of proinflammatory mediators in H9C2 cells. AKBA pretreatment significantly altered the mentioned factors induced by LPS. Our results demonstrated that AKBA might be a promising therapeutic agent for treating sepsis-related cardiac dysfunction in the future.

Hinokitiol Protects Cardiomyocyte from Oxidative Damage by Inhibiting GSK3β-Mediated Autophagy

More and more attention has been paid to the use of traditional phytochemicals. Here, we first verified the therapeutic potential of a natural bioactive compound called Hinokitiol in myocardial ischemia reperfusion injury. Hinokitiol exerts cardioprotective effect through inhibition of GSK-3β and subsequent elimination of excessive autophagy, tuning autophagic activity in moderate extent for remedial profit in acute myocardial infarction and myocardial ischemia reperfusion injury. Overall, our study establishes Hinokitiol as a novel available interventional treatment for myocardial ischemia reperfusion injury.

Bilateral Superior Cervical Sympathectomy Activates Signal Transducer and Activator of Transcription 3 Signal to Alleviate Myocardial Ischemia-Reperfusion Injury

Background

There is growing evidence about the effect of bilateral superior cervical sympathectomy on myocardial ischemia-reperfusion (I/R) injury. Studies have increasingly found that the signal transducer and activator of transcription 3 (STAT3) plays a protective role in myocardial I/R injury. However, the precise mechanism is unknown. The present study explored the bilateral superior cervical sympathectomy’s effect and potential mechanism in mice myocardial I/R injury.

Methods

The left heart I/R injury model was created by ligating the anterior descending branch of the coronary artery for 30 min followed by reperfusion. Bilateral superior cervical sympathectomy was performed before myocardial I/R injury. To evaluate the effect of bilateral superior cervical sympathectomy on the myocardium, we examined the myocardial infarct size and cardiac function. Then, myocardial apoptosis, inflammation, and oxidative stress were detected on the myocardium. Furthermore, the expression of STAT3 signal in myocardial tissue was measured by western blotting. To further examine the cardioprotective effect of STAT3 after bilateral superior cervical sympathectomy, the STAT3 inhibitor (static) was utilized to inhibit the phosphorylation of STAT3.

Results

The results showed that the myocardial I/R injury decreased and the cardiac function recovered in the myocardial I/R injury after cervical sympathectomy. Meanwhile, cervical sympathectomy reduced the myocardial distribution of the sympathetic marker tyrosine hydroxylase (TH) and systemic sympathetic tone. And levels of oxidative stress, inflammatory markers, and apoptosis were reduced in myocardial tissue. We also found that the STAT3 signal was activated in myocardial tissue after cervical sympathectomy. STAT3 inhibitor can partially reverse the myocardial protective effect of cervical sympathectomy.

Conclusion

Bilateral superior cervical sympathectomy significantly alleviated myocardial I/R injury in mice. And activation of the STAT3 signal may play an essential role in this.

Rg1 Protects Hematopoietic Stem Cells from LiCl-Induced Oxidative Stress via Wnt Signaling Pathway

Background

Ginsenoside Rg1 is a major component of ginseng with antioxidative and antiaging effects, which is a traditional Chinese medicine. In this study, we investigated the potential spillover and mechanism of action of Rg1 on LiCl-driven hematopoietic stem cell aging.

Results

Collect the purified Sca-1⁺ hematopoietic cells for differentiation ability detection and biochemical and molecular labeling. The experiment found that Rg1 plays an antiaging role in reversing the SA-β-gal staining associated with LiCl-induced hematopoietic stem cell senescence, the increase in p53 and p21 proteins, and sustained DNA damage. At the same time, Rg1 protects hematopoietic cells from the reduced differentiation ability caused by LiCl. In addition, Rg1 increased the excessive inhibition of intracellular GSK-3β protein, resulting in the maintenance of β-catenin protein levels in hematopoietic cells after LiCl treatment. Then, the target gene level of β-catenin can be maintained.

Conclusions

Rg1 exerts the pharmacological effect of maintaining the activity of GSK-3β in Sca-1⁺ hematopoietic cells, enhances the antioxidant potential of cells, improves the redox homeostasis, and thus protects cells from the decline in differentiation ability caused by aging. This study provides a potential therapeutic strategy to reduce stem cell pool failure caused by chronic oxidative damage to hematopoietic stem cells.

Salidroside attenuates cardiac dysfunction in a rat model of diabetes

AIM

This study aimed to investigate the therapeutic effects of salidroside on diabetes-induced cardiovascular disease.

METHODS

Sprague-Dawley rats treated with 65 mg/kg of streptozotocin (STZ) on a daily basis were used to establish the diabetic rat model (blood glucose levels >13.9 mmol/L). Cardiac functions of diabetic rats were evaluated by their haemodynamic alterations. Western blot assay was performed to evaluate the protein levels of multiple signalling pathway factors. Quantitative real-time PCR assay was performed to investigate the inflammation and oxidative stress of diabetic rats.

RESULTS

Salidroside treatment improved the cardiac functions of diabetic rats. In addition, salidroside therapy attenuated the cardiac oxidative stress induced by diabetes. Salidroside inhibited the diabetes-induced inflammation in diabetic rat hearts. The apoptosis of cardiomyocytes was also alleviated by the treatment of salidroside. Salidroside also upregulated the phosphorylation levels of AMPK, ACC, TSC2 and RAPTOR.

CONCLUSION

Salidroside exerts protective effects against diabetes-induced cardiac dysfunction by modulating the mTOR and AMPK signalling pathways.

miR-197 Participates in Lipopolysaccharide-Induced Cardiomyocyte Injury by Modulating SIRT1

Sepsis is a systemic inflammation and is capable of inducing myocarditis, which is a major leading cause of death in patients. Studies have found that miR-197 is correlated with the prognosis of patients with inflammatory heart disease, but its effect on sepsis-induced cardiomyocyte injury remains unclear. We treated H9c2 cells with lipopolysaccharide (LPS), then detected the cell viability via the cell counting kit-8 (CCK-8) assay and quantified miR-197 expression via quantitative real-time polymerase chain reaction (qRT-PCR). Then, we investigated the role of miR-197 in LPS-induced H9c2 cells by CCK-8 assay, flow cytometry, lactate dehydrogenase (LDH) measurement, enzyme-linked immunosorbent assay (ELISA), qRT-PCR, and western blot. Subsequently, silent information regulator 1 (SIRT1) was downregulated in H9c2 cells to explore its interaction with miR-197 under LPS induction. LPS induced miR-197 overexpression in H9c2 cells. LPS restrained viability, the expressions of B-cell lymphoma-2 (Bcl-2) and SIRT1, but promoted apoptosis, LDH release, and levels of interleukin-6 (IL-6), interleukin-1β (IL-1β), acetyl (AC)-p53, BCL2-associated X (Bax), and cleaved caspase-3 in H9c2 cells. miR-197 inhibition reversed the effects of LPS on H9c2 cells. The protective role of miR-197 downregulation in LPS-induced H9c2 cells was reversed by SIRT1 silencing. miR-197 contributed to LPS-induced cardiomyocyte injury by modulating SIRT1, which might be used as a molecular marker in the management of sepsis.

The Effects of Antioxidants from Natural Products on Obesity, Dyslipidemia, Diabetes and Their Molecular Signaling Mechanism

Obesity is a risk factor that leads to the development of other diseases such as dyslipidemia and diabetes. These three metabolic disorders can occur simultaneously, hence, the treatment requires many drugs. Antioxidant compounds have been reported to have activities against obesity, dyslipidemia and diabetes via several mechanisms. This review aims to discuss the antioxidant compounds that have activity against obesity, dyslipidemia and diabetes together with their molecular signaling mechanism. The literature discussed in this review was obtained from the PUBMED database. Based on the collection of literature obtained, antioxidant compounds having activity against the three disorders (obesity, dyslipidemia and diabetes) were identified. The activity is supported by various molecular signaling pathways that are influenced by these antioxidant compounds, further study of which would be useful in predicting drug targets for a more optimal effect. This review provides insights on utilizing one of these antioxidant compounds as opposed to several drugs. It is hoped that in the future, the number of drugs in treating obesity, dyslipidemia and diabetes altogether can be minimized consequently reducing the risk of side effects.

Phenols and terpenoids: natural products as inhibitors of NLRP3 inflammasome in cardiovascular diseases

Inflammatory infiltration has been implicated in the pathogenesis of cardiovascular diseases (CVDs). The NLRP3 inflammasome is involved in the development of several types of CVDs, including myocardial infarction, myocardial ischemia-reperfusion damage, heart failure, atrial fibrillation, and hypertension. Inhibiting the activity of NLRP3 inflammasome can inhibit the progress of CVDs. However, there is no NLRP3 inflammasome inhibitor in clinic, and it is very important to find a safe and effective NLRP3 inhibitor. Phenols and terpenoids are naturally natural products that have many anti-inflammatory effects in CVDs by modulating the NLRP3 inflammatory pathway. Thus, 20 natural products from phenols and terpenoids for the treatment of cardiovascular disease based on the inhibition of NLRP3 inflammasome were summarized and screened. Docking results showed salvianolic acid B and ellagic acid in phenols, and oridonin and triptolide in terpenoids had a better binding activity with NLRP3, which can provide theoretical support for finding novel NLRP3 inflammasome inhibitors or lead compounds in the future.

Protein disulfide-isomerase A3 knockdown attenuates oxidized low-density lipoprotein-induced oxidative stress, inflammation and endothelial dysfunction in human umbilical vein endothelial cells by downregulating activating transcription factor 2

Atherosclerosis is a chronic inflammatory disease implicated in oxidative stress and endothelial dysfunction. Protein disulfide-isomerase A3 (PDIA3) has been reported to regulate oxidative stress and suppress inflammation. This study aimed to explore the function of PDIA3 in atherosclerosis and the underlying mechanisms. PDIA3 expression in oxidized low-density lipoprotein (ox-LDL)-induced human umbilical vein endothelial cells (HUVECs) was detected using RT-qPCR and Western blotting. Following PDIA3 knockdown through transfection with small interfering RNA targeting PDIA3, cell viability, oxidative stress and inflammation in ox-LDL-induced HUVECs was examined using a Cell Counting Kit-8, corresponding kits and ELISA, respectively. The levels of CD31, α-smooth muscle, iNOS, p-eNOS, eNOS and NO were assessed using RT-qPCR, Western blotting and an NO kit to reflect endothelial dysfunction in ox-LDL-induced HUVECs. The relationship between PDIA3 and the activating transcription factor 2 (ATF2) was confirmed using co-immunoprecipitation. In addition, ATF2 expression was examined following PDIA3 silencing. The results indicated that PDIA3 was highly expressed in ox-LDL-induced HUVECs. PDIA3 silencing increased cell viability, and reduced oxidative stress and inflammation, as evidenced by the decreased levels of reactive oxygen species, malondialdehyde, TNF-α, IL-1β and IL-6, and increased superoxide dismutase and glutathione peroxidase activity. In addition, PDIA3 deletion improved endothelial dysfunction. PDIA3 interacted with ATF2, and PDIA3 deletion downregulated ATF2 expression. Furthermore, ATF2 overexpression reversed the effects of PDIA3 knockdown on ox-LDL-induced damage of HUVECs. Collectively, PDIA3 knockdown was found to attenuate ox-LDL-induced oxidative stress, inflammation and endothelial dysfunction in HUVECs by downregulating ATF2 expression, showing promise for the future treatment of atherosclerosis.

Lipopolysaccharide-induced Splenic Ferroptosis in Goslings was Alleviated by Polysaccharide of Atractylodes macrocephala Koidz Associated with Pro-inflammatory Factors

Ferroptosis is a newly discovered form of cell death due to iron-dependent lipid peroxidation. In animal breeding, many environmental factors could lead to oxidative stress, which in turn reduce animal immunity and production performance. Polysaccharide of Atractylodes macrocephala Koidz (PAMK) has antioxidation, immunomodulatory, and inflammatory modulating effects. For investigating the effect of PAMK on splenic ferroptosis in gosling caused by lipopolysaccharide (LPS), 40 one-day-old Magang goslings were randomly divided into 4 groups (CON group, LPS group, PAMK group, and LPS+PAMK group). The protein expression of the ferroptosis marker Glutathione Peroxidase 4 (GPX4), the relative mRNA expression of ferroptosis-related genes and cytokines, and the oxidative stress and iron content of spleen tissues were examined. The correlation between ferroptosis and inflammatory factors was further analyzed by principal component analysis. The results showed that, compared with CON group, LPS caused alterations in the expression of the ferroptosis pathway genes and cytokines, which could upregulate levels of ferroptosis and inflammation. However, after treated with PAMK, the inflammation and ferroptosis was alleviated. Meanwhile, PAMK restored the expression and distribution of GPX4. In addition, PAMK alleviated the oxidative stress caused by LPS and reduced the iron content in spleen. Principal component analysis showed that cytokines were more closely related to antioxidant indexes. The CON, PAMK and LPS+PAMK groups had similar effects on the four components, with the LPS and PAMK groups showing the furthest difference in results. The result indicated that PAMK could reduce the level of oxidative stress and inflammatory cytokines in spleen of gosling caused by LPS, and jointly alleviate ferroptosis by regulating genes related to the ferroptosis pathway.

Curcumin alleviated lipopolysaccharide-evoked H9c2 cells damage via suppression of intercellular adhesion molecule 1/CD40/NF-κB signaling

BACKGROUND

Curcumin has been reported to have many benefits, including anti-inflammatory, anti-cancer, and so on. In this research, we aimed to investigate the function of curcumin on lipopolysaccharide (LPS)-injured H9c2 cells.

METHODS

H9c2 cells stimulated by LPS mimic the in vitro model of myocarditis injury. Comparative Toxicogenomics Database (CTD) was applied to detect the genes associated with curcumin. GEO database was used to analyze Intercellular Adhesion Molecule 1 (ICAM1) and CD40 expression in myocarditis patients. KEGG enrichment analysis was employed to investigate the meaningful pathways related to differentially expressed genes. Cell proliferation, apoptosis, expression of ICAM1/CD40/P65- NF-κB, and level of TNF-α, IL-6, and IL-10 were observed by cell counting kit-8, flow cytometry and western blotting assays, ELISA assay, respectively.

RESULTS

After curcumin treatment, the decreased activity of H9c2 cells evoked by LPS was improved. ICAM1 and CD40, which highly expressed in myocarditis patients, were identified as targets of curcumin and negatively regulated by curcumin. Inhibition of ICAM1 or CD40 strengthened the protective effect of curcumin on LPS-evoked H9c2 cells damage, accompanied by increased cell viability and decreased cell apoptosis and inflammation. Additionally, addition of curcumin or depletion of ICAM1/CD40 suppressed p-P65 NF-κB expression.

CONCLUSIONS

Curcumin mitigated LPS-evoked H9c2 cells damage by suppression of ICAM1/CD40/NF-κB, providing a potential molecular mechanism for the clinical application of curcumin.

Compound Danshen Dripping Pill ameliorates post ischemic myocardial inflammation through synergistically regulating MAPK, PI3K/AKT and PPAR signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Compound Danshen Dripping Pill (CDDP), composed of Salvia miltiorrhiza Bunge, Panax notoginseng (Burkill) F.H. Chen and Borneol, is a famous traditional Chinese medicine formula which has made great achievements in the treatment of ischemic heart disease, but the profound mechanism of CDDP improving post ischemic myocardial inflammation hasn't been clearly discussed.

AIM OF THE STUDY

The aim of this study was to explore the biological mechanism of constituents in CDDP synergistically improving post ischemic myocardial inflammation.

MATERIALS AND METHODS

The pharmacologic studies were applied to assess the cardio protection effect of CDDP in acute myocardial ischemic rats. To identify the anti-inflammatory ingredients in CDDP, an ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry combined with a dual-luciferase reporter assay for NF-κB inhibition were used. The network pharmacology and molecular docking assay were adopted to predict targets of anti-inflammatory ingredients and then the regulation effects of these active components on their targets were also verified.

RESULTS

Our results indicated that CDDP exerted an excellent cardio protection effect by reversing echocardiographic abnormalities, attenuating histopathological lesion, ameliorating circulating myocardial markers and inflammation cytokines. Tanshinol, salvianolic acid B (Sal B), tanshinone IIA (Tan IIA) and notoginsenoside R1 (NGR1) were the pivotal anti-inflammatory ingredients in CDDP. The anti-inflammatory mechanism is that tanshinol and Sal B respectively targeted on PPARγ and JNK, while Tan IIA worked on AKT1 and NGR1 bound to PI3K.

CONCLUSIONS

Our results firstly demonstrated that CDDP effectively ameliorated post ischemic myocardial inflammation through simultaneously modulating MAPK, PI3K/AKT and PPAR pathways in a multi-components synergetic manner.

Dapagliflozin Improves Cardiac Function, Remodeling, Myocardial Apoptosis, and Inflammatory Cytokines in Mice with Myocardial Infarction

Dapagliflozin (DAPA) exerts cardioprotective effects in non-diabetic patients. Nonetheless, the protective mechanism remains unknown. This study aims to evaluate the performance of DAPA on cardiac function and remodeling as well as its potential mechanism in mice with myocardial infarction (MI). Here, a MI mice model was established. One week after MI, mice were treated with saline or DAPA (1.5 mg/kg/day) for 4 weeks. At the end of this study, echocardiography was performed to assess cardiac structure and function. Myocardial apoptosis was analyzed by Western blot and immunofluorescence. Inflammatory cytokines and cardiac fibrosis were analyzed by real-time PCR and Masson's trichrome stain, respectively. Results showed that DAPA improved cardiac structure and function, attenuated cardiac fibrosis, and inhibited inflammatory cytokines and myocardial apoptosis. Moreover, the inhibition of PI3K/AKT/mTOR pathway might be related to the cardioprotective role of DAPA. These findings reveal that dapagliflozin is a potential therapeutic agent for MI patients without diabetes.

Berberine attenuates septic cardiomyopathy by inhibiting TLR4/NF-κB signalling in rats

CONTEXT

Berberine (Ber) can increase the survival rate of septic mice and inhibit inflammation, but whether it has a protective effect on septic cardiomyopathy (SCM) is unclear.

OBJECTIVE

To investigate whether Ber ameliorates SCM in a rat model and its potential mechanism.

MATERIALS AND METHODS

Male SD rats were randomly divided into three groups: control (Con, n = 6) (DD H₂O, 2 mL/100 g, ig, qd × 3 d, then saline, 10 mg/kg, ip); sepsis [LPS (lipopolysaccharide), n = 18] (LPS 10 mg/kg instead of saline, ip); and berberine intervention (Ber, n = 18) (Ber, 50 mg/kg instead of DD H₂O, ig, qd × 3 d, LPS instead of saline, ip). Hemodynamics, HE staining, ELISA and western blot were performed at 6, 24, and 48 h after intraperitoneal injection of LPS to evaluate the effect of berberine in septic rats.

RESULT

Berberine could recover myocardial injury by partially increased ± dp/dt max (1151, 445 mmHg/s) and LVEDP levels (1.49 mmHg) with LPS-induced rats, as well as an ameliorated increase of cTnT (217.53 pg/mL) in the Ber group compared with that in the LPS group (at 24 h). In addition, HE staining results showed that berberine attenuated the myocardial cell swelling induced by LPS. In contrast to the LPS group, the up-regulation of TLR4, p65 TNF-α, and IL-1β were attenuated in the Ber group.

DISCUSSION AND CONCLUSIONS

Berberine showed a protective effect on septic cardiomyopathy rats possibly through inhibiting the activation of TLR4/NF-κB signalling pathway. Whether it improves SCM through other mechanisms is our ongoing research.

Cadmium induced cardiac toxicology in developing Japanese quail (Coturnix japonica): Histopathological damages, oxidative stress and myocardial muscle fiber formation disorder

The anthropogenic-induced cadmium (Cd) pollution poses great threats to human health and wildlife survival. Birds also suffer from Cd contamination and Cd exerts negative impacts on multiple organs in birds. However, its toxic effects on cardiac organ of birds are still unclear. In this study, one-week old male Japanese quails were exposed to 15, 30, 60 and 75 mg/kg Cd for 5 weeks when birds in control group reached sex maturity. The results showed that Cd could cause microstructural damages including congestion and myocardial fiberolysis. Ultrastructural analysis also showed myocardial muscle fiber disarrangement and rupture as well as mitochondrial swelling, vacuolation and membrane lysis in Cd concentration groups. Moreover, Cd induced oxidative stress in the heart by decreasing antioxidant enzyme activities of catalase (CAT), glutathione peroxidase (GPX), total antioxidant capacity (T-AOC), superoxide dismutase (SOD) while increasing oxidative biomarkers such as malondialdehyde (MDA), inducible nitric oxide synthase (iNOS), and content of nitric oxide (NO). In addition, mRNA expression levels of genes involved in muscle fiber formation signaling pathway such as Follistatin (FST), paired box 3 (PAX3), myogenic differentiation 1 (MYoD1) and SRY-box transcription factor 6 (SOX6), were down-regulated by Cd exposure. Furthermore, PI3K/Akt/mTOR signaling pathway were disrupted by Cd exposure implying energy supply deficiency in the heart. We concluded that Cd caused cardiac dysfunction by inducing heart underdevelopment, histopathological injury, oxidative stress and myocardial muscle fiber formation disruption.

Insight into the Protective Effect of Salidroside against H2O2-Induced Injury in H9C2 Cells

Salidroside is the important active ingredient of Rhodiola species, which shows a wide range of pharmacological activities such as antioxidative stress, anti-inflammation, and antiliver fibrosis. In this paper, we aimed to study the protective effect and mechanism of salidroside against H2O2-induced oxidative damage in H9C2 cells by determining cell proliferation rate, intracellular reactive oxygen species (ROS) level, antioxidant enzyme activities, and the expression of apoptosis-related proteins. The results showed that salidroside significantly alleviated cell growth inhibition induced by H2O2 treatment in H9C2 cells, decreased the levels of intracellular ROS and malondialdehyde (MDA), and increased the activity of superoxide dismutase (SOD) and catalase (CAT); meanwhile, salidroside upregulated the expression of Bcl-2 while downregulated the expression of Bax, p53, and caspase-3 in H2O2-treated H9C2 cells. Furthermore, the antiapoptotic effect of salidroside was almost eliminated by the knockdown of Bcl-2. In the further exploration, the Bcl-2 expression was decreased by the p53 overexpression and increased by p53 knockdown in H2O2-treated H9C2 cells. Consequently, salidroside could protect H9C2 cells against H2O2-induced oxidative damage, and the underlying mechanism may be related to scavenging intracellular ROS, increasing the activities of intracellular antioxidant enzymes and inhibiting the expression of apoptosis-related proteins.

Identification of transcriptomics biomarkers for the early prediction of the prognosis of septic shock from pneumopathies

Background

Identifying the biological subclasses of septic shock might provide specific targeted therapies for the treatment and prognosis of septic shock. It might be possible to find biological markers for the early prediction of septic shock prognosis.

Methods

The data were obtained from the Gene Expression Omnibus databases (GEO) in NCBI. GO enrichment and KEGG pathway analyses were performed to investigate the functional annotation of up- and downregulated DEGs. ROC curves were drawn, and their areas under the curves (AUCs) were determined to evaluate the predictive value of the key genes.

Results

117 DEGs were obtained, including 36 up- and 81 downregulated DEGs. The AUC for the MME gene was 0.879, as a key gene with the most obvious upregulation in septic shock. The AUC for the THBS1 gene was 0.889, as a key downregulated gene with the most obvious downregulation in septic shock.

Conclusions

The upregulation of MME via the renin-angiotensin system pathway and the downregulation of THBS1 through the PI3K–Akt signaling pathway might have implications for the early prediction of prognosis of septic shock in patients with pneumopathies.

Protective Effect of Topiroxostat on Myocardial Injury Induced by Lipopolysaccharide

BACKGROUND

Myocardial injury induced by sepsis is the most common cause of death. Topiroxostat has been found to have organ protective effects, but its role in septic shock-related cardiomyocyte damage is still unclear and needs further study.

MATERIAL AND METHODS

An endotoxemic shock model in rats was constructed. After topiroxostat treatment, hemodynamic parameters, myocardial injury marker enzymes, oxidative stress, myocardial injury, and apoptosis were measured by polyphysiograph, enzyme-linked immunosorbent assay, hematoxylin and eosin staining, TUNEL staining, and western blot. During in vitro experiments, the effect of topiroxostat on cell vitality, oxidative stress, inflammatory factors, apoptosis-related markers, phosphorylated-p65 (p-p65) and p65 expressions were measured by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), flow cytometry, enzyme-linked immunosorbent assay, quantitative real-time polymerase chain reaction, and western blot.

RESULTS

Topiroxostat improved myocardial dysfunction and superoxide dismutase activity while suppressing levels of creatine kinase, lactate dehydrogenase and malondialdehyde in serum of endotoxemic shock rats. Additionally, topiroxostat augmented dry-wet weight ratios of the hearts in rats. Meanwhile, topiroxostat was proved to alleviate interstitial edema and apoptosis in myocardial tissues of endotoxemic shock rats. During in vitro experiments, topiroxostat pretreatment elevated lipopolysaccharide (LPS)-induced H9c2 cell vitality, and alleviated oxidative stress and inflammation. Moreover, topiroxostat pretreatment downregulated apoptosis-related markers, p-p65, and p-p65/p65 levels in LPS-induced H9c2 cells.

CONCLUSIONS

Topiroxostat attenuated LPS-induced myocardial injury via repressing apoptosis and oxidative stress.

miR-21-5p inhibits inflammation injuries in LPS-treated H9c2 cells by regulating PDCD4

OBJECTIVES

To explore the expression levels and the potential regulatory mechanism of miR-21-5p in LPS-treated H9c2 cells.

METHODS

The secretions of the inflammatory cytokines induced by LPS in H9c2 cells were evaluated using ELISA. We used RT-RCR and western blot to measure the relative mRNA and protein expression levels in LPS-treated H9c2 cells. CCK-8 and EdU assays showed the viability and proliferation profiles of the H9c2 cells. TUNEL assays demonstrated the apoptotic behaviors of the H9c2 cells, and a luciferase reporter analysis was used to investigate the interactions between miR-21-5p and programmed cell death protein 4 (PDCD4).

RESULTS

LPS induced damage to the H9c2 cells by reducing the cell viability and down-regulating miR-21-5p. On the other hand, miR-21-5p overexpression inhibited the LPS-induced inflammatory damage in the H9c2 cells. Moreover, PDCD4 was verified as a downstream target gene of miR-21-5p, and its expression was inhibited by the higher miR-21-5p content. Finally, miR-21-5p inhibited septic processes, and the PDCD4 overexpression rescued the miR-21-5p effect in the LPS-treated H9c2 cells.

CONCLUSION

Our findings suggest that miR-21-5p inhibits the LPS-induced progression of sepsis in H9c2 cells. Additionally, PDCD4 is a downstream target gene of miR-21-5p, and both molecules serve as potential therapeutic targets for heart sepsis patients.

Dehydrocorydaline Protects Against Sepsis-Induced Myocardial Injury Through Modulating the TRAF6/NF-κB Pathway

We aim to investigate the effect and mechanism of dehydrocorydaline (Deh), an alkaloidal component isolated from Rhizoma corydalis, in the treatment of sepsis-mediated myocardial injury. Lipopolysaccharide (LPS) was taken to construct an in-vitro sepsis-myocardial injury models H9C2 cardiomyocytes. The in-vivo model of sepsis in C57BL/6 mice was induced by intraperitoneal injection of Escherichia coli (E. coli). The in-vitro and in-vivo models were treated with Deh in different concentrations, respectively. Hematoxylin-eosin (HE) staining, Masson staining, and immunohistochemistry (IHC) staining were taken to evaluate the histopathological changes of the heart. ELISA was applied to evaluate the levels of inflammatory factors, including IL-6, IL-1β, TNFα, IFNγ, and oxidized factors SOD, GSH-PX in the plasma or culture medium. Western blot was used to measure the expressions of Bax, Bcl2, Caspase3, iNOS, Nrf2, HO-1, TRAF6, NF-κB in heart tissues and cells. The viability of H9C2 cardiomyocytes was detected by the CCK8 method and BrdU assay. The ROS level in the H9C2 cardiomyocytes were determined using immunofluorescence. As a result, Deh treatment improved the survival of sepsis mice, reduced TUNEL-labeled apoptosis of cardiomyocytes. In vitro, Deh enhanced the viability of LPS-induced H9C2 cardiomyocytes and inhibited cell apoptosis. Additionally, Deh showed significant anti-inflammatory and anti-oxidative stress functions via decreasing IL-1β, IL-6, TNFα, and IFNγ levels, mitigating ROS level, up-regulating Nrf2/HO-1, SOD, and GSH-PX expressions dose-dependently. Mechanistically, Deh inhibited TRAF6 expression and the phosphorylation of NF-κB p65. The intervention with a specific inhibitor of TRAF6 (C25-140) or NF-κB inhibitor (BAY 11-7082) markedly repressed the protective effects mediated by Deh. In conclusion, Deh restrains sepsis-induced cardiomyocyte injury by inhibiting the TRAF6/NF-κB pathway.

Hypoxia-inducible transcription factor-1α inhibition by topotecan protects against lipopolysaccharide-induced inflammation and apoptosis of cardiomyocytes

Background

Myocarditis, an inflammatory disease of the myocardium, is a serious hazard to human life due to the expansion of inflammatory lesions in the myocardium. The aim of this study was to investigate the role of hypoxia-inducible transcription factor (HIF)-1α and its inhibitor topotecan in the pathogenesis of myocarditis.

Methods

H9c2 cardiomyoblasts was stimulated with lipopolysaccharide (LPS) to simulate myocarditis model in vitro. The levels of myocardial damage markers were determined using commercially available kits. Western blotting was used to evaluate HIF-1α expression after LPS challenge. Then, after HIF-1α silencing, the contents of inflammatory factors were determined with enzyme-linked immunosorbent assay (ELISA). Cell viability was tested by means of a cell counting kit-8 (CCK-8) assay. Cell apoptosis was assessed by flow cytometry, and the expression of apoptotic proteins was examined using western blot analysis. Subsequently, HIF-1α was overexpressed and topotecan was employed to treat H9c2 cells under LPS exposure condition. The biological functions were detected again.

Results

LPS significantly elevated the levels of lactate dehydrogenase (LDH), creatine kinase-MB (CK-MB) and cardiac troponin-I (cTn-I) in supernatant of H9c2 cell lysates. Additionally, LPS led to the notably upregulated expression of HIF-1α. HIF-1α-knockdown markedly decreased the concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-8 compared with the LPS-induced group. Moreover, the cell viability was conspicuously enhanced and cell apoptotic ratio was remarkably reduced, accompanied by downregulated expression of Bax, Bim, caspase 3 and caspase 9 after HIF-1α silencing. Consistently, HIF-1α gain-of-function significantly promoted the production of inflammatory cytokines and cell apoptosis, which was partially counteracted by topotecan administration.

Conclusion

To conclude, these findings demonstrated that HIF-1α inhibition by topotecan ameliorates LPS-induced myocarditis in vitro, providing a new approach in the treatment of myocarditis.

Salidroside alleviates taurolithocholic acid 3-sulfate-induced AR42J cell injury

OBJECTIVES

To investigate the protective effects of Salidroside (Sal) on AP cell model induced by taurolithocholic acid 3-sulfate (TLC-S) as well as its underlying mechanism.

METHODS

AR42J cells were divided into normal group (N group), AP cell model group (Mod group), Sal treated alone group (S+N group) and Sal treated AP cell model group (S+Mod group). The cell viability was examined by CCK-8 assay. Secretion of lipase and trypsin by AR42J cells, quantified using commercial assay kits, was used as the markers of TLC-S-induced pancreatitis. The levels of TNF-α, IL-1β, IL-8, IL-6 and IL-10 in the cell supernatant were measured by ELISA. The effect of Sal on molecules in the NF-κB signaling pathway and autophagy was investigated by qRT-PCR and western blot.

RESULTS

The decreased cell viability in Mod group was increased by Sal (P < 0.01). The upheaved activities of lipase and trypsin in AP cell model were declined by Sal (P < 0.01). The levels of TNF-α, IL-1β, IL-8 and IL-6 in the cell supernatant, Beclin-1 and LC3-Ⅱ mRNA and protein, p-p65/p65 protein, which were increased in AP cell model, were decreased by Sal; and IL-10 in the cell supernatant, LAMP2 mRNA and protein, p-IκBα/IκBα protein which was declined in AP cell model, was increased by Sal (P < 0.05 or 0.01). There were no significant differences in all indexes between the N and S+N groups (P > 0.05).

CONCLUSIONS

Sal alleviated AR42J cells injury induced by TLC-S, inhibited the inflammatory responses and modulated the autophagy, mainly through inhibiting the NF-κB signaling pathway.

Neuroprotective effects of salidroside on ageing hippocampal neurons and naturally ageing mice via the PI3K/Akt/TERT pathway

Studies have found that salidroside, isolated from Rhodiola rosea L, has various pharmacological activities, but there have been no studies on the effects of salidroside on brain hippocampal senescence. The purpose of this study was to investigate the mechanistic role of salidroside in hippocampal neuron senescence and injury. In this study, long-term cultured primary rat hippocampal neurons and naturally aged C57 mice were treated with salidroside. The results showed that salidroside increased the viability and MAP2 expression, reduced β-galactosidase (β-gal) levels of rat primary hippocampal neurons. Salidroside also improved cognition dysfunction in ageing mice and alleviated neuronal degeneration in the ageing mice CA1 region. Moreover, salidroside decreased the levels of oxidative stress and p21, p16 protein expressions of hippocampal neurons and ageing mice. Salidroside promoted telomerase reverse transcriptase (TERT) protein expression via the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) pathway. In conclusion, our findings suggest that salidroside has the potential to be used as a therapeutic strategy for anti-ageing and ageing-related disease treatment.

Panax Notoginseng Saponins Protect H9c2 Cells From Hypoxia-reoxygenation Injury Through the Forkhead Box O3a Hypoxia-inducible Factor-1 Alpha Cell Signaling Pathway

ABSTRACT

Panax notoginseng saponins (PNS) are commonly used in the treatment of cardiovascular diseases. Whether PNS can protect myocardial ischemia-reperfusion injury by regulating the forkhead box O3a hypoxia-inducible factor-1 alpha (FOXO3a/HIF-1α) cell signaling pathway remains unclear. The purpose of this study was to investigate the protective effect of PNS on H9c2 cardiomyocytes through the FOXO3a/HIF-1α cell signaling pathway. Hypoxia and reoxygenation of H9C2 cells were used to mimic MIRI in vitro, and the cells were treated with PNS, 2-methoxyestradiol (2ME2), and LY294002." Cell proliferation, lactate dehydrogenase, and malonaldehyde were used to evaluate the degree of cell injury. The level of reactive oxygen species was detected with a fluorescence microscope. The apoptosis rate was detected by flow cytometry. The expression of autophagy-related proteins and apoptosis-related proteins was detected by western blot assay. PNS could reduce H9c2 hypoxia-reoxygenation injury by promoting autophagy and inhibiting apoptosis through the HIF-1α/FOXO3a cell signaling pathway. Furthermore, the protective effects of PNS were abolished by HIF-1α inhibitor 2ME2 and PI3K/Akt inhibitor LY294002. PNS could reduce H9c2 hypoxia-reoxygenation injury by promoting autophagy and inhibiting apoptosis through the HIF-1α/FOXO3a cell signaling pathway.

Neferine Ameliorates Sepsis-Induced Myocardial Dysfunction Through Anti-Apoptotic and Antioxidative Effects by Regulating the PI3K/AKT/mTOR Signaling Pathway

Septic cardiomyopathy is a common complication of severe sepsis, which is one of the leading causes of death in intensive care units. Therefore, finding an effective therapy target is urgent. Neferine is an alkaloid extracted from the green embryos of mature seeds of Nelumbo nucifera Gaertn., which has been reported to exhibit various biological activities and pharmacological properties. This study aims to explore the protective effects of neferine against lipopolysaccharide (LPS)-induced myocardial dysfunction and its mechanisms. The LPS-induced cardiac dysfunction mouse model was employed to investigate the protective effects of neferine. In this study, we demonstrated that neferine remarkably improved cardiac function and survival rate and ameliorated morphological damage to heart tissue in LPS-induced mice. Neferine also improved cell viability and mitochondrial function and reduced cell apoptosis and the production of reactive oxygen species in LPS-treated H9c2 cells. In addition, neferine significantly upregulated Bcl-2 expression and suppressed cleaved caspase 3 activity in LPS-induced mouse heart tissue and H9c2 cells. Furthermore, neferine also upregulated the phosphatidylinositol 3-kinase/protein kinase B/mechanistic target of rapamycin (PI3K/AKT/mTOR) signaling pathway in vivo and in vitro. Conversely, LY294002 (a PI3K inhibitor) reversed the protective effect of neferine in LPS-induced H9c2 cells. Our findings thus demonstrate that neferine ameliorates LPS-induced cardiac dysfunction by activating the PI3K/AKT/mTOR signaling pathway and presents a promising therapeutic agent for the treatment of LPS-induced cardiac dysfunction.

Selective inhibition of PKCβ2 improves Caveolin-3/eNOS signaling and attenuates lipopolysaccharide-induced injury by inhibiting autophagy in H9C2 cardiomyocytes

Lipopolysaccharide (LPS)-induced autophagy is involved in sepsis-associated myocardial injury with increased PKCβ2 activation. We previously found hyperglycemia-induced PKCβ2 activation impaired the expression of caveolin-3 (Cav-3), the dominant isoform to form cardiomyocytes caveolae which modulate eNOS signaling to confer cardioprotection in diabetes. However, little is known about the roles of PKCβ2 in autophagy and Cav-3/eNOS signaling in cardiomyocytes during LPS exposure. We hypothesize LPS-induced PKCβ2 activation promotes autophagy and impairs Cav-3/eNOS signaling in LPS-treated cardiomyocytes. H9C2 cardiomyocytes were treated with LPS (10 µg/mL) in the presence or absence of PKCβ2 inhibitor CGP53353 (CGP, 1 µM) or autophagy inhibitor 3-methyladenine (3-MA, 10 µM). LPS stimulation induced cytotoxicity overtime in H9C2 cardiomyocytes, accompanied with excessive PKCβ2 activation. Selective inhibition of PKCβ2 with CGP significantly reduced LPS-induced cytotoxicity and autophagy (measured by LC-3II, Beclin-1, p62 and autophagic flux). In addition, CGP significantly attenuated LPS-induced oxidative injury, and improved Cav-3 expression and eNOS activation, similar effects were shown by the treatment of autophagy inhibitor 3-MA. LPS-induced myocardial injury is associated with excessive PKCβ2 activation, which contributes to elevated autophagy and impaired Cav-3/eNOS signaling. Selective inhibition of PKCβ2 improves Cav-3/eNOS signaling and attenuates LPS-induced injury through inhibiting autophagy in H9C2 cardiomyocytes.

The role of TGF-β1/Smad3 signaling pathway and oxidative stress in the inhibition of osteoblast mineralization by copper chloride

To explore the relationship of oxidative stress and TGF-β 1/Smad3 pathway in the inhibition of osteoblast mineralization by copper chloride (CuCl2), the osteoblasts were treated with CuCl2 (0, 50 μM, 100 μM, 150 μM CuCl2 5H2O) for 24 h. We found that Cu impaired the osteoblast structure, inhibited the glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities, alkaline phosphatase (ALP) content, mRNA expression of collagen I (COL-I), osteocalcin (OCN), insulin-like growth factor I (IGF-I), bone morphogenetic protein-2 (BMP-2), transforming growth factor β1 (TGF-β1) and core-binding factor α1 (Cbfα1), promoted the reactive oxygen species (ROS) production, inactivated the TGF-β1/Smad3 pathway. It indicates that the inactivated TGF-β1/Smad3 pathway leads to osteoblast impairment by CuCl2. It will contribute to clarify the influence of CuCl2 on the osteoblast mineralization.

Dietary selenomethionine ameliorates lipopolysaccharide-induced renal inflammatory injury in broilers via regulating the PI3K/AKT pathway to inhibit necroptosis

Selenomethionine (SeMet) has antioxidant and anti-inflammatory effects, as a widely used organic Se source in food supplements, and its inhibitory effect on the prevention and treatment of renal inflammatory injury is unclear. Here, in order to explore the protective effect of SeMet on kidney tissue of broilers and determine its potential molecular mechanism, we took broilers as the research object, lipopolysaccharide (LPS) was used as the source of stimulation, and the model was established by adding SeMet to the diet. The histopathological observation indicated that SeMet alleviated the LPS-induced characteristic changes of renal inflammatory injury. Besides, SeMet inhibited LPS-induced PI3K, AKT, caspase 8 and IκB-α downregulation, the necroptosis marker genes (FADD, RIP1, RIP3, MLKL and TNF-α), pro-inflammatory factors (NF-κB, PTGEs, COX-2, iNOS, IL-1β and IL-6) and HSP60, HSP70 and HSP90 overexpression. We concluded that SeMet ameliorates LPS-induced renal inflammatory injury in broilers by inhibiting necroptosis via the regulation of the PI3K/Akt pathway. Thus, we speculated that dietary SeMet may be a potential new strategy for the treatment of renal injury.

Effect of Food Endotoxin on Infant Health

Endotoxin is a complex molecule derived from the outer membrane of Gram-negative bacteria, and it has strong thermal stability. The processing of infant food can kill pathogenic bacteria but cannot remove endotoxin. Because the intestinal structure of infants is not fully developed, residual endotoxin poses a threat to their health by damaging the intestinal flora and inducing intestinal inflammation, obesity, and sepsis, among others. This paper discusses the sources and contents of endotoxin in infant food and methods for preventing endotoxin from harming infants. However, there is no clear evidence that endotoxin levels in infant food cause significant immune symptoms or even diseases in infants. However, in order to improve the safety level of infant food and reduce the endotoxin content, this issue should not be ignored. The purpose of this review is to provide a theoretical basis for manufacturers and consumers to understand the possible harm of endotoxin content in infant formula milk powder and to explore how to reduce its level in infant formula milk powder. Generally, producers should focus on cleaning the milk source, securing the cold chain, avoiding long-distance transportation, and shortening the storage time of raw milk to reduce the level of bacteria and endotoxin. After production and processing, the endotoxin content should be measured as an important index to test the quality of infant formula milk powder so as to provide high-quality infant products for the healthy growth of newborns.

Salidroside Attenuates Doxorubicin-Induced Cardiac Dysfunction Partially Through Activation of QKI/FoxO1 Pathway

Doxorubicin (DOX) is an effective chemotherapy. However, its usage has been associated with adverse effects. Salidroside (SAL) is an antioxidative drug, which confers protective effects against several diseases. Salidroside can attenuate cardiac dysfunction induced by DOX. Quaking (QKI) is identified as a protective factor that can inhibit cardiotoxicity medicated by DOX through the regulation of cardiac circular RNA expression. The present study investigated the role of QKI on the protective effect of SAL in the DOX-induced cardiotoxicity model. Results indicated that SAL attenuated DOX-induced adverse effects, including cardiac dysfunction, weight loss, and reactive oxygen species (ROS) production, and decreased the expression of BAX, caspase 3, and FoxO1. Also, it increased the Mn-SOD2 and QKI expression in vivo and in vitro. Furthermore, QKI knockdown suppressed anti-cardiotoxicity mediated by SAL. In conclusion, the results of the current study show that salidroside attenuates doxorubicin-induced cardiac dysfunction through activation of QKI/FoxO1 pathway.

mTORC1 and mTORC2 Converge on the Arp2/3 Complex to Promote KrasG12D-Induced Acinar-to-Ductal Metaplasia and Early Pancreatic Carcinogenesis

BACKGROUND & AIMS

Oncogenic KrasG12D induces neoplastic transformation of pancreatic acinar cells through acinar-to-ductal metaplasia (ADM), an actin-based morphogenetic process, and drives pancreatic ductal adenocarcinoma (PDAC). mTOR (mechanistic target of rapamycin kinase) complex 1 (mTORC1) and 2 (mTORC2) contain Rptor and Rictor, respectively, and are activated downstream of KrasG12D, thereby contributing to PDAC. Yet, whether and how mTORC1 and mTORC2 impact on ADM and the identity of the actin nucleator(s) mediating such actin rearrangements remain unknown.

METHODS

A mouse model of inflammation-accelerated KrasG12D-driven early pancreatic carcinogenesis was used. Rptor, Rictor, and Arpc4 (actin-related protein 2/3 complex subunit 4) were conditionally ablated in acinar cells to deactivate the function of mTORC1, mTORC2 and the actin-related protein (Arp) 2/3 complex, respectively.

RESULTS

We found that mTORC1 and mTORC2 are markedly activated in human and mouse ADM lesions, and cooperate to promote KrasG12D-driven ADM in mice and in vitro. They use the Arp2/3 complex as a common downstream effector to induce the remodeling the actin cytoskeleton leading to ADM. In particular, mTORC1 regulates the translation of Rac1 (Rac family small GTPase 1) and the Arp2/3-complex subunit Arp3, whereas mTORC2 activates the Arp2/3 complex by promoting Akt/Rac1 signaling. Consistently, genetic ablation of the Arp2/3 complex prevents KrasG12D-driven ADM in vivo. In acinar cells, the Arp2/3 complex and its actin-nucleation activity mediated the formation of a basolateral actin cortex, which is indispensable for ADM and pre-neoplastic transformation.

CONCLUSIONS

Here, we show that mTORC1 and mTORC2 attain a dual, yet nonredundant regulatory role in ADM and early pancreatic carcinogenesis by promoting Arp2/3 complex function. The role of Arp2/3 complex as a common effector of mTORC1 and mTORC2 fills the gap between oncogenic signals and actin dynamics underlying PDAC initiation.

Fisetin inhibits inflammation and induces autophagy by mediating PI3K/AKT/mTOR signaling in LPS-induced RAW264.7 cells

Background

Fisetin, a natural potent flavonoid, has various beneficial, pharmacological activities. In this study, we investigated expression changes of the fisetin regulating genes in lipopolysaccharide (LPS)-treated RAW264.7 cells and explored the role of fisetin in inflammation and autophagy.

Methods and results

Microarray analysis identified 1,071 genes that were regulated by fisetin in LPS-treated RAW264.7 cells, and these genes were mainly related to the process of immune system response. Quantitative real-time polymerase chain reaction and Bio-Plex analysis indicated that fisetin decreased the expression and secretion of several inflammatory cytokines in cells administered with LPS. Western blot analysis and immunofluorescence assay showed that fisetin decreased microtubule-associated protein 1 light-chain 3B (LC3B) and lysosome-associated membrane protein 1 (LAMP1) expression in LPS-treated cells, while the autophagy inhibitor chloroquine (CQ) could partially reverse this effect. In addition, fisetin reduced the elevated expression of p-PI3K, p-AKT and p-mTOR induced by LPS in a concentration-dependent manner.

Conclusions

Fisetin diminished the expression and secretion of inflammatory cytokines and facilitated autophagosome-lysosome fusion and degradation in LPS-treated RAW264.7 cells via inhibition of the PI3K/AKT/mTOR signaling pathway. Overall, the results of this study provide new clues for the anti-inflammatory mechanism of fisetin and explain the crosstalk between autophagy and inflammation to some extent.

Whole body periodic acceleration (pGz) improves endotoxin induced cardiomyocyte contractile dysfunction and attenuates the inflammatory response in mice

Sepsis-induces myocardial contractile dysfunction. We previously showed that whole body periodic acceleration (pGz), the sinusoidal motion of the supine body head-foot ward direction significantly improves survival and decreases microvascular permeability in a lethal model of sepsis. We tested the hypothesis that pGz improves LPS induced cardiomyocyte contractile dysfunction and decreases LPS pro-inflammatory cytokine response when applied pre- or post-treatment. Isolated cardiomyocytes were obtained from mice that received LPS who had been pre-treated with pGz for three days (pGz-LPS) or control. Peak shortening (PS), maximal velocity of shortening (+dL/dt), and relengthening (-dL/dt) as well as diastolic intracellular calcium concentration ([Ca⁺²]_d), sodium ([Na⁺]_d), reactive oxygen species (ROS), and cardiac troponin (cTnT) production were measured. LPS decreased PS, +dL/dt, and -dL/dt, by 37%, 41% and 35% change respectively (p < 0.01), increased [Ca⁺²]_d, [Na⁺]_d, ROS, and cTnT by 343%, 122%, 298%, and 610% change respectively (p < 0.01) compared to control. pGz pre-treatment attenuated the parameters mentioned above. In a separate cohort, the effects of a lethal dose of LPS on protein expression of nitric oxide synthases (iNOS, eNOS, nNOS), pro- and anti-inflammatory cytokines in hearts of mice was studied in pre-treated with pGz for three days prior to LPS (pGz-LPS) and post-treated with pGz 30 min after LPS (LPS-pGz) were determined. LPS increased expression of early and late iNOS and decreased expression of eNOS, phosphorylated eNOS (p-eNOS), and nNOS. Both pre- and post-treatment with pGz markedly reduced early and late pro-inflammatory surge. Therefore, pre- and post-treatment with pGz improves LPS-induced cardiomyocyte dysfunction, decreases iNOS expression, and increases cytoprotective eNOS and nNOS, with decreased pro-inflammatory response. Such results have potential for translation to benefit outcomes in human sepsis.

Fatty acid-binding protein 4 silencing protects against lipopolysaccharide-induced cardiomyocyte hypertrophy and apoptosis by inhibiting the Toll-like receptor 4-nuclear factor-κB pathway

Objective

To explore the effects and potential mechanisms of fatty acid-binding protein 4 (FABP4) in a lipopolysaccharide (LPS)-induced in vitro septic cardiomyopathy model.

Methods

Rat cardiomyocyte H9c2 cells were transfected with small interfering RNA (siRNA) against FABP4 (siFABP4), then induced with LPS. The following parameters were measured: cell viability, lactate dehydrogenase release, cardiac hypertrophy and related marker expression, apoptosis, inflammatory cytokine release and expression, and the activation of Toll-like receptor 4 (TLR4) and nuclear factor-κB (NF-κB) pathways.

Results

LPS increased the mRNA and protein expression of FABP4 in H9c2 cells. FABP4 silencing by siFABP4 significantly inhibited LPS-induced cardiac hypertrophy and reduced the mRNA expression of the myocardial hypertrophy markers atrial natriuretic peptide and brain natriuretic peptide. siFABP4 also attenuated LPS-induced increase in TUNEL-positive apoptotic cells, caspase-3 and caspase-9 activities, and the release and expression of proinflammatory cytokines. Mechanistically, we found that FABP4 silencing inhibited the mRNA and protein expression of TLR4 and suppressed the NF-kappa B signaling pathway, as evidenced by reduced nuclear NF-κB p65 and increased cytoplasmic I-κBα expression in LPS-stimulated H9c2 cells.

Conclusion

FABP4 silencing reduces LPS-induced cardiomyocyte hypertrophy and apoptosis by down-regulating the TLR4/NF-κB axis.