Vaspin protects rats against myocardial ischemia/reperfusion injury (MIRI) through the TLR4/NF-κB signaling pathway

(-)-Epicatechin protects against myocardial ischemia/reperfusion injury via autophagy-dependent ferroptosis

AIM

(-)-Epicatechin (EPI) has physiological activities such as antioxidant, anti-inflammatory and immune enhancement. In this study, we elucidated the protective effects of EPI in myocardial ischemia/reperfusion injury (MI/RI) and its mechanisms.

METHODS

An in vivo I/R model was constructed by performing left anterior descending coronary artery surgery on rats, and an in vitro I/R model was constructed by subjecting hypoxia/reperfusion treatment on H9C2 cells. The damage of cardiac tissues was detected by 2,3,5-triphenyltetrazolium chloride (TTC) and hematoxylin-eosin (H&E) staining, and expressions of ferroptosis-related proteins were examined by Western blot. Changes in the number of autophagosomes, the levels of oxidative stress and Fe2+ were also examined.

RESULTS

EPI reduced abnormal electrocardiogram waveform and infarct size caused by MI/RI in rats. The increasing trend of levels of reactive oxygen species (ROS) and Fe2+ was reversed by EPI, suggesting that EPI can reduce ferroptosis in vivo. Moreover, the levels of lipid ROS and LC3 in H9C2 cells were decreased with EPI treatment, and autophagy and ferroptosis were also alleviated in a dose-dependent manner in vitro. Co-cultivation of USP14 inhibitor IU1 and EPI further revealed that EPI regulates ferroptosis through the USP14-autophagy pathway.

CONCLUSIONS

EPI can reduce the level of oxidative stress by promoting USP14 to reduce autophagy, thus inhibiting autophagy dependent ferroptosis and reducing oxidative stress, and has a protective effect on myocardial infarction/myocardial infarction.

Systematic review and meta-analysis of the interventional effects of resveratrol in a rat model of myocardial ischemia-reperfusion injury

Objective: To evaluate the intervention effect of resveratrol on rat model of myocardial ischemia-reperfusion injury. Methods: The relevant studies on the intervention of resveratrol on rat models of myocardial ischemia reperfusion injury were searched in PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang and China Science and Technology Journal Database from the start of database establishment to January 2023. Data were extracted from studies that met the inclusion criteria. The results included electrocardiogram (ECG) and myocardial injury markers: ST changes, cardiac troponin I (cTn-I), cardiac troponin T (cTn-T), creatine kinase (CK), creatine kinase-MB (CK-MB) and lactate dehydrogenase (LDH); hemodynamic indicators: heart rate (HR), left ventricular diastolic pressure (LVDP), left ventricular end-diastolic pressure (LVEDP), left ventricular systolic pressure (LVSP), maximum rate of increase of left ventricular pressure (+dp/dtmax), maximum rate of decrease of left ventricular pressure (-dp/dtmax); oxidative damage indicators: nitric oxide (NO), reactive oxygen species (ROS), superoxide dismutase (SOD), malondialdehyde (MDA); inflammatory factors: tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6); apoptosis index: B-cell lymphoma-2 (Bcl-2), BCL2-Associated X (Bax), cardiomyocyte apoptosis index (AI); heart tissue structure: myocardial infarction size. Finally, a meta-analysis of these results was conducted. The methodological quality of the studies was assessed using the SYRCLE Bias Risk tool. Results: A total of 43 studies were included in the meta-analysis, and the quality of the included studies was assessed. It was found that the evidence quality of these 43 studies was low, and no study was judged to have low risk bias in all risk assessments. The results showed that resveratrol could reduce ST segment, cTn-I, cTn-T, CK, CK-MB, LDH, LVEDP, ROS, MDA, TNF-α, IL-6, AI levels and myocardial infarction size. HR, LVDP, LVSP, +dp/dtmax, NO, Bcl-2, and SOD levels were increased. However, resveratrol had no significant effect on -dp/dtmax and Bax outcome measures. Conclusion: Resveratrol can reduce ST segment in rat model of myocardial ischemia-reperfusion injury, alleviate myocardial injury, improve ventricular systolic and diastolic ability in hemodynamics, reduce inflammatory response and oxidative damage, and reduce myocardial necrosis and apoptosis. Due to the low quality of the methodologies included in the studies, additional research is required.

Blocking RIPK2 Function Alleviates Myocardial Ischemia/Reperfusion Injury by Regulating the AKT and NF-κB Pathways

OBJECTIVE

Inflammation and oxidation brought on by myocardial ischemia-reperfusion (MI/R) injury lead to cardiomyocyte apoptosis and necrosis. The receptor interacting serine/threonine kinase 2 (RIPK2) plays significant roles in oxidative stress and excessive inflammation. The purpose of this research is to examine the roles of RIPK2 in MI/R injury.

METHODS

The in vivo animal model was constructed by acute coronary I/R, and the in vitro cell model was established by oxygen and glucose deprivation/reperfusion (OGD/R)-stimulated cardiomyocyte injury. RIPK2 expression was examined using qRT-PCR and Western blot. CCK-8 was proposed as a method for detecting cell proliferation. ELISA was utilized to measure inflammatory cytokines (TNF-α, IL-6, and IL-1β) and myocardial injury indicators (CK-MB, Mb, cTnI, and LDH). The levels of MDA and ROS were determined by the kit and fluorescent probe. H&E was conducted to assess MI/R injury after silencing of RIPK2.

RESULTS

In MI/R rats and OGD/R-treated H9C2 cardiomyocytes, RIPK2 was overexpressed at both the mRNA and protein levels. RIPK2 inhibition promoted cell proliferation while inhibiting apoptosis, as evidenced by decreased TUNEL-positive cells and cleaved caspase-3. RIPK2 inhibition reduced MDA and ROS levels, as well as the contents of inflammatory factors. RIPK2 silencing reduced CK-MB, Mb, cTnI, and LDH levels in rat serum and alleviated MI/R injury. Furthermore, RIPK2 inhibition increased p-AKT while decreasing NF-B p-p65 expression.

CONCLUSION

Silencing of RIPK2 reduced apoptosis, proinflammatory factors, and oxidative stress in MI/R by activating AKT and suppressing NF-κB signals, suggesting a potential therapeutic strategy for MI/R injury.

CircRNA02318 Exerts Therapeutic Effects on Myocardial Ischemia-Reperfusion Injury Rats by Regulating the Nox1/Akt Through Inhibiting Drebrin

Our research aims to explore the therapeutic effect of circRNA02318 on MIRI rats and the functional mechanism. The MIRI model was constructed in rats. CircRNA02318 overexpressing adenovirus was injected in situ during MIRI perfusion. H9C2 cells were treated with hypoxia for 6 h and reoxygenation for 3 h. Overexpression of circRNA02318 downregulated Drebrin, Nox1, cleaved caspase-3 and Bax in H/R H9C2 cells and MIRI rat heart tissues, promoted the expression of p-Akt/Akt and Bcl-2, and inhibited the apoptosis of H9C2 cells. The volume of myocardial infarction and the release of LDH and TnI in MIRI rats were suppressed by circRNA02318. The Nox1, cleaved caspase-3 and Bax levels were promoted, the level of p-Akt/Akt and Bcl-2 was repressed, and the apoptosis was facilitated by the Drebrin overexpression. Furthermore, the effect of Drebrin overexpression on H9C2 cells was abolished by circRNA02318. Collectively, circRNA02318 exerted therapeutic effects on MIRI rats by inhibiting Drebrin.

TJ-M2010-5 Attenuates Severe Myocardial Ischemia/Reperfusion Injury in Heart Transplantation by Inhibiting MyD88 Homodimerization In Vivo

Survival of transplanted hearts is often limited by cold ischemia time. Here, we assessed the effects of the small molecular compound TJ-M2010-5 on graft preservation. In a cardiac cold ischemia/reperfusion model, TJ-M2010-5 ameliorated myocardial ischemia/reperfusion injury (MIRI) in histidine-tryptophan-ketoglutarate (HTK) organ preservation solution. When applied in HTK solution and on donors/recipients respectively, TJ-M2010-5 exerted optimal effects when applied as an additive in the HTK solution. TJ-M2010-5-administered mice exhibited shorter rebeating time; higher beating score; stronger and more regular sinus heart rate; and amelioration of apoptosis, inflammatory reactions, and myocardial injury. Mechanistically, TJ-M2010-5 inhibited the expression of key molecules in the toll-like receptor (TLR) signaling pathway and affected downstream proteins by inhibiting myeloid differentiation factor 88 homodimerization, thereby decreasing myocardial injury. Thus, TJ-M2010-5 may exert protective effects against MIRI by blocking the TLR signaling pathway. Our findings may lead to novel approaches for organ preservation, thereby reducing organ abandonment and improving recipient prognosis. The role of the TLR signaling pathway in MIRI progress and operation procedure of the MIRI model in vivo are presented in a graphical abstract (Online Abstract Figure).

Vaspin Attenuates Atrial Abnormalities by Promoting ULK1/FUNDC1-Mediated Mitophagy

The worldwide incidence and prevalence of atrial fibrillation (AF) are increasing, making it a life-threatening condition due to the higher numbers of people suffering from obesity. Vaspin, an adipokine derived from epicardial adipose tissue, has been reported to reduce inflammation, inhibit apoptosis, and induce autophagy; however, its role in the pathogenesis of AF is not known. In this study, we investigated the role of vaspin in patients with AF and explored the molecular mechanisms using atrial myocytes in vitro. Our data showed that vaspin levels were significantly reduced in the plasma of patients with AF. Lower plasma levels of vaspin were also associated with a higher risk of AF in patients with obesity. Vaspin treatment in vitro alleviated cardiomyocyte injury, atrial fibrosis, atrial myocyte apoptosis, and mitochondrial injury in atrial myocytes following Ang-II stress. Moreover, our results demonstrated that vaspin protected against Ang-II-induced atrial myocyte dysfunction by inducing mitophagy. We also observed that vaspin treatment enhanced the phosphorylation of Fun14 domain-containing protein 1 (FUNDC1) at Ser17 by unc-51 like autophagy activating kinase 1 (ULK1), resulting in the induction of mitophagy. These positive effects of vaspin were reversed by ULK1 silencing in Ang-II-stimulated HL-1 cells. Our study is the first to propose that vaspin plays a vital role in AF pathogenesis via ULK1/FUNDC1-regulated mitophagy and could be a novel therapeutic target for AF.

Serum vaspin as a predictor of severity and prognosis in acute ischemic stroke patients

Objective: The influence of vaspin on vascular health had been investigated, yielding conflicting results. This study is intended to investigate the relation between vaspin and stroke severity and stroke outcome in a cohort Chinese patient with acute ischemic stroke (AIS).Methods: This was a prospective single-center observational study in Xinxiang, China. From 1 July 2017 to 30 November 2019, all patients with first-ever AIS were consecutively included. Serum levels of vaspin, stroke severity at (assessed by NIHSS score) admission and functional outcome (assessed by modified Rankin Scale (mRS)) at discharge were recorded. Multivariate analyses were assessed using logistic regression models.Results: Finally, 340 patients with AIS were included. The median age of those patients was 65 (interquartile range [IQR], 56-74) years and 61.8% were men. At admission, 88 patients (25.9%) experienced severe stroke (NIHSS>10) and serum levels of vaspin (median [IQR]: 0.72[0.48-0.90]ng/ml) in those patients were significantly lower than in those mild(0.92[0.70-1.19]ng/ml) and moderate stroke (0.93[0.63-1.21]ng/ml). At discharge, 113 patients (33.2%) experienced poor functional outcome (mRS >2) and vaspin serum levels in those patients were lower as compared with patients who experienced good outcome (0.71[0.45-0.98] vs. 0.91[0.71-1.19]ng/ml). In multivariate analyses, lower level of vaspin (< median) was associated with a 2.5-fold (odds ratio [OR] 2.46; 95% confidence interval [CI]: 1.75-4.45) increased risk for severe stroke and a 2.1-fold (2.03; 1.42-3.58) increased risk for poor outcome.Conclusion: In conclusion, reduced serum levels of vaspin at admission are significantly related to stroke severity and prognosis, which illustrates a predictive role of reduced vaspin in ischemic stroke.

Vaspin Mediates the Intraorgan Crosstalk Between Heart and Adipose Tissue in Lipoatrophic Mice

Lipoatrophy is characterized as selective loss of adipose tissues, leading to the severity of cardiovascular disorders. Therefore, there was close intraorgan crosstalk between adipose tissue and cardiovascular in lipoatrophy. A-ZIP/F-1 mouse, a well-established lipoatrophic model, and primary cardiomyocytes were used for investigating the pathophysiological changes and molecular mechanisms. A-ZIP/F-1 mice had severe fat loss and impaired ventricular function during growth, but closely associated with the reduction of circulating vaspin levels. Administration of recombinant vaspin protein improved cardiac structural disorders, left ventricular dysfunction, and inflammatory response in lipoatrophic mice. In detail, vaspin decreased cardiac lipid deposits, but enhanced mitochondrial biogenesis and activities. Interestingly, A-ZIP/F-1 mice transplanted with normal visceral adipose tissues exhibited improvement in cardiac structural remodeling and mitochondrial function. Mechanistically, vaspin increased cardiac AKT activity, which guaranteed the mitochondrial benefits of vaspin in lipoatrophic mice and primary mouse cardiomyocytes. The present study suggested that vaspin possessed biological benefits in attenuating lipoatrophy-induced cardiomyopathy onset, and targeting vaspin/AKT signaling was a potential strategy to maintain heart metabolism.

Downregulation of p300/CBP-associated factor inhibits cardiomyocyte apoptosis via suppression of NF-κB pathway in ischaemia/reperfusion injury rats

Cardiomyocyte apoptosis is the main reason of cardiac injury after myocardial ischaemia-reperfusion (I/R) injury (MIRI), but the role of p300/CBP-associated factor (PCAF) on myocardial apoptosis in MIRI is unknown. The aim of this study was to investigate the main mechanism of PCAF modulating cardiomyocyte apoptosis in MIRI. The MIRI model was constructed by ligation of the rat left anterior descending coronary vessel for 30 min and reperfusion for 24 h in vivo. H9c2 cells were harvested after induced by hypoxia for 6 h and then reoxygenation for 24 h (H/R) in vitro. The RNA interference PCAF expression adenovirus was transfected into rat myocardium and H9c2 cells. The area of myocardial infarction, cardiac function, myocardial injury marker levels, apoptosis, inflammation and oxidative stress were detected respectively. Both I/R and H/R remarkably upregulated the expression of PCAF, and downregulation of PCAF significantly attenuated myocardial apoptosis, inflammation and oxidative stress caused by I/R and H/R. In addition, downregulation of PCAF inhibited the activation of NF-κB signalling pathway in cardiomyocytes undergoing H/R. Pretreatment of lipopolysaccharide, a NF-κB pathway activator, could blunt these protective effects of PCAF downregulation on myocardial apoptosis in MIRI. These results highlight that downregulation of PCAF could reduce cardiomyocyte apoptosis by inhibiting the NF-κB pathway, thereby providing protection for MIRI. Therefore, PCAF might be a promising target for protecting against cardiac dysfunction induced by MIRI.

Daphnetin Preconditioning Decreases Cardiac Injury and Susceptibility to Ventricular Arrhythmia following Ischaemia-Reperfusion through the TLR4/MyD88/NF-Κb Signalling Pathway

BACKGROUND/AIMS

Daphnetin (7,8-dihydroxycoumarin, DAP) exhibits various bioactivities, such as anti-inflammatory and antioxidant activities. However, the role of DAP in myocardial ischaemia/reperfusion (I/R) injury and I/R-related arrhythmia is still uncertain. This study aimed to investigate the mechanisms underlying the effects of DAP on myocardial I/R injury and electrophysiological properties in vivo and in vitro.

METHODS

Myocardial infarct size was measured by triphenyltetrazolium chloride staining. Cardiac function was assessed by echocardiographic and haemodynamic analyses. The levels of creatine kinase-MB, lactate dehydrogenase, malondialdehyde, superoxide dismutase, interleukin-6 (IL-6), and tumour necrosis factor-alpha (TNF-α) were detected using commercial kits. Apoptosis was measured by terminal deoxynucleotidyl-transferase-mediated dUTP nick-end labelling staining and flow cytometry. The viability of H9c2 cells was determined by the Cell Counting Kit-8 assay. In vitro, the levels of IL-6 and TNF-α were measured by quantitative PCR. The expression levels of proteins associated with apoptosis, inflammation, and the Toll-like receptor 4/myeloid differentiation factor 88/nuclear factor kappa B (TLR4/MyD88/NF-κB) signalling pathway were detected by Western blot analysis. The RR, PR, QRS, and QTc intervals were assessed by surface ECG. The 90% action potential duration (APD90), threshold of APD alternans, and ventricular tachycardia inducibility were measured by the Langendorff perfusion technique.

RESULTS

DAP preconditioning decreased myocardial I/R injury and hypoxia/reoxygenation (H/R) injury in cells. DAP preconditioning improved cardiac function after myocardial I/R injury. DAP preconditioning also suppressed apoptosis, attenuated oxidative stress, and inhibited inflammatory responses in vivo and in vitro. Furthermore, DAP preconditioning decreased the susceptibility to ventricular arrhythmia after myocardial I/R. Finally, DAP preconditioning inhibited the expression of TLR4, MyD88, and phosphorylated NF-κB (p-NF-κB)/P65 in mice subjected to I/R and cells subjected to H/R.

CONCLUSIONS

DAP preconditioning protected against myocardial I/R injury and decreased susceptibility to ventricular arrhythmia by inhibiting the TLR4/MyD88/NF-κB signalling pathway.

Resveratrol inhibits necroptosis by mediating the TNF-α/RIP1/RIP3/MLKL pathway in myocardial hypoxia/reoxygenation injury

Resveratrol (RES) protects myocardial cells from hypoxia/reoxygenation (H/R)-caused injury. However, the mechanism of this effect has not been clarified. Thus, in this study, we aimed to determine whether RES attenuates H/R-induced cell necroptosis by inhibiting the tumor necrosis factor-alpha (TNF-α)/receptor-interacting protein kinase 1 (RIP1)/RIP3/mixed-lineage kinase domain-like (MLKL) signaling pathway. Rat myocardial ischemia/reperfusion (I/R) models and H/R-injured cell models were constructed. Our study showed that myocardial H/R injury significantly increased the levels of TNF-α, RIP1, RIP3, and p-MLKL/MLKL by western blot analysis. Cell viability assay and 4,6-dianmidino-2-phenylindole (DAPI)-propidium iodide staining showed that the cell viability was decreased, and necroptosis was increased after myocardial H/R injury. The expressions of TNF-α, RIP1, RIP3, and p-MLKL/MLKL in H/R myocardial cells treated with different concentrations of RES were significantly downregulated. In addition, we also found that the cell viability was increased and necroptosis was decreased in dose-dependent manners when H/R-injured cells were treated with RES. In addition, the enhanced effect of TNF-α on necroptosis in myocardial H/R-injured cells was improved by RES, and the effect of RES was confirmed in vivo in I/R rats. This study also showed that RES suppresses necroptosis in H9c2 cells, which may occur through the inhibition of the TNF-α/RIP1/RIP3/MLKL signaling pathway. Our data suggest that necroptosis is a promising therapeutic target and may be a promising therapeutic target for the treatment of myocardial I/R injury.

Overexpression of Activating Transcription Factor 3 Alleviates Cardiac Microvascular Ischemia/Reperfusion Injury in Rats

Activating transcription factor 3 (ATF3) has been confirmed to be responsive to oxidative stress and to negatively regulate the activity of Toll-like receptor 4 (TLR4). However, the effect of ATF3 on cardiac microvascular ischemia/reperfusion (I/R) injury remains unknown. The GEO2R online tool was employed to obtain differentially expressed genes GSE4105 and GSE122020, in two rat I/R injury microarray datasets. We established a rat myocardial I/R model in vivo, and also generated an in vitro hypoxia/reoxygenation (H/R) model of cardiomyoblast H9c2 cells. Overexpression of ATF3 was achieved by adenoviral-mediated gene transfer (Ad-ATF3). Rats were randomly divided into four groups: sham, I/R, I/R + Ad-Lacz (as a control), and I/R + Ad-ATF3. ELISA, CCK-8, DCFH-DA probe, qRT-PCR and Western blotting were used to determine the expression of ATF3, oxidative indices, cellular injury and TLR4/NF-κB pathway-associated proteins. Transmission electron microscopy, immunohistochemistry and immunofluorescence were used to detect the leukocyte infiltration and the alteration of microvascular morphology and function in vivo. Echocardiographic and hemodynamic data were also obtained. Bioinformatics analysis revealed that ATF3 was upregulated in I/R myocardia in two independent rat myocardial I/R models. Cardiac microvascular I/R injury included leukocyte infiltration, microvascular integrity disruption, and microvascular perfusion defect, which eventually resulted in the deterioration of hemodynamic parameters and heart function. Ad-ATF3 significantly restored microvascular function, increased cardiac microvascular perfusion, and improved hemodynamic parameters and heart function. Mechanistically, Ad-ATF3 ameliorated oxidative stress, inhibited TLR4/NF-κB pathway activation and down-regulated the expression of downstream proinflammatory cytokines in I/R myocardium in vivo and in H/R H9c2 cells in vitro. ATF3 overexpression protects against cardiac microvascular I/R injury in part by inhibiting the TLR4/NF-κB pathway and oxidative stress.

Protective action of the ginsenoside Rh3 in a rat myocardial ischemia-reperfusion injury model by inhibition of apoptosis induced via p38 mitogen-activated protein kinase/caspase-3 signaling

OBJECTIVE

To investigate the protective effects of the ginsenoside Rh3 on rats subjected to myocardial ischemia-reperfusion (MIR) via its impact on caspase-3 and the p38 mitogen-activated protein kinase (MAPK) pathway.

METHODS

Fifteen male Sprague-Dawley rats were randomly categorized into the MIR group (MY group, n = 5), sham surgery group (SS group, n = 5), and ginsenoside Rh3 group (GR group, n = 5).

RESULTS

The MY group exhibited the largest myocardial infarctions compared with the GR and SS groups. The GR group exhibited significantly higher cell viability of cardiomyocytes and significantly decreased apoptosis compared with the MY group. Fibrils of infarcted tissue in the GR group were disordered but less swollen, with a more organized fibril orientation than those in the MY group. The GR group showed reduced p-p38 MAPK protein and caspase-3 mRNA expression levels compared with the MY and SS groups.

CONCLUSIONS

Rh3 significantly improved myocardial necrosis and caspase-3 levels in myocardial tissues by suppressing the p38 MAPK pathway, thereby inhibiting caspase-3 involvement in apoptosis. Thus, Rh3 was effective in inhibiting the escalated apoptotic pathway in myocardial infarction and can potentially serve as a useful therapeutic agent to rescue myocardial infarction.

Role of HSP90 in suppressing TLR4-mediated inflammation in ischemic postconditioning

BACKGROUND

Myocardial inflammation mediated by toll-like receptor 4 (TLR4) plays an active role in myocardial ischemia/reperfusion (I/R) injury. Studies show that heat shock protein 90 (HSP90) is involved in ischemic postconditioning (IPostC) cardioprotection. This study investigates the roles of TLR4 and HSP90 in IPostC.

METHODS

Rats were subjected to 30 min ischemia, then 2 h reperfusion. IPostC was applied by three cycles of 30 s reperfusion, then 30 s reocclusion at reperfusion onset. Sixty rats were randomly divided into four groups: sham, I/R, IPostC, and geldanamycin (GA, HSP90 inhibitor, 1 mg/kg) plus IPostC (IPostC + GA).

RESULTS

IPostC significantly reduced I/R-induced infarct size (40.2±2.1% versus 28.4±2.4%; P < 0.05); the release of cardiac Troponin T, creatine kinase-MB, and lactate dehydrogenase (191.5±3.1 versus 140.6±3.3 pg/ml, 3394.6±132.7 versus 2880.7±125.5 pg/ml, 2686.2±98.6 versus 1848.8±90.1 pg/ml, respectively; P < 0.05); and cardiomyocyte apoptosis (40.3±2.2% versus 27.0±1.6%; P < 0.05). Further, local and circulating IL-1β, IL-6, TNF-α, and ICAM-1 levels decreased; TLR4 expression and nuclear factor-KB (NF-κB) signaling decreased; and cardiac HSP90 expression increased. Blocking HSP90 function with GA inhibited IPostC protection and anti-inflammation, suggesting that IPostC has a HSP90-dependent anti-inflammatory effect.

CONCLUSION

HSP90 may play a role in IPostC-mediated cardioprotection by inhibiting TLR4 activation, local and systemic inflammation, and NF-kB signaling.

Huoxin Pill Attenuates Cardiac Inflammation by Suppression of TLR4/NF-κB in Acute Myocardial Ischemia Injury Rats

Huoxin Pill (HXP), a traditional Chinese medicine, has been prescribed widely in the treatment of coronary heart disease, angina pectoris, and other diseases. However, the possible protective mechanisms of HXP on myocardial ischemia remain unclear. In the current study, we investigated the effects and potential mechanism of HXP on myocardial ischemia and cardiac inflammation and the activation of TLR4/NF-κB pathway. Determination of electrocardiogram, echocardiography, and heart weight index (HWI) indicated that HXP treatment obviously attenuated the elevation of ST-segment, end-diastolic volume, and HWI in the AMI rat model. Enzyme-linked immunosorbent assay (ELISA) demonstrated that Huoxin Pill treatment significantly decreased the levels of CTnT, CK-MB, MDA, IL-6, and TNF-α, while it increased SOD content in serum of the AMI rat model. Moreover, hematoxylin and eosin (HE) and immunohistochemistry (IHC) staining revealed that HXP treatment alleviated pathological change, infiltration of inflammatory cells, levels of IL-6 and TNF-α, and expression of TLR4 and p-NF-κB in cardiac tissues of the AMI rat model. In conclusion, HXP treatment significantly improves cardiac function and attenuates cardiac inflammation by suppressing the activation of TLR4/NF-κB pathway in the ISO-induced AMI rat model. This study provides insights into the potential of HXP on prevention and treatment of AMI.

Downregulation of DEC1 by RNA interference attenuates ischemia/reperfusion-induced myocardial inflammation by inhibiting the TLR4/NF-κB signaling pathway

Inflammation has been implicated in the pathogenesis of myocardial ischemia/reperfusion (I/R) injury (MIRI). Previous studies have confirmed that deleted in esophageal cancer 1 (DEC1) is an important transcription factor in inflammation. However, the role of DEC1 in MIRI remains unclear. The present study aimed to determine whether the downregulation of DEC1 by RNA interference alleviated inflammation to protect against MIRI. Adult Sprague-Dawley rats (n=48) were randomly divided into four groups: Sham; I/R; adenovirus expressing green fluorescent protein control (Ad-G-Control); and DEC1-targeting RNA interference (Ad-G-DEC1) groups. Following gene delivery 4 days later, the rat myocardial I/R model was established and myocardial enzymes [creatine kinase (CK) and lactate dehydrogenase (LDH)] were detected. Hematoxylin and eosin (H&E) staining was performed to evaluate the myocardial damage and the infarct area was assessed using Evans Blue/triphenyltetrazolium chloride staining. The inflammatory mediators interleukin (IL)-β and tumor necrosis factor (TNF)-α were also detected using ELISA kits to assess the inflammatory response. Finally, western blotting and reverse transcription-quantitative PCR were used to analyze the expression levels of associated proteins and mRNAs. Ad-G-DEC1 RNA interference markedly decreased DEC1 expression levels. In addition, following the downregulation of DEC1 expression, the infarct size, CK, LDH, Toll-like receptor (TLR)4, NF-κB, IL-β and TNF-α levels were all significantly decreased. In conclusion, the results of the present study suggested that the downregulation of DEC1 may decrease the inflammation by suppressing the TLR4/NF-κB signaling pathway, which may represent a therapeutic target for MIRI.

Adeno-associated Virus 9-mediated Small RNA Interference of TLR4 Alleviates Myocardial Ischemia and Reperfusion Injury by Inhibition of the NF-κB and MAPK Signaling Pathways in Rats

BACKGROUND

Despite intensive investigation, effective therapeutic procedures for myocardial I/R injury are still in demand.

OBJECTIVE

To explore the effect of adeno-associated virus 9 (AAV9)-mediated small interfering RNA targeting TLR4 in the treatment of myocardial ischemia and reperfusion (I/R) injury and its influence on the NF-κB and MAPK signaling pathways.

METHODS

Rats were divided into 3 groups, namely, the sham, AAV9-siRNA control, and AAV9-TLR4 siRNA groups. siRNA solution or normal saline was injected through the tail vain. The rat myocardial I/R injury model was then established. HE staining and TUNEL staining were applied to compare the pathological changes in cardiomyocytes in the three groups. Immunohistochemical staining and western blotting were utilized to detect TLR4 expression under siRNA interference. Serum inflammatory factor (IL-1β, TNF-α) expression was determined by an ELISA commercial kit. Key proteins in the MAPK (p38, JNK 1/2) and NF-κB (p65) signaling pathways were determined to identify the TLR4 siRNA functional mechanism.

RESULTS

Fluorescence microscopic images of the myocardium indicated that AAV9- mediated siRNA was efficiently transfected into the myocardium, and the infarcted size after I/R injury was decreased by AAV9-TLR4 siRNA when compared with negative control rats (P<0.05). TLR4 protein expression was significantly decreased by siRNA interference (P<0.001). Apoptosis-related factor BCL-2 expression was increased in the TLR4 gene silencing group, whereas Bax expression was decreased. The Bax/BCL-2 ratio was also decreased, demonstrating a protective effect for cardiomyocytes. Inflammatory factors were lower in the TLR4 gene silencing group than in the siRNA control group (P<0.001). The MAPK and NF-κB signaling pathways were activated in myocardial I/R injury; however, the primary proteins in these two signaling pathways were downregulated upon interference of TLR4 siRNA, with significant differences (P<0.05).

CONCLUSION

AAV9-TLR4 siRNA has a positive effect on myocardial I/R injury by inhibiting the MAPK and NF-κB signaling pathways and can be used as a potential therapeutic method for myocardial I/R injury.

Metabolomics Analysis of the Effect of Hydrogen-Rich Water on Myocardial Ischemia-Reperfusion Injury in Rats

To investigate the effect of hydrogen-rich water on myocardial tissue metabolism in a myocardial ischemia-reperfusion injury (MIRI) rat model. Twelve rats were randomly divided into a hydrogen-rich water group and a control group of size 6 each. After the heart was removed, it was fixed in the Langendorff device, and the heart was perfused with 37 °C perfusion solution pre-balanced with oxygen. The control group was perfused with Kreb's-Ringers (K-R) solution, and the hydrogen-rich water group was perfused with K-R solution + hydrogen-rich water. Liquid Chromatograph Mass Spectrometer (LC-MS) analysis platform was used for metabolomics research. Principle component analysis (PCA), partial least squares discriminant analysis (PLS-DA), orthogonal partial least squares discriminant analysis (OPLS-DA), Variable importance in projection (VIP) value of OPLS-DA model (threshold value ≥1) were employed with independent sample T Test (p < 0.05) to find differentially expressed metabolites, and screen for differential metabolic pathways. VIP (OPLS-DA) analysis was performed with T test, and the metabolites of the control group and the hydrogen-rich water group were significantly different, and the glycerophospholipid metabolism was screened. Seven myocardial ischemia-reperfusion injury (MIRI)-related signaling pathways were identified, including glycerophospholipid metabolism, glycosylphosphatidylinositol (GPI) anchored biosynthesis, and purine metabolism, as well as 10 biomarkers such as phosphatidylcholine, phosphatidylethanolamine and phosphatidylserine. Hydrogen-rich water regulates the metabolic imbalance that could change MIRI myocardial tissue metabolism, and alleviate ischemia-reperfusion injury in isolated hearts of rats through multiple signaling pathways.

Plasma vaspin is an effective biomarker for evaluation of future cardiovascular events in patients with chest pain: a 5-year retrospective observational study

Background

Our previous study showed that visceral adipose tissue-derived serpin (vaspin) was an independent predictor of coronary artery disease (CAD). Further, plasma vaspin levels in patients with unstable angina pectoris were lower than those in patients with stable angina pectoris. In this study, we investigated the prognostic relevance of plasma vaspin levels in patients with CAD and non-CAD.

Methods

It was a retrospective observational study. A total of 197 patients with chest pain were enrolled, of which 88 patients with CAD and 109 patients with non-CAD were confirmed by angiography. Plasma vaspin levels and clinical parameters were measured at baseline. Incidence of major adverse cardiac event (MACE) was determined on follow-up.

Results

One hundred eighty-nine patients were successfully followed up for 5 years, of which 63 patients experienced MACEs. Patients with low vaspin levels (<0.385 ng/mL) experienced a higher incidence of MACE as compared to patients with high vaspin levels (>0.385 ng/mL) (42.55% vs. 24.21%, respectively; P=0.007). In both CAD and non-CAD groups, patients with high vaspin levels showed improvement in left ventricular ejection fraction. Kaplan Meier survival curves showed that patients with low vaspin levels had an obviously higher timing of incidence of MACE in the whole population (P=0.006) and in the non-CAD subgroup (P=0.009); however, the trend was not significant in the CAD subgroup. On multivariate analyses, plasma vaspin level was found to be an independent predictor of MACE, particularly in the non-CAD group.

Conclusions

Plasma vaspin may be a useful biomarker for prediction of MACE in patients with chest pain.

Biochanin A attenuates myocardial ischemia/reperfusion injury through the TLR4/NF-κB/NLRP3 signaling pathway

PURPOSE

Myocardial ischemia/reperfusion (Ml/R) injury is a leading cause of damage in cardiac tissues, with high rates of mortality and disability. Biochanin A (BCA) is a main constituent of Trifolium pratense L. This study was intended to explore the effect of BCA on Ml/R injury and explore the potential mechanism.

METHODS

In vivo MI/R injury was established by transient coronary ligation in Sprague-Dawley rats. Triphenyltetrazolium chloride staining (TTC) was used to measure myocardial infarct size. ELISA assay was employed to evaluate the levels of myocardial enzyme and inflammatory cytokines. Western blot assay was conducted to detect related protein levels in myocardial tissues.

RESULTS

BCA significantly ameliorated myocardial infarction area, reduced the release of myocardial enzyme levels including aspartate transaminase (AST), creatine kinase (CK-MB) and lactic dehydrogenase (LDH). It also decreased the production of inflammatory cytokines (IL-1β, IL-18, IL-6 and TNF-α) in serum of Ml/R rats. Further mechanism studies demonstrated that BCA inhibited inflammatory reaction through blocking TLR4/NF-kB/NLRP3 signaling pathway.

CONCLUSION

The present study is the first evidence demonstrating that BCA attenuated Ml/R injury through suppressing TLR4/NF-kB/NLRP3 signaling pathway-mediated anti-inflammation pathway.

The endocrine function of adipose tissues in health and cardiometabolic disease

In addition to their role in glucose and lipid metabolism, adipocytes respond differentially to physiological cues or metabolic stress by releasing endocrine factors that regulate diverse processes, such as energy expenditure, appetite control, glucose homeostasis, insulin sensitivity, inflammation and tissue repair. Both energy-storing white adipocytes and thermogenic brown and beige adipocytes secrete hormones, which can be peptides (adipokines), lipids (lipokines) and exosomal microRNAs. Some of these factors have defined targets; for example, adiponectin and leptin signal through their respective receptors that are expressed in multiple organs. For other adipocyte hormones, receptors are more promiscuous or remain to be identified. Furthermore, many of these hormones are also produced by other organs and tissues, which makes defining the endocrine contribution of adipose tissues a challenge. In this Review, we discuss the functional role of adipose tissue-derived endocrine hormones for metabolic adaptations to the environment and we highlight how these factors contribute to the development of cardiometabolic diseases. We also cover how this knowledge can be translated into human therapies. In addition, we discuss recent findings that emphasize the endocrine role of white versus thermogenic adipocytes in conditions of health and disease.

Gene expression profiling analysis to investigate the role of remote ischemic postconditioning in ischemia-reperfusion injury in rats

Background

Blood flow restoration is a definitive therapy for salvaging the myocardium following ischemic injury. Nevertheless, the sudden restoration of blood flow to the ischemic myocardium can induce ischemia-reperfusion injury (IRI).

Results

Herein, we investigated the cardioprotective effect of remote ischemic postconditioning (RPostC) through our in vivo rat model of myocardial IRI. The study included three groups: the control group, the IRI group, and the IRI + RPostC group. Ischemia-reperfusion treatment led to an increase in the myocardial infarction area, which was inhibited by RPostC. In contrast to that in the control group, the myocardial apoptosis level was enhanced in the IRI group, whereas RPostC treatment decreased IRI-induced cellular apoptosis. Affymetrix Rat Gene 2.0 ST chip data identified a total of 265 upregulated genes and 267 downregulated genes between the IRI and IRI + RPostC groups. A group of differentially expressed noncoding RNAs (ncRNAs), such as MTA_TC0600002772.mm, MTA_TC1300002394.mm, U7 small nuclear RNA (Rnu7) and RGD7543256_1, were identified. Gene Ontology (GO) enrichment analysis indicated that the positive regulation of some molecular functions, such as GTPase activity, GTP binding, cyclic-nucleotide phosphodiesterase activity and cytokine activity, may contribute to the cardioprotective role of RPostC. Moreover, pathway enrichment analysis using the Kyoto Encyclopedia of Genes and Genomes (KEGG) suggested the potential implication of the TNF signaling pathway and Toll-like receptor signaling pathway. Global signal transduction network analysis, co-expression network analysis and quantitative real-time polymerase chain reaction analysis further identified several core genes, including Pdgfra, Stat1, Lifr and Stfa3.

Conclusion

Remote ischemic postconditioning treatment can decrease IRI-mediated myocardial apoptosis by regulating multiple processes and pathways, such as GTPase activity, cytokine activity, and the TNF and Toll-like receptor signaling pathways. The potential role of the above ncRNAs and core genes in IRI-induced cardiac damage merits further study as well.

Electronic supplementary material

The online version of this article (10.1186/s12864-019-5743-9) contains supplementary material, which is available to authorized users.

Nesfatin-1 and Vaspin as Potential Novel Biomarkers for the Prediction and Early Diagnosis of Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is considered to be one of the most frequent medical complication observed among pregnant women. The role of adipokines in the pathogenesis of GDM remains strictly unknown. Different adipokines have been studied throughout gestation, and they have been proposed as biomarkers of GDM and other pregnancy-related complications; however, there is no biomarker reported for GDM screening at present. The aim of this study was to evaluate serum nesfatin-1 and vaspin levels in GDM and non-GDM women, to characterize the correlation between these adipokines, and to assess the potential role of circulating adipokines in the prediction of risk of gestational diabetes mellitus. Serum concentrations of nesfatin-1 and vaspin were measured in 153 women with GDM, and in 84 patients with uncomplicated pregnancy by enzyme-linked immunosorbent assay (ELISA) kits, according to the manufacturer's instructions. Circulating levels of nesfatin-1 and vaspin were significantly lower in the GDM group than in the control group. Nesfatin-1 levels were negatively correlated with vaspin levels. The results of this study point out the possible role of nesfatin-1 and vaspin as potential novel biomarkers for the prediction and early diagnosis of GDM. Further studies are necessary to evaluate the influence of nesfatin-1 and vaspin on glucose metabolism in the early stages of GDM.

MicroRNA-7b attenuates ischemia/reperfusion-induced H9C2 cardiomyocyte apoptosis via the hypoxia inducible factor-1/p-p38 pathway

OBJECTIVE

MicroRNAs (miRNAs) have been shown to play crucial roles in the occurrence, development, and treatment of many cardiovascular diseases. Coronary heart disease (CAD)-related miRNAs are still a growing research area. miR-7b was reported to be downregulated in acute myocardial infarction (AMI) myocardium tissues. However, it remains largely unknown whether miR-7b is involved in the pathogenesis and progression of the AMI ischemia/reperfusion (I/R) injury.

METHODS

Male C57BL/6 J mice and H9C2 cells were used as models in this study. Masson staining, real-time polymerase chain reaction, Western blot analysis, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeling immunofluorescence staining assays were performed to detect the related indicators in the study. SPSS 17.0 software was used to calculate the experimental data.

RESULTS

The results showed that miR-7b expression is downregulated after I/R in mice, and miR-7b could inhibit apoptosis in I/R-induced H9C2 cells via upregulating hypoxia-inducible factor 1a (HIF1a). The inhibitory effect of miR-7b on I/R-induced apoptosis in H9C2 cells was blocked by HIF1a silencing. In addition, our data suggested that the p-P38 pathway may be involved in the role of miR-7 in I/R-induced H9C2 cell apoptosis.

CONCLUSION

We confirmed that the overexpression of miR-7b inhibits I/R-induced apoptosis in H9C2 cells by targeting the HIF1a/p-P38 pathway. Our findings not only demonstrate the potential role of miR-7b in attenuating I/R-induced apoptosis but also provide a new insight into the better prevention of the I/R injury by mediating HIF-1 and p-P38.

Inhibition of glycogen synthase kinase-3β is involved in cardioprotection by α7nAChR agonist and limb remote ischemic postconditionings

The present study was designed to determine whether glycogen synthase kinase-3β (GSK-3β) was involved in the cardioprotection by α7 nicotinic acetylcholine receptor (α7nAChR) agonist and limb remote ischemic postconditionings. Forty male Sprague-Dawley rats were randomly divided equally into control (C), α7nAChR agonist postconditioning (P), limb remote ischemic postconditioning (L), combined α7nAChR agonist and limb remote ischemic postconditioning (P+L) groups. At the end of experiment, serum cTnI, creatine kinase-MB (CK-MB), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), high mobility group protein (HMGB1) and interleukin-10 (IL-10) levels were measured; infarct size (IS), myocardial expressions of GSK-3β, p-GSK-3β (Ser9), nuclear factor-κB (NF-κB) and p-NF-κB (Ser536) in the ischemic area were assessed. The results showed that compared with group C, IS, serum cTnI and CK-MB levels obviously decreased in groups P, L and P+L. Compared with groups P and L, IS, serum cTnI and CK-MB levels significantly decreased in group P+L. Compared with group C, serum TNF-α, IL-6 and HMGB1 levels, and myocardial expression of p-NF-κBp65 (Ser536) evidently decreased, and myocardial expression of p-GSK-3β (Ser9) obviously increased in groups P, L and P+L. Compared with group P, serum TNF-α, IL-6 and HMGB1 levels and myocardial expression of p-NF-κBp65 (Ser536) significantly increased, and myocardial expression of p-GSK-3β (Ser9) evidently decreased in group L. Compared with group L, serum TNF-α, IL-6, HMGB1 levels, and myocardial expression of p-NF-κBp65 (Ser536) significantly decreased, and myocardial expression of p-GSK-3β (Ser9) obviously increased in group P+L. In conclusion, our findings indicate that inhibition of GSK-3β to decrease NF-κB transcription is one of cardioprotective mechanisms of α7nAChR agonist and limb remote ischemic postconditionings by anti-inflammation, but improved cardioprotection by combined two interventions is not completely attributable to an enhanced anti-inflammatory mechanism.