Salvianolic acid B induced upregulation of miR-30a protects cardiac myocytes from ischemia/reperfusion injury

Crosstalk among Reactive Oxygen Species, Autophagy and Metabolism in Myocardial Ischemia and Reperfusion Stages

Myocardial ischemia is the most common cardiovascular disease. Reperfusion, an important myocardial ischemia tool, causes unexpected and irreversible damage to cardiomyocytes, resulting in myocardial ischemia/reperfusion (MI/R) injury. Upon stress, especially oxidative stress induced by reactive oxygen species (ROS), autophagy, which degrades the intracellular energy storage to produce metabolites that are recycled into metabolic pathways to buffer metabolic stress, is initiated during myocardial ischemia and MI/R injury. Excellent cardioprotective effects of autophagy regulators against MI and MI/R have been reported. Reversing disordered cardiac metabolism induced by ROS also exhibits cardioprotective action in patients with myocardial ischemia. Herein, we review current knowledge on the crosstalk between ROS, cardiac autophagy, and metabolism in myocardial ischemia and MI/R. Finally, we discuss the possible regulators of autophagy and metabolism that can be exploited to harness the therapeutic potential of cardiac metabolism and autophagy in the diagnosis and treatment of myocardial ischemia and MI/R.

Comparison of Protective Effect of Tri-circulator and Coenzyme Q10 on Myocardial Injury and the Mechanism Study by Zebrafish Model

Tri-Circulator (TC) is a product comprising coenzyme Q10 (CoQ10), Salvia miltiorrhiza, and Panax notoginseng. Individually, each of these constituents has demonstrated protective effects on myocardial injury. The purpose of this study is to evaluate the protective efficacy of TC on heart function and compare the differential effects between CoQ10 and TC. Two myocardial injury models of zebrafish, the hypoxia-reoxygenation model (H/R) and the isoproterenol (ISO, a β-receptor agonist) model, were used in this experiment. The zebrafish subjects were divided into 4 groups: control, H/R, TC, and CoQ10. Heart rate, stroke volume (SV), cardiac output (CO), ejection fraction (EF), fractional area change (FAC), and pericardial height were monitored to assess changes in heart function. The gene expression of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) was studied as markers of injury/stress. TC significantly suppresses elevated heart rate induced by H/R and prevents the decrease of heart rate induced by ISO. It alleviates the pericardial infusion induced by ISO, whereas CoQ10 does not possess a similar effect. Both TC and CoQ10 significantly inhibit the decline in SV, CO, EF, and FAC induced by H/R and ISO, and suppress the expression of ANP and BNP in cardiomyocytes induced by ISO. It is noteworthy that TC demonstrates a more pronounced effect on EF, FAC, ANP, and BNP gene expression compared to CoQ10. Both TC and CoQ10 have a protective effect on myocardial injury of zebrafish. However, TC exhibits a greater efficacy compared to CoQ10 alone in mitigating myocardial injury.

Salvianolic acids and its potential for cardio-protection against myocardial ischemic reperfusion injury in diabetes

The incidence of diabetes and related mortality rate increase yearly in modern cities. Additionally, elevated glucose levels can result in an increase of reactive oxygen species (ROS), ferroptosis, and the disruption of protective pathways in the heart. These factors collectively heighten the vulnerability of diabetic individuals to myocardial ischemia. Reperfusion therapies have been effectively used in clinical practice. There are limitations to the current clinical methods used to treat myocardial ischemia-reperfusion injury. As a result, reducing post-treatment ischemia/reperfusion injury remains a challenge. Therefore, efforts are underway to provide more efficient therapy. Salvia miltiorrhiza Bunge (Danshen) has been used for centuries in ancient China to treat cardiovascular diseases (CVD) with rare side effects. Salvianolic acid is a water-soluble phenolic compound with potent antioxidant properties and has the greatest hydrophilic property in Danshen. It has recently been discovered that salvianolic acids A (SAA) and B (SAB) are capable of inhibiting apoptosis by targeting the JNK/Akt pathway and the NF-κB pathway, respectively. This review delves into the most recent discoveries regarding the therapeutic and cardioprotective benefits of salvianolic acid for individuals with diabetes. Salvianolic acid shows great potential in myocardial protection in diabetes mellitus. A thorough understanding of the protective mechanism of salvianolic acid could expand its potential uses in developing medicines for treating diabetes mellitus related myocardial ischemia-reperfusion.

Shenmai injection ameliorates doxorubicin-induced myocardial injury by suppressing autophagy-apoptosis via miR-30a

CONTEXT

Autophagy-apoptosis is the core mechanism of doxorubicin-induced myocardial injury. miR-30a is a pivotal factor in the regulation of autophagy and apoptosis. It remains unclear whether SMI exerts cardioprotective effect by regulating autophagy and apoptosis via miR-30a.

OBJECTIVE

This study evaluates the effects of SMI on ameliorating doxorubicin-induced myocardial injury.

MATERIALS AND METHODS

The level of LDH and CK, and the expression of miR-30a was detected. mCherry-EGFP-LC3B double fluorescence was used to observe autophagy flow. Apoptosis was detected by Annexin V/PI staining. Western Blot was used to estimate the expression of autophagy related proteins and apoptosis-related proteins.

RESULTS

Compared with the control group, there were evidently decreased cell viability, elevated level of LDH and CK, down-regulated expression of miR-30a in the model group. Data from Western blot and fluorescence indicated that doxorubicin contributed to the elevated autophagy and apoptosis. Compared with the model group, there were increased cell viability, decreased level of LDH and CK, and up-regulated expression of miR-30a in the Shenmai group and the Shenmai + miR-30a inhibitor group. Meanwhile, the results manifested that there were suppressed autophagy flow accompanied by the down-regulated expression of Beclin-1, LC3-II, LC3-II/LC3-I and up-regulated expression of p62 protein, and declined apoptosis rate accompanied by the up-regulated Bcl2 expression and the down-regulated expression of Bax, Cleaved Caspase-9, Cleaved Caspase-9/Caspase-9, Cleaved Caspase-3, Cleaved Caspase-3/Caspase-3 in the Shenmai group and the Shenmai + miR-30a inhibitor group.

DISCUSSION AND CONCLUSION

Shenmai injection inhibited autophagy and apoptosis via miR-30a, thereby alleviating doxorubicin-induced myocardial injury.

Salvianolic Acid B Attenuates Hypertrophic Scar Formation In Vivo and In Vitro

BACKGROUND

Hypertrophic scars (HTSs) are a fibroproliferative disorder that occur following skin injuries. Salvianolic acid B (Sal-B) is an extractant from Salvia miltiorrhiza that has been reported to ameliorate fibrosis in multiple organs. However, the antifibrotic effect on HTSs remains unclear. This study aimed to determine the antifibrotic effect of Sal-B in vitro and in vivo.

METHODS

In vitro, hypertrophic scar-derived fibroblasts (HSFs) were isolated from human HTSs and cultured. HSFs were treated with (0, 10, 50, 100 μmol/L) Sal-B. Cell proliferation and migration were evaluated by EdU, wound healing, and transwell assays. The protein and mRNA levels of TGFβI, Smad2, Smad3, α-SMA, COL1, and COL3 were detected by Western blots and real-time PCR. In vivo, tension stretching devices were fixed on incisions for HTS formation. The induced scars were treated with 100 μL of Sal-B/PBS per day according to the concentration of the group and followed up for 7 or 14 days. The scar condition, collagen deposition, and α-SMA expression were analyzed by gross visual examination, H&E, Masson, picrosirius red staining, and immunofluorescence.

RESULTS

In vitro, Sal-B inhibited HSF proliferation, migration, and downregulated the expression of TGFβI, Smad2, Smad3, α-SMA, COL1, and COL3 in HSFs. In vivo, 50 and 100 μmol/L Sal-B significantly reduced scar size in gross and cross-sectional observations, with decreased α-SMA expression and collagen deposition in the tension-induced HTS model.

CONCLUSIONS

Our study demonstrated that Sal-B inhibits HSFs proliferation, migration, fibrotic marker expression and attenuates HTS formation in a tension-induced HTS model in vivo.

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Regulation of autophagy of the heart in ischemia and reperfusion

Ischemia/reperfusion (I/R) of the heart leads to increased autophagic flux. Preconditioning stimulates autophagic flux by AMPK and PI3-kinase activation and mTOR inhibition. The cardioprotective effect of postconditioning is associated with activation of autophagy and increased activity of NO-synthase and AMPK. Oxidative stress stimulates autophagy in the heart during I/R. Superoxide radicals generated by NADPH-oxidase acts as a trigger for autophagy, possibly due to AMPK activation. There is reason to believe that AMPK, GSK-3β, PINK1, JNK, hexokinase II, MEK, PKCα, and ERK kinases stimulate autophagy, while mTOR, PKCδ, Akt, and PI3-kinase can inhibit autophagy in the heart during I/R. However, there is evidence that PI3-kinase could stimulate autophagy in ischemic preconditioning of the heart. It was found that transcription factors FoxO1, FoxO3, NF-κB, HIF-1α, TFEB, and Nrf-2 enhance autophagy in the heart in I/R. Transcriptional factors STAT1, STAT3, and p53 inhibit autophagy in I/R. MicroRNAs could stimulate and inhibit autophagy in the heart in I/R. Long noncoding RNAs regulate the viability and autophagy of cardiomyocytes in hypoxia/reoxygenation (H/R). Nitric oxide (NO) donors and endogenous NO could activate autophagy of cardiomyocytes. Activation of heme oxygenase-1 promotes cardiomyocyte tolerance to H/R and enhances autophagy. Hydrogen sulfide increases cardiac tolerance to I/R and inhibits apoptosis and autophagy via mTOR and PI3-kinase activation.

Bioengineering exosomes for treatment of organ ischemia-reperfusion injury

Ischemia-reperfusion (I/R) injury is a leading cause of death worldwide. It arises from blood reflowing after tissue hypoxia induced by ischemia that causes severe damages due to the accumulation of reactive oxygen species and the activation of inflammatory responses. Exosomes are the smallest members of the extracellular vesicles' family, which originate from nearly all eukaryotic cells. Exosomes have a great potential in the treatment of I/R injury either in native or modified forms. Native exosomes are secreted by different cell types, such as stem cells, and contain components such as specific miRNA molecules with tissue protective properties. On the other hand, exosome bioengineering has recently received increased attention in context of current advances in the purification, manipulation, biological characterization, and pharmacological applications. There are various pre-isolation and post-isolation manipulation approaches that can be utilized to increase the circulation half-life of exosomes or the availability of their bioactive cargos in the target site. In this review, the various therapeutic actions of native exosomes in different I/R injury will be discussed first. Exosome bioengineering approaches will then be explained, including pre- and post-isolation manipulation methods, applicability for delivery of bioactive agents to injured tissue, clinical translation issues, and future perspectives.

Therapeutic Effect and Mechanism of Cinnamyl Alcohol on Myocardial Ischemia-Reperfusion Injury

Objective

To investigate the effect of CA on autophagy and its molecular mechanism after myocardial ischemia/reperfusion injury (MI/RI).

Methods

The MI/RI model was established by the ligation of the left anterior descending coronary artery with ischemia and reperfusion. In vitro cell models were established using hypoxia/reoxygenation. Western blot was used to determine the expression levels of beclin-1, P62, and LC3 II. The expression levels of IL-1β, IL-6, TNFα, and apoptosis-related genes Bax, Cyt-c, and Bcl-2 were detected by qRT-PCR. Cell activity was detected by CCK-8. Apoptosis was detected by TUNEL staining.

Results

Beclin-1, P62, and LC3 II protein expression and LC3 II/LC3 I level were significantly increased after myocardial ischemia-reperfusion injury. Compared with model group, CA downregulated beclin-1, P62, and LC3 II protein expression and LC3 II/LC3 I level in the myocardium. The results of cell-level experiments showed that CA inhibited the autophagy response of the cardiomyocytes induced by hypoxia-reperfusion injury. Mechanism studies showed that CA targeted the inhibition of ATG12. Knocking down ATG12 reduces the production of inflammatory cytokines induced by H/R. The knockdown of ATG12 also reduced apoptosis and injury of the myocardial cells.

Conclusion

Myocardial ischemia-reperfusion can enhance autophagy response and promote apoptosis. CA plays a protective role in myocardium by targeting ATG12, thereby inhibiting autophagy and improving myocardial cell apoptosis.

The Regulatory Role of Non-coding RNA in Autophagy in Myocardial Ischemia-Reperfusion Injury

Following an acute myocardial infarction (AMI), thrombolysis, coronary artery bypass grafting and primary percutaneous coronary intervention (PPCI) are the best interventions to restore reperfusion and relieve the ischemic myocardium, however, the myocardial ischemia-reperfusion injury (MIRI) largely offsets the benefits of revascularization in patients. Studies have demonstrated that autophagy is one of the important mechanisms mediating the occurrence of the MIRI, while non-coding RNAs are the main regulatory factors of autophagy, which plays an important role in the autophagy-related mTOR signaling pathways and the process of autophagosome formation Therefore, non-coding RNAs may be used as novel clinical diagnostic markers and therapeutic targets in the diagnosis and treatment of the MIRI. In this review, we not only describe the effect of non-coding RNA regulation of autophagy on MIRI outcome, but also zero in on the regulation of non-coding RNA on autophagy-related mTOR signaling pathways and mitophagy. Besides, we focus on how non-coding RNAs affect the outcome of MIRI by regulating autophagy induction, formation and extension of autophagic vesicles, and the fusion of autophagosome and lysosome. In addition, we summarize all non-coding RNAs reported in MIRI that can be served as possible druggable targets, hoping to provide a new idea for the prediction and treatment of MIRI.

miR-451-3p alleviates myocardial ischemia/reperfusion injury by inhibiting MAP1LC3B-mediated autophagy

OBJECTIVE AND DESIGN

We aim to explore the molecular mechanism of myocardial ischemia-reperfusion injury (MIRI).

METHODS

The H9C2 cells were cultured under hypoxia/reoxygenation (H/R) condition to induce myocardial injury in vitro. The expression of miR-451-3p and MAP1LC3B was detected by RT-qPCR. Dual-luciferase reporter assay and RNA pull-down assay were performed to examine the relationship between microRNA (miR)-451-3p and MAP1LC3B. CCK8 was used to test cell viability. The level of LDH and CK was evaluated via ELISA. Immunofluorescence assay and flow cytometry were applied to detect autophagy and apoptosis, respectively. Autophagy-related protein expressions were determined by western blotting. Furthermore, an in vivo rat model of MIRI was established by subjection to 30 min ischemia and subsequently 24 h reperfusion for validation of the role of miR-451-3p in regulating MIRI in vivo.

RESULTS

miR-451-3p was down-regulated in MIRI, and miR-451-3p mimics transfection alleviated autophagy and apoptosis induced by MIRI. miR-451-3p could target MAP1LC3B directly. Co-transfection miR-451-3p mimics and pcDNA 3.1 MAP1LC3B curbed the protected effects of miR-451-3p mimics on MIRI.

CONCLUSIONS

miR-451-3p played a protective role in MIRI via inhibiting MAP1LC3B-mediated autophagy, which may provide new molecular targets for the treatment of MIRI and further improves the clinical outcomes of heart diseases.

H3K14 hyperacetylation‑mediated c‑Myc binding to the miR‑30a‑5p gene promoter under hypoxia postconditioning protects senescent cardiomyocytes from hypoxia/reoxygenation injury

Our previous study reported that microRNA (miR)‑30a‑5p upregulation under hypoxia postconditioning (HPostC) exert a protective effect on aged H9C2 cells against hypoxia/reoxygenation injury via DNA methyltransferase 3B‑induced DNA hypomethylation at the miR‑30a‑5p gene promoter. This suggests that miR‑30a‑5p may be a potential preventative and therapeutic target for ischemic heart disease in aged myocardium. The present study aimed to investigate the underlying mechanisms of miR‑30a‑5p transcription in aged myocardium in ischemic heart disease. Cardiomyocytes were treated with 8 mg/ml D‑galactose for 9 days, and then exposed to hypoxic conditions. Cell viability was determined using a cell viability assay. Expression levels of histone deacetylase 2 (HDAC2), LC3B‑II/I, beclin‑1 and p62 were detected via reverse transcription‑quantitative PCR and western blotting. Chromatin immunoprecipitation‑PCR and luciferase reporter assays were performed to evaluate the effect of c‑Myc binding and activity on the miR‑30a‑5p promoter in senescent cardiomyocytes following HPostC. It was found that HPostC enhanced the acetylation levels of H3K14 at the miR‑30a‑5p gene promoter in senescent cardiomyocytes, which attributed to the decreased expression of HDAC2. In addition, c‑Myc could positively regulate miR‑30a‑5p transcription to inhibit senescent cardiomyocyte autophagy. Mechanically, it was observed that increased H3K14 acetylation level exposed to romidepsin facilitated c‑Myc binding to the miR‑30a‑5p gene promoter region, which led to the increased transcription of miR‑30a‑5p. Taken together, these results demonstrated that HDAC2‑mediated H3K14 hyperacetylation promoted c‑Myc binding to the miR‑30a‑5p gene promoter, which contributed to HPostC senescent cardioprotection.

Non-coding RNAs modulate autophagy in myocardial ischemia-reperfusion injury: a systematic review

The myocardial infarction is the main cause of morbidity and mortality in cardiovascular diseases around the world. Although the timely and complete reperfusion via Percutaneous Coronary Intervention (PCI) or thrombolysis have distinctly decreased the mortality of myocardial infarction, reperfusion itself may lead to supererogatory irreversible myocardial injury and heart function disorders, namely ischemia-reperfusion (I/R) injury. Extensive studies have indicated that non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs), play important roles in the progress of myocardial I/R injury, which is closely correlative with cardiomyocytes autophagy. Moreover, autophagy plays an important role in maintaining homeostasis and protecting cells in the myocardial ischemia reperfusion and cardiomyocyte hypoxia-reoxygenation (H/R) progress. In this review, we first introduced the biogenesis and functions of ncRNAs, and subsequently summarized the roles and relevant molecular mechanisms of ncRNAs regulating autophagy in myocardial I/R injury. We hope that this review in addition to develop a better understanding of the physiological and pathological roles of ncRNAs, can also lay a foundation for the therapies of myocardial I/R injury, and even for other related cardiovascular diseases.

Shenmai injection improves doxorubicin cardiotoxicity via miR-30a/Beclin 1

BACKGROUND

Shenmai Injection (SMI) has been widely used in the treatment of cardiovascular diseases and can reduce side effects when combined with chemotherapy drugs. However, the potential protective mechanism of SMI on the cardiotoxicity caused by anthracyclines has not been clear.

METHODS

We used network pharmacology methods to collect the compound components in SMI and myocardial injury targets, constructed a 'drug-disease' target interaction network relationship diagram, and screened the core targets to predict the potential mechanism of SMI in treating cardiotoxicity of anthracyclines. In addition, the rat model of doxorubicin cardiotoxicity was induced by injecting doxorubicin through the tail vein. The rats were randomized in the model group, miR-30a agomir group, SMI low-dose group, SMI high-dose group，and the control group. The cardiac ultrasound was used to evaluate the structure and function of the rat heart. HE staining was used to observe the pathological changes of the rat myocardium. Transmission electron microscopy was used to observe myocardial autophagosomes. The expression of miR-30a and Beclin 1 mRNA in the rat myocardium was detected by RT-qPCR. Western Blot detected the expression of LC3-II/LC3-I and p62 protein.

RESULTS

The network pharmacological analysis found that SMI could act synergistically through multiple targets and multiple pathways, which might exert a myocardial protective effect through PI3K-Akt signaling pathways and cancer microRNAs. In vivo, compared with the control group, the treatment group could improve the cardiac structure and function, and reduce myocardial pathological damage and the number of autophagosomes. The expression of miR-30a in the myocardium of rats in miR-30a agomir group and SMI group increased (P < 0.01)，Beclin 1 mRNA was decreased (P < 0.01)，LC3-Ⅱ/LC3-I protein was decreased (P < 0.01 or P < 0.05)，and p62 protein was increased (P < 0.01 or P < 0.05).

CONCLUSIONS

SMI has the characteristics of multi-component, multi-target, and multi-pathway. It can inhibit myocardial excessive autophagy by regulating the expression of miR-30a/Beclin 1 and alleviate the myocardial injury induced by doxorubicin.

Sevoflurane protects cardiomyocytes against hypoxia/reperfusion injury via LINC01133/miR-30a-5p axis

Previous studies failed to elucidate the detailed mechanisms of anesthetic preconditioning as a protective approach against ischemic/reperfusion (I/R) injury in cells. The present study mainly centered on discovering the mechanisms of Sevoflurane (Sev) in preventing cardiomyocytes against I/R injury. Human cardiomyocyte AC16 cell line was used to simulate I/R injury based on a hypoxia/reperfusion (H/R) model. After Sev treatment, cell viability and apoptosis were detected by MTT assay and flow cytometry, respectively. Lactate dehydrogenase (LDH) content was measured using an LDH Detection Kit. Relative mRNA and protein expressions of LINC01133, miR-30a-5p and apoptosis-related proteins were detected using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot as needed. Target gene of miR-30a-5p and their potential binding sites were predicted using Starbase and confirmed by dual-luciferase reporter assay. Cell behaviors were assessed again after miR-30a-5p and LINC01133 transfection. Sev could improve cell viability, reduce LDH leakage, and down-regulate the expressions of apoptosis-related proteins (Bax, cleaved caspase-3 and cleaved caspase-9) and LINC01133 as well as up-regulate miR-30a-5p and Bcl-2 expressions in H/R cells. MiR-30a-5p was the target of LINC01133, and up-regulating miR-30a-5p enhanced the effects of Sev in H/R cells, with a suppression on H/R-induced activation of the p53 signaling pathway. However, up-regulating LINC01133 reversed the enhancing effects of miR-30a-5p on Sev pretreatment in H/R cells. Sev could protect cardiomyocytes against H/R injury through the miR-30a-5p/LINC01133 axis, which may provide a possible therapeutic method for curing cardiovascular I/R injury.

MiR-30a-5p ameliorates LPS-induced inflammatory injury in human A549 cells and mice via targeting RUNX2

In this study, we aim to investigate the role of miR-30a-5p in acute lung injury/acute respiratory distress syndrome (ALI/ARDS) using LPS-induced A549 cells and mice. We found cell viability was significantly declined accompanied by cell apoptosis and cell cycle arrest at G0/G1 phase in LPS-treated A549 cells. MiR-30a-5p was down-regulated by LPS treatment and miR-30a-5p significantly protected A549 cells from LPS-induced injury by increasing cell viability, reducing cell apoptosis, promoting cell cycle progression, and inhibiting inflammatory reactions. Dual-luciferase activity demonstrated that RUNX2 was a direct target for miR-30a-5p and its expression was negatively and directly regulated by miR-30a-5p. Over-expression of RUNX2 weakened the inhibitory effect of miR-30a-5p on inflammatory injury. In vivo, over-expression of miR-30a-5p alleviated LPS-induced inflammatory responses and lung injury in LPS-administrated mice. Besides, miR-30a-5p repressed LPS-elevated phosphorylation levels of the signal transducer and activator of transcription 3 (STAT3) and c-Jun N-terminal kinase (JNK), IκBα degradation, and NF-κB p65 phosphorylation. In conclusion, miR-30a-5p ameliorates LPS-induced inflammatory injury in A549 cells and mice via targeting RUNX2 and related signaling pathways, thereby influencing the progression of ARDS.

Pharmacological Effects of Salvianolic Acid B Against Oxidative Damage

Salvianolic acid B (Sal B) is one of the main active ingredients of Salvia miltiorrhiza, with strong antioxidant effects. Recent findings have shown that Sal B has anti-inflammatory, anti-apoptotic, anti-fibrotic effects and can promote stem cell proliferation and differentiation, and has a beneficial effect on cardiovascular and cerebrovascular diseases, aging, and liver fibrosis. Reactive oxygen species (ROS) include oxygen free radicals and oxygen-containing non-free radicals. ROS can regulate cell proliferation, survival, death and differentiation to regulate inflammation, and immunity, while Sal B can scavenge oxygen free radicals by providing hydrogen atoms and reduce the production of oxygen free radicals and oxygen-containing non-radicals by regulating the expression of antioxidant enzymes. The many pharmacological effects of Sal B may be closely related to its elimination and inhibition of ROS generation, and Nuclear factor E2-related factor 2/Kelch-like ECH-related protein 1 may be the core link in its regulation of the expression of antioxidant enzyme to exert its antioxidant effect. What is confusing and interesting is that Sal B exhibits the opposite mechanisms in tumors. To clarify the specific target of Sal B and the correlation between its regulation of oxidative stress and energy metabolism homeostasis will help to further understand its role in different pathological conditions, and provide a scientific basis for its further clinical application and new drug development. Although Sal B has broad prospects in clinical application due to its extensive pharmacological effects, the low bioavailability is a serious obstacle to further improving its efficacy in vivo and promoting clinical application. Therefore, how to improve the availability of Sal B in vivo requires the joint efforts of many interdisciplinary subjects.

Salvianolic acid B alleviates myocardial ischemic injury by promoting mitophagy and inhibiting activation of the NLRP3 inflammasome

Ischemic heart disease is a major cause of mortality and disability worldwide. Salvianolic acid B (Sal B) is one of the main water-soluble components of Salvia miltiorrhiza Bge. Numerous studies have demonstrated that Sal B could exert significant anti-inflammatory and cardiovascular protective effects; however, the underlying mechanisms remain unclear. To elucidate the association between myocardial ischemia and inflammation, and to develop effective protective drugs, a rat model of myocardial ischemia was induced using isoproterenol (ISO) and an inflammation model in H9C2 cells was induced with lipopolysaccharide + adenosine triphosphate. Both of these models were treated with different concentrations of Sal B (5, 10 and 15 mg/kg in vivo; 1, 5 and 25 µM in vitro). In vivo, the serum levels of creatine kinase isoenzyme MB, glutamic oxaloacetic transaminase and IL-1β, the cardiac function and the mRNA expression levels of NLR family pyrin domain-containing 3 (NLRP3) inflammasome components were evaluated using ELISAs, an electrocardiogram, hematoxylin and eosin staining and reverse transcription-quantitative PCR, respectively. The results demonstrated that treatment with Sal B markedly alleviated the acute myocardial ischemic injury induced by hypodermic injection of ISO in rats. In vitro, the results of reactive oxygen species (ROS) detection, JC-1 staining, western blotting and TUNEL assays showed that Sal B treatment significantly inhibited intracellular ROS production, increased the mitochondrial membrane potential, regulated the expression of mitophagy-related proteins, inhibited the activation of the NLRP3 inflammasome and inhibited apoptosis in H9C2 cells. In conclusion, these findings indicated that Sal B exerted protective effects against myocardial ischemic injury by promoting mitophagy and maintaining mitochondrial function.

Autophagy and cardiac diseases: Therapeutic potential of natural products

The global incidence of cardiac diseases is expected to increase in the coming years, imposing a substantial socioeconomic burden on healthcare systems. Autophagy is a tightly regulated lysosomal degradation mechanism important for cell survival, homeostasis, and function. Accumulating pieces of evidence have indicated a major role of autophagy in the regulation of cardiac homeostasis and function. It is well established that dysregulation of autophagy in cardiomyocytes is involved in cardiac hypertrophy, myocardial infarction, diabetic cardiomyopathy, and heart failure. In this sense, autophagy seems to be an attractive therapeutic target for cardiac diseases. Recently, multiple natural products/phytochemicals, such as resveratrol, berberine, and curcumin have been shown to regulate cardiomyocyte autophagy via different pathways. The autophagy-modifying capacity of these compounds should be taken into consideration for designing novel therapeutic agents. This review focuses on the role of autophagy in various cardiac diseases and the pharmacological basis and therapeutic potential of reported natural products in cardiac diseases by modifying autophagic processes.

Salvianolic Acid B improves cognitive impairment by inhibiting neuroinflammation and decreasing Aβ level in Porphyromonas gingivalis-infected mice

Amyloid-β (Aβ) accumulation is one of the main pathological hallmarks of Alzheimer’s disease (AD). Porphyromonas gingivalis (P. gingivalis), the pathogen of chronic periodontitis, could cause Aβ accumulation and was identified in the brain of AD patients. Salvianolic Acid B (SalB) has been proven to have the neuroprotective effect. Whether SalB could protect against P. gingivalis-induced cognitive impairment is still unknown. In this study, a P. gingivalis-infected mouse model was employed to study the neuroprotective role of SalB. The results showed that SalB (20 and 40 mg/kg) treatment for 4 weeks could shorten the escape latency and improve the percentage of spontaneous alternation in the P. gingivalis-infected mice. SalB inhibited the levels of reactive oxygen species and malondialdehyde, while increased the levels of antioxidative enzymes (superoxide dismutase and glutathione peroxidase). SalB decreased the levels of IL-1β and IL-6, increased the mRNA levels of bdnf and ngf in the brain of P. gingivalis-infected mice. In addition, SalB obviously decreased the level of Aβ. SalB elevated the protein expression of ADAM10, while downregulated BACE1 and PS1. SalB increased the protein expression of LRP1, while decreased RAGE. In conclusion, SalB could improve cognitive impairment by inhibiting neuroinflammation and decreasing Aβ level in P. gingivalis-infected mice.

Salvianolic acid B protects against myocardial ischaemia-reperfusion injury in rats via inhibiting high mobility group box 1 protein expression through the PI3K/Akt signalling pathway

Salvianolic acid B (Sal B) has a significant protective effect on myocardial ischaemia-reperfusion (I/R) injury. Therefore, the aims of this study were to determine the effects of Sal B on myocardial ischaemic-reperfusion (I/R) injury in rats and to explore whether its underlying mechanism of cardioprotection occurs through activating the expression of the phosphoinositide 3-kinase/protein, kinase B (PI3K/Akt) and inhibiting the expression of high mobility group protein 1 (HMGB1). Ninety Sprague-Dawley rats were randomized into five groups: group 1 (sham-operated), group 2 (myocardial I/R), group 3 (low dose of Sal B+I/R), group 4 (high dose of Sal B+I/R), and group 5 (high dose of Sal B+I/R+LY294002, which is a specific PI3k inhibitor). All I/R rats received 30 min myocardial ischaemia followed by 24-h reperfusion. Cardiac function, infarct size, myocardial injury marker levels, inflammatory response and cardiomyocyte apoptosis as well as Bcl-2, Bax, P-Akt, HMGB1 and TLR4 expression were measured. In the current study, Sal B significantly ameliorated myocardial I/R injury in a dose-dependent manner, ameliorated cardiac function, reduced myocardial infarction size, decreased myocardial injury marker expression, decreased inflammatory responses, reduced apoptosis, activated PI3K/Akt expression and inhibited HMGB1 expression. However, all effects of Sal B were significantly reversed by LY294002. Overall, the present study indicated that Sal B attenuated myocardial I/R injury by activating PI3K/Akt and inhibiting the release of HMGB1 in rats.

Sal B Alleviates Myocardial Ischemic Injury by Inhibiting TLR4 and the Priming Phase of NLRP3 Inflammasome

Salvianolic acid B is one of the main water-soluble components of Salvia miltiorrhiza Bge. Many reports have shown that it has significant anti-myocardial ischemia effect. However, the underlying mechanism remains unclear. Our present study demonstrated that Sal B could alleviate myocardial ischemic injury by inhibiting the priming phase of NLRP3 inflammasome. In vivo, serum c-troponin I (cTn), lactate dehydrogenase (LDH) levels, the cardiac function and infract size were examined. We found that Sal B could notably reduce the myocardial ischemic injury caused by ligation of the left anterior descending coronary artery. In vitro, Sal B down-regulated the TLR4/NF-κB signaling cascades in lipopolysaccharide (LPS)-stimulated H9C2 cells. Furthermore, Sal B reduced the expression levels of IL-1β and NLRP3 inflammasome in a dose-dependent manner. In short, our study provided evidence that Sal B could attenuate myocardial ischemic injury via inhibition of TLR4/NF-κB/NLRP3 signaling pathway. And in an upstream level, MD-2 may be the potential target.

miR‑27a suppresses TLR4‑induced renal ischemia‑reperfusion injury

Ischemia reperfusion injury (IRI) is one of the primary causes of acute renal injury and even acute renal failure. An increasing body of evidence has indicated that the aberrant expression of microRNAs (miRNA/miR) is closely associated with the progression of IRI. In the process of renal IRI, inflammatory reactions, cell adhesion and the death of renal tubular epithelial cells serve important roles. The present study investigated the expression of renal miRNAs following renal IRI in an attempt to identify the miRNAs that exert pivotal functions in renal IRI. The present study revealed that miR-27a, which was downregulated in IRI, and the 3′-untranslated region (UTR) of Toll-like receptor 4 (TLR4) have associated binding sites. The levels of TLR4, miR-27a and specific associated proteins in the renal tissues of gestational rats were determined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis, immunohistochemistry and western blotting. The associations between miR-27a and TLR4 were analyzed, and the regulatory effect of miR-27a on TLR4 was detected via a luciferase reporter gene assay, western blotting and RT-qPCR in vivo and in vitro. In addition, the present study demonstrated that miR-27a suppressed the expression of TLR4 by binding to the 3′UTR of TLR4. The overexpression of miR-27a downregulated the expression of TLR4, which in turn inhibited the inflammation, cell adhesion and cell death in IRI. Therefore, miR-27a inhibited inflammation in IRI by decreasing the expression of TLR4.

miR-30e-5p Mitigates Hypoxia-Induced Apoptosis in Human Stem Cell-Derived Cardiomyocytes by Suppressing Bim

Coronary microembolization can cause slow or no reflow, which is one of the crucial reasons for reverse of clinical advantage from cardiac reperfusion therapy. miRNAs and apoptosis are dramatically involved in the occurrence and process of cardiovascular diseases. Fortunately, human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have emerged as an appealing model for the evaluation of cardiovascular diseases. Therefore, our study was designed to explore the role of miR-30e-5p and apoptosis in a hypoxia-induced hiPSC-CM injury model. Our results showed that the expression levels of miR-30e-5p were overtly downregulated in a time-dependent manner under hypoxic conditions. Expression of miR-30e-5p was significantly downregulated after 24 hours of hypoxia, hypoxia treatment dramatically induced apoptosis. Calcium handling capability significantly decreased after 24 hours of hypoxia treatment. miR-30e-5p overexpression partially mitigated hypoxia-induced apoptosis and rescued hypoxia-induced calcium handling defects in hiPSC-CMs. The luciferase reporter assay showed that miR-30e-5p can directly target the 3'-UTR of Bim, which is an apoptosis activator and autophagy suppressor. The mRNA and protein of Bim remarkably increased after hypoxia treatment and reduced with miR-30e-5p overexpression. Moreover, downregulation of Bim mitigated hypoxia-induced apoptosis and activated autophagy. These results demonstrated that miR-30e-5p mitigated hypoxia-induced apoptosis in hiPSC-CMs at least in part via Bim suppression and subsequent autophagy activation. Our study suggested miR-30e-5p may act as a potential therapeutic target for coronary microembolization.

Protective effects of resveratrol on random-pattern skin flap survival: an experimental study

Random-pattern skin flap transplantation is a common procedure in plastic surgery, but its distal area usually incurs ischemia and necrosis. Resveratrol (Rev), a natural polyphenol primarily found in peanuts, grapes, and red wine, which exerts multi-bioactivity. In this study, forty-eight rats with the modified "McFarlane flap" model were divided into Control and Rev groups, which were treated with vehicle Control and Rev, respectively. After 7 days of continuous treatment and observation, ischemic flap tissues were harvested to evaluate angiogenesis, apoptosis, oxidative stress, and autophagy. It was observed a greater survival area of flaps, accompanied with reduced water content and stronger blood supply, in the Rev group than in the Control group. In addition, Rev upregulated the expression of MMP9, VEGF, and Cadherin5, indicating that Rev promotes angiogenesis in ischemic flaps. Moreover, Rev decreased the levels of Bax, CYC, and Caspase3, suggesting that it inhibits apoptosis. Besides, Rev increased the expression of SOD1, eNOS, HO1, the activities of SOD and GSH, and reduced the levels of MDA, which uncovers that it depresses oxidative stress in ischemic flaps. Finally, it increased the expression of Beclin1, LC3II, VPS34, and CTSD, and decreased SQSTM1/p62 levels, which reveals that it activates autophagy in the flaps. These results suggest that Rev promotes random skin flap survival through proangiogenic, antiapoptotic, and antioxidative effects; moreover, autophagy is activated in the process, which might be another underlying mechanism for the flap survival.

Salvianolic Acid B Promotes the Survival of Random-Pattern Skin Flaps in Rats by Inducing Autophagy

Random-pattern skin flap transplantation is frequently applied in plastic and reconstructive surgery. However, the distal part of the flap often suffers necrosis due to ischemia. In this study, the effects of salvianolic acid B (Sal B) on flap survival were evaluated, and the underlying mechanisms were investigated. Sal B improved the survival area, reduced tissue edema, and increased the number of microvessels in skin flaps after 7 days, whereas an autophagy inhibitor (3-methyladenine) reversed the Sal B-induced increase in flap viability. In addition, Sal B stimulated angiogenesis, inhibited apoptosis, reduced oxidative stress, and upregulated autophagy in areas of ischemia. Moreover, the effects of Sal B on angiogenesis, apoptosis, and oxidative stress were reversed by autophagy inhibition. Overall, our findings suggest that Sal B has pro-angiogenesis, anti-apoptosis, and anti-oxidative stress effects by stimulating autophagy, which enhances the survival of random-pattern skin flaps.

A microRNA’s journey to the center of the mitochondria

MicroRNAs (miRNAs) are known as the master regulators of gene expression, and for the last two decades our knowledge of their functional reach keeps expanding. Recent studies have shown that a miRNA’s role in regulation extends to extracellular and intracellular organelles. Several studies have shown a role for miRNA in regulating the mitochondrial genome in normal and disease conditions. Mitochondrial dysfunction occurs in many human pathologies, such as cardiovascular disease, diabetes, cancer, and neurological diseases. These studies have shed some light on regulation of the mitochondrial genome as well as helped to explain the role of miRNA in altering mitochondrial function and the ensuing effects on cells. Although the field has grown in recent years, many questions still remain. For example, little is known about how nuclear-encoded miRNAs translocate to the mitochondrial matrix. Knowledge of the mechanisms of miRNA transport into the mitochondrial matrix is likely to provide important insights into our understanding of disease pathophysiology and could represent new targets for therapeutic intervention. For this review, our focus will be on the role of a subset of miRNAs, known as MitomiR, in mitochondrial function. We also discuss the potential mechanisms used by these nuclear-encoded miRNAs for import into the mitochondrial compartment.

Listen to this article’s corresponding podcast at http://ajpheart.podbean.com/e/microrna-translocation-into-the-mitochondria/ .

Salvia miltiorrhizaBurge (Danshen): a golden herbal medicine in cardiovascular therapeutics

Salvia miltiorrhiza Burge (Danshen) is an eminent medicinal herb that possesses broad cardiovascular and cerebrovascular protective actions and has been used in Asian countries for many centuries. Accumulating evidence suggests that Danshen and its components prevent vascular diseases, in particular, atherosclerosis and cardiac diseases, including myocardial infarction, myocardial ischemia/reperfusion injury, arrhythmia, cardiac hypertrophy and cardiac fibrosis. The published literature indicates that lipophilic constituents (tanshinone I, tanshinone IIa, tanshinone IIb, cryptotanshinone, dihydrotanshinone, etc) as well as hydrophilic constituents (danshensu, salvianolic acid A and B, protocatechuic aldehyde, etc) contribute to the cardiovascular protective actions of Danshen, suggesting a potential synergism among these constituents. Herein, we provide a systematic up-to-date review on the cardiovascular actions and therapeutic potential of major pharmacologically active constituents of Danshen. These bioactive compounds will serve as excellent drug candidates in small-molecule cardiovascular drug discovery. This article also provides a scientific rationale for understanding the traditional use of Danshen in cardiovascular therapeutics.

New and revisited approaches to preserving the reperfused myocardium

Early coronary artery reperfusion improves outcomes for patients with ST-segment elevation myocardial infarction (STEMI), but morbidity and mortality after STEMI remain unacceptably high. The primary deficits seen in these patients include inadequate pump function, owing to rapid infarction of muscle in the first few hours of treatment, and adverse remodelling of the heart in the months that follow. Given that attempts to further reduce myocardial infarct size beyond early reperfusion in clinical trials have so far been disappointing, effective therapies are still needed to protect the reperfused myocardium. In this Review, we discuss several approaches to preserving the reperfused heart, such as therapies that target the mechanisms involved in mitochondrial bioenergetics, pyroptosis, and autophagy, as well as treatments that harness the cardioprotective properties of inhaled anaesthetic agents. We also discuss potential therapies focused on correcting the no-reflow phenomenon and its effect on healing and adverse left ventricular remodelling.

αvβ3 integrin receptor specific peptide modified, salvianolic acid B and panax notoginsenoside loaded nanomedicine for the combination therapy of acute myocardial ischemia

PURPOSE

To achieve the combination therapy of acute myocardial ischemia, arginyl-glycyl-aspartic acid (RGD) conjugated lipid was synthesized and RGD modified, salvianolic acid B (Sal B) and panax notoginsenoside (PNS) co-loaded lipid-polymer hybrid nanoparticles (RGD-S/P-LPNs) was fabricated an evaluated.

METHODS

RGD was conjugated to distearoyl phosphatidylethanolamine-polyethylene glycol (DSPE-PEG-NH₂) through amide linkage. Lipid-polymer hybrid nanoparticles (LPNs) were fabricated by nanoprecipitation method. RGD-S/P-LPNs was characterized in terms of morphology, size, charge, drug loading, entrapment, stability, drug release and cytotoxicity in vitro. Cardiac distribution, pharmacokinetics study and infarct therapy effect were evaluated in vivo.

RESULTS

The LPNs are generally spherical in shape with uniform size distribution, have sizes of 100-200nm and zeta potentials range from -30.7∼ -39.8. In vitro release behaviors of drugs loaded LPNs are in a sustained release manner, which does not exhibit obviously cytotoxicity against H9c2 cardiomyocytes. RGD-S/P-LPNs group shows the most significant cardiac distribution and infarct therapy effect in vivo.

CONCLUSION

The results illustrated that RGD modified dual drugs co-loaded LPNs are stable, sustained release carriers. Cardiac distribution, pharmacokinetics, and infarct therapy effect results suggested that the RGD-S/P-LPNs could improve the in vivo therapeutic efficacy of the double drugs.

Roles of Autophagy in Ischemic Heart Diseases and the Modulatory Effects of Chinese Herbal Medicine

Autophagy is an evolutionarily conserved degradation process which eliminates dysfunctional proteins and cytoplasmic components to maintain homeostasis for cell survival. Increasing evidence has demonstrated the modulatory role of autophagy in ischemic heart diseases (IHDs). Traditionally, this process has been recognized as having protective functions, such as inhibiting atherosclerosis progression and reducing cell death during the ischemic phase. However, recent studies have suggested its dual roles in myocardial ischemia/reperfusion (MIR) injury. Excessive autophagy may play a deleterious role in cardiac function, due to overwhelming clearance of cellular constituents and proteins. Hence modulation of autophagy to increase cardiomyocyte survival and improve cardiac function is meaningful for the treatment of IHD. Chinese herbal medicine, including extractive compounds and patented drugs, has shown its potential role in treating IHD by addressing autophagy-related mechanisms. This review summarizes the updated knowledge on the molecular basis and modulatory role of autophagy in IHD and the recent progress of Chinese herbal medicine in its treatment.

Overexpression of MicroRNA-145 Ameliorates Astrocyte Injury by Targeting Aquaporin 4 in Cerebral Ischemic Stroke

Cerebral ischemic stroke, which affects the global population, is a major disease with high incidence, mortality, and disability. Accumulating evidence has indicated that abnormal microRNA (miRNA) expression plays essential roles in the pathologies of ischemic stroke. Yet, the underlying regulatory mechanism of miRNAs in cerebral ischemic stroke remains unclear. We investigated the role of miR-145 in cerebral ischemic stroke and its potential mechanism in a model using primary cultured astrocytes. We detected the expression levels of miR-145 and its target gene AQP4 and assessed the role of miR-145 in cell death and apoptosis caused by oxygen-glucose deprivation (OGD). Bioinformatics analysis was used to explore the targets of miR-145. miR-145 expression levels were significantly decreased in primary astrocytes subjected to OGD. miR-145 overexpression promoted astrocyte health and inhibited OGD-induced apoptosis. AQP4 was a direct target of miR-145, and miR-145 suppressed AQP4 expression. Moreover, AQP4 enhanced astrocyte injury in ischemic stroke, and AQP4 knockdown diminished the miR-145-mediated protective effect on ischemic injury. Taken together, our results show that miR-145 plays an important role in protecting astrocytes from ischemic injury by downregulating AQP4 expression. These findings may highlight a novel therapeutic target in cerebral ischemic stroke.

MicroRNA-143 promotes cardiac ischemia-mediated mitochondrial impairment by the inhibition of protein kinase Cepsilon

The cardioprotection of protein kinase Cepsilon (PKCε) against myocardial infarction (MI) mediated by its anti-apoptotic property and underlying mechanism of targeted regulation by microRNA (miRNA) are not established. MI-induced injury, PKCε expression, and targeted regulation of miRNA-143 (miR-143) to PKCε have been evaluated using animal MI and cellular hypoxic models conjugated with series of state-of-art molecular techniques. The results demonstrated that PKCε significantly downregulated along with increased infarcted area and apoptotic and necrotic damage in MI model, and the targeted relationship and potential binding profile were established between miR-143 and PKCε. Both in vivo and in vitro ischemic tests showed that miR-143 induced apoptosis and necrosis, which was reversed by antagomiR-143 or AMO-143. The upregulation of miR-143 by transfection of miR-143 in vitro also induced cell loss, and this effect of miR-143 was completely reversed by co-transfection of miR-143 with AMO-143. The identically deleterious action of miR-143 on mitochondrial membrane potential and ATP synthesis was also observed in both animal MI and cellular hypoxic models, as well as miR-143 overexpressed models and converted by either antagomiR or AMO. Importantly, overexpression of miR-143 downregulated PKCε in all tested models and this downregulation was reversed in the presence of antagomiR or AMO. The direct targeted regulation of miR-143 on PKCε was confirmed by luciferase reporter and miRNA-masking tests. In conclusion, MI-mediated upregulation of miR-143 inhibits PKCε expression and consequently interference with the cardioprotection of PKCε to mitochondrial, and leads to mitochondrial membrane potential dissipation and myocardial death eventually.

Modulation of autophagy in exJSRV-env-transfected cells through the Akt/mTOR and MAPK signaling pathway

The envelope (Env) of Jaagsiekte sheep retrovirus (JSRV) is an oncoprotein of ovine pulmonary adenocarcinoma (OPA). Autophagy is involved in different cancers, but how it is carcinogenic in JSRV Env is unclear. Modulation of autophagy in exJSRV-env-NM-transfected cells through the Akt/mTOR and MAPK signaling pathway was studied, and we observed strong positive labeling of p-Akt, p-mTOR, p-MEK1/2, p-ERK1/2, p-p38 and p-JNK in tumor cells and typical type II pneumocytes in naturally infected OPA lung tissues, which was co-aligned with JSRV-Env positive cells as shown by immunohistochemical and microscopic analysis. Akt/mTOR and MAPK pathways were activated in OPA lung and JSRV-Env transfected NIH 3T3 cells. Decreased Beclin1 and LC3 II/I suggested that autophagy was inhibited in OPA lung and JSRV-Env transfected NIH 3T3 cells. Beclin1 and LC3 II/I increased in JSRV-Env transfected NIH3T3 cells treated with mTOR inhibitor (rapamycin), ERK1/2 inhibitor (PD 98059), p38 inhibitor (SB 203580) and JNK inhibitor (SP 600125), suggesting that Akt/mTOR and MAPK pathways were responsible for JSRV-Env decreased autophagy. In conclusion, JSRV Env decreased autophagy in JSRV-Env transfected NIH3T3 cells through Akt/mTOR and MAPK pathways, in particular, JNK and p38 pathways.