Inhibition of Myocardial Cell Apoptosis Is Important Mechanism for Ginsenoside in the Limitation of Myocardial Ischemia/Reperfusion Injury

WTAP-mediated m6A modification of lncRNA Snhg1 improves myocardial ischemia-reperfusion injury via miR-361-5p/OPA1-dependent mitochondrial fusion

BACKGROUND

Myocardial ischemia-reperfusion injury (MIRI) is caused by reperfusion after ischemic heart disease. LncRNA Snhg1 regulates the progression of various diseases. N6-methyladenosine (m6A) is the frequent RNA modification and plays a critical role in MIRI. However, it is unclear whether lncRNA Snhg1 regulates MIRI progression and whether the lncRNA Snhg1 was modified by m6A methylation.

METHODS

Mouse cardiomyocytes HL-1 cells were utilized to construct the hypoxia/reoxygenation (H/R) injury model. HL-1 cell viability was evaluated utilizing CCK-8 method. Cell apoptosis, mitochondrial reactive oxygen species (ROS), and mitochondrial membrane potential (MMP) were quantitated utilizing flow cytometry. RNA immunoprecipitation and dual-luciferase reporter assays were applied to measure the m6A methylation and the interactions between lncRNA Snhg1 and targeted miRNA or target miRNAs and its target gene. The I/R mouse model was constructed with adenovirus expressing lncRNA Snhg1. HE and TUNEL staining were used to evaluate myocardial tissue damage and apoptosis.

RESULTS

LncRNA Snhg1 was down-regulated after H/R injury, and overexpressed lncRNA Snhg1 suppressed H/R-stimulated cell apoptosis, mitochondrial ROS level and polarization. Besides, lncRNA Snhg1 could target miR-361-5p, and miR-361-5p targeted OPA1. Overexpressed lncRNA Snhg1 suppressed H/R-stimulated cell apoptosis, mitochondrial ROS level and polarization though the miR-361-5p/OPA1 axis. Furthermore, WTAP induced lncRNA Snhg1 m6A modification in H/R-stimulated HL-1 cells. Moreover, enforced lncRNA Snhg1 repressed I/R-stimulated myocardial tissue damage and apoptosis and regulated the miR-361-5p and OPA1 levels.

CONCLUSION

WTAP-mediated m6A modification of lncRNA Snhg1 regulated MIRI progression through modulating myocardial apoptosis, mitochondrial ROS production, and mitochondrial polarization via miR-361-5p/OPA1 axis, providing the evidence for lncRNA as the prospective target for alleviating MIRI progression.

Ginsenoside Rd Attenuates Myocardial Ischemia/Reperfusion Injury by Inhibiting Inflammation and Apoptosis through PI3K/Akt Signaling Pathway

Myocardial ischemia/reperfusion (I/R) injury is the leading cause of death worldwide. Ginsenoside Rd (GRd) has cardioprotective properties but its efficacy and mechanism of action in myocardial I/R injury have not been clarified. This study investigated GRd as a potent therapeutic agent for myocardial I/R injury. Oxygen-glucose deprivation and reperfusion (OGD/R) and left anterior descending (LAD) coronary artery ligation were used to establish a myocardial I/R injury model in vitro and in vivo. In vivo, GRd significantly reduced the myocardial infarct size and markers of myocardial injury and improved the cardiac function in myocardial I/R injury mice. In vitro, GRd enhanced cell viability and protected the H9c2 rat cardiomyoblast cell line from OGD-induced injury GRd. The network pharmacology analysis predicted 48 potential targets of GRd for the treatment of myocardial I/R injury. GO and KEGG enrichment analysis indicated that the cardioprotective effects of GRd were closely related to inflammation and apoptosis mediated by the PI3K/Akt signaling pathway. Furthermore, GRd alleviated inflammation and cardiomyocyte apoptosis in vivo and inhibited OGD/R-induced apoptosis and inflammation in cardiomyocytes. GRd also increased PI3K and Akt phosphorylation, suggesting activation of the PI3K/Akt pathway, whereas LY294002, a PI3K inhibitor, blocked the GRd-induced inhibition of OGD/R-induced apoptosis and inflammation in H9c2 cells. The therapeutic effect of GRd in vivo and in vitro against myocardial I/R injury was primarily dependent on PI3K/Akt pathway activation to inhibit inflammation and cardiomyocyte apoptosis. This study provides new evidence for the use of GRd as a cardiovascular drug.

Simvastatin-Loaded Nanoniosome Protects H9c2 Cells from Oxygen-Glucose Deprivation/ Reperfusion Injury by Downregulating Inflammation

Background

Simvastatin (SIM) has anti-inflammatory and antioxidant properties against cardiac ischemia/reperfusion injury (I/RI). However, it suffers from low bioavailability and a short half-life. Nanoniosomes are novel drug delivery systems that may increase SIM effectiveness. The present research evaluates the impact of SIM-loaded nanoniosomes on the oxygen-glucose deprivation/reperfusion (OGD/R) injury model of H9c2 cells.

Methods

Cells were seeded based on five groups: (1) control; (2) OGD/R; (3) OGD/R receiving SIM; (4) OGD/R receiving nanoniosomes; and (5) OGD/R receiving SIM loaded nanoniosomes. OGD/R injury of the H9c2 cells was treated with SIM or SIM loaded nanoniosomes. Cell viability, two inflammatory factors, necroptosis factors, along with HMGB1 and Nrf2 gene expressions were assessed.

Results

The cells treated with SIM loaded nanoniosomes showed a significant elevation in the cell viability and a reduction in HMGB1, Nrf2, TNF-α, IL-1β, RIPK1, and ROCK1 expression levels compared to the OGD/R and SIM groups.

Conclusion

Based on our findings, nanoniosomes could safely serve as a drug delivery system to counterbalance the disadvantages of SIM, resulting in improved aqueous solubility and stability.

Mitochondrial dysfunction in heart diseases: Potential therapeutic effects of Panax ginseng

Heart diseases have a high incidence and mortality rate, and seriously affect people's quality of life. Mitochondria provide energy for the heart to function properly. The process of various heart diseases is closely related to mitochondrial dysfunction. Panax ginseng (P. ginseng), as a traditional Chinese medicine, is widely used to treat various cardiovascular diseases. Many studies have confirmed that P. ginseng and ginsenosides can regulate and improve mitochondrial dysfunction. Therefore, the role of mitochondria in various heart diseases and the protective effect of P. ginseng on heart diseases by regulating mitochondrial function were reviewed in this paper, aiming to gain new understanding of the mechanisms, and promote the clinical application of P. ginseng.

Molecular targets for anti-oxidative protection of açaí berry against diabetes myocardial ischemia/reperfusion injury

Myocardial ischemia/reperfusion injury (MIRI) is the principal cause of death and occurs after prolonged blockage of the coronary arteries. Diabetes represents one of the main factors aggravating myocardial injury. Restoring blood flow is the first intervention against a heart attack, although reperfusion process could cause additional damage, such as the overproduction of reacting oxygen species (ROS). In recent years, açaí berry has gained international attention as a functional food due to its antioxidant and anti-inflammatory properties; not only that but this fruit has shown glucose-lowering effects. Therefore, this study was designed to evaluate the cardioprotective effects of açaí berry on the inflammatory and oxidative responses associated with diabetic MIRI. Diabetes was induced in rats by a single intravenous inoculation of streptozotocin (60 mg/kg) and allowed to develop for 60 days. MIRI was induced by occlusion of the left anterior descending coronary artery for 30 min followed by 2 h of reperfusion. Açaí (200 mg/kg) was administered 5 min before the end of ischemia and 1 h after reperfusion. In this study, we clearly demonstrated that açaí treatment was able to reduce biomarkers of myocardial damage, infarct size, and apoptotic process. Moreover, açaí administrations reduced inflammatory and oxidative response, modulating Nf-kB and Nrf2 pathways. These results suggest that açai berry supplementation could represent a useful strategy for pathological events associated to MIRI.

Simvastatin-loaded nano-niosomes efficiently downregulates the MAPK-NF-κB pathway during the acute phase of myocardial ischemia-reperfusion injury

BACKGROUND

Simvastatin can potentially mitigate acute inflammatory phase of myocardial ischemia-reperfusion injury. However, these effects negatively influenced by its poor bioavailability, low water solubility and high metabolism. Here, we investigated the effects of SIM-loaded nano-niosomes on a rat model of MI/R injury to find a drug delivery method to tackle the barriers.

METHODS

Nano-niosomes' characteristics were identified using dynamic light scattering and transmission electron microscopy. Fifty male Wistar rats were divided into five groups: Sham; MI/R; MI/R + nano-niosome; MI/R + SIM; MI/R + SIM-loaded nano-niosomes. Left anterior descending artery was ligated for 45 min, and 3 mg/kg SIM, nano-niosomes, or SIM-loaded nano-niosomes was intramyocardially injected ten min before the onset of reperfusion. ELISA assay was used to assess cardiac injury markers (cTnI, CK-MB) and inflammatory cytokines (TNF-α, IL-6, TGF-β, MPC-1). Expression level of MAPK-NF-κB and histopathological changes were evaluated by western blot and hematoxylin & eosin staining, respectively.

RESULTS

the size of nano-niosome was 137 nm, reached to 163 nm when simvastatin was loaded. To achieve optimized niosomes span 80, a drug/cholesterol ratio of 0.4 and seven min of sonication time was applied. Optimized entrapment efficiency of SIM-loaded nano-niosomes was 98.21%. Inflammatory cytokines and the expression level of MAPK and NF-κB were reduced in rats receiving SIM-loaded nano-niosomes compared to MI/R + SIM and MI/R + SIM-loaded nano-niosomes.

CONCLUSION

Our results showed that SIM-loaded nano-niosomes could act more efficiently than SIM in alleviating the acute inflammatory response of reperfusion injury via downregulating the activation of MAPK-NF-κB.

7-Hydroxyflavone Alleviates Myocardial Ischemia/Reperfusion Injury in Rats by Regulating Inflammation

Inflammation is the primary pathological process of myocardial ischemia/reperfusion injury (MI/RI). 7-Hydroxyflavone (HF), a natural flavonoid with a variety of bioactivities, plays a crucial role in various biological processes. However, its cardioprotective effects and the underlying mechanisms of MI/RI have not been investigated. This study aimed to explore whether pretreatment with HF could attenuate MI/RI-induced inflammation in rats and investigate its potential mechanisms. The results showed that pretreatment with HF could significantly improve the anatomic data and electrocardiograph parameters, reduce the myocardial infarct size, decrease markers of myocardial injury (aspartate transaminase, creatine kinase, lactate dehydrogenase, and cardiac troponin I), inhibit inflammatory cytokines (IL-1β, IL-6, and TNF-α), suppress oxidative stress, and recover the architecture of the cardiomyocytes. The cardioprotective effect of HF was connected with the regulation of the MAPK/NF-κB signaling pathway. What is more, molecular docking was carried out to prove that HF could be stably combined with p38, ERK1/2, JNK, and NF-κB. In summary, this is a novel study demonstrating the cardioprotective effects of HF against MI/RI in vivo. Consequently, these results demonstrate that HF can be considered a promising potential therapy for MI/RI.