Resina draconis inhibits the endoplasmic-reticulum-induced apoptosis of myocardial cells via regulating miR-423-3p/ERK signaling pathway in a tree shrew myocardial ischemia–reperfusion model

Loureirin B improves H/R-induced hepatic ischemia-reperfusion injury by downregulating ALOX5 to regulate mitochondrial homeostasis

This study was conceived to explore the role and the mechanism of Loureirin B (LB) in hepatic IRI. The viability of LB-treated AML-12 cells was assessed using CCK-8 assay and inflammatory cytokines were detected using ELISA. The activities of ROS and oxidative stress markers MDA, SOD, and GSH-Px were detected using DCFH-DA and corresponding assay kits. The cell apoptosis and caspase3 activity were estimated with flow cytometry and caspase3 assay kits. The expressions of arachidonate 5-lipoxygenase (ALOX5) and apoptosis- and mitochondrial dynamics-related proteins were detected using western blot. The interaction between LB and ALOX5 was analyzed with molecular docking. The transfection efficacy of oe-ALOX5 was examined with RT-qPCR and western blot. Mitochondrial membrane potential was detected with JC-1 staining and immunofluorescence (IF) assay was employed to estimate mitochondrial fusion and fission. The present work found that LB revived the viability, inhibited inflammatory response, suppressed oxidative stress, repressed the apoptosis, and maintained mitochondrial homeostasis in H/R-induced AML-12 cells, which were all reversed by ALOX5 overexpression. Collectively, LB regulated mitochondrial homeostasis by downregulating ALOX5, thereby improving hepatic IRI.

Micro-Executor of Natural Products in Metabolic Diseases

Obesity, diabetes, and cardiovascular diseases are the major chronic metabolic diseases that threaten human health. In order to combat these epidemics, there remains a desperate need for effective, safe, and easily available therapeutic strategies. Recently, the development of natural product research has provided new methods and options for these diseases. Numerous studies have demonstrated that microRNAs (miRNAs) are key regulators of metabolic diseases, and natural products can improve lipid and glucose metabolism disorders and cardiovascular diseases by regulating the expression of miRNAs. In this review, we present the recent advances involving the associations between miRNAs and natural products and the current evidence showing the positive effects of miRNAs for natural product treatment in metabolic diseases. We also encourage further research to address the relationship between miRNAs and natural products under physiological and pathological conditions, thus leading to stronger support for drug development from natural products in the future.

Crosstalk between endoplasmic reticulum stress and non-coding RNAs in cardiovascular diseases

Cells are exposed to various pathological stimulus within the cardiovascular system that challenge cells to adapt and survive. Several of these pathological stimulus alter the normal function of the endoplasmic reticulum (ER), leading to the accumulation of unfolded and misfolded proteins, thus triggering the unfolded protein response (UPR) to cope with the stress or trigger apoptosis of damaged cells. Downstream components of the UPR regulate transcription and translation reprogramming to ensure selective gene expression in response to pathological stimulus, including the expression of non-coding RNAs (ncRNAs). The ncRNAs play crucial roles in regulating transcription and translation, and their aberrant expression is associated with the development of cardiovascular disease (CVD). Notably, ncRNAs and ER stress can modulate each other and synergistically affect the development of CVD. Therefore, studying the interaction between ER stress and ncRNAs is necessary for effective prevention and treatment of CVD. In this review, we discuss the UPR signaling pathway and ncRNAs followed by the interplay regulation of ER stress and ncRNAs in CVD, which provides further insights into the understanding of the pathogenesis of CVD and therapeutic strategies. This article is categorized under: RNA in Disease and Development > RNA in Disease.

Non-coding RNA mediates endoplasmic reticulum stress-induced apoptosis in heart disease

Apoptosis is a complex and highly self-regulating form of cell death, which is an important cause of the continuous decline in ventricular function and is widely involved in the occurrence and development of heart failure, myocardial infarction, and myocarditis. Endoplasmic reticulum stress plays a crucial role in apoptosis-inducing. Accumulation of misfolded or unfolded proteins causes cells to undergo a stress response called unfolded protein response (UPR). UPR initially has a cardioprotective effect. Nevertheless, prolonged and severe ER stress will lead up to apoptosis of stressed cells. Non-coding RNA is a type of RNA that does not code proteins. An ever-increasing number of studies have shown that non-coding RNAs are involved in regulating endoplasmic reticulum stress-induced cardiomyocyte injury and apoptosis. In this study, the effects of miRNA and LncRNA on endoplasmic reticulum stress in various heart diseases were mainly discussed to clarify their protective effects and potential therapeutic strategies for apoptosis.

Advances in research on the protective mechanisms of traditional Chinese medicine (TCM) in myocardial ischaemia-reperfusion injury

CONTEXT

Developing effective drugs to treat myocardial ischaemia-reperfusion (MI/R) injury is imperative. Traditional Chinese medicines (TCMs) have had considerable success in the treatment of cardiovascular diseases. Elucidating the mechanisms by which TCMs improve MI/R injury can supplement the literature on MI/R prevention and treatment.

OBJECTIVE

To summarise TCMs and their main protective mechanisms against MI/R injury reported over the past 40 years.

METHODS

Relevant literature published between 1980 and 2020 in Chinese and English was retrieved from the Web of Science, PubMed, SpringerLink, PubMed Central, Scopus, and Chinese National Knowledge Infrastructure (CNKI) databases. Search terms included 'medicinal plants', 'myocardial ischaemia reperfusion injury', 'Chinese medicine prescriptions', 'mechanisms', 'prevention', 'treatment' and 'protection'. For inclusion in the analysis, medicinal plants had to be searchable in the China Medical Information Platform and Plant Database.

RESULTS

We found 71 medicinal species (from 40 families) that have been used to prevent MI/R injury, of which Compositae species (8 species) and Leguminosae species (7 species) made up the majority. Most of the effects associated with these plants are described as antioxidant and anti-inflammatory. Furthermore, we summarised 18 kinds of Chinese compound prescriptions, including the compound Danshen tablet and Baoxin pill, which mainly reduce oxidative stress and regulate mitochondrial energy metabolism.

DISCUSSION AND CONCLUSIONS

We summarised TCMs that protect against MI/R injury and their pharmacological mechanisms. This in-depth explanation of the roles of TCMs in MI/R injury protection provides a theoretical basis for the research and development of TCM-based treatment drugs.

Inhibition of extracellular signal-regulated kinase downregulates endoplasmic reticulum stress-induced apoptosis and decreases brain injury in a cardiac arrest rat model

Cerebral ischemia-reperfusion injury (CIRI) is the predominant cause of neurological disability after cardiac arrest/cardiopulmonary resuscitation (CA/CPR). The endoplasmic reticulum stress (ERs)-induced apoptosis plays an important role in neuronal survival/death in CIRI. Our previous studies reported that the extracellular signal-regulated kinase (ERK) inhibitor, PD98059, alleviates CIRI after CA/CPR. Whether ERs-induced apoptosis is involved in the neuroprotection of PD98059 remains unknown. This study aims to investigate the effects of ERK inhibition by PD98059 on ERs-induced apoptosis after CIRI in the CA/CPR rat model. The baseline characteristics of male adult Sprague-Dawley (SD) rats in all groups were evaluated before CA/CPR. The SD rats that survived from CA/CPR were randomly divided into 3 groups (n=12/group): normal saline group (1 ml/kg), dimethylsulfoxide (DMSO, the solvent of PD98059, 1 ml/kg) group, PD98059 group (0.3 mg/kg). Another 12 SD rats were randomly selected as the Sham group. Twenty-four hours after resuscitation, neural injury was assessed by survival rate, neurological deficit scores (NDS) and Nissl staining; apoptosis of brain cells was detected using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining; mRNA expression and protein levels of ERs-related protein BIP, PERK, ATF4 and CHOP were checked with RT-PCR and Western Blot. The results showed that there were no significant differences in baseline characteristics before CA/CPR among all groups. PD98059 significantly improved survival rate and NDS, increased the Nissl bodies in neurons, reduced apoptosis, downregulated the mRNA transcription and expression levels of BIP, PERK, ATF4 and CHOP at 24 h after CA/CPR. Our results demonstrate that inhibition of ERK by PD98059 alleviates ERs-induced apoptosis via BIP-PERK-ATF4-CHOP signaling pathway and mitigates CIRI in the CA/CPR rat model.

Loureirin B Alleviates Myocardial Ischemia/Reperfusion Injury via Inhibiting PAI-1/TGF-β1/Smad Signaling Pathway

Myocardial ischemia/reperfusion (MI/R) injury is a common clinical problem after myocardial infarction without effective therapy. Loureirin B (LrB) is a kind of flavonoid with anti-inflammatory and antifibrotic activities. However, the effect of LrB on MI/R and its underlying mechanism remains elusive. In the present study, a mouse model of MI/R was established by coronary artery occlusion. Administration of LrB (0.5 mg/kg or 1 mg/kg) for 4 weeks effectively improved left ventricular (LV) function and reduced myocardial infarction in MI/R mice. MI/R-induced expression of IL-6, TNF-α, and IL-1β in the hearts was reduced by LrB treatment. Histological analysis showed that LrB attenuated myocardial collagen deposition. LrB downregulated fibronectin, collagen I, collagen III, and α-SMA expression. Notably, LrB inhibited the expression of profibrotic plasminogen activator inhibitor-1 (PAI-1), transforming growth factor (TGF)-β1, TGF-β1R, and p-Smad2/3. Consistently, LrB inhibited the activation of TGF-β1/Smad signaling pathway and the expression of fibrosis-related proteins in angiotensin (Ang) II-treated cardiac fibroblasts (CFs). Overexpression of PAI-1 abolished the effects of LrB on Ang II-treated CFs, suggesting that LrB may function through regulating PAI-1. These results indicated that LrB may alleviate MI/R-induced myocardial fibrosis by inhibiting PAI-1/TGF-β1/Smad signaling pathway. Thus, LrB may be a potential drug in the treatment of MI/R injury.

Dragon's Blood from Dracaena Worldwide: Species, Traditional Uses, Phytochemistry and Pharmacology

Dragon's blood (DB) refers mainly to the crimson resin of many Dracaena spp. DB has been used by different traditional medicine systems worldwide, including Arabic medicine, African medicine, traditional Chinese medicine, Thai medicine, etc. DB are mainly used to heal wounds, kill pain, stop bleeding, and cure various diseases such as diarrhea, dysentery and ulcers for over 1000 years. 11 Dracaena spp. and 3 subspecies are reported to be able to produce red resin. However, the resources are extremely deficient. Several Dracaena spp. are in threatened status. Over 300 compounds have been isolated from Dracaena spp., mainly including flavonoids, steroids, and phenolics. DB exhibits anti-inflammatory, analgesic, antithrombotic, anti-oxidant, antimicrobial, antidiabetic, and anticancer properties, which explain its wound healing effects, preventive effects on cardiovascular and cerebrovascular diseases, dual-directional regulation of blood flow, neuroprotection and radioprotective effects. No apparent side effects or toxicity have been reported. DB are restricted from being exploited due to limited resources and unclear resin formation mechanism. It is necessary to expand the cultivation of Dracaena spp. and fully understand the mechanism underlying the resin formation process to develop an effective induction method for the sustainable utilization of DB.

Circular RNA-DENND4C in H9c2 cells relieves OGD/R-induced injury by down regulation of microRNA-320

Ischemic heart disease (IHD) is one of the most deadly diseases worldwide. To detect the regulatory mechanism, the circular RNA (circRNA)-differentially expressed in normal cells and neoplasia domain containing 4 C (DENND4C) was explored in the H9c2 cells. The circRNA-DENND4C overexpressing plasmid, si-circRNA-DENND4C and miR-320 mimic were transfected into the H9c2 cells and treated with OGD/R stimulation. We took CCK-8 method, Annexin V-FITC/PI-flow cytometer to search for viability and apoptotic ability. With the help of qRT-PCR and western blot, the expression of circRNA-DENND4C and miR-320, as well as the Bax, Cleaved PARP/caspase 3 and signal proteins were separately determined. Regulation of circRNA-DENND4C and miR-320 was confirmed by dual-luciferase reporter assay. OGD/R induced suppression of cell viability, but enhancement of apoptosis and block of ERK and mTOR pathways. Moreover, circRNA-DENND4C was up-regulated after OGD/R stimulation and augmented OGD/R-stimulated damage while circRNA-DENND4C silencing displayed opposite influences. miR-320 was negatively controlled and targeted by the circRNA-DENND4C.The overexpressed miR-320 impeded the effects of circRNA-DENND4C. Besides, circRNA-DENND4C relieved the suppression of ERK and mTOR pathways caused by OGD/R stimulation, and all promoting impacts of circRNA-DENND4C were reversed by the miR-320 mimic. Overexpressed circRNA-DENND4C in H9c2 cells attenuated OGD/R-induced injuries by the down-regulation of miR-320 through the ERK and mTOR activation.

Allergic Inflammation Alters microRNA Expression Profile in Adipose Tissue in the Rat

Adipose tissue is a major source of circulating exosomal microRNAs (miRNAs) that are modulators of the immune response in various types of tissues and organs, including airways. Still, no evidence exists if allergic airway inflammation may affect fat tissue inflammation via alterations in the miRNA expression profile. Therefore, we investigated the miRNA expression profile in the adipose tissue upon induced allergic inflammation in the airways in the rat. Brown Norway rats were chronically sensitized to house dust mite extract for seven weeks. Body composition was performed using MiniSpec Plus. The eosinophil count and the total IgE level were determined to confirm the induction of allergic inflammation. MiRNA expression profiling was done using the next-generation sequencing with validation by qPCR. We found that allergic airway inflammation significantly increased fat in adipose tissue, glucose concentration, and the gene expression of adipose tissue-derived proinflammatory peptides (leptin, TNFα). In miRNA-seq analysis, we showed significant differences in the expression of 36 mature miRNAs, three precursors, and two miRNA families in adipose tissue of allergic rats. Two miRNAs—miRNA-151-5p and miRNA-423-3p—showed significantly increased expression in qPCR in adipose tissue and lungs of sensitized animals. Allergic airway inflammation affects fat tissue and alters miRNA expression profile in adipose tissue in the rat.

Ghrelin promotes the osteogenic differentiation of rMSCs via miR-206 and the ERK1/2 pathway

OBJECTIVE

Mesenchymal stem cells (MSCs) can differentiate into chondroblasts, adipocytes, or osteoblasts under appropriate stimulation. Ghrelin, an endogenous ligand for the growth hormone secretagogue receptor (GHSR), stimulates growth hormone (GH) secretion and exerts both orexigenic and adipogenic effects. The ERK1/2 signaling pathway is known to trigger osteogenic differentiation of rabbit bone marrow-derived mesenchymal stromal cells. In the present study, the function of miR-206 in the ghrelin-mediated osteogenic differentiation of rabbit bone marrow-derived mesenchymal stromal cells (rMSCs) was explored.

METHODS

The expression of miR-206 was detected by qPCR, and phosphorylated ERK1/2 and the protein expression levels of ALP, RUNX2, and Osterix were assessed by western blotting.

RESULTS

Ghrelin inhibited the expression of miR-206 to promote the osteogenic differentiation of rMSCs. Moreover, ghrelin increased the phosphorylation of ERK1/2, while overexpression of miR-206 suppressed ERK1/2 phosphorylation, indicating that miR-206 can regulate the ERK1/2 pathway. Further, inhibition of ERK1/2 had no influence on miR-206 expression; however, the phosphorylation of ERK1/2 was decreased, and the protein expression levels of ALP, RUNX2, and Osterix were downregulated.

CONCLUSIONS

Ghrelin promotes the osteogenic differentiation of rMSCs via miR-206 and the ERK1/2 pathway.

Circulating MicroRNA-423-3p Improves the Prediction of Coronary Artery Disease in a General Population - Six-Year Follow-up Results From the China-Cardiovascular Disease Study

BACKGROUND

Circulating microRNAs (miRNA) are potential prognostic biomarkers for cardiovascular disease. We aimed to identify serum miRNA as an effective predictor for coronary artery disease (CAD) events in a general population cohort.Methods and Results:Serum miRNAs associated with CAD were determined by small RNA sequencing and quantitative RT-PCR. Further, the predictive ability of identified serum miRNAs was measured in a general population of 2,812 people. As a main outcome measure, CAD events were collected for 6 years and included acute myocardial infarction and subsequent myocardial infarction. Out of the 48 miRNA candidates, 5 miRNAs (miR-10a-5p, miR-126-3p, miR-210-3p, miR-423-3p and miR-92a-3p) showed better reliability and repeatability in serum. Then, the association of serum levels of the 5 miRNAs with CAD was validated. Furthermore, miR-10a-5p and miR-423-3p, which showed better performance, were tested in the large cohort, with a median follow up of 6.0 years. In multivariable Cox regression analysis, only miR-423-3p (P for trend<0.001) was able to precisely predict CAD events. Moreover, the addition of circulating miR-423-3p with the traditional risk factors together markedly improved the various model performance measures, including the area under the operating characteristics curve (0.782 vs. 0.806), Akaike Information Criterion (965.845 vs. 943.113) and net reclassification improvement (19.18%).

CONCLUSIONS

Circulating miR-423-3p can improve the prediction of primary CAD outcomes on the basis of a traditional risk factor model in general population.