MicroRNA-210 alleviates oxidative stress-associated cardiomyocyte apoptosis by regulating BNIP3

Myocardial ischemia-reperfusion injury; Molecular mechanisms and prevention

Cardiovascular diseases are one of the leading causes of mortality in developed countries. Among cardiovascular disorders, myocardial infarction remains a life-threatening problem predisposing to the development and progression of ischemic heart failure. Ischemia/reperfusion (I/R) injury is a critical cause of myocardial injury. In recent decades, many efforts have been made to find the molecular and cellular mechanisms underlying the development of myocardial I/R injury and post-ischemic remodeling. Some of these mechanisms are mitochondrial dysfunction, metabolic alterations, inflammation, high production of ROS, and autophagy deregulation. Despite continuous efforts, myocardial I/R injury remains a major challenge in medical treatments of thrombolytic therapy, heart disease, primary percutaneous coronary intervention, and coronary arterial bypass grafting. The development of effective therapeutic strategies to reduce or prevent myocardial I/R injury is of great clinical significance.

miR-210/NF-κB axis: A new direction for regulating cadmium-induced pig artery inflammatory injury

Cadmium (Cd) is a toxic metal pollutant that still exists in the environment. The microRNA (miRNA) is a type of noncoding RNA that plays an important role in gene posttranscriptional regulation and disease development. Although the toxic effects of Cd have been extensively studied, studies on the mechanism of Cd from the perspective of miRNA are still limited. So, we established a Cd-exposure pig model, which confirmed that Cd exposure would cause pig artery damage. The miR-210 with the most reduced expression and the nuclear factor kappa B (NF-κB) that had a targeting relationship with miR-210 were screened. The effect of miR-210/NF-κB on the artery damage induced by Cd exposure was investigated by acridine orange/ethidium bromide staining, reactive oxygen species (ROS) staining, quantitative PCR, and western blotting. The results showed that miR-210 inhibitor, pcDNA-NF-κB could induce ROS overproduction in pig hip artery endothelial cells, thus inducing Th1/Th2 imbalance and necroptosis, leading to increased inflammation, while small interfering RNA-NF-κB played a mitigating role. In conclusion, Cd can induce artery necroptosis and Th1/Th2 imbalance by regulating the miR-210/NF-κB axis, so as to lead to artery inflammatory damage. In this study, we explored the way in which Cd exposure causes artery damage in pig, providing a new perspective on the regulatory damage of miR-210/NF-κB axis.

Paracrine effects of mir-210-3p on angiogenesis in hypoxia-treated c-kit-positive cardiac cells

Objective: Treatment with c-kit-positive cardiac cells (CPCs) has been shown to improve the prognosis of ischemic heart disease. MicroRNAs (miRNAs) confer protection by enhancing the cardiac repair process, but their specific functional mechanisms remain unclear. This study aimed to screen for differentially expressed miRNAs in CPCs under hypoxia and explore their effects on the function of CPCs.Methods: We harvested CPCs from C57 adult mice and later performed a high-throughput miRNA sequencing for differential expression profiling analysis. Subsequently, we intervened with the differentially expressed gene miR-210-3p in CPCs and detected changes in the secretion of angiogenesis-related factors through a protein-chip analysis. Finally, we applied CPC supernatants of different groups as conditioned medium to treat mouse cardiac microvascular endothelial cells (CMECs) and further investigated the functional effects of miR-210-3p on c-kit+CPCs under ischemia and hypoxia conditions.Results: The miR-210-3p was highly increased in hypoxia-treated CPCs. Protein-chip detection revealed that CPCs expressed cytokines such as FGF basic, angiogenin, and vascular endothelial growth factor (VEGF) and that hypoxia enhanced their release. Silencing miR-210-3p resulted in a reduction in the release of these angiogenesis-related factors. In addition, the conditioned medium of hypoxia-treated CPCs promoted the proliferation, migration, and tube-forming capabilities of CMECs. In contrast, the conditioned media of CPCs with silenced miR-210-3p after hypoxia decreased the proliferation, migration, and tube-forming ability of CMEC.Conclusions: The CPCs exert proangiogenic effects via paracrine pathways mediated by miR-210-3p. Upregulation of miR-210-3p in hypoxia-treated CPCs may enhance their paracrine function by regulating the secretion of angiogenic factors, thereby promoting angiogenesis in ischemic heart disease.

Plasma microRNA expression and immunoregulatory cytokines in an Indian population occupationally exposed to cadmium

Following its accumulation in the body, cadmium (Cd) exposure is associated with devastating effects on multiple organ system of the human body. The immune system is one of the sensitive targets for Cd-induced toxicity. Recently, studies have demonstrated a significant role of Cd in inducing epigenetic alterations. With this background, the present study was planned to study the changes in candidate microRNA (miRNA) expression associated with immune regulation in occupationally Cd-exposed workers. One hundred individuals involved in welding and metal handicraft manufacturing, while 80 apparently healthy subjects without any prior history of occupational exposure were recruited for the study. Blood Cd level was determined by atomic absorption spectrometry. Serum cytokine levels were measured using an enzyme-linked immunosorbent assay and serum miRNA expression of candidate miRNAs (miR-146a, miR-210, and miR-222) were determined by real-time polymerase chain reaction. The median Cd level (2.40 μg/L) in the occupationally exposed workers was significantly higher than the nonexposed subjects (0.90 μg/L). Among the cytokines, interleukin-4 (IL-4), and tumor necrosis factor-alpha (TNF-α) were significantly higher while IL-2 and IL-10 were significantly lower in the exposed. The expression level of miR-146a and miR-222 were significantly different between the groups with the former showing downregulation and later showing upregulation. Correlation analysis revealed a positive and negative association of miR-222 and miR-146a with blood cadmium level, IL-17 as well as TNF-α, respectively. Furthermore, the in-silico analysis revealed a significant role of the studied miRNAs in various cellular and genetic pathways. The findings of the present study demonstrate significant involvement of Cd-induced alteration in miRNAs in varied immune regulatory changes in exposed individuals.

Activation of PTEN/P13K/AKT Signaling Pathway by miRNA-124-3p-Loaded Nanoparticles to Regulate Oxidative Stress Attenuates Cardiomyocyte Regulation and Myocardial Injury

As a common cardiovascular disease, acute myocardial infarction seriously affects the health and life of patients. miRNAs play an important role in acute myocardial infarction. Based on miRNA obtained from the previous sequencing, this study investigated whether miRNA (miR)-124-3p-loaded nanoparticles (NPs) affect the phenotype of the acute myocardial infarction (AMI) rat. Nano-miR-124-3p decreased the myocardial infarction area, improved the myocardial tissue structure, and increased the degree of fibrosis. Nano-miR-124-3p decreased apoptosis and the expression of cleaved caspase 3, indicating its role in protecting and repairing the myocardium. To further verify the action mechanism of miRNA, a potential target gene of miR-124-3p, PTEN was identified by STARBASE and further confirmed using double luciferase assays. Following cotransfection of nano-miR-124-3p and PTEN, the areas of tissue structure damage, myocardial infarction, and fibrosis were substantially elevated. The expression of cleaved caspase 3 and the apoptosis rate in the nano-miR-124-3p and PTEN cotransfection group was also significantly increased. Bioinformatics analysis revealed that miRNA-124-3 may regulate oxidative stress injury by targeting PTEN. Taken together, miR-124-3p could protect and repair myocardial tissues through targeting PTEN.

The promising role of hypoxia-resistant insulin-producing cells in ameliorating diabetes mellitus in vivo

Aim:

This study aimed to evaluate the efficacy of hypoxia-persistent insulin-producing cells (IPCs) against diabetes in vivo.

Materials & methods:

Mesenchymal stem cells (MSCs) differentiation into IPCs in the presence of Se/Ti (III) or CeO₂ nanomaterials. IPCs were subjected to hypoxia and hypoxia genes were analyzed. PKH-26-labeled IPCs were infused in diabetic rats to evaluate their anti-diabetic potential.

Results:

MSCs were differentiated into functional IPCs. IPCs exhibited overexpression of anti-apoptotic genes and down-expression of hypoxia and apoptotic genes. IPCs implantation elicited glucose depletion and elevated insulin, HK and G6PD levels. They provoked VEGF and PDX-1 upregulation and HIF-1α and Caspase-3 down-regulation. IPCs transplantation ameliorated the destabilization of pancreatic tissue architecture.

Conclusion:

The chosen nanomaterials were impressive in generating hypoxia-resistant IPCs that could be an inspirational strategy for curing diabetes.

Transplantation of cells that can release insulin have been reported as an alternate method to islet transfer for curing diabetes; however, the main difficulty facing the quality of the pancreatic cells is the deficiency of oxygen. Thus, this study was done to discover a new curing method for diabetes by producing cells that can release insulin and could survive under low oxygen circumstances, and assessing their healing ability against diabetes in rats.

miR-107 Attenuates Sepsis-Induced Myocardial Injury by Targeting PTEN and Activating the PI3K/AKT Signaling Pathway

Sepsis is a public health problem worldwide. This study investigated the mechanism of miR-107 on sepsis-induced myocardial injury. Sepsis rat models were established by cecal ligation and puncture (CLP), and the cell model was established using lipopolysaccharide (LPS)-induced cardiomyocytes. Cardiac function indexes of rats were measured using echocardiography. Pathological changes in the rat myocardium were observed using histological staining. Expression of miR-107 in the serum of rats and in cardiomyocytes was detected after the treatment with miR-107 mimic and/or pcDNA3.1-PTEN, followed by assessment of cell cycle, proliferation, and apoptosis. Binding sites of miR-107 and PTEN were predicted. PTEN, PI3K, p-PI3K, AKT, and p-AKT levels in LPS-induced cardiomyocytes were measured. miR-107 was significantly downregulated in the serum of CLP rats and LPS-induced cardiomyocytes. miR-107 overexpression remarkably improved cardiac function and histological changes, decreased inflammatory factors, and alleviated the sepsis-induced myocardial injury in rats. In LPS-induced cardiomyocytes, miR-107 overexpression increased cardiomyocyte proliferation, inhibited apoptosis, and enhanced the proportion of cardiomyocytes arrested in S and G2/M phases. miR-107 targeted PTEN. PTEN overexpression partially reversed the inhibition of miR-107 mimic on cardiomyocyte apoptosis. miR-107 overexpression activated the PI3K/AKT pathway by inhibiting PTEN. To conclude, miR-107 activates the PI3K/AKT pathway by inhibiting PTEN, thus attenuating sepsis-induced myocardial injury and LPS-induced cardiomyocyte apoptosis.

miR-210 hypoxamiR in Angiogenesis and Diabetes

Significance: microRNA-210 (miR-210) is the master hypoxia-inducible miRNA (hypoxamiR) since it has been found to be significantly upregulated under hypoxia in a wide range of cell types. Recent advances: Gene ontology analysis of its targets indicates that miR-210 modulates several aspects of cellular response to hypoxia. Due to its high pleiotropy, miR-210 not only plays a protective role by fine-tuning mitochondrial metabolism and inhibiting red-ox imbalance and apoptosis, but it can also promote cell proliferation, differentiation, and migration, substantially contributing to angiogenesis. Critical issues: As most miRNAs, modulating different gene pathways, also miR-210 can potentially lead to different and even opposite effects, depending on the physio-pathological contexts in which it acts. Future direction: The use of miRNAs as therapeutics is a fast growing field. This review aimed at highlighting the role of miR-210 in angiogenesis in the context of ischemic cardiovascular diseases and diabetes in order to clarify the molecular mechanisms underpinning miR-210 action. Particular attention will be dedicated to experimentally validated miR-210 direct targets involved in cellular processes related to angiogenesis and diabetes mellitus, such as mitochondrial metabolism, redox balance, apoptosis, migration, and adhesion. Antioxid. Redox Signal. 36, 685-706.

Mitochondrial Quality Control in Cardiac-Conditioning Strategies against Ischemia-Reperfusion Injury

Mitochondria are the central target of ischemic preconditioning and postconditioning cardioprotective strategies, which consist of either the application of brief intermittent ischemia/reperfusion (I/R) cycles or the administration of pharmacological agents. Such strategies reduce cardiac I/R injury by activating protective signaling pathways that prevent the exacerbated production of reactive oxygen/nitrogen species, inhibit opening of mitochondrial permeability transition pore and reduce apoptosis, maintaining normal mitochondrial function. Cardioprotection also involves the activation of mitochondrial quality control (MQC) processes, which replace defective mitochondria or eliminate mitochondrial debris, preserving the structure and function of the network of these organelles, and consequently ensuring homeostasis and survival of cardiomyocytes. Such processes include mitochondrial biogenesis, fission, fusion, mitophagy and mitochondrial-controlled cell death. This review updates recent advances in MQC mechanisms that are activated in the protection conferred by different cardiac conditioning interventions. Furthermore, the role of extracellular vesicles in mitochondrial protection and turnover of these organelles will be discussed. It is concluded that modulation of MQC mechanisms and recognition of mitochondrial targets could provide a potential and selective therapeutic approach for I/R-induced mitochondrial dysfunction.

Ochratoxin A induces human kidney tubular epithelial cell apoptosis through regulating lipid raft/PTEN/AKT signaling pathway

Ochratoxin A (OTA) is a fungal toxin that causes serious threat to human health. OTA could lead to the injury of various tissues, especially kidney injury. However, the toxic effects of OTA on human kidney tubular epithelial cell (HK-2) and the possible mechanism remains poorly understood. This study was to investigate the toxic effects of OTA on HK-2 and elucidate the molecular mechanism. HK-2 cells were treated OTA to evaluate the effect of OTA on cell viability and apoptosis. OTA inhibited the growth of HK-2 in a concentration-dependent manner. With the concentration increased, OTA significantly lead to the apoptosis of HK-2. OTA could increase the levels of reactive oxygen species (ROS) and Malondialdehyde (MDA). Superoxide dismutase (SOD) and glutathione (GSH) activities were decreased by OTA. Furthermore, OTA increased Caspase-3 and Bax expression and decreased BCL2 expression. Compared to the control group, the expression of PTEN was increased and the expression of PI3K and AKT were decreased in OTA treated groups. In addition, we found OTA could disrupt the formation of lipid raft by attenuating sphingomyelin and cholesterol levels. In conclusion, our results indicated that OTA induces apoptosis in HK-2 through regulating PTEN/AKT signaling pathway via disrupting lipid raft formation.

Leonurine Alleviates Hypoxia-Induced Myocardial Damage by Regulating miRNAs

Objective

miRNAs as pharmaco-targets have been investigated in multifarious diseases. Our study aimed to determine whether leonurine was a potential cardioprotective agent by targeting miRNAs in hypoxia-stimulated mice and H9c2 cardiomyocytes.

Methods

Cell proliferation and apoptosis were examined by CCK-8 and TUNEL assay in hypoxia-stimulated rat H9c2 cardiomyocytes. miRNAs expression levels in cardiomyocytes in response to hypoxia stimulation were detected by RT-qPCR. Mice with myocardial injury were induced by chronic intermittent hypoxia stimulation.

Results

Leonurine alleviated hypoxia-induced cardiac hypertrophy in mice. Moreover, up-regulation of miR-31 and down-regulation of miR-210 in hypoxia-stimulated mice were reversed by leonurine administration. Leonurine exhibited cardioprotective activity in an vitro cell model of hypoxia-stimulated rat H9c2 cardiomyocytes, reflecting that the compound improved hypoxia-induced growth inhibition and apoptosis of cardiomyocytes. TUNEL assay revealed that transfection of miR-31 inhibitors or miR-210 mimics abrogated hypoxia-induced cardiomyocyte apoptosis. In contrast to that, miR-31 mimics or miR-210 inhibitors counteracted the anti-apoptotic effect of leonurine on hypoxia-treated rat H9c2 cardiomyocytes.

Conclusion

Our findings suggest that miR-31 and miR-210 as the upstream regulators of leonurine are involved in hypoxia-induced cardiomyocyte apoptosis. Leonurine can target miRNAs to protect against hypoxia-induced myocardial damage. miRNAs as potential drug targets may provide prospective therapeutic strategies for the treatment of myocardial damage.

Omega-3 fatty acid protects cardiomyocytes against hypoxia-induced injury through targeting MiR-210-3p/CASP8AP2 axis

MicroRNAs (miRs) regulate diverse biological functions in both normal and pathological cellular conditions by post-transcriptional regulation of various genes expression. Nevertheless, the role of miRs in regulating the protective functions of omega-3 fatty acid in relation to hypoxia in cardiomyocytes remains unknown. The aim of this study was to investigate the effects of omega-3 fatty acid supplementation on cardiomyocyte apoptosis and further delineate the mechanisms underlying microRNA-210 (miRNA-210)-induced cardiomyocyte apoptosis in vitro. H9C2 cultured cells were first subjected to hypoxia followed by a subsequent treatment with main component of the Omega-3 fatty acid, Docosahexaenoic Acid (DHA). Cell apoptosis were detected by flow cytometry and the expression of miR-210-3p were detected by RT-qPCR and caspase-8-associated protein 2 (CASP8AP2) at protein levels by immunoblotting. Dual luciferase assay was used to verify the mutual effect between miR-210-3p and the 3'-untranslated region (UTR) of CASP8AP2 gene. DHA was shown to reduce apoptosis in H9C2 cells subjected to hypoxia. While DHA caused a significant increase in the expression of miR-210-3p, there was a marked reduction in the protein expression of CASP8AP2. MiR-210-3p and CASP8AP2 were significantly increased in H9C2 cardiomyocyte subjected to hypoxia. Overexpression of miR-210-3p could ameliorate hypoxia-induced apoptosis in H9C2 cells. MiR-210-3p negatively regulated CASP8AP2 expression at the transcriptional level. Both miR-210-3p mimic and CASP8AP2 siRNA could efficiently inhibit apoptosis in H9C2 cardiomyocyte subjected to hypoxia. We provide strong evidence showing that Omega-3 fatty acids can attenuate apoptosis in cardiomyocyte under hypoxic conditions via the up-regulation of miR-210-3p and targeting CASP8AP2 signaling pathway.

miR-210 Participates in Hepatic Ischemia Reperfusion Injury by Forming a Negative Feedback Loop With SMAD4

BACKGROUND AND AIMS

Hepatic ischemia-reperfusion (IR) injury is a major complication of liver transplantation, resection, and hemorrhagic shock. Hypoxia is a key pathological event associated with IR injury. MicroRNA-210 (miR-210) has been characterized as a micromanager of hypoxia pathway. However, its function and mechanism in hepatic IR injury is unknown.

APPROACH AND RESULTS

In this study, we found miR-210 was induced in liver tissues from patients subjected to IR-related surgeries. In a murine model of hepatic IR, the level of miR-210 was increased in hepatocytes but not in nonparenchymal cells. miR-210 deficiency remarkably alleviated liver injury, cell inflammatory responses, and cell death in a mouse hepatic IR model. In vitro, inhibition of miR-210 decreased hypoxia/reoxygenation (HR)-induced cell apoptosis of primary hepatocytes and LO2 cells, whereas overexpression of miR-210 increased cells apoptosis during HR. Mechanistically, miR-210 directly suppressed mothers against decapentaplegic homolog 4 (SMAD4) expression under normoxia and hypoxia condition by directly binding to the 3' UTR of SMAD4. The pro-apoptotic effect of miR-210 was alleviated by SMAD4, whereas short hairpin SMAD4 abrogated the anti-apoptotic role of miR-210 inhibition in primary hepatocytes. Further studies demonstrated that hypoxia-induced SMAD4 transported into nucleus, in which SMAD4 directly bound to the promoter of miR-210 and transcriptionally induced miR-210, thus forming a negative feedback loop with miR-210.

CONCLUSIONS

Our study implicates a crucial role of miR-210-SMAD4 interaction in hepatic IR-induced cell death and provides a promising therapeutic approach for liver IR injury.

Histopathological significance of microRNA-210 expression in acute peripheral ischemia in a murine femoral artery ligation model

Under hypoxic conditions, microRNA-210 is upregulated and plays multiple physiological roles including in cell growth arrest, stem cell survival, repression of mitochondrial respiration, angiogenesis, and arrest of DNA repair. In this study, we investigated the histopathological expression of microRNA-210 under hypoxic conditions using a femoral artery ligation model established in C57BL/6J mice to determine the pathological significance of microRNA-210. Following femoral artery ligation, ischemia was represented by decreased blood flow compared to the control, in which a sham operation was performed. On histopathology, degeneration/necrosis of the muscle fibers, inflammatory cell infiltration, and regeneration of the muscle fibers were sequentially observed from 3 h to 3 d after ligation of the artery. The degree of these effects was more severe in the area in which type I muscular fibers are dominant. The histological expression of hypoxia-inducible factor 1α, a well-known biomarker of hypoxia, and microRNA-210 was observed in a few necrotic muscle fibers, macrophages, and myoblasts, a distribution consistent with the histopathological lesions, and their signal increased over time. The expression of microRNA-210 in macrophages and myoblasts under ischemia might be indicative of a significant role in the recovery from ischemic lesions. In addition, the in situ hybridization of microRNA-210 could potentially be used for the detection of hypoxia as a histological marker in addition to the immunohistochemistry of hypoxia-inducible factor 1α.

Liraglutide Increases Serum Levels of MicroRNA-27b, -130a and -210 in Patients with Type 2 Diabetes Mellitus: A Novel Epigenetic Effect

Liraglutide has shown favourable effects on several cardiometabolic risk factors, beyond glucose control. MicroRNAs (miRNAs) regulate gene expression, resulting in post-transcriptional modifications of cell response and function. Specific miRNAs, including miRNA-27b, miRNA-130a, and miRNA-210, play a role in cardiometabolic disease. We aimed to determine the effect of liraglutide on the serum levels of miRNA-27b, miRNA-130a and miRNA-210. Twenty-five subjects with type-2 diabetes mellitus (T2DM), naïve to incretin-based therapy, were treated with liraglutide (1.2 mg/day as an add-on to metformin) for 4 months. miRNAs were quantified using real-time polymerase chain reaction. After liraglutide treatment, we found significant reductions in fasting glucose (from 9.8 ± 5.3 to 6.7 ± 1.6 mmol/L, p = 0.0042), glycosylated haemoglobin (HbA1c) (from 8.1 ± 0.8 to 6.6 ± 1.0%, p = 0.0008), total cholesterol (from 5.0 ± 1.0 to 4.0 ± 0.7 mmol/L, p = 0.0011), triglycerides (from 1.9 ± 1.0 to 1.5 ± 0.8 mmol/L, p = 0.0104) and low-density lipoprotein cholesterol (from 2.9 ± 1.2 to 2.2 ± 0.6 mmol/L, p = 0.0125), while the serum levels of miRNA-27b, miRNA-130a and miRNA-210a were significantly increased (median (interquartile range, IQR) changes: 1.73 (7.12) (p = 0.0401), 1.91 (3.64) (p = 0.0401) and 2.09 (11.0) (p = 0.0486), respectively). Since the changes in miRNAs were independent of changes in all the metabolic parameters investigated, liraglutide seems to exert a direct epigenetic effect in T2DM patients, regulating microRNAs involved in the maintenance of endothelial cell homeostasis. These changes might be implicated in liraglutide’s benefits and may represent useful targets for cardiometabolic management.

Small molecule inhibition of cyclic GMP-AMP synthase ameliorates sepsis-induced cardiac dysfunction in mice

AIMS

Cardiac dysfunction is the main cause of multi-organ failure following sepsis within critical care units. The present study aimed to investigate the effects of the small molecule inhibition of cyclic GMP-AMP synthase (cGAS), RU.521, on cardiac function in mice with sepsis.

MATERIALS AND METHODS

Sepsis was induced in mice via intraperitoneal lipopolysaccharide (LPS) injection (10 mg/kg, i.p.). Mice subsequently received 5 mg/kg RU.521 within 10 min form LPS injection. The cardiac function, inflammatory factor and oxidative stress of mice were examined for 24 h following LPS injection.

KEY FINDINGS

RU.521 was indicated to significantly increase the cardiac function of mice with sepsis. In addition, the inflammatory responses, oxidative stress and apoptosis in hearts of sepsis mice were markedly mitigated by RU.521. Moreover, inhibition of Sirt3 inhibited the protective effects of RU.521 on mice with sepsis.

SIGNIFICANCE

The current study indicated that RU.521 alleviated the inflammatory response and alleviated the damage induced by oxidative stress, leading to cardiac protection via increased Sirt3 expression in the hearts of mice with sepsis.

MiR-181a-5p is involved in the cardiomyocytes apoptosis induced by hypoxia-reoxygenation through regulating SIRT1

MiR-181a-5p's mechanism in hypoxia-reoxygenation (H/R)-induced cardiomyocytes apoptosis has not been clarified. This study verified that SIRT1 was the target of miR-181a-5p. MiR-181a-5p expression was up-regulated or down-regulated in H/R-induced cardiomyocytes, and SIRT1 was transfected into cells alone or in combination with miR-181a-5p. Cell viability, apoptosis, levels of released lactate dehydrogenase (LDH), malondialdehyde (MDA), and superoxide dismutase (SOD), as well as the Bcl-2, Bax, and Caspase 3 levels in treated cells were tested. On the one hand, down-regulated miR-181a-5p promoted cell viability, reduced released LDH and MDA, and increased SOD level in H/R-induced cardiomyocytes. On the other hand, miR-181a-5p inhibited apoptosis and elevated Bcl-2 expression while decreasing the expressions of Bax and Caspase 3 in treated cells, but the effects of miR-181a-5p could be rescued by SIRT1. In conclusion, miR-181a-5p involved in H/R-induced cardiomyocytes apoptosis through regulating SIRT1, which might become a novel direction for related diseases.

Mending a broken heart: current strategies and limitations of cell-based therapy

The versatility of pluripotent stem cells, attributable to their unlimited self-renewal capacity and plasticity, has sparked a considerable interest for potential application in regenerative medicine. Over the past decade, the concept of replenishing the lost cardiomyocytes, the crux of the matter in ischemic heart disease, with pluripotent stem cell-derived cardiomyocytes (PSC-CM) has been validated with promising pre-clinical results. Nevertheless, clinical translation was hemmed in by limitations such as immature cardiac properties, long-term engraftment, graft-associated arrhythmias, immunogenicity, and risk of tumorigenicity. The continuous progress of stem cell-based cardiac therapy, incorporated with tissue engineering strategies and delivery of cardio-protective exosomes, provides an optimistic outlook on the development of curative treatment for heart failure. This review provides an overview and current status of stem cell-based therapy for heart regeneration, with particular focus on the use of PSC-CM. In addition, we also highlight the associated challenges in clinical application and discuss the potential strategies in developing successful cardiac-regenerative therapy.

Inhibition of MiR-122 Decreases Cerebral Ischemia-reperfusion Injury by Upregulating DJ-1-Phosphatase and Tensin Homologue Deleted on Chromosome 10 (PTEN)/Phosphonosinol-3 Kinase (PI3K)/AKT

BACKGROUND Ischemia-reperfusion injury is caused by a blood reperfusion injury in ischemic brain tissue, and usually occurs in the treatment stage of ischemic disease, which can aggravate brain tissue injury. MiR-122 is closely related to ischemia-reperfusion injury in the myocardium, kidney, and liver; however, the role in cerebral ischemia-reperfusion injury has not been established. MATERIAL AND METHODS In this study, cerebral ischemia-reperfusion injury was established in a rat model, and the control group was a sham-operated group. After ischemia-reperfusion injury for 6, 12, and 24 hours, brain tissue specimens were collected and the expression of miR-122 and DJ-1 were determined using quantitative real-time polymerase chain reaction. Flow cytometry was used to determine the reactive oxygen species (ROS) content. The modified Neurological Severity Score (mNSS) scale was used to evaluate the sensory and motor function defects of the rats. The malondialdehyde (MDA), superoxide dismutase (SOD), and enzyme activity were determined. The rats in the cerebral ischemia-reperfusion injury model were divided into 2 groups (antagomir-NC group and antagomir miR-122 group). Brain neuron RN-c cells were divided into the following 4 groups: antagomir-NC, antagomir miR-122, pIRES2-blank, and pIRES2-DJ-1. Seventy-two hours after transfection, ischemia-reperfusion treatment was carried out and conventional cultured RN-c cells were used as the control group. Flow cytometry was used to detect apoptosis and western blot was used to detect the expression of DJ-1, PTEN, AKT, and p-AKT. RESULTS The expression of miR-122 increased significantly in the process of ischemia-reperfusion damage after cerebral infarction, while the expression of DJ-1 decreased significantly. Downregulation of miR-122 significantly increased the expression of DJ-1, enhanced the activity of the PTEN/PI3K/AKT pathway, reduced cell apoptosis, and alleviated cerebral ischemia-reperfusion injury. CONCLUSIONS Inhibition of miR-122 can decrease cerebral ischemia-reperfusion injury by upregulating DJ-1-PTEN/PI3K/AKT pathway.

Cardiac shock wave therapy protects cardiomyocytes from hypoxia‑induced injury by modulating miR‑210

Cardiac shock wave therapy (SWT) has been described as a novel therapeutic strategy that is able to alleviate myocardial ischemic injury. microRNA (miRNA/miR)‑210 plays a cytoprotective role in cardiomyocytes in response to hypoxia by regulating cell apoptosis. The aim of the present study was to investigate whether cardiac SWT could protect cardiomyocytes from hypoxia‑induced injury by regulating miR‑210 expression. The murine adult cardiomyocyte cell line HL‑1 was incubated for 5 h in hypoxic conditions, followed by reoxygenation for 12 h and treatment with SWT immediately following hypoxia in the present study. The cell viability was determined using an MTS assay. Western blot analyses were performed in order to detect cell signaling changes. Reactive oxygen species production was detected using dihydroethidium staining, and malondialdehyde levels were measured using the thiobarbituric acid method. miRNA and mRNA expression levels were confirmed via reverse transcription‑quantitative PCR. Apoptosis was evaluated by means of flow cytometry. HL‑1 cells were then transfected with miR‑210 mimics or inhibitors in order to alter miR‑210 expression levels, and the effects on HL‑1 cells were determined. Hypoxia led to elevated oxidative stress, enhanced cell apoptosis and upregulated miR‑210 expression levels in HL‑1 cells, while SWT could alleviate hypoxia‑induced cell injury and further promote miR‑210 expression. miR‑210 overexpression decreased apoptosis and oxidative stress during hypoxic stress in HL‑1 cells, whereas inhibition of miR‑210 increased cell apoptosis and promoted oxidative stress. Furthermore, miR‑210 inhibition could reverse the effects of SWT on HL‑1 cells. Finally, the mRNA analysis revealed that SWT significantly attenuated apoptosis‑inducing factor mitochondrion‑associated 3 and caspase 8 associated protein 2 mRNA expression levels in cardiomyocytes exposed to hypoxia, which were two targets of miR‑210. SWT could exert cardioprotective effects against hypoxia‑induced cardiac injury by modulating miR‑210.

miR‑455 targets FABP4 to protect human endometrial stromal cells from cytotoxicity induced by hydrogen peroxide

Oxidative stress and dysregulation of antioxidant systems are associated with various complications in pregnancy. Endometriosis is a common gynecologic disease that affects women of reproductive age. Recent studies have indicated that oxidative stress may be involved in the pathophysiology of endometriosis. It has been reported that microRNAs can regulate the cellular response to oxidative stress, and mounting evidence indicates that fatty acid binding protein 4 (FABP4) plays an essential role in the regulation of systemic redox capacity. In the present study, we demonstrated that miR-455 is a putative FABP4-targeting miRNA. A luciferase activity assay revealed that miR-455 can successfully bind to the 3′-UTR of FABP4. Overexpression of miR-455 led to the downregulation of FABP4 at both the mRNA and protein levels in a human endometrial stromal cell line. Then, the roles of miR-455 and FABP4 in oxidative stress induced by hydrogen peroxide (H₂O₂) in human endometrial stromal cells were examined. We found that ectopic expression of miR-455 protected cells from damage caused by H₂O₂. Further investigation found that forced expression of miR-455 reduced the level of reactive oxygen species (ROS) and malondialdehyde (MDA), while the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were promoted. Silencing of FABP4 also generated cytoprotective effects against H₂O₂ in human endometrial stromal cells. Moreover, overexpression FABP4 abrogated the miR-455-mediated antioxidative stress effects in cells. Taken together, we propose that miR-455 protects human endometrial stromal cells from oxidative stress at least partly via regulation of FABP4.

Role of cardiac progenitor cell-derived exosome-mediated microRNA-210 in cardiovascular disease

Cardiac progenitor cells are considered to be one of the most promising stem cells for heart regeneration and repair. The cardiac protective effect of CPCs is mainly achieved by reducing tissue damage and/or promoting tissue repair through a paracrine mechanism. Exosome is a factor that plays a major role in the paracrine effect of CPCs. By delivering microRNAs to target cells and regulating their functions, exosomes have shown significant beneficial effects in slowing down cardiac injury and promoting cardiac repair. Among them, miRNA-210 is an important anoxic-related miRNA derived from CPCs exosomes, which has great cardiac protective effect of inhibiting myocardial cell apoptosis, promoting angiogenesis and improving cardiac function. In addition, circulating miR-210 may be a useful biomarker for the prediction or diagnosis of related cardiovascular diseases. In this review, we briefly reviewed the mechanism of miR-210 derived from CPCs exosomes in cardiac protection in recent years.

RNA-Seq analysis and functional characterization revealed lncRNA NONRATT007560.2 regulated cardiomyocytes oxidative stress and apoptosis induced by high glucose

Hyperglycemia in diabetic patients would cause cardiomyocytes oxidative stress and apoptosis due to the excessive reactive oxygen species (ROS) accumulation, leading to progressive deterioration of cardiac structure and function. Long noncoding RNAs (lncRNAs) play essential roles on controlling oxidative stress and apoptotic activity. In the present study, RNA sequencing was used to detect the differentially expressed lncRNAs during high glucose-induced cardiomyocytes oxidative stress and apoptosis. A total of 306/400 lncRNAs were identified as differentially expressed, including 156/198 lncRNAs with increased expression and 150/202 lncRNAs with decreased expression at 24 hours/48 hours after high-glucose stimulation respectively. Among these dysregulated lncRNAs, 45 lncRNAs were consistently differentially expressed in cardiomyocytes at both two time points after high-glucose stimulation. Twenty lncRNAs were upregulated and 25 lncRNAs were downregulated at both 24 hours and 48 hours, respectively. The top three upregulated lncRNAs, NONRATT029805.2, NONRATT007560.2, and NONRATT002486.2 were selected for functional studies to determine the role in oxidative stress-related apoptosis. The results showed that inhibition of non-ratt007560.2 could abate the formation of ROS and reduce apoptosis, suggesting NONRATT007560.2 might play critical roles in the development of cardiomyopathy. The dysregulated lncRNAs might participate in regulating cardiomyocytes oxidative stress and apoptosis. These findings would be important theoretical and experimental basis for investigation on diabetic cardiomyopathy pathogenesis.

Effect of Hypoxia-Induced MicroRNA-210 Expression on Cardiovascular Disease and the Underlying Mechanism

Cardiovascular diseases have high morbidity and mortality rates worldwide, and their treatment and prevention are challenging. MicroRNAs are a series of noncoding RNAs with highly conserved sequences and regulate gene expression by inhibiting mRNA transcription or degrading targeting proteins. MicroRNA-210 is significantly upregulated during hypoxia and plays a protective role by inhibiting apoptosis and regulating cell proliferation, differentiation, migration, mitochondrial metabolism, and angiogenesis in hypoxic cells. MicroRNA-210 expression is altered in cardiovascular diseases such as atherosclerosis, acute myocardial infarction, preeclampsia, aortic stenosis, and heart failure, and overexpression of microRNA-210 in some of these diseases exerts protective effects on target organs. Furthermore, chronically upregulated miR-210 potentially plays a marked pathogenic role in specific situations. This review primarily focuses on the upstream pathways, downstream targets, clinical progress in cardiovascular disease, and potential applications of microRNA-210.

MicroRNAs as Potential Pharmaco-targets in Ischemia-Reperfusion Injury Compounded by Diabetes

BACKGROUND

Ischemia-Reperfusion (I/R) injury is the tissue damage that results from re-oxygenation of ischemic tissues. There are many players that contribute to I/R injury. One of these factors is the family of microRNAs (miRNAs), which are currently being heavily studied. This review aims to critically summarize the latest papers that attributed roles of certain miRNAs in I/R injury, particularly in diabetic conditions and dissect their potential as novel pharmacologic targets in the treatment and management of diabetes.

METHODS

PubMed was searched for publications containing microRNA and I/R, in the absence or presence of diabetes. All papers that provided sufficient evidence linking miRNA with I/R, especially in the context of diabetes, were selected. Several miRNAs are found to be either pro-apoptotic, as in the case of miR-34a, miR-144, miR-155, and miR-200, or anti-apoptotic, as in the case of miR-210, miR-21, and miR-146a. Here, we further dissect the evidence that shows diverse cell-context dependent effects of these miRNAs, particularly in cardiomyocytes, endothelial, or leukocytes. We also provide insight into cases where the possibility of having two miRNAs working together to intensify a given response is noted.

CONCLUSIONS

This review arrives at the conclusion that the utilization of miRNAs as translational agents or pharmaco-targets in treating I/R injury in diabetic patients is promising and becoming increasingly clearer.

Postnatal Expression Profile of microRNAs Associated with Cardiovascular and Cerebrovascular Diseases in Children at the Age of 3 to 11 Years in Relation to Previous Occurrence of Pregnancy-Related Complications

Children descending from pregnancies complicated by gestational hypertension (GH), preeclampsia (PE) or fetal growth restriction (FGR) have a lifelong cardiovascular risk. The aim of the study was to verify if pregnancy complications induce postnatal alterations in gene expression of microRNAs associated with cardiovascular/cerebrovascular diseases. Twenty-nine microRNAs were assessed in peripheral blood, compared between groups, and analyzed in relation to both aspects, the current presence of cardiovascular risk factors and cardiovascular complications and the previous occurrence of pregnancy complications with regard to the clinical signs, dates of delivery, and Doppler ultrasound examination. The expression profile of miR-21-5p differed between controls and children with a history of uncomplicated pregnancies with abnormal clinical findings. Abnormal expression profile of multiple microRNAs was found in children affected with GH (miR-1-3p, miR-17-5p, miR-20a-5p, miR-21-5p, miR-23a-3p, miR-26a-5p, miR-29a-3p, miR-103a-3p, miR-125b-5p, miR-126-3p, miR-133a-3p, miR-146a-5p, miR-181a-5p, miR-195-5p, and miR-342-3p), PE (miR-1-3p, miR-20a-5p, miR-20b-5p, miR-103a-3p, miR-133a-3p, miR-342-3p), and FGR (miR-17-5p, miR-126-3p, miR-133a-3p). The index of pulsatility in the ductus venosus showed a strong positive correlation with miR-210-3p gene expression in children exposed to PE and/or FGR. Any of changes in epigenome (up-regulation of miR-1-3p and miR-133a-3p) that were induced by pregnancy complications are long-acting and may predispose children affected with GH, PE, or FGR to later development of cardiovascular/cerebrovascular diseases. Novel epigenetic changes (aberrant expression profile of microRNAs) appeared in a proportion of children that were exposed to GH, PE, or FGR. Screening of particular microRNAs may stratify a highly risky group of children that might benefit from implementation of early primary prevention strategies.

Di (2-ethylhexyl) Phthalate Exposure Impairs the microRNAs Expression Profile During Primordial Follicle Assembly

This research was performed to estimate the potential effects of Di (2-ethylhexyl) phthalate (DEHP) on changes of ovarian miRNA expression profile during mouse primordial follicle assembly using miRNAs-seq analysis. The ovaries of newborn mice were collected and in vitro cultured with different concentration of DEHP for 72 h. Then they were prepared for miRNAs-seq analysis. The results indicated that DEHP exposure altered ovarian miRNA expression profile of newborn mice. Eighteen differentially expressed miRNAs were screened after 100 μM DEHP exposure. The target mRNAs of differentially expressed miRNAs were predicted and further analyzed through gene ontology (GO) enrichment analysis and pathway enrichment analysis. Our results showed that the differentially expressed miRNAs from DEHP exposure can regulate ovarian development by targeting mRNAs involved in MAPK, mTOR, FoxO signaling pathways. Three miRNAs of miR-32-5p, miR-19a-3p, and miR-141-3p were randomly selected from the differentially expressed miRNAs to quantify their expression level by miRNA qRT-PCR. The results of qRT-PCR and miRNA-seq were consistent. Considering one of its target gene PTEN of miR-19a-3p and the decreased level of pAKT and increased Bax/Bcl-2 under DEHP exposure, we speculated that the altered expression of miR-19a-3p by DEHP exposure affected mouse primordial follicle assembly via PI3K/AKT1/mTOR signaling pathway. Epigenetic changes are one of the most important targets of toxicant exposure. The effects of DEHP exposure on microRNA (one of the epigenetic regulators) expression profile were uncovered to enrich the research on relationship of epigenetics and toxicant exposure.

MicroRNA-494-3p protects rat cardiomyocytes against septic shock via PTEN

The aim of the present study was to investigate the role of microRNA (miR)-494-3p in myocardial injury in patients with septic shock and the underlying mechanism. A total of 22 patients with sepsis and 17 patients with septic shock were included in the present study. In addition, 20 healthy subjects were recruited as the control group. Peripheral blood was collected from all subjects and a rat cardiomyocyte model of myocardial injury was constructed. Reverse transcription-quantitative polymerase chain reaction was used to measure miR-494-3p expression, while cell counting kit-8 assays were performed to assess cell proliferation. Flow cytometry was performed to investigate cell cycle distribution and apoptosis. Lactate dehydrogenase (LDH) assays were performed to measure LDH levels. ELISA was also performed to measure LDH, tumor necrosis factor (TNF)-α and interleukin (IL)-6 levels in cell culture supernatants. Western blotting was employed to detect phosphatase and tensin homolog (PTEN) protein expression and dual luciferase reporter assays were performed to identify the interaction between miR-494-3p and PTEN mRNA. Reduced miR-494-3p expression was correlated with myocardial damage in patients with septic shock. Sera from patients with septic shock downregulated miR-494-3p expression in rat cardiomyocytes. miR-494-3p overexpression inhibited rat cardiomyocyte injury induced by treatment with sera from patients with septic shock. Furthermore, miR-494-3p overexpression reduced the synthesis and release of TNF-α and IL-6 from rat cardiomyocytes. PTEN knockdown alleviated rat cardiomyocyte injury following treatment with serum from patients with septic shock. PTEN was demonstrated to induce the release of TNF-α and IL-6 from rat cardiomyocytes treated with septic shock serum, while miR-494-3p was demonstrated to bind to the 3′-untranslated seed region of PTEN mRNA to regulate its expression. The results of the present study suggest that miR-494-3p is downregulated in the peripheral blood of patients with septic shock and is negatively correlated with myocardial injury. The present study also indicates that miR-494-3p regulates PTEN expression, inhibits sepsis-induced myocardial injury and protects the function of cardiomyocytes. The protective effect and mechanism of action of miR-494-3p indicate that it has potential for use in the clinical diagnosis and therapy of myocardial damage.

A PDX1-ATF transcriptional complex governs β cell survival during stress

Objective

Loss of insulin secretion due to failure or death of the insulin secreting β cells is the central cause of diabetes. The cellular response to stress (endoplasmic reticulum (ER), oxidative, inflammatory) is essential to sustain normal β cell function and survival. Pancreatic and duodenal homeobox 1 (PDX1), Activating transcription factor 4 (ATF4), and Activating transcription factor 5 (ATF5) are transcription factors implicated in β cell survival and susceptibility to stress. Our goal was to determine if a PDX1-ATF transcriptional complex or complexes regulate β cell survival in response to stress and to identify direct transcriptional targets.

Methods

Pdx1, Atf4 and Atf5 were silenced by viral delivery of gRNAs or shRNAs to Min6 insulinoma cells or primary murine islets. Gene expression was assessed by qPCR, RNAseq analysis, and Western blot analysis. Chromatin enrichment was measured in the Min6 β cell line and primary isolated mouse islets by ChIPseq and ChIP PCR. Immunoprecipitation was used to assess interactions among transcription factors in Min6 cells and isolated mouse islets. Activation of caspase 3 by immunoblotting or by irreversible binding to a fluorescent inhibitor was taken as an indication of commitment to an apoptotic fate.

Results

RNASeq identified a set of PDX1, ATF4 and ATF5 co-regulated genes enriched in stress and apoptosis functions. We further identified stress induced interactions among PDX1, ATF4, and ATF5. PDX1 chromatin occupancy peaks were identified over composite C/EBP-ATF (CARE) motifs of 26 genes; assessment of a subset of these genes revealed co-enrichment for ATF4 and ATF5. PDX1 occupancy over CARE motifs was conserved in the human orthologs of 9 of these genes. Of these, Glutamate Pyruvate Transaminase 2 (Gpt2), Cation transport regulator 1 (Chac1), and Solute Carrier Family 7 Member 1 (Slc7a1) induction by stress was conserved in human islets and abrogated by deficiency of Pdx1, Atf4, and Atf5 in Min6 cells. Deficiency of Gpt2 reduced β cell susceptibility to stress induced apoptosis in both Min6 cells and primary islets.

Conclusions

Our results identify a novel PDX1 stress inducible complex (es) that regulates expression of stress and apoptosis genes to govern β cell survival.

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PDX1 binds to composite CEBP/ATF (CARE) sites of stress and apoptosis genes.

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A novel stress inducible transcriptional complex involving PDX1, ATF4, and ATF5 is discovered.

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Novel stress induced targets of the complex involved in fate decisions are identified.

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Silencing of one of these targets, Gpt2, protects β cells from apoptosis due to stress.

miR-210 promotes human osteosarcoma cell migration and invasion by targeting FGFRL1

Osteosarcoma is a common bone tumor and a frequently occuring cancer-associated threat to children. Notably, the prognosis of osteosarcoma is very poor when it is diagnosed with metastasis. A growing number of studies have indicated that various microRNAs (miRs) serve important regulatory roles in the pathogeny of different types of cancer. However, the functions of miR-210 in osteosarcoma need to be elucidated comprehensively. The aim of the present study was to investigate the potential roles of miR-210 in osteosarcoma by targeting fibroblast growth factor receptor-like 1 (FGFRL1). Reverse transcription-quantitative polymerase chain reaction results revealed that the expression of miR-210 was highly elevated while FGFRL1 expression was reduced inversely in osteosarcoma tissues compared with matched normal tissues. The results of Transwell assays showed that miR-210 promoted osteosarcoma cell migration and invasion. Furthermore, the luciferase reporter assay results suggested that miR-210 could directly bind to FGFRL1 in osteosarcoma cells. In addition, the present findings demonstrated that miR-210 could negatively regulate FGFRL1 expression by targeting the 3′untranslated region. In conclusion, the findings of the present study suggested that miR-210 exerted tumor carcinogenic functions in osteosarcoma by targeting FGFRL1. The findings of this study demonstrated that FGFRL1 was a direct target of miR-210 in osteosarcoma involved in the promoting functions mediated by miR-210 in the invasion and migration of osteosarcoma, suggesting that miR-210/FGFRL1 may be promising for discovering diagnostic and prognostic biomarkers for the therapies of osteosarcoma.

Stem Cell-Derived Exosome in Cardiovascular Diseases: Macro Roles of Micro Particles

The stem cell-based therapy has emerged as the promising therapeutic strategies for cardiovascular diseases (CVDs). Recently, increasing evidence suggest stem cell-derived active exosomes are important communicators among cells in the heart via delivering specific substances to the adjacent/distant target cells. These exosomes and their contents such as certain proteins, miRNAs and lncRNAs exhibit huge beneficial effects on preventing heart damage and promoting cardiac repair. More importantly, stem cell-derived exosomes are more effective and safer than stem cell transplantation. Therefore, administration of stem cell-derived exosomes will expectantly be an alternative stem cell-based therapy for the treatment of CVDs. Furthermore, modification of stem cell-derived exosomes or artificial synthesis of exosomes will be the new therapeutic tools for CVDs in the future. In addition, stem cell-derived exosomes also have been implicated in the diagnosis and prognosis of CVDs. In this review, we summarize the current advances of stem cell-derived exosome-based treatment and prognosis for CVDs, including their potential benefits, underlying mechanisms and limitations, which will provide novel insights of exosomes as a new tool in clinical therapeutic translation in the future.