Targeting MIAT reduces apoptosis of cardiomyocytes after ischemia/reperfusion injury

Cardiomyocyte-restricted MIAT deletion is sufficient to protect against murine myocardial infarction

Myocardial infarction-associated transcript (MIAT), an intergenic long noncoding RNA (lncRNA), is conserved between rodents and humans and is directly linked to maladaptive cardiac remodeling in both patients and mouse models with various forms of heart failure (HF). We previously reported attenuation of cardiac stress, apoptosis, and fibrosis in a murine model of myocardial infarction (MI) with global MIAT ablation. Our transcriptomic profiling and mechanistic studies further revealed MIAT-induced activation of maladaptive genes, such as Hoxa4, Fmo2, Lrrn4, Marveld3, and Fat4. However, the source of MIAT and its contribution to MI and HF remain unknown. In this study, we generate a novel cardiomyocyte (CM)-specific MIAT conditional knockout mouse model, which exhibits improved cardiac function after MI. We further report that CM-specific MIAT ablation is sufficient to reduce cardiac damage, apoptosis, and fibrosis following chronic MI. Mechanistically, CM-specific MIAT deletion in mice leads to decreased expression of proapoptotic and pathological profibrotic genes, such as p53, Bak1, Col3a1, Col6a1, Postn, and Snail1 after chronic MI. These results enable us to begin to dissect cell-specific contributions to MIAT signaling and bolster the idea that MIAT plays a direct pathological role in CMs after MI.

Bibliometrics of trends in global research on the roles of stem cells in myocardial fibrosis therapy

BACKGROUND

Myocardial fibrosis, a condition linked to several cardiovascular diseases, is associated with a poor prognosis. Stem cell therapy has emerged as a potential treatment option and the application of stem cell therapy has been studied extensively. However, a comprehensive bibliometric analysis of these studies has yet to be conducted.

AIM

To map thematic trends, analyze research hotspots, and project future directions of stem cell-based myocardial fibrosis therapy.

METHODS

We conducted a bibliometric and visual analysis of studies in the Web of Science Core Collection using VOSviewer and Microsoft Excel. The dataset included 1510 articles published between 2001 and 2024. Countries, organizations, authors, references, keywords, and co-citation networks were examined to identify evolving research trends.

RESULTS

Our findings revealed a steady increase in the number of publications, with a projected increase to over 200 publications annually by 2030. Initial research focused on stem cell-based therapy, particularly for myocardial infarction and heart failure. More recently, there has been a shift toward cell-free therapy, involving extracellular vesicles, exosomes, and microRNAs. Key research topics include angiogenesis, inflammation, apoptosis, autophagy, and oxidative stress.

CONCLUSION

This analysis highlights the evolution of stem cell therapies for myocardial fibrosis, with emerging interest in cell-free approaches. These results are expected to guide future scientific exploration and decision-making.

Exercise mediates myocardial infarction via non-coding RNAs

Myocardial infarction (MI), a widespread cardiovascular issue, mainly occurs due to blood clot formation in the coronary arteries, which reduces blood flow to the heart muscle and leads to cell death. Incorporating exercise into a lifestyle can significantly benefit recovery and reduce the risk of future cardiac events for MI patients. Non-coding RNAs (ncRNAs) play various roles in the effects of exercise on myocardial infarction (MI). ncRNAs regulate gene expression, influence cardiac remodeling, angiogenesis, inflammation, oxidative stress, apoptosis, cardioprotection, and cardiac electrophysiology. The expression of specific ncRNAs is altered by exercise, leading to beneficial changes in heart structure, function, and recovery after MI. These ncRNAs modulate molecular pathways that contribute to improved cardiac health, including reducing inflammation, enhancing angiogenesis, promoting cell survival, and mitigating oxidative stress. Furthermore, they are involved in regulating changes in cardiac remodeling, such as hypertrophy and fibrosis, and can influence the electrical properties of the heart, thereby decreasing the risk of arrhythmias. Knowledge on MI has entered a new phase, with investigations of ncRNAs in physical exercise yielding invaluable insights into the impact of this therapeutic modality. This review compiled research on ncRNAs in MI, with an emphasis on their applicability to physical activity.

Isoflurane pretreatment protects against myocardial ischemia/reperfusion injury via mediating lncRNA CASC15/miR-542-3p axis

The protective effect of isoflurane on cardiomyocyte ischemia/reperfusion injury (I/RI) was explored in hypoxia and reoxygenation (H/R) induced cardiomyocyte injury model. In terms of mechanism, the participation of long non-coding RNA CASC15/microR-542-3p axis was further discussed. H9c2 cells received H/R treatment to mimic myocardial I/RI. RT-qPCR was performed to quantify mRNA levels. Cell viability and apoptosis were evaluated after isoflurane pretreatment and cell transfection. ELISA was performed to measure the concentrations of inflammatory/oxidative stress-related cytokines (TNF-α, IL-6, MDA, SOD). The target relationship between CASC12 and miR-542-3p was determined via dual-luciferase reporter assay. Isoflurane pretreatment alleviated H/R-induced cell viability suppression and cell apoptosis promotion, which was accompanied by CASC15 downregulation. CASC15 overexpression abolished the influence of isoflurane on cardiomyocytes' viability and apoptosis. H/R-induced excessive release of TNF-α and IL-6 was hold down by isoflurane, which was re-activated after CASC15 overexpression. The concentration changes of both MDA and SOD by isoflurane were reversed by CASC15 overexpression. CASC15 functioned as miR-542-3p sponger, and miR-542-3p overexpression attenuated the effect of isoflurane and CASC15 on H/R-induced cardiac I/RI. Isoflurane pretreatment was beneficial for the alleviation of cardiac I/RI by inhibiting oxidative stress and myocardial inflammatory response. CASC15/miR-542-3p axis was required for isoflurane to exhibit its protective activity against cardiac I/RI.

Hypoxia triggers cardiomyocyte apoptosis via regulating the m6A methylation-mediated LncMIAT/miR-708-5p/p53 axis

Long-time hypoxia induced cardiomyocyte apoptosis is an important mechanism of myocardial ischemia (MI) injury. Interestingly, long noncoding RNA myocardial infarction-associated transcript (LncMIAT) has been involved in the regulation of MI injury; however, the underlying mechanism by which LncMIAT affects the progression of hypoxia-induced cardiomyocyte apoptosis remains unclear. In the present study, hypoxia was found to promote cardiomyocyte apoptosis through an increased expression of LncMIAT in vitro. Biological investigations and dual-luciferase gene reporter assay further revealed that LncMIAT was able to bind with miR-708-5p to upregulate the p53-mediated cell death of the cardiomyocytes. Silencing of LncMIAT or overexpression of miR-708-5p led to a significant reduction in p53-mediated cardiomyocyte apoptosis. The methylated RNA immunoprecipitation (MeRIP)-qPCR results showed that hypoxia exerted its effects on LncMIAT through AKLBH5-N6-methyladenosine (m6A) methylation and therefore hypoxia was shown to trigger HL-1 cardiomyocyte apoptosis via the m6A methylation-mediated LncMIAT/miR-708-5p/p53 axis. Silencing of AKLBH5 significantly alleviated the m6A methylation-mediated LncMIAT upregulation and p53-mediated cardiomyocyte apoptosis, while promoted miR-708-5p expression. Taken together, the present study highlighted that LncMIAT could act as a key biological target during hypoxia-induced cardiomyocyte apoptosis. In addition, it was shown that hypoxia could promote cardiomyocyte apoptosis through regulation of the m6A methylation-mediated LncMIAT/miR-708-5p/p53 signaling axis.

MIAT LncRNA: A multifunctional key player in non-oncological pathological conditions

The discovery of non-coding RNAs (ncRNAs) has unveiled a wide range of transcripts that do not encode proteins but play key roles in several cellular and molecular processes. Long noncoding RNAs (lncRNAs) are specific class of ncRNAs that are longer than 200 nucleotides and have gained significant attention due to their diverse mechanisms of action and potential involvement in various pathological conditions. In the current review, the authors focus on the role of lncRNAs, specifically highlighting the Myocardial Infarction Associated Transcript (MIAT), in non-oncological context. MIAT is a nuclear lncRNA that has been directly linked to myocardial infarction and is reported to control post-transcriptional processes as a competitive endogenous RNA (ceRNA) molecule. It interacts with microRNAs (miRNAs), thereby limiting the translation and expression of their respective target messenger RNA (mRNA) and regulating protein expression. Yet, MIAT has been implicated in other numerous pathological conditions such as other cardiovascular diseases, autoimmune disease, neurodegenerative diseases, metabolic diseases, and many others. In this review, the authors emphasize that MIAT exhibits distinct expression patterns and functions across different pathological conditions and is emerging as potential diagnostic, prognostic, and therapeutic agent. Additionally, the authors highlight the regulatory role of MIAT and shed light on the involvement of lncRNAs and specifically MIAT in various non-oncological pathological conditions.

Pro-fibrotic and apoptotic activities of circARAP1 in myocardial ischemia-reperfusion injury

Reperfusion modality can cause damage to cardiomyocytes, known as myocardial ischemia-reperfusion injury (MI/RI). Circular RNAs (circRNAs) are fundamental regulators associated with many cardiac diseases, including MI/RI. However, their functional impact on cardiomyocyte fibrosis and apoptosis remains elusive. Therefore, this study aimed to explore possible molecular mechanisms of circARPA1 in animal models and in hypoxia/reoxygenation (H/R)-treated cardiomyocytes. GEO dataset analysis showed that has_circ_0023461 (circARPA1) was differentially expressed in myocardial infarction samples. Real-time quantitative PCR further supported that circARPA1 was expressed at high levels in animal models and in H/R-triggered cardiomyocytes. Then, loss-of-function assays were performed to show that circARAP1 suppression effectively ameliorated cardiomyocyte fibrosis and apoptosis in MI/RI mice. Mechanistic experiments showed that miR-379-5p, KLF9 and Wnt signaling pathways were associated with circARPA1. circARPA1 can sponge miR-379-5p to regulate KLF9 expression, thereby activating the wnt/β-catenin pathway. Finally, gain-of-function assays revealed that circARAP1 aggravated MI/RI in mice and H/R-induced cardiomyocyte injury by regulating the miR-379-5p/KLF9 axis to activate Wnt/β-catenin signaling.

A tRNA-derived fragment of ginseng protects heart against ischemia/reperfusion injury via targeting the lncRNA MIAT/VEGFA pathway

Traditional Chinese medicines (TCMs) have been widely used for treating ischemic heart disease (IHD), and secondary metabolites are generally regarded as their pharmacologically active components. However, the effects of nucleic acids in TCMs remain unclear. We reported for the first time that a 22-mer double-strand RNA consisting of HC83 (a tRNA-derived fragment [tRF] from the 3' end of tRNAGln(UUG) of ginseng) and its complementary sequence significantly promoted H9c2 cell survival after hypoxia/reoxygenation (H/R) in vitro. HC83_mimic could also significantly improve cardiac function by maintaining both cytoskeleton integrity and mitochondrial function of cardiomyocytes. Further in vivo investigations revealed that HC83_mimic is more potent than metoprolol by >500-fold against myocardial ischemia/reperfusion (MI/R) injury. In-depth studies revealed that HC83 directly downregulated a lncRNA known as myocardial infarction-associated transcript (MIAT) that led to a subsequent upregulation of VEGFA expression. These findings provided the first evidence that TCM-derived tRFs can exert miRNA-like functions in mammalian systems, therefore supporting the idea that TCM-derived tRFs are promising RNA drug candidates shown to have extraordinarily potent effects. In summary, this study provides a novel strategy not only for discovering pharmacologically active tRFs from TCMs but also for efficiently exploring new therapeutic targets for various diseases.

An update on the functional roles of long non‑coding RNAs in ischemic injury (Review)

Ischemic injuries result from ischemia and hypoxia in cells. Tissues and organs receive an insufficient supply of nutrients and accumulate metabolic waste, which leads to the development of inflammation, fibrosis and a series of other issues. Ischemic injuries in the brain, heart, kidneys, lungs and other organs can cause severe adverse effects. Acute renal ischemia induces acute renal failure, heart ischemia induces myocardial infarction and cerebral ischemia induces cerebrovascular accidents, leading to loss of movement, consciousness and possibly, life-threatening disabilities. Existing evidence suggests that long non-coding RNAs (lncRNAs) are regulatory sequences involved in transcription, post-transcription, epigenetic regulation and multiple physiological processes. lncRNAs have been shown to be differentially expressed following ischemic injury, with the severity of the ischemic injury being affected by the upregulation or downregulation of certain types of lncRNA. The present review article provides an extensive summary of the functional roles of lncRNAs in ischemic injury, with a focus on the brain, heart, kidneys and lungs. The present review mainly summarizes the functional roles of lncRNA MALAT1, lncRNA MEG3, lncRNA H19, lncRNA TUG1, lncRNA NEAT1, lncRNA AK139328 and lncRNA CAREL, among which lncRNA MALAT1, in particular, plays a crucial role in ischemic injury and is currently a hot research topic.

Dexmedetomidine prevents cardiomyocytes from hypoxia/reoxygenation injury via modulating tetmethylcytosine dioxygenase 1-mediated DNA demethylation of Sirtuin1

Myocardial hypoxia/reoxygenation (H/R) injury is a common pathological change in patients with acute myocardial infarction undergoing reperfusion therapy. Dexmedetomidine (DEX) has been found to substantially improve ischemia-mediated cell damage. Here, we focus on probing the role and mechanism of DEX in ameliorating myocardial H/R injury. Oxygen–glucose deprivation and reoxygenation (OGD/R) were applied to construct the H/R injury model in human myocardial cell lines. After different concentrations of DEX’s treatment, cell counting kit-8 (CCK-8) assay and BrdU assay were employed to test cell viability. The profiles of apoptosis-related proteins Bcl2, Bax, Bad and Caspase3, 8, 9 were determined by Western blot (WB). The expression of inflammatory factors interleukin 1β (IL-1β) and tumor necrosis factor-α (TNF-α) was checked by reverse transcription-polymerase chain reaction (RT-PCR). By conducting WB, we examined the expression of NF-κB, Sirt1, Tet methylcytosine dioxygenase 1 (TET1) and DNA methylation-related proteins (DNA methyltransferase 1, DNMT1; DNA methyltransferase 3 alpha, DNMT3A; and DNA methyltransferase 3 beta, DNMT3B). Our data showed that OGD/R stimulation distinctly hampered the viability and elevated apoptosis and inflammatory factor expression in cardiomyocytes. DEX treatment notably impeded myocardial apoptosis and inflammation and enhanced cardiomyocyte viability. OGD/R enhanced total DNA methylation levels in cardiomyocytes, while DEX curbed DNA methylation. In terms of mechanism, inhibiting TET1 or Sirtuin1 (Sirt1) curbed the DEX-mediated myocardial protection. TET1 strengthened demethylation of the Sirt1 promoter and up-regulated Sirt1. DEX up-regulates Sirt1 by accelerating TET1 and mediating demethylation of the Sirt1 promoter and improves H/R-mediated myocardial injury.

MiR-150 Attenuates Maladaptive Cardiac Remodeling Mediated by Long Noncoding RNA MIAT and Directly Represses Profibrotic Hoxa4

BACKGROUND

MicroRNA-150 (miR-150) plays a protective role in heart failure (HF). Long noncoding RNA, myocardial infarction-associated transcript (MIAT) regulates miR-150 function in vitro by direct interaction. Concurrent with miR-150 downregulation, MIAT is upregulated in failing hearts, and gain-of-function single-nucleotide polymorphisms in MIAT are associated with increased risk of myocardial infarction (MI) in humans. Despite the correlative relationship between MIAT and miR-150 in HF, their in vivo functional relationship has never been established, and molecular mechanisms by which these 2 noncoding RNAs regulate cardiac protection remain elusive.

METHODS

We use MIAT KO (knockout), Hoxa4 (homeobox a4) KO, MIAT TG (transgenic), and miR-150 TG mice. We also develop DTG (double TG) mice overexpressing MIAT and miR-150. We then use a mouse model of MI followed by cardiac functional, structural, and mechanistic studies by echocardiography, immunohistochemistry, transcriptome profiling, Western blotting, and quantitative real-time reverse transcription-polymerase chain reaction. Moreover, we perform expression analyses in hearts from patients with HF. Lastly, we investigate cardiac fibroblast activation using primary adult human cardiac fibroblasts and in vitro assays to define the conserved MIAT/miR-150/HOXA4 axis.

RESULTS

Using novel mouse models, we demonstrate that genetic overexpression of MIAT worsens cardiac remodeling, while genetic deletion of MIAT protects hearts against MI. Importantly, miR-150 overexpression attenuates the detrimental post-MI effects caused by MIAT. Genome-wide transcriptomic analysis of MIAT null mouse hearts identifies Hoxa4 as a novel downstream target of the MIAT/miR-150 axis. Hoxa4 is upregulated in cardiac fibroblasts isolated from ischemic myocardium and subjected to hypoxia/reoxygenation. HOXA4 is also upregulated in patients with HF. Moreover, Hoxa4 deficiency in mice protects the heart from MI. Lastly, protective actions of cardiac fibroblast miR-150 are partially attributed to the direct and functional repression of profibrotic Hoxa4.

CONCLUSIONS

Our findings delineate a pivotal functional interaction among MIAT, miR-150, and Hoxa4 as a novel regulatory mechanism pertinent to ischemic HF.

LncRNA MIAT can regulate the proliferation, apoptosis, and osteogenic differentiation of bone marrow-derived mesenchymal stem cells by targeting miR-150-5p

Osteoporosis (OP) is a systemic bone metabolic disease with complicated pathogenesis and is difficult to cure clinically. The regulatory mechanisms of OP are needed to be further investigated. In the present study, we focused on the role of myocardial infarction-associated transcript (MIAT) in OP development and examined the underlying mechanism. The serum expression levels of MIAT in samples from patients with OP and healthy controls were compared using quantitative reverse transcription-PCR (qRT-PCR). The dual-luciferase reporter assay was used to confirm the relationship between MIAT and its potential target microRNA, i.e., miR-150-5p. Moreover, bone marrow-derived mesenchymal stem cells (BMSCs) were cultured and transfected with MIAT shRNA, with or without miR-150-5p inhibitor. EdU staining and colony formation analysis were performed to determine the proliferation ability of these cells. Furthermore, the TUNEL assay and flow cytometry were used to assess BMSC apoptosis. Finally, RT-PCR and Western blot assays were employed to assess the expression of osteogenic differentiation biomarkers. Compared with controls, the expression of MIAT was significantly increased, whereas that of miR-150-5p was markedly decreased in patients with OP. MIAT and miR-150-5p expression levels exhibited a strong negative correlation. Furthermore, osteogenic differentiation indicators were suppressed in serum of OP patients. MIAT was downregulated, and miR-150-5p was upregulated in induced to osteogenic differentiation BMSCs. Furthermore, downregulation of MIAT dramatically promoted osteogenic differentiation, increased proliferation, and inhibited apoptosis in BMSCs; miR-150-5p inhibitor abrogated the effects of MIAT. In conclusion, lncRNA MIAT can regulate the proliferation, apoptosis, and osteogenic differentiation of BMSCs.

Overexpression of microRNA-381-3p ameliorates hypoxia/ischemia-induced neuronal damage and microglial inflammation via regulating the C-C chemokine receptor type 2 /nuclear transcription factor-kappa B axis

microRNAs, as small endogenous RNAs, influence umpteen sophisticated cellular biological functions regarding neurodegenerative and cerebrovascular diseases. Here, we interrogated miR-381-3p’s influence on BV2 activation and neurotoxicity in ischemic and hypoxic environment. Oxygen-glucose deprivation (OGD) was adopted to induce microglial activation and HT-22 neuron damage. Quantitative polymerase chain reaction (qRT-PCR) was taken to check miR-381-3p expression in OGD-elicited BV2 cells and HT-22 neurons. It transpired that miR-381-3p expression was lowered in BV2 cells and HT-22 cells elicited by OGD. miR-381-3p up-regulation remarkably hampered inflammatory mediator expression in BV2 cells induced by OGD and weakened HT22 neuron apoptosis. In vivo, miR-381-3p expression was abated in HI rats’ ischemic lesions, and miR-381-3p up-regulation could ameliorate inflammation and neuron apoptosis in their brain. C-C chemokine receptor type 2 (CCR2) was identified as the downstream target of miR-381-3p, and miR-381-3p suppressed the CCR2/NF-κB pathway to mitigate microglial activation and neurotoxicity. Therefore, we believed that miR-381-3p overexpression exerts anti-inflammation and anti-apoptosis in ischemic brain injury by targeting CCR2

Circular RNA Rbms1 inhibited the development of myocardial ischemia reperfusion injury by regulating miR-92a/BCL2L11 signaling pathway

Acute myocardial infarction (AMI) is characterized by high morbidity and mortality rates. Circular RNAs collectively participate in the initiation and development of AMI. The purpose of this study was to investigate the role of circRbms1 in AMI. Ischemia-reperfusion (I/R) was performed to establish an AMI model. RT-qPCR and Western blotting were performed to detect mRNA and analyze protein expression, respectively. The interaction between miR-92a and circRbms1/BCL2L11 was confirmed by luciferase and RNA pull-down assays. circRbms1 is overexpressed in AMI. However, circRbms1 knockdown alleviated H9c2 cell apoptosis and reduced the release of reactive oxygen species. circRbms1 targeted miR-92a, the downregulation of which alleviated the effects of circRbms1 knockdown and increased oxidative stress and H9c2 cell apoptosis. Moreover, circRbms1 sponged miR-92a to upregulate BCL2L11, which modulated the expression of apoptosis-related genes. circRbms1 participated in myocardial I/R injury by regulating the miR-92a/BCL2L11 signaling pathway, which may provide a new strategy for the treatment of AMI.

Knockdown of forkhead box protein P1 alleviates hypoxia reoxygenation injury in H9c2 cells through regulating Pik3ip1/Akt/eNOS and ROS/mPTP pathway

Forkhead box protein P1 (Foxp1) exerts an extensive array of physiological and pathophysiological impacts on the cardiovascular system. However, the exact function of myocardial Foxp1 in myocardial ischemic reperfusion injury (MIRI) stays largely vague. The hypoxia reoxygenation model of H9c2 cells (the rat ventricular myoblasts) closely mimics myocardial ischemia-reperfusion injury. This report intends to research the effects and mechanisms underlying Foxp1 on H9c2 cells in response to hypoxia (12 h)/reoxygenation (4 h) (HR) stimulation. Expressions of Foxp1 and Phosphatidylinositol 3-kinase interacting protein 1 (Pik3ip1) were both upregulated in ischemia/reperfusion (IR)/HR-induced injury. Stimulation through HR led to marked increases in cellular apoptosis, mitochondrial dysfunction, and superoxide generation in H9c2 cells, which were rescued with knockdown of Foxp1 by siRNA. Silence of Foxp1 depressed expression of Pik3ip1 directly activated the PI3K/Akt/eNOS pathway and promoted nitric oxide (NO) release. Moreover, the knockdown of Foxp1 blunted HR-induced enhancement of reactive oxygen species (ROS) generation, thus alleviating excessive persistence of mitochondrial permeability transition pore (mPTP) opening and decreased mitochondrial apoptosis-associated protein expressions in H9c2 cells. Meanwhile, these cardioprotective effects can be abolished by LY294002, NG-nitro-L-arginine methyl ester (L-NAME), and Atractyloside (ATR), respectively. In summary, our findings indicated that knockdown of Foxp1 prevented HR-induced encouragement of apoptosis and oxidative stress via PI3K/Akt/eNOS signaling activation by targeting Pik3ip1 and improved mitochondrial function by inhibiting ROS-mediated mPTP opening. Inhibition of Foxp1 may be a promising therapeutic avenue for MIRI.

Mirtazapine prevents cell activation, inflammation, and oxidative stress against isoflurane exposure in microglia

Mirtazapine is an antidepressant drug that has been proven to possess a cognitive enhancer efficiency. In this study, we evaluated the potential protective effects of mirtazapine on BV2 microglia in response to isoflurane exposure. Our results show that mirtazapine attenuated isoflurane-induced expression of microglia-specific protein Iba1 in BV2 microglia. Mirtazapine prevented isoflurane-induced production of the pro-inflammatory factors interleukin (IL)-1β and IL-18 by inhibiting the activation of the nod-like receptor family protein 3 (NLRP3) inflammasome in BV2 microglia. The increased reactive oxygen species (ROS) production and elevated expression level of NADPH oxidase 4 (NOX4) in isoflurane-induced BV2 microglia were mitigated by mirtazapine. Isoflurane exposure reduced triggering receptor expressed on myeloid cells 2 (TREM2) expression in BV2 microglia, which was restored by mirtazapine. Moreover, silencing of TREM2 abolished the inhibitory effects of mirtazapine on ionized calcium-binding adapter molecule 1 (Iba1) expression and inflammation in BV2 microglia. From these results, we could infer that mirtazapine exerted a protective effect on BV2 microglia against isoflurane exposure-caused microglia activation, neuroinflammation, and oxidative stress via inducing TREM2 activation. Hence, mirtazapine might be a potential intervention strategy to prevent isoflurane exposure-caused cognitive dysfunction in clinical practice.

Dexmedetomidine attenuates ischemia and reperfusion-induced cardiomyocyte injury through p53 and forkhead box O3a (FOXO3a)/p53-upregulated modulator of apoptosis (PUMA) signaling signaling

Dexmedetomidine (DEX) has been reported to attenuate the ischemia and reperfusion (I/R) induced cardiomyocyte apoptosis. However, mechanisms underlying these protective effect remain to be fully elucidated. Cardiomyocyte apoptosis is associated with ischemic heart disease. Here we investigated the role of DEX in I/R -induced cardiomyocyte apoptosis. Mice and H9c2 cardiomyocyte cells were subjected to cardiomyocyte I/R injury and hypoxia/reoxygenation (H/R) injury, respectively. The roles and mechanisms of DEX on H9c2 cardiomyocyte cells and mice cardiomyocyte cells exposured to H/R or I/R injury were explored. The results showed that DEX attenuates H/R injury-induced H9c2 cell apoptosis and alleviated mitochondrial oxidative stress; it also reduced myocardial infarct size and protected the cardiac function following cardiomyocyte I/R injury. In addition, H/R and I/R injury increased p53 expression and forkhead box O3a (FOXO3a)/p53-upregulated modulator of apoptosis (PUMA) signaling in H9c2 cardiomyocyte cells and cardiomyocytes. Targeting p53 expression or FOXO3a/PUMA signaling inhibited cell apoptosis and protected against H/R injury in H9c2 cardiomyocyte cells and cardiomyocytes. Pretreatment with DEX reduced the H/R or I/R injury-induced activation of p53 expression and FOXO3a/PUMA signaling, and alleviated H/R or I/R injury-induced apoptosis and mitochondrial oxidative stress. Therefore, DEX could alleviate H/R- or I/R-induced cardiomyocytes injury by reducing cell apoptosis and blocking p53 expression and FOXO3a/PUMA signaling. Targeting p53 or/and FOXO3a/PUMA signaling could alleviate cardiomyocyte I/R injury.

Sitagliptin ameliorates hypoxia-induced damages in endometrial stromal cells: an implication in endometriosis

Hypoxia-induced damage in endometrial stromal cells (ESCs) is an important event in the pathological progression of Endometriosis. It is reported that significant inflammation is induced by hypoxia in ESCs, mediated by serval inflammatory progressions, pathways, or factors. Sitagliptin, an important member of the dipeptidyl peptidase-4 (DPP-4) inhibitors family and has been widely used for the management of type 2 diabetes. It has been recently reported to exert significant anti-inflammatory effects. Here, we aim to assess whether Sitagliptin possesses a protective effect against hypoxia-induced damages in ESCs. Our findings indicate that exposure to hypoxia significantly increased oxidative stress in ESCs by increasing the production of reactive oxygen species (ROS) and decreasing the levels of reduced glutathione (GSH), which was ameliorated by Sitagliptin. Additionally, the excessively produced inflammatory mediators, including tumor necrosis factor (TNF)-α, interleukin (IL)-6, monocyte chemoattractant protein-1 (MCP-1), cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE₂), and high mobility group box (HMGB)-1, in hypoxia-treated HESCs were pronouncedly repressed by Sitagliptin. The activated p38 mitogen-activated protein kinases (MAPK) pathway was observed in hypoxia-stimulated HESCs, then greatly inhibited by the introduction of Sitagliptin. Lastly, hypoxia-induced phosphorylation and degradation of IκBα, as well as the upregulation of nuclear factor kappa-B (NF-κB) p65 and increased transcriptional activity of NF-κB, were dramatically abolished by Sitagliptin. Collectively, Sitagliptin ameliorated hypoxia-induced damages in ESCs by suppressing the inflammation.

MIAT, a potent CVD-promoting lncRNA

The initial identification of long non-coding RNA myocardial infarction associated transcript (MIAT) as a genetic risk factor of myocardial infarction has made this lncRNA (designated as lncR-MIAT here) a focus of intensive studies worldwide. Emerging evidence supports that lncR-MIAT is susceptible in its expression to multiple deleterious factors like angiotensin II, isoproterenol, hypoxia, and infection and is anomaly overexpressed in serum, plasma, blood cells and myocardial tissues under a variety of cardiovascular conditions including myocardial infarction, cardiac hypertrophy, diabetic cardiomyopathy, dilated cardiomyopathy, sepsis cardiomyopathy, atrial fibrillation and microvascular dysfunction. Experimental results consistently demonstrated that upregulation of lncR-MIAT plays active roles in the pathological processes of the cardiovascular system and knockdown of this lncRNA effectively ameliorates the adverse conditions. The available data revealed that lncR-MIAT acts through multiple mechanisms such as competitive endogenous RNA, natural antisense RNA and RNA/protein interactions. Moreover, the functional domains of lncR-MIAT accounting for certain specific cellular functions of the full-length transcript have been identified and characterized. These insights will not only tremendously advance our understanding of lncRNA biology and pathophysiology, but also offer good opportunities for more innovative and precise design of agents that have the potential to be developed into new drugs for better therapy of cardiovascular diseases (CVDs) in the future. Herein, we provide an overview of lncR-MIAT, focusing on its roles in cardiovascular diseases, underline the unique cellular/molecular mechanisms for its actions, and speculate the perspectives about the translational studies on the potential diagnostic and therapeutic applications of lncR-MIAT.

Long Noncoding RNAs Involved in Cardiomyocyte Apoptosis Triggered by Different Stressors

Cardiomyocytes are essential to maintain the normal cardiac function. Ischemia, hypoxia, and drug stimulation can induce pathological apoptosis of cardiomyocytes which eventually leads to heart failure, arrhythmia, and other cardiovascular diseases. Understanding the molecular mechanisms that regulate cardiomyocyte apoptosis is of great significance for the prevention and treatment of cardiovascular diseases. In recent years, more and more evidences reveal that long noncoding RNAs (lncRNAs) play important regulatory roles in myocardial cell apoptosis. They can modulate the expression of apoptosis-related genes at post-transcriptional level by altering the translation efficacy of target mRNAs or functioning as a precursor for miRNAs or competing for miRNA-mediated inhibition. Moreover, reversing the abnormal expression of lncRNAs can attenuate and even reverse the pathological apoptosis of cardiomyocytes. Therefore, apoptosis-related lncRNAs may become a potential new field for studying cardiomyocyte apoptosis and provide new ideas for the treatment of cardiovascular diseases.

Knock out hepatic Krüppel-like factor 16 (KLF16) improve myocardial damage and promoted myocardial protection of myocardial ischemia-reperfusion via anti-oxidative and anti-inflammation effects by TFAM/PPARβ signal passage

This study is aimed at investigating mechanisms and effects of Krüppel-like factor 16 (KLF16) affects myocardial ischemia-reperfusion. Patients with myocardial ischemia-reperfusion and normal volunteer were collected. C57BL6J male mice were located left anterior descending coronary artery (LAD). H9c2 cell was induced with hydrogen peroxide (H2O2) and Lipopolysaccharide (LPS). Serum KLF16 mRNA expression was increased in myocardial ischemia-reperfusion. Serum mRNA of KLF16 was positive correlation with serum creatine kinase MB (CK-MB) or creatine kinase (CK) levels in patients with myocardial ischemia-reperfusion. The expression of KLF16 mRNA and protein in mice with myocardial ischemia-reperfusion were also increased. The inhibition of KLF16 reduced oxidative stress and inflammation, and presented myocardial ischemia (MI) in vivo model of myocardial ischemia-reperfusion. Mitochondrial transcription factor A (TFAM)/peroxisome proliferator-activated receptor-beta (PPARβ) signal passage is target spot of KLF16 in Myocardial ischemia-reperfusion. TFAM interlink KLF16 in myocardial ischemia-reperfusion. TFAM participate in KLF16 affects myocardial ischemia-reperfusion. PPARβ promoter region KLF16 affects myocardial ischemia-reperfusion. These results firstly demonstrated that knock-out KLF16 reduced oxidative stress and inflammation, and presented MI in vivo model of myocardial ischemia-reperfusion through the induction of PPARβ by TFAM, may provide a novel therapeutic strategy for myocardial ischemia-reperfusion.

A narrative review of non-coding RNAs in atrial fibrillation: potential therapeutic targets and molecular mechanisms

Objective

This review summarizes the advances in the study of ncRNAs and atrial remodeling mechanisms to explore potential therapeutic targets and strategies for AF.

Background

Atrial fibrillation (AF) is one of the most common arrhythmias, and its morbidity and mortality rates are gradually increasing. Non-coding ribonucleic acid RNAs (ncRNAs) are transcribed from the genome and do not have the ability to be translated into proteins. A growing body of evidence has shown ncRNAs are extensively involved in the pathophysiological processes underlying AF. However, the precise molecular mechanisms of these associations have not been fully elucidated. Atrial remodeling plays a key role in the occurrence and development of AF, and includes electrical remodeling, structural remodeling, and autonomic nerve remodeling. Research has shown that ncRNA expression is altered in the plasma and tissues of AF patients that mediate cardiac excitation and arrhythmia, and is closely related to atrial remodeling.

Methods

Literatures about ncRNAs and atrial fibrillation were extensively reviewed to discuss and analyze.

Conclusions

The biology of ncRNAs represents a relatively new field of research and is still in an emerging stage. Recent studies have laid a foundation for understanding the molecular mechanisms of AF, future studies aimed at identifying how ncRNAs act on atrial fibrillation to provide potentially promising therapeutic targets for the treatment of atrial fibrillation.

Epigallocatechin-3-gallate protects cardiomyocytes from hypoxia-reoxygenation damage via raising autophagy related 4C expression

Myocardial ischemia/reperfusion (I/R) injury is a serious issue during the therapy of myocardial infarction. Herein, we explored the beneficial influence of Epigallocatechin-3-gallate (EGCG) on hypoxia/reoxygenation (H/R)-stimulated cardiomyocyte H9c2 cells damage, along with possible internal molecular mechanism related autophagy related 4C (ATG4C). H9c2 cells were subjected to H/R stimulation and/or EGCG treatment. ATG4C mRNA expression was measured via q-PCR assay. ATG4C overexpression plasmid (OE-ATG4C) was transfected to arise ATG4C level. Cell viability, apoptosis, reactive oxygen species (ROS) production, ATP level were tested via CCK-8 assay, Annexin V-FITC/PI staining, DCFH-DA staining and ATP Assay Kit, respectively. Western blotting was performed to test Cleaved-caspase 3, Cleaved-caspase 9, cytochrome C, and LC3B protein levels. H/R stimulation resulted in H9c2 cell viability loss, promoted cell apoptosis, and ROS overproduction, as well as lowered ATP level in cells. EGCG treatment alleviated H/R-resulted H9c2 cell viability loss, cell apoptosis, ROS overproduction, and reduction of ATP level. Moreover, H/R stimulation reduced the ATG4C expression in H9c2 cells, while EGCG raised the ATG4C expression. Overexpression of ATG4C strengthened the beneficial influence of EGCG on H/R-stimulated H9c2 cell viability, apoptosis and ROS production. Besides, ATG4C overexpression weakened the H/R-stimulated H9c2 cell autophagy via reducing LC3B II/I expression. EGCG exerted beneficial influence on H/R-stimulated cardiomyocytes, which protected cardiomyocytes from H/R-stimulated viability loss, apoptosis, and ROS overproduction via enhancing ATG4C expression.

Divergent regulation of lncRNA expression by ischemia in adult and aging mice

Elderly patients have increased susceptibility to acute kidney injury (AKI). Long noncoding RNAs (lncRNA) are key regulators of cellular processes, and have been implicated in both aging and AKI. Our aim was to study the effects of aging and ischemia-reperfusion injury (IRI) on the renal expression of lncRNAs. Adult and old (10- and 26-30-month-old) C57BL/6 N mice were subjected to unilateral IRI followed by 7 days of reperfusion. Renal expression of 90 lncRNAs and mRNA expression of injury, regeneration, and fibrosis markers was measured by qPCR in the injured and contralateral control kidneys. Tubular injury, regeneration, and fibrosis were assessed by histology. Urinary lipocalin-2 excretion was increased in old mice prior to IRI, but plasma urea was similar. In the control kidneys of old mice tubular cell necrosis and apoptosis, mRNA expression of kidney injury molecule-1, fibronectin-1, p16, and p21 was elevated. IRI increased plasma urea concentration only in old mice, but injury, regeneration, and fibrosis scores and their mRNA markers were similar in both age groups. AK082072 and Y lncRNAs were upregulated, while H19 and RepA transcript were downregulated in the control kidneys of old mice. IRI upregulated Miat, Igf2as, SNHG5, SNHG6, RNCR3, Malat1, Air, Linc1633, and Neat1 v1, while downregulated Linc1242. LncRNAs H19, AK082072, RepA transcript, and Six3os were influenced by both aging and IRI. Our results indicate that both aging and IRI alter renal lncRNA expression suggesting that lncRNAs have a versatile and complex role in aging and kidney injury. An Ingenuity Pathway Analysis highlighted that the most downregulated H19 may be linked to aging/senescence through p53.

LncRNA MIAT enhances cerebral ischaemia/reperfusion injury in rat model via interacting with EGLN2 and reduces its ubiquitin-mediated degradation

Long non-coding RNA (lncRNA) MIAT (myocardial infarction associated transcript) has been characterized as a functional lncRNA modulating cerebral ischaemic/reperfusion (I/R) injury. However, the underlying mechanisms remain poorly understood. This study explored the functional partners of MIAT in primary rat neurons and their regulation on I/R injury. Sprague-Dawley rats were used to construct middle cerebral artery occlusion (MCAO) models. Their cerebral cortical neurons were used for in vitro oxygen-glucose deprivation/reoxygenation (OGD/R) models. Results showed that MIAT interacted with EGLN2 in rat cortical neurons. MIAT overexpression or knockdown did not alter EGLN2 transcription. In contrast, MIAT overexpression increased EGLN2 stability after I/R injury via reducing its ubiquitin-mediated degradation. EGLN2 was a substrate of MDM2, a ubiquitin E3 ligase. MDM2 interacted with the N-terminal of EGLN2 and mediated its K48-linked poly-ubiquitination, thereby facilitating its proteasomal degradation. MIAT knockdown enhanced the interaction and reduced EGLN2 stability. MIAT overexpression enhanced infarct volume and induced a higher ratio of neuronal apoptosis. EGLN2 knockdown significantly reversed the injury. MIAT overexpression reduced oxidative pentose phosphate pathway flux and increased oxidized/reduced glutathione ratio, the effects of which were abrogated by EGLN2 knockdown. In conclusion, MIAT might act as a stabilizer of EGLN2 via reducing MDM2 mediated K48 poly-ubiquitination. MIAT-EGLN2 axis exacerbates I/R injury via altering redox homeostasis in neurons.

Non-coding RNAs in cardiac regeneration: Mechanism of action and therapeutic potential

In the past two decades, thousands of non-coding RNAs (ncRNAs) have been discovered, annotated, and characterized in nearly every tissue under both physiological and pathological conditions. Here, we will focus on the role of ncRNAs, including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) in ischemic heart disease (IHD), which remains the leading cause of morbidity and mortality in humans-resulting in 8.9 million deaths annually. Cardiomyocyte (CM) proliferation, differentiation, and survival in addition to neovascularization of injured tissues and the prevention of fibrosis are commonly regarded as critically important for the recovery of the heart following myocardial infarction (MI). An abundance of evidence has been accumulated to show ncRNAs participate in cardiac recovery after MI. Because miRNAs are important regulators of cardiac regeneration, the therapeutic potential of at least five of these molecules has been assessed in large animal models of human IHD. In particular, miRNA-based interventions based on miR-132 and miR-92a inhibition in related diseases have displayed favorable outcomes that have provided the impetus for miRNA-based clinical trials for IHD. At the same time, the functional roles of lncRNAs and circRNAs in cardiac regeneration are also being explored. In the present review, we will summarize the latest ncRNA studies aimed at reversing damage to the ischemic heart and discuss the therapeutic potential of targeting miRNAs, lncRNAs, and circRNAs to stimulate cardiac regeneration.

Ozone protects cardiomyocytes against ischemia/reperfusion injury: Regulating the heat shock protein 70 (HPS70) expression through activating the JAK2/STAT3 Pathway

Ischemia/reperfusion (I/R) injury causes complications in early coronary artery reperfusion for acute myocardial infarction (AMI). Ozone (O₃) has been reported to be applied for protecting I/R injury, but its detailed mechanism remains unclear. Our study focused on the protective effect of O₃ pretreatment on myocardial I/R injury and JAK2/STAT3 signaling and HSP70 regulation involving in the mediation. The rat hearts which were perfused and isolated as well as the cultured cardiomyocytes of neonatal rat were exposed to hypoxia/reoxygenation (H/R) and different concentrations of O₃ followed by heat shock protein 70 (HSP70) siRNA treatment. The results showed O₃ attenuated the suppression of cell viability induced by H/R and decreased the release of activity of creatine kinase (CK), lactate dehydrogenase (LDH) and apoptosis of cardiomyocytes in vitro. Moreover, O₃ also activated the JAK2/STAT3 signaling, upregulated the expression of HSP70 both in vitro and vivo, and decreased the index of apoptosis of cardiomyocytes caused by I/R as well as myocardial infarct area in vivo. In addition, HSP70 siRNA and JAK2 inhibitor AG490 inhibited the cardioprotective effect of O₃. And the expression of HSP70 increased by ozone was reduced by AG-490. In conclusion, our results demonstrated that ozone protects cardiomyocytes in I/R injury through regulation of the expression of HSP70 by activating the JAK2/STAT3 pathway.

LncRNA MIAT knockdown alleviates oxygen-glucose deprivation‑induced cardiomyocyte injury by regulating JAK2/STAT3 pathway via miR-181a-5p

BACKGROUND

Coronary artery disease (CAD) is a common heart disease with high incidence and mortality. Myocardial ischemia is the main type of CAD, which negatively affects health worldwide. The aim of the present study was to investigate the function and mechanism of myocardial infarction-associated transcript (MIAT) in myocardial ischemia.

METHODS

Human cardiomyocytes (HCM) were treated with oxygen-glucose deprivation (OGD) to set the in vitro model and mouse myocardial ischemia/reperfusion (I/R) was set for in vivo model. Cell viability and apoptosis were detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay, flow cytometry, and immunofluorescence analysis. Inflammatory cytokines levels were detected by enzyme-linked immunosorbent assay. Gene and protein expressions were identified by quantitative real time-polymerase chain reaction or Western blotting. The interaction of MIAT, miR-181a-5p, and janus kinase 2 (JAK2) was identified by dual-luciferase report assay. Mouse heart tissues histopathological condition were observed by hematoxylin and eosin assays.

RESULTS

Expression of MIAT and JAK2 were increased in OGD-treated HCM and mice of I/R model group, and miR-181a-5p was decreased. MIAT silencing could reverse the OGD treatment induced cell proliferation inhibition, cleaved caspase-3 and Bcl2-associated X (Bax) levels increased, while those of B-cell lymphoma-2 (Bcl-2) and mitochondria's cyt-C decreased. Besides, MIAT knockdown attenuated the OGD-induced increase of tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 levels. Moreover, MIAT targeted miR-181a-5p to enhance the expression of JAK2 and signal Transducer and Activator of Transcription 3 (STAT3), and miR-181a-5p overexpression promoted proliferation, whereas it inhibited apoptosis in OGD-induced cardiomyocytes. Furthermore, the regulatory effects of MIAT knockdown in cell proliferation, apoptosis, and inflammatory injury was reversed by inhibition of miR-181a-5p or overexpression of JAK2 in OGD-treated HCM. Knockdown of MIAT reduced myocardial injury caused by I/R treatment in vivo.

CONCLUSION

MIAT knockdown inhibited apoptosis and inflammation by regulating JAK2/STAT3 signaling pathway via targeting miR-181a-5p in myocardial ischemia model. MIAT can be a possible therapeutic target for controlling the progression of myocardial ischemia.

Coordination of PRKCA/PRKCA-AS1 interplay facilitates DNA methyltransferase 1 recruitment on DNA methylation to affect protein kinase C alpha transcription in mitral valve of rheumatic heart disease

In the present study, mitral valve tissues from three mitral stenosis patients with RHD by valve replacement and two healthy donors were harvested and conducted DNA methylation signature on PRKCA by MeDIP-qPCR. The presence of hypomethylated CpG islands at promoter and 5' terminal of PRKCA was observed in RHD accompanied with highly expressed PRKCA and down-regulated antisense long non-coding RNA (lncRNA) PRKCA-AS1 compared to health control. Furthermore, the enrichments of DNMT1/3A/3B on PRKCA were detected by ChIP-qPCR assay in vivo and in human cardiomyocyte AC16 and RL-14 cells exposed to TNF-α in vitro, and both demonstrated that DNMT1 substantially contributed to DNA methylation. Additionally, PRKCA-AS1 was further determined to bind with promoter of PRKCA via 5' terminal and interact with DNMT1 via 3' terminal. Taken together, our results illuminated a novel regulatory mechanism of DNA methylation on regulating PRKCA transcription through lncRNA PRKCA-AS1, and shed light on the molecular pathogenesis of RHD occurrence.

Pharmacology of Catechins in Ischemia-Reperfusion Injury of the Heart

Catechins represent a group of polyphenols that possesses various beneficial effects in the cardiovascular system, including protective effects in cardiac ischemia-reperfusion (I/R) injury, a major pathophysiology associated with ischemic heart disease, myocardial infarction, as well as with cardioplegic arrest during heart surgery. In particular, catechin, (−)-epicatechin, and epigallocatechin gallate (EGCG) have been reported to prevent cardiac myocytes from I/R-induced cell damage and I/R-associated molecular changes, finally, resulting in improved cell viability, reduced infarct size, and improved recovery of cardiac function after ischemic insult, which has been widely documented in experimental animal studies and cardiac-derived cell lines. Cardioprotective effects of catechins in I/R injury were mediated via multiple molecular mechanisms, including inhibition of apoptosis; activation of cardioprotective pathways, such as PI3K/Akt (RISK) pathway; and inhibition of stress-associated pathways, including JNK/p38-MAPK; preserving mitochondrial function; and/or modulating autophagy. Moreover, regulatory roles of several microRNAs, including miR-145, miR-384-5p, miR-30a, miR-92a, as well as lncRNA MIAT, were documented in effects of catechins in cardiac I/R. On the other hand, the majority of results come from cell-based experiments and healthy small animals, while studies in large animals and studies including comorbidities or co-medications are rare. Human studies are lacking completely. The dosages of compounds also vary in a broad scale, thus, pharmacological aspects of catechins usage in cardiac I/R are inconclusive so far. Therefore, the aim of this focused review is to summarize the most recent knowledge on the effects of catechins in cardiac I/R injury and bring deep insight into the molecular mechanisms involved and dosage-dependency of these effects, as well as to outline potential gaps for translation of catechin-based treatments into clinical practice.

MicroRNA-29b reduces myocardial ischemia-reperfusion injury in rats via down-regulating PTEN and activating the Akt/eNOS signaling pathway

Reperfusion may cause injuries to the myocardium in ischemia situation, which is called ischemia/reperfusion (I/R) injury. The study aimed to explore the roles of microRNA-29b (miR-29b) in myocardial I/R injury. Myocardial I/R injury rat model was established. Differentially expressed miRNAs between the model rats and the sham-operated rats were analyzed. miR-29b expression in myocardial tissues was measured. Gain-of-function of miR-29b was performed, and then the morphological changes, infarct size, myocardial function, oxidative stress, and the cell apoptosis in myocardial tissues were detected. The target relation between miR-29b and PTEN was detected through bio-information prediction and dual luciferase reporter gene assay. Activation of Akt/eNOS signaling was detected. H9C2 cells were subjected to hypoxia/reoxygenation treatment to perform in vitro experiments. I/R rats presented severe inflammatory infiltration, increased infarct size and cell apoptosis, increased oxidative stress and decreased myocardial function. miR-29b was downregulated in I/R rats, and up-regulation of miR-29b reversed the above changes. miR-29b directly bound to PTEN, and overexpression of miR-29b reduced PTEN expression level and increased the protein levels of p-Akt/Akt and p-eNOS/eNOS. In vivo results were confirmed in in vitro experiments. This study provided evidence that miR-29b could alleviate the myocardial I/R injury in vivo and in vitro by inhibiting PTEN expression and activating the Akt/eNOS signaling pathway.

Long non-coding RNA AK006774 inhibits cardiac ischemia-reperfusion injury via sponging miR-448

In recent years, the incidence and mortality of myocardial infarction (MI) have been increasing throughout the world, threatening public health. Non-coding RNAs (ncRNAs), including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), play critical roles in the progression of MI. The present study aimed to investigate the role of lncRNA AK006774 in the progression of myocardial infarction and find out novel therapeutic or diagnostic target of myocardial infarction. A mouse ischemia/reperfusion (I/R) model and 2,3,5-Triphenyte-trazoliumchloride (TTC) staining were performed to evaluate the effects of AK006774 on I/R injury in vivo. Hypoxia/reoxygenation (H/R) models using primary cardiomyocytes have been established. Flow cytometry and Terminal Deoxynucleotide Transferase dUTP Nick End Labeling (TUNEL) assays were performed to evaluate the effects of AK006774 on cardiomyocyte apoptosis. Luciferase and RNA pull-down assays were performed to verify the interaction between miR-448 and its targets. Western blotting and quantitative PCR were performed to determine protein and gene expression, respectively. We first found that AK006774 overexpression reduced I/R-induced infarct area and cardiomyocyte apoptosis in vivo. Accordingly, AK006774 inhibited apoptosis and oxidative stress in cardiomyocytes subjected to H/R treatment in vitro. Mechanistically, AK006774 modulated the expression of bcl-2 by sponging miR-448. Overexpression of miR-448 antagonized the effects of AK006774 on cardiomyocyte apoptosis. The AK006774/miR-448/bcl-2 signaling axis acts as a key regulator of I/R injury and may be a potential therapeutic or diagnostic target for the treatment of MI.

PTB domain and leucine zipper motif 1 (APPL1) inhibits myocardial ischemia/hypoxia-reperfusion injury via inactivation of apoptotic protease activating factor-1 (APAF-1)/Caspase9 signaling pathway

Myocardial ischemia/hypoxia-reperfusion injury mediates the progression of multiple cardiovascular diseases. It has been reported that knockdown of adaptor protein containing a PH domain, PTB domain and leucine zipper motif 1 (APPL1) is a significant factor for the progression of myocardial injury. However, the role of APPL1 in myocardial ischemia remains unclear. Hence, the aim of the present study was to investigate the specific mechanism underlying the role of APPL1 in myocardial ischemia.In our study, the mRNA level of APPL1 was detected by quantitative real-time PCR (RT-qPCR). The expressions of APPL1, Apoptotic protease activating factor-1 (APAF-1), cleaved caspase9 and other inflammation- and apoptosis-related proteins were determined by western blotting. The secretion of inflammatory cytokines and lactate dehydrogenase (LDH) levels were measured by commercial assay kits. The H9C2 cell viability was analyzed by cell counting kit-8 (CCK-8) assay. The apoptosis rate of H9C2 cells was analyzed by TUNEL assay. The interaction between APPL1 and APAF-1/caspase9 was determined by Immunoprecipitation (IP).Our findings demonstrated that APPL1 was low expressed in myocardial ischemia tissues and cells. APPL1 knockdown suppressed the viability of myocardial ischemia cells and aggravated hypoxia/reperfusion-induced LDH hypersecretion, inflammation and apoptosis. In addition, the overexpression of APPL1 induced inactivation of APAF-1/Caspase9 signaling pathway. Significantly, APAF1 inhibitor reversed the effect of APPL1 knockdown on viability, LDH secretion, inflammation and apoptosis.We conclude that APPL1 inhibits myocardial ischemia/hypoxia-reperfusion injury via inactivation of APAF-1/Caspase9 signaling pathway. Hence, APPL1 may be a novel and effective target for the treatment of myocardial ischemia.

Long non-coding RNA MIAT impairs neurological function in ischemic stroke via up-regulating microRNA-874-3p-targeted IL1B

OBJECTIVE

Long non-coding RNAs (lncRNAs) have diagnostic and therapeutic values in the setting of ischemic stroke (IS). Here, we evaluated the value of myocardial infarction-associated transcript (MIAT) in IS with the involvement of microRNA (miR)-874-3p/interleukin (IL) 1B.

METHODS

MIAT, miR-874-3p and IL1B levels in serum of patients with IS were measured. A middle cerebral artery occlusion (MCAO) model was established in mice. MCAO mice were injected with Agomir of miR-874-3p, shRNA or overexpression vector of MIAT or siRNA of IL1B. Subsequently, behavioral activities and neurological function of mice were assessed. The number of Nissl bodies, brain damage, neuronal apoptosis and inflammatory factors in brain tissues of mice were measured. The targeting relationship between MIAT and miR-874-3p, as well as that between miR-874-3p and IL1B was explored.

RESULTS

In patients with IS, MIAT and IL1B were up-regulated and miR-874-3p was down-regulated. MIAT absorbed miR-874-3p while miR-874-3p targeted IL1B. Silencing of MIAT or IL1B, or promotion of miR-874-3p improved behavioral activities and neurological function of mice, reduced the number of Nissl bodies, as well as improved brain damage, neuronal apoptosis and inflammation. Overexpression of miR-874-3p abrogated up-regulated MIAT-mediated influence on MCAO mice.

CONCLUSION

Shortly, this study figures out that MIAT impairs neurological function in IS via up-regulating miR-874-3p-targeted IL1B.

Long Noncoding RNAs in Myocardial Ischemia-Reperfusion Injury

Following an acute myocardial infarction, reperfusion therapy is currently the most effective way to save the ischemic myocardium; however, restoring blood flow may lead to a myocardial ischemia-reperfusion injury (MIRI). Recent studies have confirmed that long-chain noncoding RNAs (LncRNAs) play important roles in the pathophysiology of MIRIs. These LncRNA-mediated roles include cardiomyocyte apoptosis, autophagy, necrosis, oxidative stress, inflammation, mitochondrial dysfunction, and calcium overload, which are regulated through the expression of target genes. Thus, LncRNAs may be used as clinical diagnostic markers and therapeutic targets to treat or prevent MIRI. This review evaluates the research on LncRNAs involved in MIRIs and provides new ideas for preventing and treating this type of injury.

Long non-coding RNA nuclear enriched abundant transcript 1 (NEAT1) sponges microRNA-124-3p to up-regulate phosphodiesterase 4B (PDE4B) to accelerate the progression of Parkinson's disease

Reportedly, long non-coding RNA (lncRNA) are crucial modulators in neurodegenerative diseases. Herein, we investigated the role of lncRNA nuclear enriched abundant transcript 1 (NEAT1) in Parkinson's disease (PD). In-vitro PD model was established based on SH-SY5Y cells treated with 1-methyl-4-phenylpyridinium (MPP+). NEAT1, microRNA (miR) -124-3p and phosphodiesterase 4B (PDE4B) expression levels were examined by qRT-PCR. CCK-8 assay and LDH release assay were adopted to delve into the cell viability and cytotoxicity, respectively. Besides, western blot was utilized to determine mTOR, p-mTOR and PDE4B expression levels. ELISA was executed to detect the levels of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β) and interleukin 6 (IL-6). Dual-luciferase reporter assay and RIP assay were used to probe the relationship between miR-124-3p and NEAT1 or PDE4B. We demonstrated that, in SH-SY5Y cells treated with MPP+, NEAT1 and PDE4B expression levels were raised, while miR-124-3p expression was repressed; NEAT1 depletion or miR-124-3p overexpression increased the cell viability and suppressed cell injury. Besides, miR-124-3p was confirmed as the direct target of NEAT1, and its down-regulation counteracted the impact of NEAT1 depletion on SH-SY5Y cells. PDE4B was as the downstream target of miR-124-3p, and its overexpression weakens the impact of miR-124-3p on SH-SY5Y cells. Additionally, NEAT1 decoyed miR-124-3p to modulate PDE4B expression. Collectively, in MPP+-induced SH-SY5Y cells, NEAT1 depletion increases cell viability, represses cytotoxicity and reduces inflammatory response by regulating miR-124-3p and PDE4B expression levels, suggesting that NEAT1 may be a promising target for treating PD.

Modulation of the Expression of Long Non-Coding RNAs H19, GAS5, and MIAT by Endurance Exercise in the Hearts of Rats with Myocardial Infarction

Long non-coding RNAs (lncRNAs) have a critical role in the regulation of cardiovascular function. Dysregulation of lncRNAs is implicated in the progression of cardiovascular diseases including myocardial infarction (MI). Regarding the beneficial effects of exercise (Ex) on the improvement of MI, this study aimed to investigate the effects of post-MI Ex on the expression of MI-associated lncRNAs: H19, myocardial infarction association transcript (MIAT), and growth arrest specific 5 (GAS5). MI was induced by left anterior descending (LAD) coronary artery ligation in male Wistar rats. One week later, rats were exercised under a moderate-intensity protocol for 4 weeks. In the end, hemodynamic parameters and cardiac function indices were measured. Assessment of fibrotic areas and apoptosis was performed by Masson's trichrome staining and immunohistochemistry, respectively. Expression of genes was evaluated by real-time PCR. Ex significantly reduced the fibrotic areas (P < 0.05) and apoptosis and increased contractility indices (P < 0.01), and cardiac function (P < 0.05) in MI groups. The reduced expression of H19 (P < 0.01) in MI rats returned to normal levels by Ex. Ex significantly (P < 0.001) reduced the expression of MIAT and increased the expression of GAS5 (P < 0.01), which had changed in the hearts of rats with MI. The present study indicated the beneficial effect of Ex on the improvement of cardiac function and reduction of fibrosis in infarcted heart possibly through regulation of the expression of lncRNAs: H19, GAS5, and MIAT.

Conditioned medium from adipose-derived stem cells attenuates ischemia/reperfusion-induced cardiac injury through the microRNA-221/222/PUMA/ETS-1 pathway

Rationale: Cardiovascular diseases, such as myocardial infarction (MI), are the leading causes of death worldwide. Reperfusion therapy is the common standard treatment for MI. However, myocardial ischemia/reperfusion (I/R) causes cardiomyocyte injury, including apoptosis and fibrosis. We aimed to investigate the effects of conditioned medium from adipose-derived stem cells (ADSC-CM) on apoptosis and fibrosis in I/R-treated hearts and hypoxia/reoxygenation (H/R)-treated cardiomyocytes and the underlying mechanisms.

Methods: ADSC-CM was collected from ADSCs. The effects of intramuscular injection of ADSC-CM on cardiac function, cardiac apoptosis, and fibrosis examined by echocardiography, Evans blue/TTC staining, TUNEL assay, and Masson's trichrome staining in I/R-treated mice. We also examined the effects of ADSC-CM on apoptosis and fibrosis in H/R-treated H9c2 cells by annexin V/PI flow cytometry, TUNEL assay, and immunocytochemistry.

Results: ADSC-CM treatment significantly reduced heart damage and fibrosis of I/R-treated mice and H/R-treated cardiomyocytes. In addition, the expression of apoptosis-related proteins, such as p53 upregulated modulator of apoptosis (PUMA), p-p53 and B-cell lymphoma 2 (BCL2), as well as the fibrosis-related proteins ETS-1, fibronectin and collagen 3, were significantly reduced by ADSC-CM treatment. Moreover, we demonstrated that ADSC-CM contains a large amount of miR-221/222, which can target and regulate PUMA or ETS-1 protein levels. Furthermore, the knockdown of PUMA and ETS-1 decreased the induction of apoptosis and fibrosis, respectively. MiR-221/222 overexpression achieved similar results. We also observed that cardiac I/R markedly increased apoptosis and fibrosis in miR-221/222 knockout (KO) mice, while ADSC-CM decreased these effects. The increased phosphorylation of p38 and NF‐κB not only mediated myocardial apoptosis through the PUMA/p53/BCL2 pathway but also regulated fibrosis through the ETS-1/fibronectin/collagen 3 pathway.

Conclusions: Overall, our results show that ADSC-CM attenuates cardiac apoptosis and fibrosis by reducing PUMA and ETS-1 expression, respectively. The protective effect is mediated via the miR-221/222/p38/NF-κB pathway.

miR-22 protect PC12 from ischemia/reperfusion-induced injury by targeting p53 upregulated modulator of apoptosis (PUMA)

MicroRNAs have been implicated as critical regulatory molecules in many cerebrovascular diseases. Recent studies demonstrated miR-22 might provide a potential neuroprotective effect. However, the neuroprotective effect of miR-22 in ischemia/reperfusion (I/R) injury has not been thoroughly elucidated. In this study, the PC12 cells were subjected to 4 h oxygen and glucose deprivation (I) and 24 h reoxygenation (R). The PC12 cells were pre-transfected with miR-22 or anti-miR-22 or siRNA-mediated downregulation of p53-upregulated-modulator-of-apoptosis (PUMA)(PUMA siRNA) or their controls at 24 h prior to exposure to I/R. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot were employed to analyze mRNA and protein expression. PI and Annexin V assays and terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) assay were used to quantify the rate of apoptosis. We found that miR-22 expression was significantly downregulated in the PC12 cells subjected to I/R. Loss of function of miR-22 increased PC12 apoptosis after I/R, and overexpression of miR-22 decreases PC12 apoptosis after I/R. PUMA protein was upregulated in the I/R group as compared with the sham group. The increased PUMA protein expression and apoptosis induced by I/R was reversed by transfection with PUMA siRNA. We concluded that I/R enhanced apoptosis and PUMA expression in PC12 cells via downregulation of miR-22. Enhanced miR-22 expression reversed both PUMA expression and apoptosis induced by I/R in PC12 cells. miR-22/PUMA axis has important implications for their clinical applications.

MiR-211 protects cerebral ischemia/reperfusion injury by inhibiting cell apoptosis

MicroRNAs (miRNAs) have emerged as critical regulators of neuronal survival during cerebral ischemia/reperfusion injury. Accumulating evidence has shown that miR-211 plays a crucial role in regulating apoptosis and survival in various cell types. However, whether miR-211 is involved in regulating neuronal survival during cerebral ischemia/reperfusion injury remains unknown. In this study, we aimed to explore the biological role of miR-211 in regulating neuronal injury induced by oxygen-glucose deprivation/reoxygenation (OGD/R) and transient cerebral ischemia/reperfusion (I/R) injury in vitro and in vivo. We found that miR-211 expression was significantly downregulated in PC12 cells in response to OGD/R and in the penumbra of mouse in response to MCAO. Overexpression of miR-211 alleviated OGD/R-induced PC12 cell apoptosis, whereas miR-211 inhibition facilitated OGD/R-induced PC12 cell apoptosis in vitro. Moreover, overexpression of miR-211 reduced infarct volumes, neurologic score, and neuronal apoptosis in vivo, whereas miR-211 inhibition increased infarct volumes, neurologic score and neuronal apoptosis in vivo. Notably, our results identified P53-up-regulated modulator of apoptosis (PUMA) as a target gene of miR-211. Our findings suggested that miR-211 may protect against MCAO injury by targeting PUMA in rats, which paves a potential new way for the therapy of cerebral I/R injury.

LncRNA MIAT regulated by selenium and T-2 toxin increases NF-κB-p65 activation, promoting the progress of Kashin-Beck Disease

LncRNA myocardial infarction associated transcript (MIAT) has been shown to be involved in osteoarthritis (OA), but its role in Kashin-Beck Disease (KBD) has rarely been reported. In this study, rats were administered with low selenium and/or T-2 toxin for 4 weeks to establish a KBD animal model. The serum selenium level, TNF-α and IL-1β contents, phosphorylated p65 (p-p65) and MIAT expression were increased in each intervention group. Next, we isolated the primary epiphyseal chondrocytes, and found that selenium treatment reversed the effects of T-2 toxin on chondrocyte injury, p-p65 and MIAT expression. In addition, MIAT overexpression or T-2 toxin treatment led to increased cell death, apoptosis, inflammation, NF-κB-p65 pathway activation and MIAT expression, which was rescued by selenium treatment or MIAT siRNA transfection. Our results suggested that lncRNA MIAT regulated by selenium and T-2 toxin increased the activation of NF-κB-p65, thus being involved in the progress of KBD.

Knockdown of long non-coding RNA PVT1 protects human AC16 cardiomyocytes from hypoxia/reoxygenation-induced apoptosis and autophagy by regulating miR-186/Beclin-1 axis

Myocardial ischemia/reperfusion (I/R) injury is a common consequence of restored blood supply after acute myocardial infarction (AMI), but its underlying mechanisms remain largely elusive. In this study, we aimed to investigate the functional role of long non-coding RNA PVT1 in hypoxia/reoxygenation (H/R)-treated AC16 cardiomyocytes. Our experimental results demonstrated that H/R treatment impaired the viability and increased the apoptosis of AC16 cells, and knockdown of PVT1 blocked the H/R injury. Besides, PVT1 knockdown also reduced excessive autophagy in H/R-treated AC16 cells. Furthermore, we confirmed that PVT1 might serve as a ceRNA for miR-186 in AC16 cells, and rescue experiments showed that miR-186 inhibition blocked the effects of PVT1 knockdown in H/R-treated AC16 cells. In summary, this study implied that PVT1 might be a promising therapeutic target for treating myocardial I/R injury.

Construction for Long Non-Coding RNA (lncRNA)-Associated Competing Endogenous RNA (ceRNA) Network in Human Retinal Detachment (RD) with Proliferative Vitreoretinopathy (PVR)

Background

The aim of this study was to analyze the long non-coding RNA (lncRNA)-associated competing endogenous RNA (ceRNA) network in human retinal tissues following detachment with proliferative vitreoretinopathy (PVR).

Material/Methods

Expression data of 19 human detached retinas with PVR and 19 normal retinas from postmortem donors were downloaded from Gene Expression Omnibust (GEO) database (GSE28133). The R package “limma” was utilized to discriminate the dysregulated lncRNA and mRNA profiles. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses of differentially expressed mRNAs were performed using R packages “Clusterprofiler.” The ceRNA network of dysregulated genes was constructed by using mircode, miRDB, miRTarBase and TargetScan databases, and was visualized by Cytoscape v3.6.1.

Results

A total of 23 lncRNAs and 994 mRNAs were identified significantly expressed between the human detached retinas with PVR and the normal retina tissues, with thresholds of |log₂FoldChange| >1.0 and adjusted P-value <0.05. The constructed ceRNA network (lncRNA-miRNA-mRNA regulatory axis) included 9 PVR-specific lncRNAs, as well as 27 miRNAs and 73 mRNAs.

Conclusions

We demonstrated the differential lncRNA expression profile and constructed a lncRNA-associated ceRNA network in human detached retinas with PVR. This may ferret out an unknown ceRNA regulatory network in human retinal detachment with PVR.

Catechin relieves hypoxia/reoxygenation-induced myocardial cell apoptosis via down-regulating lncRNA MIAT

Background

Catechin protects heart from myocardial ischaemia/reperfusion (MI/R) injury. However, whether catechin inhibits H/R‐induced myocardial cell apoptosis is largely unknown.

Objective

This study aims to investigate the underlying mechanism of catechin in inhibiting the apoptosis of H/R‐induced myocardial cells.

Methods

LncRNA MIAT expression was detected by qRT‐PCR. Cell viability of H9C2 cells was detected using CCK‐8 assay. The apoptosis of H9C2 cells was detected by flow cytometry. The interaction between CREB and MIAT promoter regions was confirmed by dual‐luciferase reporter gene assay and ChIP assay.

Results

In MI/R rats, catechin improved heart function and down‐regulated lncRNA MIAT expression in myocardial tissue. In H/R‐induced H9C2 cells, catechin protected against cell apoptosis, and lncRNA MIAT overexpression attenuated this protective effect of catechin. We confirmed that transcription factor CREB could bind to MIAT promoter region, and catechin suppressed lncRNA MIAT expression through up‐regulating CREB. Catechin improved mitochondrial function and relieved apoptosis through promoting Akt/Gsk‐3β activation. In addition, MIAT inhibited Akt/Gsk‐3β activation and promoted cell apoptosis in H/R‐induced H9C2 cells. Finally, we found catechin promoted Akt/Gsk‐3β activation through inhibiting MIAT expression in H/R‐induced H9C2 cells.

Conclusion

Catechin relieved H/R‐induced myocardial cell apoptosis through regulating CREB/lncRNA MIAT/Akt/Gsk‐3β pathway.

Bergenin Exerts Hepatoprotective Effects by Inhibiting the Release of Inflammatory Factors, Apoptosis and Autophagy via the PPAR-γ Pathway

Objective

Hepatic ischemia reperfusion (IR) limits the development of liver transplantation technology. The aim of this study was to explore the protective effects of Bergenin on hepatic IR, particularly the elimination of reactive oxygen species (ROS) and activation of the peroxisome proliferators activated receptor γ (PPAR-γ) pathway.

Methods

Initial experiments were performed to confirm the non-toxicity of Bergenin. Mice were randomly divided into sham, IR, and IR + Bergenin (10, 20 and 40 mg/kg) groups, and serum and tissue samples were obtained at 2, 8 and 24 h for detection of liver enzymes (ALT and AST), inflammatory factors (TNF-α, IL-6 and IL-1β), ROS, cell death markers (Bcl-2, Bax, Beclin-1 and LC3) and related important pathways (PPAR-γ, P38 MAPK, NF-κB p65 and JAK2/STAT1).

Results

Bergenin reduced the release of ROS, down-regulated inflammatory factors, and inhibited apoptosis and autophagy. Additionally, expression of PPAR-γ-related genes was increased and phosphorylation of P38 MAPK, NF-κB p65 and JAK2/STAT1-related proteins was decreased in Bergenin pre-treatment groups in a dose-dependent manner.

Conclusion

Bergenin exerts hepatic protection by eliminating ROS, affecting the release of inflammatory factors, and influencing apoptosis- and autophagy-related genes via the PPAR-γ pathway in this model of hepatic IR injury.

Long non-coding RNAs and nuclear factor-κB crosstalk in cancer and other human diseases

The regulation of the pleiotropic transcription factor, nuclear factor-κB (NF-κB) by miRNAs and proteins is extensively studied. More recently, the NF-κB signaling was also reported to be regulated by several long non-coding RNAs (lncRNAs) that constitute the major portion of the noncoding component of the human genome. The common NF-κB associated lncRNAs include NKILA, HOTAIR, MALAT1, ANRIL, Lethe, MIR31HG, and PACER. The lncRNA and NF-κB signaling crosstalk during cancer and other diseases such as cardiomyopathy, celiac disease, cerebral infarction, chronic kidney disease, diabetes mellitus, Kawasaki disease, pregnancy loss, and rheumatoid arthritis. Some NF-κB related lncRNAs can affect gene expression without modulating NF-κB signaling. Most of the lncRNAs with a potential to modulate NF-κB signaling are regulated by NF-κB itself suggesting a feedback regulation. The discovery of lncRNAs have provided a new type of regulation for the NF-κB signaling and thus could be explored for therapeutic interventions. The manner in which lncRNA and NF-κB crosstalk affects human pathophysiology is discussed in this review. The challenges associated with the therapeutic interventions of this crosstalk are also discussed.

Downregulation of long non-coding RNA nuclear enriched abundant transcript 1 promotes cell proliferation and inhibits cell apoptosis by targeting miR-193a in myocardial ischemia/reperfusion injury

Background

This study aimed to investigate the effect of long non-coding RNA nuclear enriched abundant transcript 1 (lnc-NEAT1) on cell proliferation and apoptosis in myocardial ischemia/reperfusion (I/R) injury cells, and explore its target miRNAs.

Methods

H9c2 cells were cultured in oxygen and glucose deprivation followed by reperfusion (OGD/R) condition to construct a myocardial I/R injury model. Blank shRNA and lnc-NEAT1 shRNA were transferred into normal H9c2 cells and I/R injury H9c2 cells as Normal&sh-NC, OGD/R&sh-NC and OGD/R&sh-NEAT1 groups. Rescue experiment was performed by transfection of NC inhibitor plasmids, miR-193a inhibitor plasmids and NEAT1 shRNA into I/R injury cardiocytes. RNA expression, cell proliferation and cell apoptosis rate were detected by qPCR, CCK-8 and AV/PI respectively.

Results

After OGD/R induction, H9c2 cell apoptosis was greatly increased while cell proliferation was decreased, which indicated successful establishment of myocardial I/R injury model, and lnc-NEAT1 expression was elevated as well. Cell proliferation rate was increased in OGD/R&sh-NEAT1 group at 48 h and 72 h compared to OGD/R&sh-NC group, while cell apoptosis was reduced in OGC/R&sh-NEAT1 group compared to OGD/R&sh-NC group. Target miRNAs detection indicated the negative regulation of lnc-NEAT1 on miR-193a but not miR-182 or miR-141. In rescue experiment, downregulation of lnc-NEAT1 promoted cell proliferation and inhibited cell apoptosis through targeting miR-193a in I/R injury H9c2 cells.

Conclusion

Lnc-NEAT1 is overexpressed in myocardial I/R injury cells compared to normal myocardial cells, and downregulation of lnc-NEAT1 enhances cell proliferation while inhibits cell apoptosis through targeting miR-193a in I/R injury H9c2 cells.