Long non‐coding RNA SNHG16 promotes proliferation and inhibits apoptosis of diffuse large B‐cell lymphoma cells by targeting miR‐497‐5p/PIM1 axis

The aberrant expression and dysfunction of long non‐coding RNAs (lncRNAs) have been identified as critical factors governing the initiation and progression of different human cancers, including diffuse large B‐cell lymphoma (DLBCL). LncRNA small nucleolar RNA host gene 16 (SNHG16) has been recognized as a tumour‐promoting factor in various types of cancer. However, the biological role of SNHG16 and its underlying mechanism are still unknown in DLBCL. Here we disclosed that SNHG16 was overexpressed in DLBCL tissues and the derived cell lines. SNHG16 knockdown significantly suppressed cell proliferation and cell cycle progression, and it induced apoptosis of DLBCL cells in vitro. Furthermore, silencing of SNHG16 markedly repressed in vivo growth of OCI‐LY7 cells. Mechanistically, SNHG16 directly interacted with miR‐497‐5p by acting as a competing endogenous RNA (ceRNA) and inversely regulated the abundance of miR‐497‐5p in DLBCL cells. Moreover, the proto‐oncogene proviral integration site for Moloney murine leukaemia virus 1 (PIM1) was identified as a novel direct target of miR‐497‐5p. SNHG16 overexpression rescued miR‐497‐5p‐induced down‐regulation of PIM1 in DLBCL cells. Importantly, restoration of PIM1 expression reversed SNHG16 knockdown‐induced inhibition of proliferation, G0/G1 phase arrest and apoptosis of OCI‐LY7 cells. Our study suggests that the SNHG16/miR‐497‐5p/PIM1 axis may provide promising therapeutic targets for DLBCL progression.     

Ubiquitin‐specific protease 19 blunts pathological cardiac hypertrophy via inhibition of the TAK1‐dependent pathway

Ubiquitin‐specific protease 19 (USP19) belongs to USP family and is involved in promoting skeletal muscle atrophy. Although USP19 is expressed in the heart, the role of USP19 in the heart disease remains unknown. The present study provides in vivo and in vitro data to reveal the role of USP19 in preventing pathological cardiac hypertrophy. We generated USP19‐knockout mice and isolated neonatal rat cardiomyocytes (NRCMs) that overexpressed or were deficient in USP19 to investigate the effect of USP19 on transverse aortic constriction (TAC) or phenylephrine (PE)‐mediated cardiac hypertrophy. Echocardiography, pathological and molecular analysis were used to determine the extent of cardiac hypertrophy, fibrosis, dysfunction and inflammation. USP19 expression was markedly increased in rodent hypertrophic heart or cardiomyocytes underwent TAC or PE culturing, the increase was mediated by the reduction of Seven In Absentia Homolog‐2. The extent of TAC‐induced cardiac hypertrophy, fibrosis, dysfunction and inflammation in USP19‐knockout mice was exacerbated. Consistently, gain‐of‐function and loss‐of‐function approaches that involved USP19 in cardiomyocytes suggested that the down‐regulation of USP19 promoted the hypertrophic phenotype, while the up‐regulation of USP19 improved the worsened phenotype. Mechanistically, the USP19‐elicited cardiac hypertrophy improvement was attributed to the abrogation of the transforming growth factor beta‐activated kinase 1 (TAK1)‐p38/JNK1/2 transduction. Furthermore, the inhibition of TAK1 abolished the aggravated hypertrophy induced by the loss of USP19. In conclusion, the present study revealed that USP19 and the downstream of TAK1‐p38/JNK1/2 signalling pathway might be a potential target to attenuate pathological cardiac hypertrophy.     

LncRNA SNHG1 functions as a ceRNA to antagonize the effect of miR‐145a‐5p on the down‐regulation of NUAK1 in nasopharyngeal carcinoma cell

How lncRNA SNHG1 influences the aggressiveness of nasopharyngeal carcinoma cells as well as the underlying mechanism was studied. The lncRNA differences were analysed by GSE12452 gene microarray. The expression of SNHG1, MiR‐145‐5p and NUAK1 was identified by qRT‐PCR and western blot. Transfection was conducted to construct nasopharyngeal carcinoma cells with different expressions of SNHG1, miR‐145‐5p and NUAK1. Dual‐luciferase reporter assay was performed to explore the relationship between SNHG1, miR‐145‐5p and NUAK1. Wound‐healing assay and transwell invasion experiments were employed to study changes in cell migration capacity and cell invasion, respectively. Tumour xenografts were performed to observe lung metastasis of nude mice inoculated with transfected CNE cells. SNHG1 is highly expressed in nasopharyngeal carcinoma tissues and in cell lines. Down‐regulation of SNHG1 facilitated the expression of miR‐145‐5p and further suppressed the level of NAUK1 in CNE and HNE‐1 cells. Silencing of SNHG1, up‐regulation of miR‐145‐5p and inhibition of NAUK1 by relative transfection all attenuated the aggressiveness of CNE and HNE‐1 cells both in vivo and in vitro. Moreover, the impaired cell migration and invasion by SNHG1 siRNA could be rescued by cotransfection of miR‐145‐5p in CNE and HNE‐1 cells. LncRNA SNHG1 promoted the expression of NUAK1 by down‐regulating miR‐145‐5p and thus promoted the aggressiveness of nasopharyngeal carcinoma cells through AKT signalling pathway and induced epithelial‐mesenchymal transition (EMT).     

Long non‐coding RNA SNHG16 regulates human aortic smooth muscle cell proliferation and migration via sponging miR‐205 and modulating Smad2

The present study investigated the role of long non‐coding RNA (lncRNA) small nucleolar RNA host gene 16 (SNHG16) in the human aortic smooth muscle cell (HASMC) proliferation and migration and explored the potential link between SNHG16 and atherosclerosis. Our results showed that platelet‐derived growth factor (PDGF)‐bb treatment promoted cell proliferation and migration with concurrent up‐regulation of SNHG16 in HASMCs. Small nucleolar RNA host gene 16 overexpression promoted HASMC proliferation and migration, while SNHG16 knockdown suppressed cell proliferation and migration in PDGF‐bb‐stimulated HASMCs. The bioinformatic analyses showed that SNHG16 possessed the complementary binding sequence with miR‐205, where the interaction was confirmed by luciferase reporter assay and RNA pull‐down assay in HASMCs, and SNHG16 inversely regulated miR‐205 expression. MiR‐205 overexpression attenuated the enhanced effects of PDGF‐bb treatment on HASMC proliferation and migration. Moreover, Smad2 was targeted and inversely regulated by miR‐205, while being positively regulated by SNHG16 in HASMCs. Smad2 knockdown attenuated PDGF‐bb‐mediated actions on HASMC proliferation and migration. Both miR‐205 overexpression and Smad2 knockdown partially reversed the effects of SNHG16 overexpression on HASMC proliferation and migration. Moreover, SNHG16 and Smad2 mRNA were up‐regulated, while miR‐205 was down‐regulated in the plasma from patients with atherosclerosis. Small nucleolar RNA host gene 16 expression was inversely correlated with miR‐205 expression and positively correlated with Smad2 expression in the plasma from atherosclerotic patients. In conclusion, our data showed the up‐regulation of SNHG16 in pathogenic‐stimulated HASMCs and clinical samples from atherosclerotic patients. Small nucleolar RNA host gene 16 regulated HASMC proliferation and migration possibly via regulating Smad2 expression by acting as a competing endogenous RNA for miR‐205.     

Long non‐coding RNA SNHG15 promotes CDK14 expression via miR‐486 to accelerate non‐small cell lung cancer cells progression and metastasis

Long non‐coding RNAs (lncRNAs) have been validated to play important role in multiple cancers, including non‐small cell lung cancer (NSCLC). In present study, our team investigate the biologic role of SNHG15 in the NSCLC tumorigenesis. LncRNA SNHG15 was significantly upregulated in NSCLC tissue samples and cells, and its overexpression was associated with poor prognosis of NSCLC patients. In vitro, loss‐of‐functional cellular experiments showed that SNHG15 silencing significantly inhibited the proliferation, promoted the apoptosis, and induced the cycle arrest at G0//G1 phase. In vivo, xenograft assay showed that SNHG15 silencing suppressed tumor growth of NSCLC cells. Besides, SNHG15 silencing decreased CDK14 protein expression both in vivo and vitro. Bioinformatics tools and luciferase reporter assay confirmed that miR‐486 both targeted the 3′‐UTR of SNHG15 and CDK14 and was negatively correlated with their expression levels. In summary, our study conclude that the ectopic overexpression of SNHG15 contribute to the NSCLC tumorigenesis by regulating CDK14 protein via sponging miR‐486, providing a novel insight for NSCLC pathogenesis and potential therapeutic strategy for NSCLC patients.     

MicroRNA‐129‐1‐3p protects cardiomyocytes from pirarubicin‐induced apoptosis by down‐regulating the GRIN2D‐mediated Ca2+ signalling pathway

Pirarubicin (THP), an anthracycline anticancer drug, is a first‐line therapy for various solid tumours and haematologic malignancies. However, THP can cause dose‐dependent cumulative cardiac damage, which limits its therapeutic window. The mechanisms underlying THP cardiotoxicity are not fully understood. We previously showed that MiR‐129‐1‐3p, a potential biomarker of cardiovascular disease, was down‐regulated in a rat model of THP‐induced cardiac injury. In this study, we used Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genome (KEGG) pathway enrichment analyses to determine the pathways affected by miR‐129‐1‐3p expression. The results linked miR‐129‐1‐3p to the Ca²⁺ signalling pathway. TargetScan database screening identified a tentative miR‐129‐1‐3p‐binding site at the 3′‐UTR of GRIN2D, a subunit of the N‐methyl‐D‐aspartate receptor calcium channel. A luciferase reporter assay confirmed that miR‐129‐1‐3p directly regulates GRIN2D. In H9C2 (rat) and HL‐1 (mouse) cardiomyocytes, THP caused oxidative stress, calcium overload and apoptotic cell death. These THP‐induced changes were ameliorated by miR‐129‐1‐3p overexpression, but exacerbated by miR‐129‐1‐3p knock‐down. In addition, miR‐129‐1‐3p overexpression in cardiomyocytes prevented THP‐induced changes in the expression of proteins that are either key components of Ca²⁺ signalling or important regulators of intracellular calcium trafficking/balance in cardiomyocytes including GRIN2D, CALM1, CaMKⅡδ, RyR2‐pS2814, SERCA2a and NCX1. Together, these bioinformatics and cell‐based experiments indicate that miR‐129‐1‐3p protects against THP‐induced cardiomyocyte apoptosis by down‐regulating the GRIN2D‐mediated Ca²⁺ pathway. Our results reveal a novel mechanism underlying the pathogenesis of THP‐induced cardiotoxicity. The miR‐129‐1‐3p/Ca²⁺ signalling pathway could serve as a target for the development of new cardioprotective agents to control THP‐induced cardiotoxicity.     

α1 adrenoceptor activation by norepinephrine inhibits LPS‐induced cardiomyocyte TNF‐α production via modulating ERK1/2 and NF‐κB pathway

Cardiomyocyte tumour necrosis factor α (TNF‐α) production contributes to myocardial depression during sepsis. This study was designed to observe the effect of norepinephrine (NE) on lipopolysaccharide (LPS)‐induced cardiomyocyte TNF‐α expression and to further investigate the underlying mechanisms in neonatal rat cardiomyocytes and endotoxaemic mice. In cultured neonatal rat cardiomyocytes, NE inhibited LPS‐induced TNF‐α production in a dose‐dependent manner. α₁‐ adrenoceptor (AR) antagonist (prazosin), but neither β₁‐ nor β₂‐AR antagonist, abrogated the inhibitory effect of NE on LPS‐stimulated TNF‐α production. Furthermore, phenylephrine (PE), an α₁‐AR agonist, also suppressed LPS‐induced TNF‐α production. NE inhibited p38 phosphorylation and NF‐κB activation, but enhanced extracellular signal‐regulated kinase 1/2 (ERK1/2) phosphorylation and c‐Fos expression in LPS‐treated cardiomyocytes, all of which were reversed by prazosin pre‐treatment. To determine whether ERK1/2 regulates c‐Fos expression, p38 phosphorylation, NF‐κB activation and TNF‐α production, cardiomyocytes were also treated with U0126, a selective ERK1/2 inhibitor. Treatment with U0126 reversed the effects of NE on c‐Fos expression, p38 mitogen‐activated protein kinase (MAPK) phosphorylation and TNF‐α production, but not NF‐κB activation in LPS‐challenged cardiomyocytes. In addition, pre‐treatment with SB202190, a p38 MAPK inhibitor, partly inhibited LPS‐induced TNF‐α production in cardiomyocytes. In endotoxaemic mice, PE promoted myocardial ERK1/2 phosphorylation and c‐Fos expression, inhibited p38 phosphorylation and IκBα degradation, reduced myocardial TNF‐α production and prevented LPS‐provoked cardiac dysfunction. Altogether, these findings indicate that activation of α₁‐AR by NE suppresses LPS‐induced cardiomyocyte TNF‐α expression and improves cardiac dysfunction during endotoxaemia via promoting myocardial ERK phosphorylation and suppressing NF‐κB activation.     

Up‐regulation of miR‐195 contributes to cardiac hypertrophy‐induced arrhythmia by targeting calcium and potassium channels

Previous studies have confirmed that miR‐195 expression is increased in cardiac hypertrophy, and the bioinformatics website predicted by Targetscan software shows that miR‐195 can directly target CACNB1, KCNJ2 and KCND3 to regulate Cavβ1, Kir2.1 and Kv4.3 proteins expression. The purpose of this study is to confirm the role of miR‐195 in arrhythmia caused by cardiac hypertrophy. The protein levels of Cavβ1, Kir2.1 and Kv4.3 in myocardium of HF mice were decreased. After miR‐195 was overexpressed in neonatal mice cardiomyocytes, the expression of ANP, BNP and β‐MHC was up‐regulated, and miR‐195 inhibitor reversed this phenomenon. Overexpression of miR‐195 reduced the estimated cardiac function of EF% and FS% in wild‐type (WT) mice. Transmission electron microscopy showed that the ultrastructure of cardiac tissues was damaged after miR‐195 overexpression by lentivirus in mice. miR‐195 overexpression increased the likelihood of arrhythmia induction and duration of arrhythmia in WT mice. Lenti‐miR‐195 inhibitor carried by lentivirus can reverse the decreased EF% and FS%, the increased incidence of arrhythmia and prolonged duration of arrhythmia induced by TAC in mice. After miR‐195 treatment, the protein expressions of Cavβ1, Kir2.1 and Kv4.3 were decreased in mice. The results were consistent at animal and cellular levels, respectively. Luciferase assay results showed that miR‐195 may directly target CACNB1, KCNJ2 and KCND3 to regulate the expression of Cavβ1, Kir2.1 and Kv4.3 proteins. MiR‐195 is involved in arrhythmia caused by cardiac hypertrophy by inhibiting Cavβ1, Kir2.1 and Kv4.3.     

LncRNA SNHG6 functions as a ceRNA to regulate neuronal cell apoptosis by modulating miR‐181c‐5p/BIM signalling in ischaemic stroke

Long non‐coding RNAs (lncRNAs) play important roles in the pathogenesis of brain and neurodegenerative disorders. As far as we know, the functions and potential mechanisms of small nucleolar RNA host gene 6 (SNHG6) in ischaemic stroke have not been explored. This study aimed to examine the functional role of SNHG6 in the ischaemic stroke. Middle cerebral artery occlusion (MCAO) in mice and the oxygen glucose deprivation (OGD)‐induced injury in neuronal cells were applied to mimic ischaemic stroke. TTC staining, quantitative real‐time PCR, cell apoptosis assay, caspase‐3 activity assay, Western blot, RNA immunoprecipitation and luciferase reporter assay were performed to evaluate the function and possible mechanisms of SNHG6 in the pathogenesis of ischaemic stroke. The results show that SNHG6 expression was significantly increased both OGD‐induced neuronal cells and MCAO model mice. In vitro results showed that inhibition of SNHG6 increased cell viability, inhibited cell apoptosis and caspase‐3 activity in OGD‐induced neuronal cells. Consistently, knockdown of SNHG6 reduced brain infarct size and improved neurological scores in the MCAO mice. Mechanistic study further revealed that SNHG6 functioned as a competing endogenous RNA (ceRNA) for miR‐181c‐5p, which in turn repressed its downstream target of Bcl‐2 interacting mediator of cell death (BIM) and inhibiting cell apoptosis. This study revealed a novel function of SNHG6 in the modulating neuronal apoptosis in the ischaemic stroke model, and the role of SNHG6 in the regulating of neuronal apoptosis was at least partly via targeting miR‐181c‐5p/BIM signalling pathway.     

MiR‐451 is decreased in hypertrophic cardiomyopathy and regulates autophagy by targeting TSC1

The molecular mechanisms that drive the development of cardiac hypertrophy in hypertrophic cardiomyopathy (HCM) remain elusive. Accumulated evidence suggests that microRNAs are essential regulators of cardiac remodelling. We have been suggested that microRNAs could play a role in the process of HCM. To uncover which microRNAs were changed in their expression, microRNA microarrays were performed on heart tissue from HCM patients (n = 7) and from healthy donors (n = 5). Among the 13 microRNAs that were differentially expressed in HCM, miR‐451 was the most down‐regulated. Ectopic overexpression of miR‐451 in neonatal rat cardiomyocytes (NRCM) decreased the cell size, whereas knockdown of endogenous miR‐451 increased the cell surface area. Luciferase reporter assay analyses demonstrated that tuberous sclerosis complex 1 (TSC1) was a direct target of miR‐451. Overexpression of miR‐451 in both HeLa cells and NRCM suppressed the expression of TSC1. Furthermore, TSC1 was significantly up‐regulated in HCM myocardia, which correlated with the decreased levels of miR‐451. As TSC1 is a known positive regulator of autophagy, we examined the role of miR‐451 in the regulation of autophagy. Overexpression of miR‐451 in vitro inhibited the formation of the autophagosome. Conversely, miR‐451 knockdown accelerated autophagosome formation. Consistently, an increased number of autophagosomes was observed in HCM myocardia, accompanied by up‐regulated autophagy markers, and the lipidated form of LC3 and Beclin‐1. Taken together, our findings indicate that miR‐451 regulates cardiac hypertrophy and cardiac autophagy by targeting TSC1. The down‐regulation of miR‐451 may contribute to the development of HCM and may be a potential therapeutic target for this disease.