Sp1-induced LncRNA CTBP1-AS2 is a novel regulator in cardiomyocyte hypertrophy by interacting with FUS to stabilize TLR4

Unveiling the multifaceted roles of long non-coding RNA CTBP1-DT in human diseases: Special attention to its microprotein-encoding potential

C-terminal binding protein 1 divergent transcript (CTBP1-DT) is a novel long non-coding RNA (lncRNA) located on human chromosome 4p16.3. Numerous studies have shown that CTBP1-DT plays a critical regulatory role in various human malignancies and non-malignant diseases. In several cancers, the expression of CTBP1-DT is upregulated, closely associated with the risk of 12 types of cancer, and strongly correlated with the clinical pathological features and poor prognosis of 10 of these cancers. Mechanistically, CTBP1-DT is stimulated by the transcription factors ETV5 and Sp1, or methylated by YTHDC1. By competitively inhibiting 12 microRNAs, it activates 3 signaling pathways that influence malignant behaviors of tumor cells, including proliferation, apoptosis, cell cycle arrest, migration, invasion, immune evasion, and chemoresistance. Importantly, it also encodes the microprotein DNA damage up-regulated protein (DDUP), which mediates cisplatin resistance through sustained response to DNA damage signals. Furthermore, CTBP1-DT has been implicated in the progression of non-malignant diseases such as diabetes and related conditions, cardiovascular diseases, and osteoarthritis. This review summarizes the latest research on the RNA and protein functions of CTBP1-DT in human diseases, outlines various molecular regulatory networks centered around CTBP1-DT, and discusses the opportunities and challenges of its clinical applications.

Integrative analysis of transcriptome, DNA methylome, and chromatin accessibility reveals candidate therapeutic targets in hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease and is characterized by primary left ventricular hypertrophy usually caused by mutations in sarcomere genes. The mechanism underlying cardiac remodeling in HCM remains incompletely understood. An investigation of HCM through integrative analysis at multi-omics levels will be helpful for treating HCM. DNA methylation and chromatin accessibility, as well as gene expression, were assessed by nucleosome occupancy and methylome sequencing (NOMe-seq) and RNA-seq, respectively, using the cardiac tissues of HCM patients. Compared with those of the controls, the transcriptome, DNA methylome, and chromatin accessibility of the HCM myocardium showed multifaceted differences. At the transcriptome level, HCM hearts returned to the fetal gene program through decreased sarcomeric and metabolic gene expression and increased extracellular matrix gene expression. In the DNA methylome, hypermethylated and hypomethylated differentially methylated regions were identified in HCM. At the chromatin accessibility level, HCM hearts showed changes in different genome elements. Several transcription factors, including SP1 and EGR1, exhibited a fetal-like pattern of binding motifs in nucleosome-depleted regions in HCM. In particular, the inhibition of SP1 or EGR1 in an HCM mouse model harboring sarcomere mutations markedly alleviated the HCM phenotype of the mutant mice and reversed fetal gene reprogramming. Overall, this study not only provides a high-precision multi-omics map of HCM heart tissue but also sheds light on the therapeutic strategy by intervening in the fetal gene reprogramming in HCM.

Role of Specificity Protein 1 (SP1) in Cardiovascular Diseases: Pathological Mechanisms and Therapeutic Potentials

In mammals, specificity protein 1 (SP1) was the first Cys2-His2 zinc finger transcription factor to be isolated within the specificity protein and Krüppel-like factor (Sp/KLF) gene family. SP1 regulates gene expression by binding to Guanine-Cytosine (GC)-rich sequences on promoter regions of target genes, affecting various cellular processes. Additionally, the activity of SP1 is markedly influenced by posttranslational modifications, such as phosphorylation, acetylation, glycosylation, and proteolysis. SP1 is implicated in the regulation of apoptosis, cell hypertrophy, inflammation, oxidative stress, lipid metabolism, plaque stabilization, endothelial dysfunction, fibrosis, calcification, and other pathological processes. These processes impact the onset and progression of numerous cardiovascular disorders, including coronary heart disease, ischemia-reperfusion injury, cardiomyopathy, arrhythmia, and vascular disease. SP1 emerges as a potential target for the prevention and therapeutic intervention of cardiac ailments. In this review, we delve into the biological functions, pathophysiological mechanisms, and potential clinical implications of SP1 in cardiac pathology to offer valuable insights into the regulatory functions of SP1 in heart diseases and unveil novel avenues for the prevention and treatment of cardiovascular conditions.

LncRNA CASC9 enhances the stability of SOCS-1 by combining with FUS to alleviate sepsis-induced liver injury

BACKGROUND

Liver injury plays a major role in the development of sepsis. Liver damage after sepsis is an independent risk factor for multiple organ failure and death. Cancer susceptibility candidate 9 (CASC9) exerts a protective effect on sepsis-induced acute lung injury (ALI). However, the role and underlying mechanism haven't been fully evaluated.

METHODS

Animal and cell models of sepsis were established in vivo and in vitro experiments. The histological and apoptosis analyses of liver tissues were tested by hematoxylin-eosin (HE) staining and terminal dUTP nick end labeling (TUNEL) assay, respectively. Serum levels of inflammatory cytokines were detected via using an enzyme-linked immunosorbent assay (ELISA). The expressions of CASC9, suppressor of cytokine signaling (SOCS)-1, Bcl-2, Bax, Bad, and caspase3 were measured by reverse-transcription quantitative polymerase chain reaction (RT-qPCR) and western blotting. Cell counting kit-8 (CCK-8) and flow cytometry were applied to examine cell viability and apoptosis, respectively. RNA immunoprecipitation (RIP) and RNA-pull down assay were used to verify the binding relationships among CASC9, SOCS-1 and FUS.

RESULTS

CASC9 and SOCS-1 were lowly expressed in animal and cell models of sepsis liver injury. CASC9 or SOCS-1 overexpression could inhibit cell apoptosis upon lipopolysaccharide (LPS) induction. Meanwhile, the serum levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6 and IL-8 were reduced by CASC9 or SOCS-1 overexpression in LPS-induced LO2 cells. Mechanistically, CASC9 interacted with fused in sarcoma (FUS) to stabilize the mRNA of SOCS-1. SOCS-1 silencing antagonized the effects of CASC9 on improving sepsis liver injury.

CONCLUSION

CASC9 overexpression ameliorated the sepsis-induced liver injury, and the probable underlying mechanism may be that CASC9 stabilized the SOCS-1 mRNA by interacting with FUS.

The regulation of circRNA and lncRNAprotein binding in cardiovascular diseases: Emerging therapeutic targets

Noncoding ribonucleic acids (ncRNAs) are a class of ribonucleic acids (RNAs) that carry cellular information and perform essential functions. This class encompasses various RNAs, such as small nuclear ribonucleic acids (snRNA), small interfering ribonucleic acids (siRNA) and many other kinds of RNA. Of these, circular ribonucleic acids (circRNAs) and long noncoding ribonucleic acids (lncRNAs) are two types of ncRNAs that regulate crucial physiological and pathological processes, including binding, in several organs through interactions with other RNAs or proteins. Recent studies indicate that these RNAs interact with various proteins, including protein 53, nuclear factor-kappa B, vascular endothelial growth factor, and fused in sarcoma/translocated in liposarcoma, to regulate both the histological and electrophysiological aspects of cardiac development as well as cardiovascular pathogenesis, ultimately leading to a variety of genetic heart diseases, coronary heart disease, myocardial infarction, rheumatic heart disease and cardiomyopathies. This paper presents a thorough review of recent studies on circRNA and lncRNAprotein binding within cardiac and vascular cells. It offers insight into the molecular mechanisms involved and emphasizes potential implications for treating cardiovascular diseases.

Toll-like receptors in cardiac hypertrophy

Toll-like receptors (TLRs) are a family of pattern recognition receptors (PRRs) that can identify pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs). TLRs play an important role in the innate immune response, leading to acute and chronic inflammation. Cardiac hypertrophy, an important cardiac remodeling phenotype during cardiovascular disease, contributes to the development of heart failure. In previous decades, many studies have reported that TLR-mediated inflammation was involved in the induction of myocardium hypertrophic remodeling, suggesting that targeting TLR signaling might be an effective strategy against pathological cardiac hypertrophy. Thus, it is necessary to study the mechanisms underlying TLR functions in cardiac hypertrophy. In this review, we summarized key findings of TLR signaling in cardiac hypertrophy.

Comparative Analysis of Non-Coding RNA Transcriptomics in Heart Failure

Heart failure constitutes a clinical complex syndrome with different symptomatic characteristics depending on age, sex, race and ethnicity, among others, which has become a major public health issue with an increasing prevalence. One of the most interesting tools seeking to improve prevention, diagnosis, treatment and prognosis of this pathology has focused on finding new molecular biomarkers since heart failure relies on deficient cardiac homeostasis, which is regulated by a strict gene expression. Therefore, currently, analyses of non-coding RNA transcriptomics have been oriented towards human samples. The present review develops a comparative study emphasizing the relevance of microRNAs, long non-coding RNAs and circular RNAs as potential biomarkers in heart failure. Significantly, further studies in this field of research are fundamental to supporting their widespread clinical use. In this sense, the various methodologies used by the authors should be standardized, including larger cohorts, homogeneity of the samples and uniformity of the bioinformatic pipelines used to reach stratification and statistical significance of the results. These basic adjustments could provide promising steps to designing novel strategies for clinical management of patients with heart failure.

Circ-TLR4 promotes cardiac hypertrophy through recruiting FUS to stabilize TLR4 mRNA

BACKGROUND

Cardiac hypertrophy is an adaptive and compensatory mechanism preserving cardiac output during detrimental stimuli. Circular RNAs (circRNAs) have been illustrated to exert important implications in the pathogenesis of multiple cardiovascular diseases (CVD) including demonstrated cardiac hypertrophy. Toll-like receptor 4 (TLR4) has been previously reported to be a crucial regulator in inflammatory response and cardiac hypertrophy. However, the role of circular isoforms derived from TLR4 in cardiac hypertrophy remains unclear.

METHODS

Expression of circ-TLR4 and TLR4 in cardiomyocytes was detected by RT-qPCR. The indicators of cardiac hypertrophy responses, including cell surface area, atrial natriuretic factor (ANF), B-type natriuretic peptide (BNP) and β-myosin heavy chain (β-MHC) were measured by immunofluorescence staining and western blot. RIP assay was used to validate the interaction between circ-TLR4 and TLR4.

RESULTS

Circ-TLR4 and TLR4 was up-regulated in cellular models of cardiac hypertrophy. Circ-TLR4 knockdown attenuated angiotensin II (Ang II)-induced hypertrophy responses in cardiomyocytes. Moreover, circ-TLR4 positively regulated TLR4 expression through recruiting FUS to stabilize TLR4 mRNA. Furthermore, TLR4 overexpression rescued the cardiac responses mediated by circ-TLR4 silencing.

CONCLUSION

Circ-TLR4 promotes cardiac hypertrophy through recruiting FUS to stabilize TLR4 mRNA.

Long Non-Coding RNAs in Cardiac Hypertrophy

Heart disease represents one of the main challenges in modern medicine with insufficient treatment options. Whole genome sequencing allowed for the discovery of several classes of non-coding RNA (ncRNA) and widened our understanding of disease regulatory circuits. The intrinsic ability of long ncRNAs (lncRNAs) and circular RNAs (circRNAs) to regulate gene expression by a plethora of mechanisms make them candidates for conceptually new treatment options. However, important questions remain to be addressed before we can fully exploit the therapeutic potential of these molecules. Increasing our knowledge of their mechanisms of action and refining the approaches for modulating lncRNAs expression are just a few of the challenges we face. The accurate identification of novel lncRNAs is hampered by their relatively poor cross-species sequence conservation and their low and context-dependent expression pattern. Nevertheless, progress has been made in their annotation in recent years, while a few experimental studies have confirmed the value of lncRNAs as new mechanisms in the development of cardiac hypertrophy and other cardiovascular diseases. Here, we explore cardiac lncRNA biology and the evidence that this class of molecules has therapeutic benefit to treat cardiac hypertrophy.

LINC00857 regulated by ZNF460 enhances the expression of CLDN12 by sponging miR-150-5p and recruiting SRSF1 for alternative splicing to promote epithelial-mesenchymal transformation of pancreatic adenocarcinoma cells

Recent research unveiled that LINC00857 plays a regulatory role in multiple human cancers, such as lung adenocarcinoma and gastric cancer. Nevertheless, the function of LINC00857 in pancreatic adenocarcinoma (PAAD) remains unclear. This study concentrates on LINC00857 to discuss the relevant molecular mechanism of this gene in PAAD. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) and western blot were implemented for measuring the expressions of RNAs and proteins. Wound healing and Transwell assays were used to assess cell migration and invasion, and fluorescent in situ hybridization (FISH) to locate LINC00857 in PAAD cells. Additionally, mechanism assays were conducted to validate the interaction between genes. Results indicated that LINC00857 was upregulated in PAAD cells and the knockdown of LINC00857 impeded PAAD cell migration, invasion and epithelial-mesenchymal transition (EMT). Further, it was found that LNC00857 regulates CLDN12 expression by targeting miR-150-5p. Moreover, LINC00857 was confirmed to recruit serine/arginine-rich splicing factor 1 (SRSF1) to promote the alternative splicing (AS) targeting CLDN12, affecting the phenotypes of PAAD cells. In addition, the transcription factor ZNF460 was proven to positively regulate LINC00857 expression. To sum up, LINC00857 regulated by ZNF460 upregulates CLDN12 expression by sponging miR-150-5p and recruiting SRSF1 to facilitate the progression of PAAD cells.[Figure: see text].

SNHG12 regulates biological behaviors of ox-LDL-induced HA-VSMCs through upregulation of SPRY2 and NUB1

BACKGROUND AND AIMS

Human vascular smooth muscle cells (HA-VSMCs) are an important cell type involved in atherosclerosis. Low density lipoprotein (LDL) is a lipoprotein particle that carries cholesterol into peripheral tissue cells, and oxidized modified LDL (ox-LDL) is a well-known inducer of the atherosclerosis-related phenotype switch in VSMCs, leading to the occurrence of atherosclerosis. Accumulating studies have revealed that long non-coding RNAs (lncRNAs) mediate the effect of ox-LDL on the atherosclerosis-related biological activities of HA-VSMCs, including proliferation, migration, and apoptosis. However, the mechanism of small nucleolar RNA host gene 12 (SNHG12) in ox-LDL-induced phenotype switch of VSMCs remains unclear. Thus, this research dug in whether SNHG12 mediated the influence of ox-LDL on HA-VSMCs and the potential mechanism.

METHODS

Fundamental experiments and functional assays were performed to measure the function of SNHG12 on HA-VSMCs. Then, mechanism assays and rescue assays were performed to study the regulatory mechanism of SNHG12 in HA-VSMCs.

RESULTS

SNHG12 reversed the influence of ox-LDL treatment in enhancing cell proliferative and migratory abilities and weakening apoptotic ability in HA-VSMCs. SNHG12 was a competitive endogenous RNA (ceRNA) competing with sprouty RTK signaling antagonist 2 (SPRY2) to bind to miR-1301-3p, thus up-regulating SPRY2 expression in ox-LDL-treated HA-VSMCs. Besides, SNHG12 recruited serine and arginine rich splicing factor 1 (SRSF1) to stabilize negative regulator of ubiquitin like proteins 1 (NUB1) expression.

CONCLUSIONS

This study illustrated that SNHG12 inhibited cell proliferation, migration and facilitated cell apoptosis in ox-LDL-induced HA-VSMCs by up-regulating SPRY2 and NUB1.

LncRNA KCNQ1OT1 activated by c-Myc promotes cell proliferation via interacting with FUS to stabilize MAP3K1 in acute promyelocytic leukemia

Uncontrolled proliferation is the hallmark of cancer cells. Previous studies mainly focused on the role of protein-coding genes in cancer cell proliferation. Emerging evidence showed that long non-coding RNAs (lncRNAs) also play critical roles in cancer cell proliferation and growth. LncRNA KCNQ1OT1 is found to contribute to carcinogenesis, but its role in acute promyelocytic leukemia (APL) is unclear. In this study, by analyzing data from Gene Expression Omnibus, The Cancer Genome Atlas database and our clinical samples, we found that KCNQ1OT1 was selectively highly expressed in APL. Functional assays demonstrated that knockdown of KCNQ1OT1 reduced APL cell proliferation and increased apoptosis. Further evidence showed that KCNQ1OT1 was mainly located in the cytoplasm of APL patient-derived NB4 cells and APL patient bone marrow samples. Mechanistically, KCNQ1OT1 bound to RNA binding protein FUS, and silencing either KCNQ1OT1 or FUS reduced the expression level and stability of MAP3K1 mRNA. Whereas KCNQ1OT1 and FUS did not affect each other. Importantly, knockdown of MAP3K1 impaired APL cell proliferation. Finally, c-Myc transactivated KCNQ1OT1 in APL cells through binding to its promoter while knockdown of c-Myc decreased KCNQ1OT1 expression. Our results not only revealed that c-Myc transactivated KCNQ1OT1 and upregulated KCNQ1OT1 promoted APL cell proliferation, but also demonstrated that KCNQ1OT1 bound to FUS to synergistically stabilize MAP3K1 mRNA, thus facilitating APL cell proliferation. This study established a previously unidentified role of KCNQ1OT1 in the development of APL, and KCNQ1OT1 may serve as a potential therapeutic target for APL.

Multi-factor regulatory network and different clusters in hypertrophic obstructive cardiomyopathy

BACKGROUND

Practical biosignatures and thorough understanding of regulatory processes of hypertrophic obstructive cardiomyopathy (HOCM) are still lacking.

METHODS

Firstly, public data from GSE36961 and GSE89714 datasets of Gene Expression Omnibus (GEO), Gene database of NCBI (National Center of Biotechnology Information) and Online Mendelian Inheritance in Man (OMIM) database were merged into a candidate gene set of HOCM. Secondly, weighted gene co-expression network analysis (WGCNA) for the candidate gene set was carried out to determine premier co-expressed genes. Thirdly, significant regulators were found out by virtue of a multi-factor regulatory network of long non-coding RNAs (lncRNAs), messenger RNAs (mRNAs), microRNAs (miRNAs) and transcription factors (TFs) with molecule interreactions from starBase v2.0 database and TRRUST v2 database. Ultimately, HOCM unsupervised clustering and "tsne" dimensionality reduction was employed to gain hub genes, whose classification performance was evaluated by a multinomial model of lasso logistic regression analysis binded with receiver operating characteristic (ROC) curve.

RESULTS

Two HOCM remarkably-interrelated modules were from WGCNA, followed by the recognition of 32 crucial co-expressed genes. The multi-factor regulatory network disclosed 7 primary regulatory agents, containing lncRNAs (XIST, MALAT1, and H19), TFs (SPI1 and SP1) and miRNAs (hsa-miR-29b-39 and has-miR-29a-3p). Four clusters of HOCM and 4 hub genes (COMP, FMOD, AEBP1 and SULF1) significantly expressing in preceding four subtypes were obtained, while ROC curve demonstrated satisfactory performance of clustering and 4 genes.

CONCLUSIONS

Our consequences furnish valuable resource which may bring about prospective mechanistic and therapeutic anatomization in HOCM.

Traditional and Emerging Biomarkers in Asymptomatic Left Ventricular Dysfunction-Promising Non-Coding RNAs and Exosomes as Biomarkers in Early Phases of Cardiac Damage

Heart failure (HF) is one of the major causes of morbidity and mortality worldwide and represents an escalating problem for healthcare systems. The identification of asymptomatic patients with underlying cardiac subclinical disease would create an opportunity for early intervention and prevention of symptomatic HF. Traditional biomarkers are very useful as diagnostic and prognostic tools in the cardiovascular field; however, their application is usually limited to overt cardiac disease. On the other hand, a growing number of studies is investigating the diagnostic and prognostic potential of new biomarkers, such as micro-RNAs (miRNA), long non-coding RNAs, and exosome cargo, because of their involvement in the early phases of cardiac dysfunction. Unfortunately, their use in asymptomatic phases remains a distant goal. The aim of this review is to gather the current knowledge of old and novel biomarkers in the early diagnosis of cardiac dysfunction in asymptomatic individuals.

Fus knockdown inhibits the profibrogenic effect of cardiac fibroblasts induced by angiotensin II through targeting Pax3 thereby regulating TGF-β1/Smad pathway

The Angiotensin II/transforming growth factor-β1 (AngII/TGF-β1) signal axis is an important regulatory pathway for atrial fibrosis, which can contribute to atrial fibrillation (AF). Fused in sarcoma (FUS) was recently found to regulate cardiac diseases. This study aimed to investigate whether FUS could regulate AngII induced fibrosis and uncover the possible mechanisms. The expression of FUS in AF patients and AngII-induced cardiac fibroblasts was measured by RT-qPCR and western blot assays. Fus was silenced in cells using short hairpin RNA (shRNA), then cell proliferation, migration, collagen synthesis and TGF-β1/Smad signaling were detected by CCK-8, wound healing and western blot assays, respectively. The possible target for Fus was predicted by searching Starbase database and verified by RNA-binding protein immunoprecipitation (RIP) and RNA pull down. Cells were overexpressed with Pax3 in the presence of Fus silence and AngII stimulation, then the above cellular processes were further evaluated. Results showed that FUS was upregulated in AF patients and AngII-induced cardiac fibroblasts. Fus knockdown inhibited AngII-enhanced cell proliferation, migration, collagen synthesis and TGF-β1/Smad signaling activation. Furthermore, Fus functions as an RNA-binding protein to bind to Pax3 mRNA and positively regulate its expression. Further studies demonstrated that Pax3 overexpression canceled the above effects of Fus knockdown on cell proliferation, migration, collagen synthesis, and TGF-β1/Smad signaling activation in AngII-induced cells. In conclusion, Fus could target Pax3 to increase the pro-fibrotic effect of AngII in cardiac fibroblasts via activating TGF-β1/Smad signaling. Knockdown of Fus/Pax3 axis may provide a potential therapy for relieving AF.

Downregulating Long Non-coding RNAs CTBP1-AS2 Inhibits Colorectal Cancer Development by Modulating the miR-93-5p/TGF-β/SMAD2/3 Pathway

Background: Colorectal cancer (CRC), the most commonly diagnosed cancer in the world, has a high mortality rate. In recent decades, long non-coding RNAs (lncRNAs) have been proven to exert an important effect on CRC growth. However, the CTBP1-AS2 expression and function in CRC are largely unknown.

Materials and Methods: The CTBP1-AS2 and miR-93-5p expression in CRC and para-cancerous tissues was detected by reverse transcription-PCR. The expression of CTBP1-AS2, miR-93-5p and the transforming growth factor-beta (TGF-β)/small mothers against decapentaplegic 2/3 (SMAD2/3) pathway was selectively regulated to study the correlation between CTBP1-AS2 expression and prognosis of patients with CRC. CRC cell proliferation, apoptosis, and invasion were measured in vivo and in vitro. In addition, bioinformatics was applied to explore the targeting relationship between CTBP1-AS2 and miR-93-5p. The targeting binding sites between CTBP1-AS2 and miR-93-5p, as well as between miR-93-5p and TGF-β, were verified by the dual-luciferase reporter assay and the RNA immunoprecipitation experiment.

Results: Compared with normal para-cancerous tissues, CTBP1-AS2 was considerably overexpressed in CRC tissues and was closely associated with worse survival of patients with CRC. Functionally, gain and loss in experiments illustrated that CTBP1-AS2 accelerated CRC cell proliferation and invasion and inhibited cell apoptosis. Mechanistically, CTBP1-AS2 regulated the malignant phenotype of tumor cells through the TGF-β/SMAD2/3 pathway. Moreover, miR-93-5p, as an endogenous competitive RNA of CTBP1-AS2, attenuated the oncogenic effects mediated by CTBP1-AS2.

Conclusion: CTBP1-AS2 promotes the TGF-β/SMAD2/3 pathway activation by inhibiting miR-93-5p, thereby accelerating CRC development.

lncRNA CTBP1-AS2 promotes proliferation and migration of glioma by modulating miR-370-3p-Wnt7a-mediated epithelial-mesenchymal transition

Glioma is one of the most common and aggressive malignant primary brain tumors, with a poor 5-year survival rate. The long noncoding RNA (lncRNA) CTBP1-AS2 has been shown to be correlated with the prognosis of cancer, but the role of CTBP1-AS2 in glioma and its concrete mechanism is fully unknown. The clinical data and tissues of glioma patients were analyzed. Cell viability and migration assays were performed. Western blotting and qRT-PCR were adopted for investigation of target protein expressions. Double luciferase assay was used to investigate the interaction between different elements. The lncRNA CTBP1-AS2 had increased expression profiles in tumor tissues, which is associated with poor prognosis. In detail, CTBP1-AS2 knockdown decreased proliferation and migration phenotypes in both U87-MG and LN229 cells. Moreover, CTBP1-AS2 knockdown suppressed the key epithelial-mesenchymal transition (EMT) markers by downregulating Wnt7a-mediated signaling. Furthermore, miR-370-3p functioned as a link that could be absorbed by CTBP1-AS2, thus regulating Wnt7a expression. Lastly, the CTBP1-AS2-miR-370-3p-Wnt7a axis modulated EMT in glioma cells in vitro and in vivo. This study provides new insights that a novel lncRNA, CTBP1-AS2, regulates EMT of glioma by modulating the miR-370-3p-Wnt7a axis.

Strategies and technologies for exploring long noncoding RNAs in heart failure

Long non-coding RNA (lncRNA) was once considered to be the "noise" of genome transcription without biological function. However, increasing evidence shows that lncRNA is dynamically expressed in developmental stage or disease status, playing a regulatory role in the process of gene expression and translation. In recent years, lncRNA is considered to be a core node of functional regulatory networks that controls cardiac and also involves in multiple process of heart failure such as myocardial hypertrophy, fibrosis, angiogenesis, etc., which would be a therapeutic target for diseases. In fact, it is the development of technology that has improved our understanding of lncRNAs and broadened our perspective on heart failure. From transcriptional "noise" to star molecule, progress of lncRNAs can't be achieved without the combination of multidisciplinary technologies, especially the emergence of high-throughput approach. Thus, here, we review the strategies and technologies available for the exploration lncRNAs and try to yield insights into the prospect of lncRNAs in clinical diagnosis and treatment in heart failure.

Expression profiling revealed up-regulation of three lncRNAs in breast cancer samples

Long non-coding RNAs (lncRNAs) have been vastly investigated for their critical roles in the pathogenesis of breast cancer. Yet, the expression pattern and clinical significance of three lncRNAs namely CTBP1AS2, LINC-ROR and SPRY4-IT1 in breast cancer are not completely clarified. In the present investigation, we assessed expression of these lncRNAs in breast cancer tissues and paired non-cancerous specimens from the same patients using quantitative real time PCR. Notably, expression of CTBP1AS2, LINC-ROR and SPRY4-IT1 were upregulated in breast cancer tissues compared with non-cancerous tissues (ER = 17.62, P value<0.000; ER = 4.62, P value = 0.001 and ER = 3.47, P value = 0.005, respectively). Relative expression of LINC-ROR in tumoral tissues compared with non-tumoral tissues was associated with a history of hormone replacement therapy (P = 0.04). Expression levels of CTBP1AS2, LINC-ROR and SPRY4-IT1 were significantly correlated with each other in both tumoral and non-tumoral tissues. The strongest correlations were detected between CTBP1AS2/ LINC-ROR and CTBP1AS2/ SPRY4-IT1 pairs in non-tumoral tissues. CTBP1AS2 and SPRY4-IT1 had the best sensitivity (80%) and specificity (64%) values, respectively. Based on AUC values, the best diagnostic power belonged to CTBP1AS2. The current study potentiates CTBP1AS2, LINC-ROR and SPRY4-IT1 as putative contributors in the pathogenesis of breast cancer and suggests these lncRNAs as candidates for functional analysis in this kind of cancer.

LncRNA CTBP1-AS2 alleviates high glucose-induced oxidative stress, ECM accumulation, and inflammation in diabetic nephropathy via miR-155-5p/FOXO1 axis

BACKGROUND

This study aimed to investigate the involvement of lncRNA CTBP1-AS2 in the progression of diabetic nephropathy (DN) by affecting high glucose (HG)-induced human glomerular mesangial cells (HGMCs).

METHODS

HGMCs were selected for the establishment of cell injury induced by HG. The expression of CTBP1-AS2, miR-155-5p and FOXO1 was detected by real-time PCR and western blotting. The target association between miR-155-5p and CTBP1-AS2 or FOXO1 was confirmed by dual-luciferase reporter assays. Cell proliferation and oxidative stress were revealed by CCK-8 colorimetry, and the measurement of reactive oxygen species (ROS) and the activities of antioxidant enzymes. Extracellular matrix (ECM) protein accumulation and the production of inflammatory cytokines were investigated by western blotting and ELISA.

RESULTS

The expression of CTBP1-AS2 was downregulated, and miR-155-5p was highly expressed in peripheral blood of DN patients and HG-treated HGMCs. Further investigation revealed that CTBP1-AS2 overexpression inhibited proliferation, oxidative stress, ECM accumulation and inflammatory response in HG-induced HGMCs. Mechanical analysis revealed that CTBP1-AS2 regulated FOXO1 expression via sponging miR-155-5p. Rescue experiments demonstrated that miR-155-5p overexpression or FOXO1 inhibition reversed the effects of CTBP1-AS2 in HG-stimulated HGMCs.

CONCLUSION

Taken together, this study revealed CTBP1-AS2 attenuated HG-induced HGMC proliferation, oxidative stress, ECM accumulation, and inflammation through miR-155-5p/FOXO1 signaling.

LncRNA CTBP1-AS2 regulates miR-216a/ PTEN to suppress ovarian cancer cell proliferation

Background

We analyzed TCGA dataset and observed the downregulation of CTBP1-AS2 in ovarian cancer (OC), while the function of CTBP1-AS2 has only been investigated in diabetes and cardiomyocyte hypertrophy, but not in cancer biology. We therefore analyzed the involvement of CTBP1-AS2 in OC.

Result

We found that CTBP1-AS2 was downregulated in OC and predicted poor survival. CTBP1-AS2 in luciferase activity assay interacted with miR-216a, while overexpression of CTBP1-AS2 and miR-216a had no significant effects on the expression of each other. However, increased expression level of PTEN, a target of miR-216a, was observed after CTBP1-AS2 overexpression. Increased proliferation rate of OC cells was observed after the overexpression of miR-216a. CTBP1-AS2 and PTEN overexpression resulted in the reduced proliferation rate of OC cells and reduced effects of miR-216a overexpression.

Conclusion

CTBP1-AS2 regulates miR-216a/PTEN to suppress OC cell proliferation.

LncRNA CTBP1-AS2 Promotes Cell Proliferation in Hepatocellular Carcinoma by Regulating the miR-623/Cyclin D1 Axis

This study investigated the role of lncRNA CTBP1-AS2 in hepatocellular carcinoma (HCC). The authors found that CTBP1-AS2 was upregulated in HCC by analyzing TCGA dataset. The downregulation of CTBP1-AS2 in HCC was confirmed by measuring the expression level of CTBP1-AS2 in both HCC and nontumor tissues from HCC patients. MiR-623 is predicted to target CTBP1-AS2, while it failed to downregulate its expression. Interestingly, CTBP1-AS2 overexpression led to the upregulation of cyclin D1, a target of miR-623. CCK-8 analysis showed that CTBP1-AS2 and cyclin D1 overexpression promoted the proliferation of HCC cells. MiR-623 overexpression played an opposite role and reduced the effects of CTBP1-AS2 and cyclin D1 overexpression. Therefore, CTBP1-AS2 promotes cell proliferation in HCC by regulating the miR-623/cyclin D1 axis.

CTBP1‑AS2 inhibits proliferation and induces autophagy in ox‑LDL‑stimulated vascular smooth muscle cells by regulating miR‑195‑5p/ATG14

Atherosclerosis (AS) is a chronic progressive disease caused by injury and functional changes in vascular smooth muscle cells (VSMCs). Long non‑coding RNAs (lncRNAs) are pivotal regulators in AS development. The present study aimed to explore the roles and molecular mechanisms of lncRNA CTBP1‑AS2 in AS progression. A dual‑luciferase reporter assay confirmed that miR‑195‑5p is a downstream target miRNA of lncRNA CTBP1‑AS2 and miR‑195‑5p was increased in AS. The expression levels of miR‑195‑5p and CTBP1‑AS2 in the serums of patients with AS and human aorta vascular smooth muscle cells was increased or decreased, respectively, following treatment with oxidized low‑density lipoprotein (ox‑LDL). Functional experiments showed that the overexpression of lncRNA CTBP1‑AS2 inhibited the proliferation of HA‑VSMCs and promoted their autophagy following ox‑LDL treatment. This effect could be reversed by treatment with ROC‑325, the inhibitor of autophagy, or miR‑195‑5p mimics. Autophagy related 14 (ATG14) was identified to be a target of miR‑195‑5p, and lncRNA CTBP1‑AS2 promoted ATG14 expression by serving as a competing endogenous RNA of miR‑195‑5p. The present study revealed that lncRNA CTBP1‑AS2 may serve a role in AS by inhibiting the proliferation and promoting the autophagy of VSMCs through ATG14 modulation via miR‑195‑5p. These data may provide a novel therapeutic target for AS.

SP1-induced SNHG14 aggravates hypertrophic response in in vitro model of cardiac hypertrophy via up-regulation of PCDH17

Cardiac hypertrophy (CH) is a common cardiac disease and is closely associated with heart failure. Protocadherin 17 (PCDH17) was reported to aggravate myocardial infarction. Present study was designed to illustrate the impact of PCDH17 and the mechanism of PCDH17 expression regulation in CH. CH model in vivo and in vitro was established by transverse aortic constriction (TAC) and Ang‐II treatment. Hypertrophy was evaluated in PMC and H9c2 cells by examining cell surface area and hypertrophic markers. Results demonstrated that PCDH17 was up‐regulated in CH in vivo and in vitro. PCDH17 knock‐down alleviated hypertrophic response in Ang‐II‐induced cardiomyocytes. By means of ENCORI database and a series of mechanism assays, miR‐322‐5p and miR‐384‐5p were identified to interact with and inhibit PCDH17. Next, lncRNA SNHG14 (small nucleolar RNA host gene 14) was validated to sponge both miR‐322‐5p and miR‐384‐5p to elevate PCDH17 level. The subsequent rescue assays revealed that miR‐322‐5p and miR‐384‐5p restored SNHG14 depletion‐mediated suppression on hypertrophy in Ang‐II‐induced cardiomyocytes. Besides, Sp1 transcription factor (SP1) was verified as the transcription factor activating both SNHG14 and PCDH17. Both SNHG14 and PCDH17 reversed SP1 knock‐down‐mediated repression on hypertrophy in Ang‐II‐induced cardiomyocytes. Together, present study first uncovered ceRNA network of SNHG14/miR‐322‐5p/miR‐384‐5p/PCDH17 in Ang‐II‐induced cardiomyocytes.

LncRNA CTBP1-AS2 is upregulated in osteoarthritis and increases the methylation of miR-130a gene to inhibit chondrocyte proliferation

OBJECTIVES

LncRNA CTBP1-AS2 has been reported to be involved in type 2 diabetes and cardiomyocyte hypertrophy, while its roles in other human diseases are unknown. Our preliminary deep sequencing analysis showed altered expression of CTBP1-AS2 in osteoarthritis (OA). In addition, CTBP1-AS2 was inversely correlated with miR-130a. This study was therefore carried out to investigate the interactions between CTBP1-AS2 and miR-130a in OA.

METHODS

Synovial fluid was collected from 62 OA patients and 62 healthy controls. RT-qPCR was performed to determine the expression levels of CTBP1-AS2 and miR-130a in synovial fluid. Cell transfections were performed to investigate the interactions between CTBP1-AS2 and miR-130a. Methylation-specific PCR (MSP) was performed to assess the effects of CTBP1-AS2 on the methylation of miR-130a. Cell counting Kit-8 (CCK-8) assay was performed to evaluate the roles of CTBP1-AS2 and miR-130a in regulating proliferation of chondrocytes.

RESULTS

The results showed that CTBP1-AS2 was upregulated in OA and inversely correlated with miR-130a. In chondrocytes of OA patients, overexpression of CTBP1-AS2 led to increased methylation of miR-130a gene and downregulated expression of miR-130a, while overexpression of miR-130a did not affect the expression of CTBP1-AS2. In contrast, no interaction between CTBP1-AS2 and miR-130a was observed in chondrocytes from healthy adults. Analysis of chondrocyte proliferation showed that overexpression of miR-130a led to increased proliferation rate of chondrocytes extracted from OA patients. Overexpression of CTBP1-AS2 led to decreased proliferation rate of chondrocytes and reversed the effects of overexpressing miR-130a.

CONCLUSION

Therefore, CTBP1-AS2 is upregulated in OA and may increase the methylation of miR-130a gene to inhibit chondrocyte proliferation. Key Points • CTBP1-AS2 is overexpressed in OA and may downregulate miR-130a through methylation to suppress the proliferation of chondrocytes. • The interaction between CTBP1-AS2 and miR-130a is indirect and mediated by certain pathological mediators.

LncRNA CTBP1-AS2 sponges miR-216a to upregulate PTEN and suppress endometrial cancer cell invasion and migration

Background

Although lncRNA CTBP1-AS2 has been functionally analyzed only in cardiomyocyte hypertrophy and diabetes, analysis of TCGA dataset revealed its downregulation in endometrial carcinoma (EC), indicating its involvement in EC.

Results

In this study we found that CTBP1-AS2 was downregulated in EC and correlated with poor survival. MiR-216a might form base pairs with CTBP1-AS2 based on RNA-RNA interaction, which was confirmed by luciferase activity assay. Interestingly, upregulation of PTEN was observed after CTBP1-AS2 overexpression. Transwell assay showed that CTBP1-AS2 and PTEN overexpression led to decreased cancer cell invasion and migration and reduced enhancing effects of miR-216a on cell invasion and migration. It was known that miR-216a targeted PTEN.

Conclusion

Therefore, CTBP1-AS2 may sponge miR-216a to upregulate PTEN, thereby suppressing endometrial cancer cell invasion and migration.

Positive feedback loop SP1/SNHG1/miR-199a-5p promotes the malignant properties of thyroid cancer

Abundant evidences have demonstrated the essential roles of long noncoding RNA (lncRNA) in the papillary thyroid cancer (PTC). Here, we aim to explore the biological roles of lncRNA SNHG1 in the PTC tumorigenesis. Firstly, we discovered the ectopically expressed ncRNAs using lncRNA microarray profiling. Among these candidate lncRNAs, SNHG1 was identified to be up-regulated in both PTC tissue and cells. Functionally, knockdown of SNHG1 repressed the proliferation, invasion and tumor growth in vitro and in vivo. Mechanistically, SNHG1 sponged miR-199a-5p by complementary binding with specificity protein 1 (SP1) 3'-UTR. Interestingly, transcription factor SP1 targeted the promoter region of SNHG1 to promote its transcriptional level. The interaction within lncRNA, miRNA and target mRNA constructed the feedback loop of SP1/SNHG1/miR-199a-5p/SP1 in PTC. Collectively, these findings unveil the potential regulation of SNHG1 on the PTC tumorigenesis via feedback loop, providing a novel insight for PTC.

Non-coding RNAs Shaping Muscle

In 1957, Francis Crick speculated that RNA, beyond its protein-coding capacity, could have its own function. Decade after decade, this theory was dramatically boosted by the discovery of new classes of non-coding RNAs (ncRNAs), including long ncRNAs (lncRNAs) and circular RNAs (circRNAs), which play a fundamental role in the fine spatio-temporal control of multiple layers of gene expression. Recently, many of these molecules have been identified in a plethora of different tissues, and they have emerged to be more cell-type specific than protein-coding genes. These findings shed light on how ncRNAs are involved in the precise tuning of gene regulatory mechanisms governing tissues homeostasis. In this review, we discuss the recent findings on the mechanisms used by lncRNAs and circRNAs to sustain skeletal and cardiac muscle formation, paying particular attention to the technological developments that, over the last few years, have aided their genome-wide identification and study. Together with lncRNAs and circRNAs, the emerging contribution of Piwi-interacting RNAs and transfer RNA-derived fragments to myogenesis will be also discussed, with a glimpse on the impact of their dysregulation in muscle disorders, such as myopathies, muscle atrophy, and rhabdomyosarcoma degeneration.

ZEB1 induced-upregulation of long noncoding RNA ZEB1-AS1 facilitates the progression of triple negative breast cancer by binding with ELAVL1 to maintain the stability of ZEB1 mRNA

Triple-negative breast cancer (TNBC) is one of the malignant type of breast cancer. Previous study indicated that long noncoding RNA (lncRNA) ZEB1-AS1 was associated with the progression of several cancers. However, its underlying molecular mechanism in TNBC remains to be elucidated. In this study, ZEB1-AS1 expression was boosted in TNBC tissues and cell lines according to reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Inhibition of ZEB1-AS1 suppressed cell proliferation, migration, invasion, and promoted cell apoptosis in TNBC. Moreover, ZEB1-AS1 positively regulated ZEB1 expression. RT-qPCR disclosed ZEB1 expression was elevated in TNBC tissues and ZEB1 silence blocked TNBC progression. RNA pull-down and RNA immunoprecipitation assays revealed ZEB1-AS1 and ZEB1 both could bind with ELAVL1. ZEB1-AS1 maintained ZEB1 messenger RNA (mRNA) stability by binding with ELAVL1. In addition chromatin, immunoprecipitation and luciferase reporter assays confirmed that ZEB1 could bind with ZEB1-AS1 promoter and promoted ZEB1-AS1 expression. Rescue assays manifested ZEB1 overexpression could abolish the inhibitory effect caused by ZEB1-AS1 inhibition on TNBC progression. To sum up, ZEB1 induced-upregulation of ZEB1-AS1 maintained the stability of ZEB1 mRNA by binding with ELAVL1, which formed a feedback loop to facilitate TNBC progression. These findings might provide a new target for TNBC treatment.

LINC00311 promotes cancer stem-like properties by targeting miR-330-5p/TLR4 pathway in human papillary thyroid cancer

Growing evidence has suggested that long noncoding RNAs (lncRNAs) play an essential role in the progression of papillary thyroid cancer (PTC). LncRNA LINC00311 was found to be able to regulate many cellular process in several diseases. However, the function and regulatory mechanism of LINC00311 remains unclear in PTC. In the present study, the results showed that the expression of LINC00311 was upregulated in PTC tissues and cells. Furthermore, knockdown of LINC00311 dramatically suppressed spheroid formation, proliferation, migration, and invasion in PTC cells in vitro. Mechanistic investigations revealed that LINC00311 was negatively correlated with the expression of miR‐330‐5p, meanwhile, TLR4 was a direct target of miR‐330‐5p. In addition, rescue assays further determined that LINC00311 contributed to the progression of PTC through regulating TLR4 expression. Taken together, these findings indicated that LINC00311 could promote cancer stem‐like properties by targeting miR‐330‐5p/TLR4 pathway in PTC.