Upregulation of lncRNA VDR/CASC15 induced by facilitates cardiac hypertrophy through modulating miR-432-5p/TLR4 axis

MicroRNA-specific therapeutic targets and biomarkers of apoptosis following myocardial ischemia-reperfusion injury

MicroRNAs are single-stranded non-coding RNAs that participate in post-transcriptional regulation of gene expression, it is involved in the regulation of apoptosis after myocardial ischemia-reperfusion injury. For example, the alteration of mitochondrial structure is facilitated by MicroRNA-1 through the regulation of apoptosis-related proteins, such as Bax and Bcl-2, thereby mitigating cardiomyocyte apoptosis. MicroRNA-21 not only modulates the expression of NF-κB to suppress inflammatory signals but also activates the PI3K/AKT pathway to mitigate ischemia-reperfusion injury. Overexpression of MicroRNA-133 attenuates reactive oxygen species (ROS) production and suppressed the oxidative stress response, thereby mitigating cellular apoptosis. MicroRNA-139 modulates the extrinsic death signal of Fas, while MicroRNA-145 regulates endoplasmic reticulum calcium overload, both of which exert regulatory effects on cardiomyocyte apoptosis. Therefore, the article categorizes the molecular mechanisms based on the three classical pathways and multiple signaling pathways of apoptosis. It summarizes the targets and pathways of MicroRNA therapy for ischemia-reperfusion injury and analyzes future research directions.

Association of exosomes in patients with compromised myocardial perfusion on functional imaging

BACKGROUND

Exosomes are membrane vesicles that are actively secreted in response to microenvironmental stimuli. In this study, we quantified the amount of exosomes in patients with significant coronary artery disease (CAD) and evaluated its relationship with myocardial perfusion imaging (MPI) results.

METHODS

Patients who underwent both MPI and coronary angiography were recruited. Plasma was collected during angiography, and exosomes were extracted via the precipitation method. The summed stress scores (SSS), summed difference scores, and ventricular functional parameters were calculated from the MPI and compared with the amounts of exosomes and extracted miRNAs.

RESULTS

In total, 115 patients were enrolled (males: 78 %; mean age: 66.6 ± 10.6 years). Those with abnormal SSS according to the MPI had significantly fewer exosomes (p = 0.032). After multivariate analysis, the SSS remained significantly related to the amount of exosomes (p = 0.035). In forty randomly selected samples, miRNA-432-5p and miRNA-382-3p were upregulated in patients with abnormal SSS.

CONCLUSION

Patients with compromised poststress myocardial perfusion on MPI tended to have fewer exosomes in association with CAD-related miRNAs. This is the first study to clarify the fundamental and pathophysiological causes of CAD using radiographic examinations.

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.

Physiological Evidence and Therapeutic Outcomes of Vitamin D on Cardiovascular Diseases

Vitamin D hormone is an important regulator of various physiological functions, and its deficiency is characterized by an imbalance in parathyroid hormone and calcium homeostasis. The role of vitamin D in cardiovascular physiology is well demonstrated in animal and humanbased studies. In this context, hyperlipidemia, increased atherogenic plaques, cardiac inflammation, hypertension, myocarditis, myocardial infarction, and heart failure are some of the commonest known conditions connected with vitamin D deficiency. Supplementation of vitamin D is recommended to achieve normal serum vitamin D concentrations, nonetheless, in clinical trials often seen discrepancies concerning the supplementation effects and effectiveness. This review summarizes the data on the role of vitamin D in cardiovascular health along with some recent clinical findings regarding the effects of vitamin D supplementation.

Posttranscriptional Regulation by Proteins and Noncoding RNAs

Posttranscriptional regulation comprises those mechanisms occurring after the initial copy of the DNA sequence is transcribed into an intermediate RNA molecule (i.e., messenger RNA) until such a molecule is used as a template to generate a protein. A subset of these posttranscriptional regulatory mechanisms essentially are destined to process the immature mRNA toward its mature form, conferring the adequate mRNA stability, providing the means for pertinent introns excision, and controlling mRNA turnover rate and quality control check. An additional layer of complexity is added in certain cases, since discrete nucleotide modifications in the mature RNA molecule are added by RNA editing, a process that provides large mature mRNA diversity. Moreover, a number of posttranscriptional regulatory mechanisms occur in a cell- and tissue-specific manner, such as alternative splicing and noncoding RNA-mediated regulation. In this chapter, we will briefly summarize current state-of-the-art knowledge of general posttranscriptional mechanisms, while major emphases will be devoted to those tissue-specific posttranscriptional modifications that impact on cardiac development and congenital heart disease.

LncRNA CASC15 inhibition relieves renal fibrosis in diabetic nephropathy through down-regulating SP-A by sponging to miR-424

Study has demonstrated the abnormal expression and role of lncRNA CASC15 in diabetes patients with chronic renal failure. However, its role in diabetes nephropathy (DN) is still unclear. This study aimed to investigate the potential mechanism and role of lncRNA CASC15 in DN. The relationship between miR-424 and CASC15/SP-A was predicted by Starbase software and verified by luciferase reporter assay. HK-2 cells were treated with 25 mM glucose (HG) for 24 h to establish DN cell model. MTT and flow cytometry analysis were carried out to test cell proliferation and apoptosis. Epithelial-to-mesenchymal transition (EMT) markers were analyzed by RT-qPCR and western blot assay. We proved that CASC15 could interact with miR-424, and SP-A was a target of miR-424. HG-treatment significantly enhanced lncRNA CASC15 level and decreased miR-424 level in HK-2 cells. LncRNA CASC15-siRNA significantly improved cell viability, repressed apoptosis, promoted E-cadherin expression, and inhibited N-cadherin expression in HG-treated HK-2 cells, and these effects were reversed by miR-424 inhibitor. SP-A was highly expressed in HG-treated HK-2 cells. The biological effects of miR-424 mimic on HG-treated HK-2 cells were reversed by SP-A-plasmid. In conclusion, lncRNA CASC15 inhibition relieved HG-induced HK-2 cell injury and EMT through miR-424/SP-A axis.

Knockdown of deleterious miRNA in progenitor cell-derived small extracellular vesicles enhances tissue repair in myocardial infarction

Small extracellular vesicles (sEVs) play a critical role in cardiac cell therapy by delivering molecular cargo and mediating cellular signaling. Among sEV cargo molecule types, microRNA (miRNA) is particularly potent and highly heterogeneous. However, not all miRNAs in sEV are beneficial. Two previous studies using computational modeling identified miR-192-5p and miR-432-5p as potentially deleterious in cardiac function and repair. Here, we show that knocking down miR-192-5p and miR-432-5p in cardiac c-kit+ cell (CPC)-derived sEVs enhances the therapeutic capabilities of sEVs in vitro and in a rat in vivo model of cardiac ischemia reperfusion. miR-192-5p- and miR-432-5p-depleted CPC-sEVs enhance cardiac function by reducing fibrosis and necrotic inflammatory responses. miR-192-5p-depleted CPC-sEVs also enhance mesenchymal stromal cell-like cell mobilization. Knocking down deleterious miRNAs from sEV could be a promising therapeutic strategy for treatment of chronic myocardial infarction.

LncRNA Gm43843 Promotes Cardiac Hypertrophy via miR-153-3p/Cacna1c Axis

Long noncoding RNAs (lncRNAs) have been reported to engage in many human diseases, including cardiac hypertrophy. Cardiac hypertrophy was mainly caused by excessive pressure load, which can eventually lead to a decline in myocardial contractility. Gm43843, a novel lncRNA, has not been well explored in cardiac hypertrophy so far. Herein, we are going to search the function and the underlying molecular mechanism of Gm43843 in cardiac hypertrophy. Gm43843 levels were measured via qRT-PCR in mouse myocardial cells when they are treated with angiogenin II (Ang II) or transfected with different plasmids. Western blot assay was implemented to detect the cardiac hypertrophy-related protein markers, while the cell was analyzed via immunofluorescence (IF) assay to evaluate the hypertrophy. Meanwhile, the binding of Gm43843 and the putative targets was examined based on mechanistic assay results. We found that Gm43843 expression was increased with the elevated concentration of Ang II. Inhibited Gm43843 was detected to reduce the hypertrophy of mouse myocardial cells. Meanwhile, Gm43843/miR-153-3p/Cacna1c axis was found to modulate cardiac hypertrophy. In short, Gm43843 promotes cardiac hypertrophy via miR-153-3p/Cacna1c axis.

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.

lncRNA NBR2 attenuates angiotensin II-induced myocardial hypertrophy through repressing ER stress via activating LKB1/AMPK/Sirt1 pathway

Myocardial hypertrophy leads to heart failure (HF), and emerging researchers have illustrated that long noncoding RNAs (lncRNAs) modulate myocardial hypertrophy. Here, we explored the role and mechanism of a novel lncRNA, NBR2, in modulating angiotensin II (Ang II)-induced myocardial hypertrophy. First, we examined plasma NBR2 levels in 25 patients with HF and myocardial hypertrophy and ten healthy donors and analyzed the correlation between NBR2 profiles and patients’ clinical indicators. In addition, the overexpression experiment of NBR2 was carried out to probe the influence of NBR2 on myocardial hypertrophy. lncRNA NBR2 was down-regulated in plasma of patients with HF and myocardial hypertrophy (vs. healthy controls), and its level was negatively correlated with cardiac function (represented by left ventricular end-diastolic diameter and left ventricular ejection fraction) and degree of myocardial hypertrophy. Besides, Ang II treatment intensified the hypertrophy of human myocardial cell lines (HCM and AC16) and curbed the NBR2 expression. Overexpressing lncRNA NBR2 alleviated Angiotension II–induced myocardial hypertrophy and declined the profiles of hypertrophic markers. Moreover, up-regulating lncRNA NBR2 weakened Ang II-mediated endoplasmic reticulum (ER) stress and activated the LKB1/AMPK/Sirt1 pathway. Interfering with the LKB1/AMPK/Sirt1 axis abated the lncRNA NBR2-mediated inhibitory effect on myocardial hypertrophy and ER stress. This study confirmed that lncRNA NBR2 dampened myocardial hypertrophy and ER stress by modulating the LKB1/AMPK/Sirt1 pathway. Our study provides the first evidence that lncRNA NBR2 is positively associated with myocardial hypertrophy.

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.

Exosomes-loaded thermosensitive hydrogels for corneal epithelium and stroma regeneration

Corneal damage forms scar tissue and manifests as permanent corneal opacity, which is the main cause of visual impairment caused by corneal diseases. To treat these diseases, herein, we developed a novel approach based on the exosome derived from induced pluripotent stem cell-derived mesenchymal stem cells (iPSC-MSCs) combined with a thermosensitive hydrogel, which reduces scar formation and accelerates the healing process. We found that a thermosensitive chitosan-based hydrogels (CHI hydrogel) sustained-release iPSC-MSC exosomes can effectively promote the repair of damaged corneal epithelium and stromal layer, downregulating mRNA expression coding for the three most enriched collagens (collagen type I alpha 1, collagen type V alpha 1 and collagen type V alpha 2) in corneal stroma and reducing scar formation in vivo. Furthermore, iPSC-MSCs secrete exosomes that contain miR-432-5p, which suppresses translocation-associated membrane protein 2 (TRAM2), a vital modulator of the collagen biosynthesis in the corneal stromal stem cells to avert the deposition of extracellular matrix (ECM). Our findings indicate that iPSC-MSCs secrete miRNA-containing exosomes to promote corneal epithelium and stroma regeneration, and that miR-432-5p can prevent ECM deposition via a mechanism most probably linked to direct repression of its target gene TRAM2. Overall, our exosomes-based thermosensitive CHI hydrogel, is a promising technology for clinical therapy of various corneal diseases.

LncRNA CASC15 Promotes Cerebral Ischemia/Reperfusion Injury via miR-338-3p/ETS1 Axis in Acute Ischemic Stroke

Purpose

Acute ischemic stroke (AIS) is a leading health problem caused by cerebral ischemia/reperfusion (CI/R). This study aimed to unveil the potential clinical value and mechanism of lncRNA CASC15.

Patients and Methods

The expression of CASC15, miR-338-3p was detected by quantitative real-time PCR (qRT-PCR). The correlations between CASC15 and national institutes of health stroke scale (NIHSS) scores or miR-338-3p were evaluated by Pearson correlation. A receiver operating characteristic (ROC) curve was performed to provide the diagnostic value of CASC15. Cell Counting Kit-8 (CCK-8) and flow cytometer were used to detect the condition of cell viability and apoptosis. The levels of interleukin-1beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) was detected by enzyme-linked immunosorbent assay (ELISA) assay.

Results

The expression of CASC15 was increased and the levels of miR-338-3p were decreased in AIS patients. A positive association between CASC15 and NIHSS score and an inverse association between CASC15 and miR-338-3p were revealed by Pearson correlation. CASC15 might discriminate AIS patients from healthy people. Silenced CASC15 exerted neuroprotective roles on cell viability, apoptosis, and inflammation via the miR-338-3p/ETS1 axis.

Conclusion

CASC15 might act as a potential diagnostic biomarker for AIS patients. CASC15/miR-338-3p/ETS1 axis played an essential role in cell viability, apoptosis, and neuroinflammation.

Reconnoitering the Role of Long-Noncoding RNAs in Hypertrophic Cardiomyopathy: A Descriptive Review

Hypertrophic cardiomyopathy (HCM) is the most common form of hereditary cardiomyopathy. It is characterized by an unexplained non-dilated hypertrophy of the left ventricle with a conserved or elevated ejection fraction. It is a genetically heterogeneous disease largely caused by variants of genes encoding for cardiac sarcomere proteins, including MYH7, MYBPC3, ACTC1, TPM1, MYL2, MYL3, TNNI3, and TNNT23. Preclinical evidence indicates that the enhanced calcium sensitivity of the myofilaments plays a key role in the pathophysiology of HCM. Notably, this is not always a direct consequence of sarcomeric variations but may also result from secondary mutation-driven alterations. Long non-coding RNAs (lncRNAs) are a large class of transcripts ≥200 nucleotides in length that do not encode proteins. Compared to coding mRNAs, most lncRNAs are not as well-annotated and their functions are greatly unexplored. Nevertheless, increasing evidence shows that lncRNAs are involved in a variety of biological processes and diseases including HCM. Accumulating evidence has indicated that lncRNAs are dysregulated in HCM, and closely related to sarcomere construction, calcium channeling and homeostasis of mitochondria. In this review, we have summarized the known regulatory and functional roles of lncRNAs in HCM.

The function of LncRNA-H19 in cardiac hypertrophy

Cardiac hypertrophy, characterized by the enlargement of cardiomyocytes, is initially an adaptive response to physiological and pathological stimuli. Decompensated cardiac hypertrophy is related to fibrosis, inflammatory cytokine, maladaptive remodeling, and heart failure. Although pathological myocardial hypertrophy is the main cause of hypertrophy-related morbidity and mortality, our understanding of its mechanism is still poor. Long noncoding RNAs (lncRNAs) are noncoding RNAs that regulate various physiological and pathological processes through multiple molecular mechanisms. Recently, accumulating evidence has indicated that lncRNA-H19 is a potent regulator of the progression of cardiac hypertrophy. For the first time, this review summarizes the current studies about the role of lncRNA-H19 in cardiac hypertrophy, including its pathophysiological processes and underlying pathological mechanism, including calcium regulation, fibrosis, apoptosis, angiogenesis, inflammation, and methylation. The context within which lncRNA-H19 might be developed as a target for cardiac hypertrophy treatment is then discussed to gain better insight into the possible biological functions of lncRNA-H19 in cardiac hypertrophy.

Long non-coding RNAs in cardiac hypertrophy

Cardiac hypertrophy (CH) is generally considered adaptive responses that may occur after myocardial infarction, pressure overload, volume overload, inflammatory heart muscle disease, or idiopathic dilated cardiomyopathy, whereas long-term stimulation eventually leads to heart failure (HF). However, the current molecular mechanisms involved in CH are unclear. Recently, increasing evidences reveal that long non-coding RNAs (lncRNAs) play vital roles in CH. Different lncRNAs can promote or inhibit the pathological process of CH by different mechanisms, while the regulation of lncRNAs expression can improve CH. Thus, CH-related lncRNAs may become a novel field of research on CH.

Interaction between non-coding RNAs and Toll-like receptors

Toll-like receptors (TLRs) are a large group of pattern recognition receptors which are involved in the regulation of innate immune responses. Based on the interplay between TLRs and adapter molecules, two distinctive signaling cascades, namely the MyD88-dependent and TRIF-dependent pathways have been recognized. TLRs are involved in the development of a wide variety of diseases including cancer and autoimmune disorders. A large body of evidence has shown interaction between two classes of non-coding RNAs, namely microRNAs (miRNAs) and long noncoding RNAs (lncRNAs). These interactions have prominent roles in the pathogenesis of several disorders including infectious disorders, autoimmune conditions and neoplastic disorders. This review aims at description of the interaction between these non-coding RNAs and TLRs.

CASC15: A Tumor-Associated Long Non-Coding RNA

BACKGROUND

CASC15, one of long non-coding RNA, is involved in the regulation of many tumor biological processes, and is expected to become a new biological therapeutic target. This paper aims to elucidate the pathophysiological function of CASC15 in various tumors.

METHODS

The relationship between CASC15 and tumors was analyzed by searching references, and summarized the specific pathophysiological mechanism of CASC15.

RESULTS

LncRNA CASC15 is closely related to tumor development, and has been shown to be abnormally high expressed in all kinds of tumors, including breast cancer, cervical cancer, lung cancer, hepatocellular carcinoma, gastric cancer, bladder cancer, colon cancer, colorectal cancer, cardiac hypertrophy, intrahepatic cholangiocarcinoma, leukemia, melanoma, tongue squamous cell carcinoma and nasopharyngeal carcinoma. However, CASC15 has been found to be down-expressed abnormally in ovarian cancer, glioma and neuroblastoma. Besides, it is identified that CASC15 can affect the proliferation, invasion and apoptosis of tumors.

CONCLUSION

LncRNA CASC15 has the potential to become a new therapeutic target or marker for a variety of tumors.

Functional characterization of long noncoding RNAs

PURPOSE OF REVIEW

Mounting evidence suggests that long noncoding RNAs (lncRNAs) are essential regulators of gene expression. Although few lncRNAs have been the subject of detailed molecular and functional characterization, it is believed that lncRNAs play an important role in tissue homeostasis and development. In fact, gene expression profiling studies reveal lncRNAs are developmentally regulated in a tissue-type and cell-type specific manner. Such findings have brought significant attention to their potential contribution to disease cause. The current review summarizes recent studies of lncRNAs in the heart.

RECENT FINDINGS

lncRNA discovery has largely been driven by the implementation of next generation sequencing technologies. To date, such technologies have contributed to the identification of tens of thousands of distinct lncRNAs in humans -- accounting for a large majority of all RNA sequences transcribed across the human genome. Although the functions of these lncRNAs remain largely unknown, gain-of-function and loss-of-function studies (in vivo and in vitro) have uncovered a number of mechanisms by which lncRNAs regulate gene expression and protein function. Such mechanisms have been stratified according to three major functional categories: RNA sponges (RNA-mediated sequestration of free miRNAs; e.g. H19, MEG3, and MALAT1); transcription-modulating lncRNAs (RNA influences regulatory factor recruitment by binding to histone modifiers or transcription factors; e.g. CAIF, MANTIS, and NEAT1); and translation-modulating lncRNAs (RNA modifies protein function via directly interacting with a protein itself or binding partners; e.g. Airn, CCRR, and ZFAS1).

SUMMARY

Recent studies strongly suggest that lncRNAs function via binding to macromolecules (e.g. genomic DNA, miRNAs, or proteins). Thus, lncRNAs constitute an additional mode by which cells regulate gene expression.

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.

Up-regulation of SNHG16 induced by CTCF accelerates cardiac hypertrophy by targeting miR-182-5p/IGF1 axis

Long non-coding RNA (lncRNA) SNHG16 has been reported to be significant regulators in multiple cancers. However, never has the relationship between it and cardiac hypertrophy been studied until now. In this study, angiotensin II (Ang II)-treated cardiomyocytes isolated from neonatal mice were used as a model of cardiac hypertrophy in vitro. Real-time quantitative polymerase chain reaction was performed to measure the expression of SNHG16, miR-182-5p, and insulin-like growth factor 1 (IGF1). The relationship between SNHG16 and its downstream genes were corroborated by RNA pull-down and luciferase reporter experiments. Western blot was conducted to detect the expression of markers of hypertrophy. The results disclosed that SNHG16 expression was in a high level in the cardiac hypertrophic model. Down-regulation of SNHG16 could decline the expression of hypertrophic markers and reduce cell surface area induced by Ang II. Moreover, SNHG16 was discovered to be activated by transcription factor CCCTC-binding factor. In addition, SNHG16 could enlarge cell surface area and increase the expression of hypertrophic markers by inhibiting miR-182-5p expression in Ang II-treated cardiomyocytes. Finally, overexpression of IGF1 could rescue the effects of silenced SNHG16 on cardiac hypertrophy cells. In brief, our study illustrated that silenced SNHG16 repressed Ang II-imposed cardiac hypertrophy via targeting miR-182-5p/IGF1 axis.

LncRNA TUG1 alleviates cardiac hypertrophy by targeting miR-34a/DKK1/Wnt-β-catenin signalling

The current study was designed to explore the role and underlying mechanism of lncRNA taurine up‐regulated gene 1 (TUG1) in cardiac hypertrophy. Mice were treated by transverse aortic constriction (TAC) surgery to induce cardiac hypertrophy, and cardiomyocytes were treated by phenylephrine (PE) to induce hypertrophic phenotype. Haematoxylin‐eosin (HE), wheat germ agglutinin (WGA) and immunofluorescence (IF) were used to examine morphological alterations. Real‐time PCR, Western blots and IF staining were used to detect the expression of RNAs and proteins. Luciferase assay and RNA pull‐down assay were used to verify the interaction. It is revealed that TUG1 was up‐regulated in the hearts of mice treated by TAC surgery and in PE‐induced cardiomyocytes. Functionally, overexpression of TUG1 alleviated cardiac hypertrophy both in vivo and in vitro. Mechanically, TUG1 sponged and sequestered miR‐34a to increase the Dickkopf 1 (DKK1) level, which eventually inhibited the activation of Wnt/β‐catenin signalling. In conclusion, the current study reported the protective role and regulatory mechanism of TUG1 in cardiac hypertrophy and suggested that TUG1 may serve as a novel molecular target for treating cardiac hypertrophy.

Long Non-Coding RNA (LncRNA) CASC15 Is Upregulated in Diabetes-Induced Chronic Renal Failure and Regulates Podocyte Apoptosis

BACKGROUND CASC15 has been recently characterized as an oncogenic lncRNA. This study aimed to investigate the role of CASC15 in diabetic patients complicated with chronic renal failure (DCRF). MATERIAL AND METHODS Levels of CASC15 in plasma derived from 3 groups of participants were measured by qPCR and compared by ANOVA and Tukey test. The interaction between CASC15 and miR-34c was analyzed by performing cell transfections. Cell apoptosis assay was performed to analyze the effects of transfections on the apoptosis of CIHP-1 cells (podocytes). RESULTS We found that CASC15 in plasma was upregulated in DCRF compared with diabetic patients (no obvious complications) and healthy controls. Upregulation of CASC15 distinguished DCRF patients from healthy controls and diabetic patients. High D-glucose environment induced the upregulation of CASC15 in cells of the human podocyte cell line CIHP-1. Overexpression of CASC15 did not affect miR-34c in CIHP-1 cells, but bioinformatics analysis showed that CASC15 can sponge miR-34c. Overexpression of CASC15 led to an increased apoptotic rate of CIHP-1 cells, and miR-34c overexpression led to a decreased apoptotic rate of CIHP-1 cells. In addition, CASC15 overexpression attenuated the effects of miR-34c overexpression on cell apoptosis. CONCLUSIONS Therefore, CASC15 is upregulated in DCRF patients and promotes the apoptosis of podocytes by sponging miR-34c. Our study adds to our understanding of the pathogenesis of DCRF and suggests that CASC15 could serve as a potential therapeutic target of DCRF.

Inhibiting SLC26A4 reverses cardiac hypertrophy in H9C2 cells and in rats

Background

It has been confirmed that mutations in solute carrier family 26 member 4 (SLC26A4) contribute to pendred syndrome. However, the role of SLC26A4 in cardiac hypertrophy and the signaling pathways remain unclear.

Methods

Cardiomyocytes were treated by 200 µM phenylephrine (PE) to induce cardiac hypertrophy. Also, the expression of SLC26A4, GSK3, cardiac hypertrophy markers including atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) was detected through real-time quantitative polymerase chain reaction (RT-qPCR). Flow cytometry assay was used to test the apoptosis of PE-induced cardiomyocytes transfected by small interfere RNA (siRNA)-SLC26A4. Furthermore, we detected the expression of autophagy-related markers including light chain 3 (LC3) and P62. Finally, we established a rat model of abdominal aortic constriction (AAC)-induced cardiac hypertrophy in vivo.

Results

RT-qPCR results showed that the mRNA expression of SLC26A4 was significantly up-regulated in PE-induced cardiac hypertrophy. After inhibiting SLC26A4, the release of ANP and BNP was significantly decreased and GSK3β was elevated in vivo and in vitro. Furthermore, inhibiting SLC26A4 promoted apoptosis of cardiac hypertrophy cells. In addition, LC3 was down-regulated and P62 was enhanced after transfection of siRNA-SLC26A4.

Conclusion

Our findings revealed that SLC26A4 increases cardiac hypertrophy, and inhibiting SLC26A4 could decrease the release of ANP/BNP and promote the expression of GSK-3β in vitro and in vivo. Moreover, SLC26A4 silencing inhibits autophagy of cardiomyocytes and induces apoptosis of cardiomyocytes. Therefore, SLC26A4 possesses potential value to be a therapeutic target of cardiac hypertrophy, and our study provides new insights into the mechanisms of cardiac hypertrophy.

Interactions Among Regulatory Non-coding RNAs Involved in Cardiovascular Diseases

Non-coding RNAs (ncRNAs) are important regulatory players in human cells that have been shown to modulate different cellular processes and biological functions through controlling gene expression, being also involved in pathological conditions such as cardiovascular diseases. Among them, long non-coding RNAs (lncRNAs) and circular (circRNAs) could act as competing endogenous RNAs (ceRNAs) sequestering other ncRNAs. This entangled network of interactions has been reported to trigger the decay of the targeted ncRNAs having important roles in gene regulation. Growing evidences have been demonstrated that the regulatory mechanism underlying the crosstalk between different ncRNA species, namely lncRNAs, circRNAs and miRNAs has also an important role in the pathophysiological processes of cardiovascular diseases. In this chapter, the main regulatory relationship among lncRNAs, circRNAs and miRNAs were summarized and their role in the control and development of cardiovascular diseases was highlighted.

Long Non-Coding RNA-CASC15 Promotes Cell Proliferation, Migration, and Invasion by Activating Wnt/β-Catenin Signaling Pathway in Melanoma

BACKGROUND

Melanoma is one of the most aggressive and high mortality skin cancers in the world. Long non-coding RNA-CASC15, as a carcinogen, plays an important role in a variety of tumorigenesis; however, the role and underlying mechanism of CASC15 in melanoma remain unclear.

METHODS

Quantitative real-time polymerase chain reaction was applied to explore CASC15 and β-catenin expression in melanoma tissues and cells. Western blotting was carried out to investigate β-catenin, glycogen synthase kinase-3β, Survivin, Bax, Bcl-2, and epithelial-mesenchymal transition (EMT)-related protein expression level. Cell proliferation, apoptosis, migration, and invasion were observed by colony formation assay, flow cytometry, and transwell migration and invasion assays, respectively. The activity of Wnt/β-catenin signaling pathway was measured by Topflash luciferase reporter assay.

RESULTS

The expression of CASC15 and β-catenin was upregulated in melanoma tissues and cells. Knockdown of CASC15 suppressed Wnt/β-catenin signaling pathway and inhibited β-catenin expression. Furthermore, inhibition of CASC15 decreased proliferation and increased apoptosis of melanoma cells by downregulating Survivin and Bcl-2 and upregulating Bax in A375 and SK-MEL-28 cells. Silencing of CASC15 inhibited migration and invasion of melanoma cells by repressing EMT process.

CONCLUSION

Our study demonstrated that CASC15 promoted the proliferation, migration, and invasion of melanoma cells via activating Wnt/β-catenin signaling pathway, implying that CASC15 might be a potential therapeutic target and prognostic biomarker for melanoma.

MicroRNA-200a-3p Is a Positive Regulator in Cardiac Hypertrophy Through Directly Targeting WDR1 as Well as Modulating PTEN/PI3K/AKT/CREB/WDR1 Signaling

Cardiac hypertrophy is an adaptive expansion of the myocardium due to the overloaded stress of heart. Recently, emerging studies have drawn a conclusion that microRNAs (miRNAs) are involved in myocardial hypertrophy and even heart failure. To figure out the role of microRNA-200a-3p (miR-200a-3p) in cardiac hypertrophy, the in vitro cardiac hypertrophy model was established in H9c2 cells using angiotensin II (Ang-II) as previously described. First of all, we observed a significant increase of miR-200a-3p expression in Ang-II-induced hypertrophic H9c2 cells. Moreover, inhibition of miR-200a-3p dramatically reversed the Ang-II-upregulated expression of hypertrophic markers (atrial natriuretic peptide, brain natriuretic peptide, and β-MHC) and the expanded cell surface area in H9c2 cells. In addition, our results indicated that miR-200a-3p directly targeted both WDR1 and phosphatase and tensin homolog (PTEN). In this regard, miR-200a-3p further activated PI3K/AKT/CREB pathway so as to intensify its negative regulation on WDR1. At length, WDR1 silence, PTEN inhibitor, and PI3K activator recovered the repressive effect of miR-200a-3p suppression on the development of cardiac hypertrophy. Jointly, our study suggested that miR-200a-3p facilitated cardiac hypertrophy by not only directly targeting WDR1 but also through modulating PTEN/PI3K/AKT/CREB/WDR1 signaling, therefore proving novel downstream molecular pathway of miR-200a-3p in cardiac hypertrophy.

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

Cardiomyocyte hypertrophy is a heart response adapting to increasing cardiac load. Prolonged cardiomyocyte hypertrophy indicates a higher risk of heart failure or even cardiac death. Long noncoding RNAs have been largely reported to modulate human diseases. CTPB1-AS2 is a newly discovered lncRNA reported as an oncogene in papillary thyroid cancer, but its function in cardiomyocyte hypertrophy has never been probed. Toll-like receptor 4 (TLR4) is recognized to play important roles in cardiomyocyte hypertrophy. The present study aimed to investigate the role of CTBP1-AS2 in cardiomyocyte hypertrophy. First, we discovered the low expression of CTBP1-AS2 in normal heart tissues in GETx database. Then, we established cardiomyocyte hypertrophy models on mice and cardiomyocytes through transverse aortic constriction surgery and Ang II treatment. We revealed the up-regulation of CTBP1-AS2 and TLR4 in cardiomyocyte hypertrophy models. Also, we confirmed the positive correlation between CTBP1-AS2 and TLR4 expressions in cardiomyocyte hypertrophy tissues. Loss-of-function assays confirmed that inhibiting CTBP1-AS2 attenuated the Ang II-induced cardiomyocyte hypertrophy. Mechanism research showed that CTBP1-AS2 stabilized TLR4 mRNA by recruiting FUS. Rescue assays certified that CTBP1-AS2 regulated cardiomyocyte hypertrophy through TLR4. Finally, we found Sp1 as an upstream activator for CTBP1-AS2 expression. In conclusion, our study uncovered CTBP1-AS2 as a novel regulator of cardiomyocyte hypertrophy through regulating TLR4, providing a new potential treatment target for cardiomyocyte hypertrophy.

LncRNA TUG1 contributes to cardiac hypertrophy via regulating miR-29b-3p

Cardiac hypertrophy with maladjusted cardiac remodeling is the leading cause of heart failure. In the past decades, long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been proved to exert multiple functions in cellular biological behaviors; however, their role in cardiac hypertrophy remains largely unclear. Presently, we first obtained hypertrophic H9c2 cells by treating with angiotensin II (Ang II) and uncovered upregulation of lncRNA taurine upregulated gene 1 (TUG1) in such H9c2 cells. Then, we demonstrated that silencing TUG1 attenuated Ang II-induced cardiac hypertrophy. Besides, a strong interactivity of TUG1 with miR-29b-3p at the putative sites was validated, suggesting that TUG1 was an endogenous sponge of miR-29b-3p in H9c2 cells. Additionally, the expression of miR-29b-3p was strikingly reduced by TUG1 upregulation and also inhibited under Ang II treatment, whereas it was restored after silencing TUG1 in hypertrophic cells. Also, we proved miR-29b-3p as a negative regulator in cardiac hypertrophy. Finally, miR-29b-3p inhibition abolished the anti-hypertrophy effect of TUG1 depletion in Ang II-treated H9c2 cells. Collectively, our findings confirmed that TUG1 functioned as a positive modulator of cardiac hypertrophy via sponging miR-29b-3p, indicating that TUG1 might serve as a potential target for the treatment of cardiac hypertrophy and even heart failure.

Long noncoding RNA/circular noncoding RNA-miRNA-mRNA axes in cardiovascular diseases

Cardiovascular diseases (CVDs) are the leading cause of death worldwide. Non-coding RNAs including long non-coding RNAs (lncRNAs), circular RNAs (circRNAs) and microRNAs (miRNAs) have been reported to participate in pathological developments of CVDs through various mechanisms. Among them, the networks among lncRNAs/circRNAs, miRNAs, and mRNAs have recently attracted attention. Understanding the molecular mechanism could aid the discovery of therapeutic targets or strategies in CVDs including atherosclerosis, myocardial infarction (MI), hypertrophy, heart failure (HF) and cardiomyopathy. In this review, we summarize the latest research involving the lncRNA/circRNA-miRNA-mRNA axis in CVDs, with emphasis on the molecular mechanism.

The long noncoding RNA XIST protects cardiomyocyte hypertrophy by targeting miR-330-3p

Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) are implicated in numerous kinds of cardiovascular diseases, and their vital role in regulating cardiac hypertrophy still needs to be explored. In this study, we demonstrated that lncRNA X-inactive specific transcript (XIST) was upregulated in hypertrophic cardiac of mice and phenylephrine (PE)-treated cardiomyocytes. Next, we observed that inhibition of XIST induced hypertrophic response of cardiomyocyte and overexpression of XIST attenuated cardiomyocyte hypertrophy induced by PE. Furthermore, through online predictive tools and functional experiments, we demonstrated that XIST and S100B were targets of miR-330-3p. XIST and miR-330-3p suppressed each other in a reciprocal way in cardiomyocytes. Additionally, XIST promoted S100B expression through harboring the complementary binding sites with miR-330-3p, eventually prevented cardiac hypertrophy. In conclusion, our findings revealed a novel molecular mechanism that XIST/miR-330-3p/S100B pathway modulates the progression of cardiomyocyte hypertrophy.