The long non-coding RNA uc.4 influences cell differentiation through the TGF-beta signaling pathway

Epigenetic determinants and non-myocardial signaling pathways contributing to heart growth and regeneration

Congenital heart disease is the most common birth defect worldwide. Defective cardiac myogenesis is either a major presentation or associated with many types of congenital heart disease. Non-myocardial tissues, including endocardium and epicardium, function as a supporting hub for myocardial growth and maturation during heart development. Recent research findings suggest an emerging role of epigenetics in nonmyocytes supporting myocardial development. Understanding how growth signaling pathways in non-myocardial tissues are regulated by epigenetic factors will likely identify new disease mechanisms for congenital heart diseases and shed lights for novel therapeutic strategies for heart regeneration.

Ultra-conserved RNA: a novel biological tool with diagnostic and therapeutic potential

Ultra-conserved RNA (ucRNA) is a subset of long non-coding RNA, that is highly conserved among mice, rats and humans. UcRNA has attracted extensive attention in recent years for its potential biological significance in normal physiological function and diseases. However, due to the instability of RNA and the technical limitation, the function and mechanism of ucRNAs are largely unknown. Over the last two decades, researchers have made a lot of efforts to try to lift the veil of ucRNA in nervous, cardiovascular system and other systems as well as cancers. Since the concept of the glymphatic system is relatively new, we summarized here recent findings on the functions, regulation and the underlying mechanisms of ucRNAs in physiology and pathology. Meanwhile, pathology in some diseases is likely to contribute to abnormal expression of ucRNA in turn. We also discuss the technical challenges and bright prospects for future applications of ucRNAs in the diagnosis and treatment of diseases.

A novel peptide HSP-17 ameliorates oxidative stress injury and apoptosis in H9c2 cardiomyocytes by activating the PI3K/Akt pathway

Background

Oxidative stress and cell apoptosis play pivotal roles in the pathogenesis of doxorubicin (DOX)-induced myocardial injury. Heat shock protein-derived peptide (HSP-17) is a peptide which is low-expressed in DOX treated mouse heart tissue. It has high bioactivity and interspecies sequence consistency, and is predicted to have myocardial protective effect.

Methods

Firstly, we added 1 µM DOX to H9c2 cell culture medium for 24 hours to construct the myocardial cytotoxicity model. Then we detected the effect of HSP-17 on DOX induced H9c2 cardiomyocyte injury by measuring cell viability and lactate dehydrogenase (LDH) level. In addition, reactive oxygen species (ROS) and tetraethylbenzimidazolylcarbocyanine iodide kits are used to evaluate the effect of the HSP-17 peptide on DOX-induced oxidative stress injury to cardiomyocytes, and the detection of apoptosis related proteins and flow cytometry were applied to detect the level of apoptosis. Furthermore, the protein expression levels [phosphorylated Akt (p-Akt) and phosphorylated PI3K (p-PI3K)] of the PI3K/Akt pathway were also detected by western blotting.

Results

We found that the HSP-17 peptide can increase cell viability, protect mitochondrial potential, reduce LDH levels, and reduce ROS and cardiomyocyte apoptosis. In addition, we also observed that HSP-17 upregulated the expression level of p-Akt, and LY294002, a typical inhibitor of PI3K/Akt, was found to eliminate the protective roles of HSP-17.

Conclusions

In conclusion, this study demonstrated that the HSP-17 peptide protected H9c2 cells against oxidative stress and apoptosis via PI3K/Akt pathway activation, which provides a new idea for the treatment of DOX-induced myocardial injury.

Triclosan regulates alternative splicing events of nerve-related genes through RNA-binding protein CELF2 to induce zebrafish neurotoxicity

Herein, we demonstrated that triclosan (TCS) induced neurotoxicity mediated by pre-mRNA alternative splicing (AS). TCS exposure resulted in a series of phenotypic malformations, abnormal locomotor behavior, circadian rhythm disorder and inhibited AChE activity. High throughput mRNA sequencing revealed that TCS regulated the AS events of nerve-related genes. Meanwhile, abnormal expression was observed in marker genes related to nerve cell migration, axon guidance and myelination. The expression of mitochondrial apoptosis activator bcl2l11 was significantly increased under TCS exposure. Interestingly, CELF2 as one of the important RNA-binding proteins was closely related to the AS events, and its mRNA and protein expression levels were significantly increased in zebrafish brain under acute or chronic TCS exposure. Functional knock-down and over-expression of celf2 confirmed that TCS led to nervous system injury and developmental defects through the CELF2-mediated AS events of genes (mbpa, mef2d, u2af2b and matn3b). Histopathological injury, phenotypic malformation, abnormal locomotor behavior and changes in neuromarkers all confirmed the biological functions of CELF2 in zebrafish brain. These findings demonstrate that TCS might regulate some of the AS events of nerve-related genes through upregulating the expression of CELF2. Thus, CELF2 may serve as a target for the prevention, diagnosis and treatment of contaminant-induced neurological diseases.

Long Non-coding RNA MEG3 Promotes Pyroptosis in Testicular Ischemia-Reperfusion Injury by Targeting MiR-29a to Modulate PTEN Expression

Increasing evidence shows that the abnormal long non-coding RNAs (lncRNAs) expression is closely related to ischemia-reperfusion injury (I/R) progression. Studies have previously described that lncRNA MEG3 regulates pyroptosis in various organs I/R. Nevertheless, the related mechanisms of MEG3 in testicular I/R has not been clarified. The aim of this research is to unravel underlying mechanisms of the regulation of pyroptosis mediated by MEG3 during testicular I/R. We have established a testicular torsion/detorsion (T/D) model and an oxygen-glucose deprivation/reperfusion (OGD/R)-treated spermatogenic cell model. Testicular ischemic injury was assessed by H&E staining. Western blotting, quantitative real-time PCR, MDA, and SOD tests and immunohistochemistry measured the expression of MEG3 and related proteins and the level of ROS production in testicular tissues. Quantitative real-time PCR and western blotting determined the relative expression of MEG3, miR-29a, and relevant proteins in GC-1. Cell viability and cytotoxicity were measured by CCK-8 and LDH assays. Secretion and expression levels of inflammatory proteins were determined by ELISA, immunofluorescence and western blotting. The interaction among MEG3, miR-29a, and PTEN was validated through a dual luciferase reporter assay and Ago2-RIP. In this research, we identified that MEG3 was upregulated in animal specimens and GC-1. In loss of function or gain of function assays, we verified that MEG3 could promote pyroptosis. Furthermore, we found that MEG3 negatively regulated miR-29a expression at the posttranscriptional level and promoted PTEN expression, and further promoted pyroptosis. Therefore, we explored the interaction among MEG3, miR-29a and PTEN and found that MEG3 directly targeted miR-29a, and miR-29a targeted PTEN. Overexpression of miR-29a effectively eliminated the upregulation of PTEN induced by MEG3, indicating that MEG3 regulates PTEN expression by targeting miR-29a. In summary, our research indicates that MEG3 contributes to pyroptosis by regulating miR-29a and PTEN during testicular I/R, indicating that MEG3 may be a potential therapeutic target in testicular torsion.

Knockdown of lncRNA RMST protect against myocardial infarction through regulating miR-5692 and MAGI3 axis

AIMS

Myocardial infarction is the leading cause of death worldwide. The aim of this study was to investigate the function and mechanism of lncRNA RMST in myocardial infarction.

MATERIALS AND METHODS

H/R and H₂O₂ models were established to assess the function of lncRNA RMST in vitro. Mouse myocardial infarction was used to analyze the function of lncRNA RMST in vivo. Bioinformatics analysis was performed to predict the potential binding target of lncRNA RMST. Rescue experiments were performed to verify the relationship between RMST and its target.

RESULTS

The expression of lncRNA RMST was significantly increased with H/R or H₂O₂ treatment. Knockdown of lncRNA RMST improved cell death and protected mitochondria from H/R injury in vitro. In vivo, cardiac function was significantly attenuated by knockdown of lncRNA RMST. We also provided evidence that miR-5692 was a direct target of lncRNA RMST. Rescue experiments showed that knockdown of miR-5692 could restore the function of RMST.

CONCLUSION

Our study is the first to prove the function and mechanism of lncRNA RMST in myocardial infarction. Thus, a deeper understanding of the role of lncRNA RMST in myocardial infarction may provide new insights for the clinical intervention of MI.

Functional long non-coding and circular RNAs in zebrafish

The utility of model organisms to understand the function of a novel transcript/genes has allowed us to delineate their molecular mechanisms in maintaining cellular homeostasis. Organisms such as zebrafish have contributed a lot in the field of developmental and disease biology. Attributable to advancement and deep transcriptomics, many new transcript isoforms and non-coding RNAs such as long noncoding RNA (lncRNA) and circular RNAs (circRNAs) have been identified and cataloged in multiple databases and many more are yet to be identified. Various methods and tools have been utilized to identify lncRNAs/circRNAs in zebrafish using deep sequencing of transcriptomes as templates. Functional analysis of a few candidates such as tie1-AS, ECAL1 and CDR1as in zebrafish provides a prospective outline to approach other known or novel lncRNA/circRNA. New genetic alteration tools like TALENS and CRISPRs have helped in probing for the molecular function of lncRNA/circRNA in zebrafish. Further latest improvements in experimental and computational techniques offer the identification of lncRNA/circRNA counterparts in humans and zebrafish thereby allowing easy modeling and analysis of function at cellular level.

The physiological function of long-noncoding RNAs

The physiological processes of cells and organisms are regulated by various biological macromolecules, including long-noncoding RNAs (lncRNAs), which cannot be translated into protein and are different from small-noncoding RNAs on their length. In animals, lncRNAs are involved in development, metabolism, reproduction, aging and other life events by cis or trans effects. For many functional lncRNAs, there is growing evidence that they play different roles on cellular level and organismal level. On the other hand, many annotated lncRNAs are not essential and could be transcription noises. In this minireview, we investigate the physiological function of lncRNAs in cells and focus on their functions and functional mechanisms on the organismal level. The studies on lncRNAs using different classic animal models such as worms and flies are summarized and discussed in this article.

Transcribed ultraconserved region uc.242 is a novel regulator of cardiomyocyte hypertrophy induced by angiotensin II

Cardiomyocyte hypertrophy is a response to stress or hormone stimulation and is characterized by an increase of cardiomyocyte size. Abnormal long non-coding RNA (lncRNA) expression profile has been identified in various cardiovascular diseases. Though some lncRNAs had been reported to participate in regulation of cardiac hypertrophy, the universal lncRNA profile of cardiomyocyte hypertrophy had not been established. In the present study, we aimed to identify the differentially expressed lncRNA-mRNA network in angiotensin II-stimulated cardiomyocytes, and screen the potential lncRNAs involved in regulation of cardiomyocyte hypertrophy. The hypertrophic cardiomyocytes were induced by angiotensin II (0.1 μmol/L) for 48 hours. High-throughput microarray analysis combined with quantitative real-time PCR assay were then performed to screen the differentially expressed lncRNAs and mRNAs. A total of 1577 lncRNAs and 496 mRNAs transcripts were identified differentially expressed in hypertrophic cardiomyocytes. Among them, 59 transcribed ultraconserved non-coding RNAs (T-UCRs) were found by evolutionary conservation analysis. Subsequently, the lncRNA-mRNA coexpression network was constructed based on Pearson's correlation analysis results, including 4 T-UCRs and 215 mRNAs. The results revealed that uc.242 was positively interacted with prohypertrophic genes (Hgf and Tnc). Functional study showed that inhibition of uc.242 dramatically decreased hypertrophic marker expression levels and cardiomyocyte surface area under the condition of angiotensin II stimulation. The expression of Hgf and Tnc was also decreased in cardiomyocytes after silencing of uc.242. Summarily, the present study provided crucial clues to explore therapeutic targets for pathological cardiac hypertrophy.

Long Noncoding RNA CDKN2B-AS1 Facilitates Lung Cancer Development Through Regulating miR-378b/NR2C2

Aim

Long noncoding RNA (lncRNA) have proved to be important regulators in various diseases. CDKN2B-AS1 was a newly identified tumor-related lncRNA, and previous studies have reported its function in laryngeal squamous cancer and osteosarcoma. However, the function and mechanism of lncRNA CDKN2B-AS1 in lung cancer are still unknown.

Methods

Cell proliferation, invasion, migration and apoptosis were detected via CCK-8, transwell assay and Western blot. Bioinformatics analysis was used to predict the potential target of CDKN2B-AS1. A rescue experiment was performed to identify the relationship between CDKN2B-AS1 and miR-378b.

Results

The expression of lncRNA CDKN2B-AS1 was significantly upregulated in lung cancer tissues and cell lines. Overexpression of CDKN2B-AS1 promoted cell proliferation, invasion and reduced cell apoptosis. Knockdown of CDKN2B-AS1 inhibited cell proliferation, invasion and increased cell apoptosis. Bioinformatics analysis predicted that miR-378b was the direct target. We also provided evidence that NR2C2 was the target of miR-378b. The expression of NR2C2 was significantly upregulated in lung cancer tissues and cell lines. The rescue experiment further confirmed the relationship between CDKN2B-AS1 and miR-378b. Overexpression of miR-378b completely reversed the function of CDKN2B-AS1.

Conclusion

Taken together, our results comprehensively analyzed the function of CDKN2B-AS1 in lung cancer and provided a possible mechanism that CDKN2B-AS1 facilitates lung cancer development by regulating miR-378b and NR2C2. Thus, our study offers a potential therapeutic target for treating lung cancer.

MiR-33a-5p targets NOMO1 to modulate human cardiomyocyte progenitor cells proliferation and differentiation and apoptosis

PURPOSE

MicroRNA (miRNA) is known to be involved in the pathological process of congenital heart disease (CHD), and nodal modulator1 (NOMO1) is a critical determinant of heart formation. The present study aims to discover the effect of miR-33a-5p and NOMO1 on CHD.

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect expressions of miR-33a-5p mimic or inhibitor and overexpressed NOMO1 plasmid orNOMO1 knockdown. Human cardiomyocyte progenitor cells (hCMPCs) proliferation was measured by cell counting kit-8 (CCK-8) at 24, 48 and 72 h. Flow cytometry was applied to investigate hCMPCs cell cycle progression and apoptosis. Expressions of cell apoptotic proteins Bax, Cleaved(C) caspase-3 and Bcl-2, and expressions of cardiomyocyte differentiation markers GATA4, troponin T (cTnT) and myocyte enhancer factor2C (MEF2C) in hCMPCs were identified by qRT-PCR and western blot. Target genes and potential binding sites of NOMO1 and miR-33a-5p were predicted with Targetscan 7.2, and was confirmed through dual-luciferase reporter assay.

RESULTS

Up-regulation of miR-33a-5p inhibited hCMPCs proliferation, cell cycle G0/S transition but promoted hCMPCs apoptosis, which was partially mitigated by overexpressed NOMO1. NOMO1 was the target gene of miR-33a-5p. Expressions of Bax and C caspase-3 were enhanced but expressions of Bcl-2, GATA4, cTnT and MEF2C were reduced by up-regulation of miR-33a-5p, which was partially mitigated by overexpressed NOMO1.

CONCLUSION

Up-regulation of miR-33a-5p inhibited hCMPCs proliferation, cell cycle G0/S transition and differentiation into cardiomyocytes but promoted apoptosis via targeting NOMO1.

Long non-coding RNA SAP30-2:1 is downregulated in congenital heart disease and regulates cell proliferation by targeting HAND2

Congenital heart disease (CHD) is the most common birth defect worldwide. Long non-coding RNAs (lncRNAs) have been implicated in many diseases. However, their involvement in CHD is not well understood. This study aimed to investigate the role of dysregulated lncRNAs in CHD. We used Gene Expression Omnibus data mining, bioinformatics analysis, and analysis of clinical tissue samples and observed that the novel lncRNA SAP30-2:1 with unknown function was significantly downregulated in damaged cardiac tissues from patients with CHD. Knockdown of lncRNA SAP30-2:1 inhibited the proliferation of human embryonic kidney and AC16 cells and decreased the expression of heart and neural crest derivatives expressed 2 (HAND2). Moreover, lncRNA SAP30-2:1 was associated with HAND2 by RNA immunoprecipitation. Overall, these results suggest that lncRNA SAP30-2:1 may be involved in heart development through affecting cell proliferation via targeting HAND2 and may thus represent a novel therapeutic target for CHD.

Long non coding RNA NRON inhibited breast cancer development through regulating miR-302b/SRSF2 axis

AIMS

Long noncoding RNA NRON has been investigated in various tumors, such as hepatocellular carcinoma. However, the role of lncRNA NRON in breast cancer remains unclear. The aim of this study was to explore the function and mechanism of lncRNA NRON in breast cancer.

MATERIALS AND METHODS

Overexpression and knockdown vectors were constructed. Proliferation and invasion were measured to evaluate the function of lncRNA NRON. A dual-luciferase reporter assay was utilized to analyze the potential binding target of lncRNA NRON. A rescue experiment was performed to verify the relationship between lncRNA NRON and SRSF2.

RESULTS

Our results showed that the expression of lncRNA NRON was significantly downregulated in breast cancer tissues. Overexpression of lncRNA NRON significantly inhibited proliferation and invasion in breast cancer cell lines. Knockdown of lncRNA NRON promoted breast cancer development. We also provided evidence that lncRNA NRON negatively regulated miR-302b. Moreover, we identified SRSF2 as a downstream target of miR-302b.

CONCLUSION

Overall, we performed a comprehensive analysis to indicate that the lncRNA NRON/miR-302b/SRSF2 axis plays an important role in breast cancer. Our study is the first to prove that lncRNA NRON functions as a tumor suppressor in breast cancer.

Hypermethylation-mediated down-regulation of lncRNA TBX5-AS1:2 in Tetralogy of Fallot inhibits cell proliferation by reducing TBX5 expression

Tetralogy of Fallot (TOF) is the most common complex congenital heart disease (CHD) with uncertain cause. Although long non‐coding RNAs (lncRNAs) have been implicated in heart development and several CHDs, their role in TOF is not well understood. This study aimed to investigate how dysregulated lncRNAs contribute to TOF. Using Gene Expression Omnibus data mining, bioinformatics analysis and clinical heart tissue sample detecting, we identified a novel antisense lncRNA TBX5‐AS1:2 with unknown function that was significantly down‐regulated in injured cardiac tissues from TOF patients. LncRNA TBX5‐AS1:2 was mainly located in the nucleus of the human embryonic kidney 293 (HEK293T) cells and formed an RNA‐RNA double‐stranded structure in the overlapping region with its sense mRNA T‐box transcription factor 5 (TBX5), which is an important regulator in heart development. Knock‐down of lncRNA TBX5‐AS1:2 via promoter hypermethylation reduced TBX5 expression at both the mRNA and protein levels by affecting its mRNA stability through RNA‐RNA interaction. Moreover, lncRNA TBX5‐AS1:2 knock‐down inhibited the proliferation of HEK293T cells. In conclusion, these results indicated that lncRNA TBX5‐AS1:2 may be involved in TOF by affecting cell proliferation by targeting TBX5.

Congenital heart diseases: genetics, non-inherited risk factors, and signaling pathways

Background

Congenital heart diseases (CHDs) are the most common congenital anomalies with an estimated prevalence of 8 in 1000 live births. CHDs occur as a result of abnormal embryogenesis of the heart. Congenital heart diseases are associated with significant mortality and morbidity. The damage of the heart is irreversible due to a lack of regeneration potential, and usually, the patients may require surgical intervention. Studying the developmental biology of the heart is essential not only in understanding the mechanisms and pathogenesis of congenital heart diseases but also in providing us with insight towards developing new preventive and treatment methods.

Main body

The etiology of congenital heart diseases is still elusive. Both genetic and environmental factors have been implicated to play a role in the pathogenesis of the diseases. Recently, cardiac transcription factors, cardiac-specific genes, and signaling pathways, which are responsible for early cardiac morphogenesis have been extensively studied in both human and animal experiments but leave much to be desired. The discovery of novel genetic methods such as next generation sequencing and chromosomal microarrays have led to further study the genes, non-coding RNAs and subtle chromosomal changes, elucidating their implications to the etiology of congenital heart diseases. Studies have also implicated non-hereditary risk factors such as rubella infection, teratogens, maternal age, diabetes mellitus, and abnormal hemodynamics in causing CHDs.

These etiological factors raise questions on multifactorial etiology of CHDs. It is therefore important to endeavor in research based on finding the causes of CHDs. Finding causative factors will enable us to plan intervention strategies and mitigate the consequences associated with CHDs. This review, therefore, puts forward the genetic and non-genetic causes of congenital heart diseases. Besides, it discusses crucial signaling pathways which are involved in early cardiac morphogenesis. Consequently, we aim to consolidate our knowledge on multifactorial causes of CHDs so as to pave a way for further research regarding CHDs.

Conclusion

The multifactorial etiology of congenital heart diseases gives us a challenge to explicitly establishing specific causative factors and therefore plan intervention strategies. More well-designed studies and the use of novel genetic technologies could be the way through the discovery of etiological factors implicated in the pathogenesis of congenital heart diseases.

Overexpression of the long non-coding RNA Oprm1 alleviates apoptosis from cerebral ischemia-reperfusion injury through the Oprm1/miR-155/GATA3 axis

Numerous differentially expressed long non-coding RNAs (lncRNAs) have been identified in cerebral ischemia-reperfusion (I/R) injury using RNA-Seq analysis. However, little is known about whether and how lncRNAs are involved in cerebral I/R injury. In this study, we investigated the function of the lncRNA Oprm1 in cerebral I/R injury and explored the underlying mechanism. An oxygen-glucose deprivation model in N2a cells was utilized to mimic cerebral I/R injury in vitro. Trypan blue staining, terminal deoxytransferase-mediated dUTP-biotin nick end labelling and caspase-3 were measured to evaluate apoptosis. Middle cerebral artery occlusion was performed in mice to evaluate the function of lncRNA Oprm1 in vivo. Real-time PCR and western blotting were used to measure the expression levels of lncRNA Opmr1, caspase-3, miR-155, GATA binding protein 3 (GATA3) and nuclear factor (NF)-κB. lncRNA Oprm1 was mainly located in the cytoplasm. Overexpression of lncRNA Oprm1 alleviated the apoptosis induced by oxygen-glucose deprivation and significantly reduced cleaved caspase-3 levels. Infarct size was distinctly decreased in the lncRNA Oprm1-overexpression group. The neurological score was also improved. Our findings showed that the lncRNA Oprm1/miR-155/GATA3 axis plays an important role in cerebral I/R injury. lncRNA Oprm1 may attenuate cerebral injury through the NF-κB pathway. lncRNA Oprm1 may serve as a potential target for new therapeutic interventions in patients with ischemic stroke.

Overexpression of lncRNA Gm2691 attenuates apoptosis and inflammatory response after myocardial infarction through PI3K/Akt signaling pathway

Acute myocardial infarction is one of the most threatening disease in the world. In previous studies, numerous dysregulated lncRNAs exposed to ischemic reperfusion injury have been identified. In this differential lncRNAs, Gm2691 attracted our attention due to its high fold change. The aim of the study was to investigate the function and mechanism of lncRNA Gm2691 in ischemic reperfusion injury. AnaeroPack anaerobic system treated neonatal rat ventricular cardiomyocytes were used to analyze the function of lncRNA Gm2691 in vitro. Tunel, Caspase3, and inflammation markers were detected to evaluate apoptosis and inflammatory response. Rat acute myocardial infarction was performed to elucidate the function of lncRNA Gm2691 in vivo. The results showed that LncRNA Gm2691 improved the cardiac function and attenuated the inflammatory response in vivo. We also found that lncRNA Gm2691 reduced the apoptosis and improved cell survival rates in anaeroPack anaerobic system treated neonatal rat ventricular cardiomyocytes. Western blot analysis revealed that lncRNA Gm2691 decreased Akt and ERK1/2 activities, suggesting that lncRNA Gm2691 may functioned through Akt signaling pathway. We verified the function and mechanism of lncRNA Gm2691 and provide evidence that lncRNA Gm2691 may play important role in ischemic reperfusion injury, and understanding the precise role of Gm2691 will undoubtedly shed new light on the clinical treatment.

Long noncoding RNA uc.4 inhibits cell differentiation in heart development by altering DNA methylation

In previous studies, we have demonstrated that long noncoding RNA uc.4 may influence the cell differentiation through the TGF-β signaling pathway, suppressed the heart development of zebrafish and resulting cardiac malformation. DNA methylation plays a significant role in the heart development and disordered of DNA methylation may cause disruption of control of gene promoter. In this study, methylated DNA immunoprecipitation was performed to identify the different expression levels of methylation regions. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were also performed to identify the possible biological process and pathway that uc.4 may join, associated with Rap1 signaling pathway, gonadotropin-releasing hormone signaling pathway, and Calcium signaling pathway. We found that the distribution of differentially methylated regions peaks was mainly located in intergenic and intron regions. Altogether, our result showed that differentially methylated genes are significantly expressed in uc.4-overexpression cells, providing valuable data for further exploration of the role of uc.4 in heart development.

Effects of miR-181a-5p abnormal expression on zebrafish (Danio rerio) vascular development following triclosan exposure

Triclosan (TCS), one of the important bactericides, is widely used in personal care products, and its chronic exposure leads to severe toxic effects on the growth and development of blood vessels in zebrafish (Danio rerio). Herein, we screened out three differentially expressed miRNAs (miR-181a-5p, miR-132-3p and miR-128-3p) by sequencing and qRT-PCR analyses of 4-96-hpf TCS-exposed zebrafish, among which miR-181a-5p was found to regulate many signaling pathways involved in fatty acid biosynthesis and phosphatidylimositol signaling systems. By O-dianisidine staining, TCS-exposure resulted in decreased distribution of red blood cells and induced blood hypercoagulable state and thrombotic effects. Defective subintestinal veins (SIVs), and decreased branching and curvature of blood vessels were observed with increasing TCS-exposure concentrations. After microinjection of miR-181a-5p mimic and inhibitor, zebrafish malformation type and percentage were prominently increased such as distorted SIV vessels along with reduced venation and abnormal branches by ALP staining. Overexpressed miR-181a-5p had a greater effect on development and branching patterns of arteries and veins than its knockdown. By laser confocal microscopy observation, the 72-hpf Tg (flk1: mCherry) zebrafish obviously displayed vascular proliferation and ablation in the miR-181a-5p mimic group. Microinjection of miR-181a-5p mimics and inhibitors led to abnormal expressions (20-50%) of two key target genes (pax2a and vash2) by WISH, and increased malformation percentages (18-45%) by IOD analysis. Overexpression of vash2 led to the inhibitory or promoting effects on the expression of PI3K signaling pathway-related genes, proving that the effect of vash2 on development of blood vessels could be realized by inhibiting PI3K signaling pathway. These observations lay theoretical foundation for deep insight into the molecular mechanisms on TCS-induced cardiovascular diseases.

Long noncoding RNAs: a missing link in osteoporosis

Osteoporosis is a systemic disease that results in loss of bone density and increased fracture risk, particularly in the vertebrae and the hip. This condition and associated morbidity and mortality increase with population ageing. Long noncoding (lnc) RNAs are transcripts longer than 200 nucleotides that are not translated into proteins, but play important regulatory roles in transcriptional and post-transcriptional regulation. Their contribution to disease onset and development is increasingly recognized. Herein, we present an integrative revision on the studies that implicate lncRNAs in osteoporosis and that support their potential use as therapeutic tools. Firstly, current evidence on lncRNAs involvement in cellular and molecular mechanisms linked to osteoporosis and its major complication, fragility fractures, is reviewed. We analyze evidence of their roles in osteogenesis, osteoclastogenesis, and bone fracture healing events from human and animal model studies. Secondly, the potential of lncRNAs alterations at genetic and transcriptomic level are discussed as osteoporosis risk factors and as new circulating biomarkers for diagnosis. Finally, we conclude debating the possibilities, persisting difficulties, and future prospects of using lncRNAs in the treatment of osteoporosis.