sPIF promotes myoblast differentiation and utrophin expression while inhibiting fibrosis in Duchenne muscular dystrophy via the H19/miR-675/let-7 and miR-21 pathways

Noncoding RNA network crosstalk in organ fibrosis

Fibrosis is a process involving excessive accumulation of extracellular matrix components, the severity of which interferes with the function of the organ in question. With the advances in RNA sequencing and in-depth molecular studies, a large number of current studies have pointed out the irreplaceable role of non-coding RNAs (ncRNAs) in the pathophysiological development of organ fibrosis. Here, by summarizing the results of a large number of studies on the interactions between ncRNAs, some studies have found that long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), among others, are able to act as sponges or decoy decoys for microRNAs (miRNAs), act as competing endogenous RNAs (ceRNAs) to regulate the expression of miRNAs, and subsequently act on different mRNA targets, playing a role in the development of fibrosis in a wide variety of organs, including the heart, liver, kidneys, and spleen. parenchymal organs, including heart, liver, kidney, and spleen, play important roles in the development of fibrosis. These findings elucidate the intricate involvement of the lncRNA/circRNA-miRNA-mRNA axis in the pathophysiological processes underpinning organ fibrosis, thereby enhancing our comprehension of the onset and progression of this condition. Furthermore, they introduce novel potential therapeutic targets within the realm of ncRNA-based therapeutics, offering avenues for the development of innovative drugs aimed at mitigating or reversing the effects of organ fibrosis.

Identification of reference microRNAs in skeletal muscle of a canine model of Duchenne muscular dystrophy

Background

Duchenne muscular dystrophy (DMD) is a fatal muscle wasting disease caused by mutations in the dystrophin gene. DE50-MD dogs are an animal model of DMD used as a final translational model for evaluation of promising treatments. MicroRNA (miR) expressions in the muscle of DE50-MD dogs represent potential biomarkers, but stable reference miRs must first be identified. The aim of this paper was to establish a panel of reference miRs for WT and DE50-MD dogs over a range of ages and muscle groups.

Methods

RNA was extracted from WT and DE50-MD dog (N=6 per genotype) vastus lateralis muscle samples collected longitudinally at 3, 6, 9, 12, 15 and 18 months of age, and from muscles collected post-mortem (N=3 per genotype; cranial tibial, semimembranosus, lateral triceps and diaphragm). 87 RNAs were quantified in a subset of 6-month-old WT and DE50-MD muscles (N=4 per genotype) using the QIAcuity miFinder panel. GeNorm, BestKeeper and Normfinder were used to identify a candidate panel of the 8 most stable small RNAs, which were then quantified in all RNA samples, alongside the commonly used reference RNA snRNA U6.

Results

The most stable miRs of this subset were used to normalise quantities of dystromiRs miR-1, miR-133a and miR-206, and fibromiR miR-214. MicroRNAs miR-191, let-7b, miR-125a and miR-15a were the most stable miRs tested, while snRNA U6 performed poorly. DystromiR expression, normalised to the geometric mean of the panel of reference miRs, was lower for miR-1 and miR-133a in DE50-MD compared to WT muscles, while miR-206 levels did not significantly differ between genotypes. FibromiR miR-214 was 2- to 4-fold higher in DE50-MD versus WT muscles.

Conclusions

A normalisation factor derived from miR-191, let-7b, miR-125a and miR-15a is suitable for normalising miR expression data from WT and DE50-MD muscle over a range of ages and muscle types.

Idiopathic inflammatory myopathy and non-coding RNA

Idiopathic inflammatory myopathies (IIMs) are common autoimmune diseases that affect skeletal muscle quality and function. The lack of an early diagnosis and treatment can lead to irreversible muscle damage. Non-coding RNAs (ncRNAs) play an important role in inflammatory transfer, muscle regeneration, differentiation, and regulation of specific antibody levels and pain in IIMs. ncRNAs can be detected in blood and hair; therefore, ncRNAs detection has great potential for diagnosing, preventing, and treating IIMs in conjunction with other methods. However, the specific roles and mechanisms underlying the regulation of IIMs and their subtypes remain unclear. Here, we review the mechanisms by which micro RNAs and long non-coding RNA-messenger RNA networks regulate IIMs to provide a basis for ncRNAs use as diagnostic tools and therapeutic targets for IIMs.

Promising therapeutic approaches of utrophin replacing dystrophin in the treatment of Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a serious genetic neuromuscular rare disease that is prevalent and caused by the mutation/deletion of the X-linked DMD gene that encodes dystrophin. Utrophin is a dystrophin homologous protein on human chromosome 6. Dystrophin and utrophin are highly homologous. They can recruit many dystrophin-glycoprotein complex (DGC)-related proteins and co-localize at the sarcolemma in the early stage of human embryonic development. Moreover, utrophin is overexpressed naturally at the mature myofiber sarcolemma in DMD patients. Therefore, utrophin is considered the most promising homologous protein to replace dystrophin. This review summarizes various modulating drugs and gene therapy approaches for utrophin replacement. As a universal method to treat DMD disease, utrophin has a promising therapeutic prospect and deserves further investigation.

MicroRNAs in Dystrophinopathy

Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD), which represent the range of dystrophinopathies, account for nearly 80% of muscle dystrophy. DMD and BMD result from the loss of a functional dystrophin protein, and the leading cause of death in these patients is cardiac remodeling and heart failure. The pathogenesis and progression of the more severe form of DMD have been extensively studied and are controlled by many determinants, including microRNAs (miRNAs). The regulatory role of miRNAs in muscle function and the differential miRNA expression in muscular dystrophy indicate the clinical significance of miRNAs. This review discusses the relevant microRNAs as potential biomarkers and therapeutic targets for DMD and DMD cardiomyopathy as examples of dystrophinopathies.

Regulation of Pyroptosis by ncRNA: A Novel Research Direction

Pyroptosis is a novel form of programmed cell death (PCD), which is characterized by DNA fragmentation, chromatin condensation, cell swelling and leakage of cell contents. The process of pyroptosis is performed by certain inflammasome and executor gasdermin family member. Previous researches have manifested that pyroptosis is closely related to human diseases (such as inflammatory diseases) and malignant tumors, while the regulation mechanism of pyroptosis is not yet clear. Non-coding RNA (ncRNA) such as microRNA (miRNA), long non-coding RNA (lncRNA) and circular RNA (circRNA) have been widely identified in the genome of eukaryotes and played a paramount role in the development of cell function and fate after transcription. Accumulating evidences support the importance of ncRNA biology in the hallmarks of pyroptosis. However, the associations between ncRNA and pyroptosis are rarely reviewed. In this review, we are trying to summarize the regulation and function of ncRNA in cell pyroptosis, which provides a new research direction and ideas for the study of pyroptosis in different diseases.

Therapeutic Implications of miRNAs for Muscle-Wasting Conditions

MicroRNAs (miRNAs) are small, non-coding RNA molecules that are mainly involved in translational repression by binding to specific messenger RNAs. Recently, miRNAs have emerged as biomarkers, relevant for a multitude of pathophysiological conditions, and cells can selectively sort miRNAs into extracellular vesicles for paracrine and endocrine effects. In the overall context of muscle-wasting conditions, a multitude of miRNAs has been implied as being responsible for the typical dysregulation of anabolic and catabolic pathways. In general, chronic muscle disorders are associated with the main characteristic of a substantial loss in muscle mass. Muscular dystrophies (MDs) are a group of genetic diseases that cause muscle weakness and degeneration. Typically, MDs are caused by mutations in those genes responsible for upholding the integrity of muscle structure and function. Recently, the dysregulation of miRNA levels in such pathological conditions has been reported. This revelation is imperative for both MDs and other muscle-wasting conditions, such as sarcopenia and cancer cachexia. The expression levels of miRNAs have immense potential for use as potential diagnostic, prognostic and therapeutic biomarkers. Understanding the role of miRNAs in muscle-wasting conditions may lead to the development of novel strategies for the improvement of patient management.

Non-Coding RNAs as Regulators of Myogenesis and Postexercise Muscle Regeneration

miRNAs and lncRNAs do not encode proteins, but they play an important role in the regulation of gene expression. They differ in length, biogenesis, and mode of action. In this work, we focus on the selected miRNAs and lncRNAs involved in the regulation of myogenesis and muscle regeneration. We present selected miRNAs and lncRNAs that have been shown to control myogenic differentiation and show that manipulation of their levels could be used to improve myogenic differentiation of various types of stem and progenitor cells. Finally, we discuss how physical activity affects miRNA and lncRNA expression and how it affects muscle well-being.

Preimplantation factor modulates oligodendrocytes by H19-induced demethylation of NCOR2

Failed or altered gliogenesis is a major characteristic of diffuse white matter injury in survivors of premature birth. The developmentally regulated long noncoding RNA (lncRNA) H19 inhibits S-adenosylhomocysteine hydrolase (SAHH) and contributes to methylation of diverse cellular components, such as DNA, RNA, proteins, lipids, and neurotransmitters. We showed that the pregnancy-derived synthetic PreImplantation Factor (sPIF) induces expression of the nuclear receptor corepressor 2 (NCOR2) via H19/SAHH-mediated DNA demethylation. In turn, NCOR2 affects oligodendrocyte differentiation markers. Accordingly, after hypoxic-ischemic brain injury in rodents, myelin protection and oligodendrocytes' fate are in part modulated by sPIF and H19. Our results revealed an unexpected mechanism of the H19/SAHH axis underlying myelin preservation during brain recovery and its use in treating neurodegenerative diseases can be envisioned.

Neuron-Glia Crosstalk Plays a Major Role in the Neurotoxic Effects of Ketamine via Extracellular Vesicles

Background: There is a compelling evidence from animal models that early exposure to clinically relevant general anesthetics (GAs) interferes with brain development, resulting in long-lasting cognitive impairments. Human studies have been inconclusive and are challenging due to numerous confounding factors. Here, we employed primary human neural cells to analyze ketamine neurotoxic effects focusing on the role of glial cells and their activation state. We also explored the roles of astrocyte-derived extracellular vesicles (EVs) and different components of the brain-derived neurotrophic factor (BDNF) pathway.

Methods: Ketamine effects on cell death were analyzed using live/dead assay, caspase 3 activity and PARP-1 cleavage. Astrocytic and microglial cell differentiation was determined using RT-PCR, ELISA and phagocytosis assay. The impact of the neuron-glial cell interactions in the neurotoxic effects of ketamine was analyzed using transwell cultures. In addition, the role of isolated and secreted EVs in this cross-talk were studied. The expression and function of different components of the BDNF pathway were analyzed using ELISA, RT-PCR and gene silencing.

Results: Ketamine induced neuronal and oligodendrocytic cell apoptosis and promoted pro-inflammatory astrocyte (A1) and microglia (M1) phenotypes. Astrocytes and microglia enhanced the neurotoxic effects of ketamine on neuronal cells, whereas neurons increased oligodendrocyte cell death. Ketamine modulated different components in the BDNF pathway: decreasing BDNF secretion in neurons and astrocytes while increasing the expression of p75 in neurons and that of BDNF-AS and pro-BDNF secretion in both neurons and astrocytes. We demonstrated an important role of EVs secreted by ketamine-treated astrocytes in neuronal cell death and a role for EV-associated BDNF-AS in this effect.

Conclusions: Ketamine exerted a neurotoxic effect on neural cells by impacting both neuronal and non-neuronal cells. The BDNF pathway and astrocyte-derived EVs represent important mediators of ketamine effects. These results contribute to a better understanding of ketamine neurotoxic effects in humans and to the development of potential approaches to decrease its neurodevelopmental impact.

The FibromiR miR-214-3p Is Upregulated in Duchenne Muscular Dystrophy and Promotes Differentiation of Human Fibro-Adipogenic Muscle Progenitors

Fibrosis is a deleterious invasion of tissues associated with many pathological conditions, such as Duchenne muscular dystrophy (DMD) for which no cure is at present available for its prevention or its treatment. Fibro-adipogenic progenitors (FAPs) are resident cells in the human skeletal muscle and can differentiate into myofibroblasts, which represent the key cell population responsible for fibrosis. In this study, we delineated the pool of microRNAs (miRNAs) that are specifically modulated by TGFβ1 in FAPs versus myogenic progenitors (MPs) by a global miRNome analysis. A subset of candidates, including several “FibromiRs”, was found differentially expressed between FAPs and MPs and was also deregulated in DMD versus healthy biopsies. Among them, the expression of the TGFβ1-induced miR-199a~214 cluster was strongly correlated with the fibrotic score in DMD biopsies. Loss-of-function experiments in FAPs indicated that a miR-214-3p inhibitor efficiently blocked expression of fibrogenic markers in both basal conditions and following TGFβ1 stimulation. We found that FGFR1 is a functional target of miR-214-3p, preventing the signaling of the anti-fibrotic FGF2 pathway during FAP fibrogenesis. Overall, our work demonstrates that the « FibromiR » miR-214-3p is a key activator of FAP fibrogenesis by modulating the FGF2/FGFR1/TGFβ axis, opening new avenues for the treatment of DMD.

Identification of potential microRNAs and KEGG pathways in denervation muscle atrophy based on meta-analysis

The molecular mechanism of muscle atrophy has been studied a lot, but there is no comprehensive analysis focusing on the denervated muscle atrophy. The gene network that controls the development of denervated muscle atrophy needs further elucidation. We examined differentially expressed genes (DEGs) from five denervated muscle atrophy microarray datasets and predicted microRNAs that target these DEGs. We also included the differentially expressed microRNAs datasets of denervated muscle atrophy in previous studies as background information to identify potential key microRNAs. Finally, we compared denervated muscle atrophy with disuse muscle atrophy caused by other reasons, and obtained the Den-genes which only differentially expressed in denervated muscle atrophy. In this meta-analysis, we obtained 429 up-regulated genes, 525 down-regulated genes and a batch of key microRNAs in denervated muscle atrophy. We found eight important microRNA-mRNA interactions (miR-1/Jun, miR-1/Vegfa, miR-497/Vegfa, miR-23a/Vegfa, miR-206/Vegfa, miR-497/Suclg1, miR-27a/Suclg1, miR-27a/Mapk14). The top five KEGG pathways enriched by Den-genes are Insulin signaling pathway, T cell receptor signaling pathway, MAPK signaling pathway, Toll-like receptor signaling pathway and B cell receptor signaling pathway. Our research has delineated the RNA regulatory network of denervated muscle atrophy, and uncovered the specific genes and terms in denervated muscle atrophy.

Dysregulation of lncRNA-H19 in cardiometabolic diseases and the molecular mechanism involved : a systematic review

Introduction: Cardiometabolic diseases are a global public health problem, with significant increases in their prevalence. Different epigenetic factors involved in the progression of metabolic alterations have been described, such as long non-coding RNAs (lncRNAs). H19 is a multifunctional lncRNA expressed from the maternal allele, with low expression after birth, except in the skeletal muscle and heart. Recent studies have linked its dysregulation to alterations in cell metabolism.Areas covered: H19 plays a role in the pathogenesis of coronary artery disease, nonalcoholic fatty liver disease, hepatic and renal fibrosis, insulin resistance, type 2 diabetes, and inflammation. H19 acts mainly as a competitive endogenous RNA of molecules involved in pathways that regulate cell metabolism. In this review, we analyzed the dysregulation of H19 in cardiometabolic diseases and its relationship with molecular alterations in different signaling pathways.Expert opinion: The association of H19 with the development of cardiometabolic diseases, indicates that H19 could be a therapeutic target and prognostic biomarker for these diseases. Controversies have been reported regarding the expression of H19 in some metabolic diseases, therefore, it is necessary to continue research to clarify its pathogenic effect in different organs.

Long non-coding RNA H19 promotes myoblast fibrogenesis via regulating the miR-20a-5p-Tgfbr2 axis

Emerging evidence has indicated long non-coding RNAs (lncRNAs) play important roles in diverse biological processes, including fibrosis. Here, we report that lncRNA H19 is able to promote skeletal muscle fibrosis. lnc-H19 was identified to be highly expressed in skeletal muscle fibrosis in vivo and in vitro; while lnc-H19 knockdown attenuated fibrosis in vitro. The knockdown of lnc-H19 was proved to inhibit the activation of the TGFβ/Smad pathway in C2C12 myoblasts by sponging miR-20a-5p to regulate Tgfbr2 expression through the competing endogenous RNA function. Our study elucidates the roles of the lnc-H19-miR-20a-5p-Tgfbr2 axis in regulating the TGFβ/Smad pathway of myoblast fibrogenesis, which might provide a promising therapeutic target for skeletal muscle fibrosis.

Utrophin modulator drugs as potential therapies for Duchenne and Becker muscular dystrophies

Utrophin is an autosomal paralogue of dystrophin, a protein whose deficit causes Duchenne and Becker muscular dystrophies (DMD/BMD). Utrophin is naturally overexpressed at the sarcolemma of mature dystrophin‐deficient fibres in DMD and BMD patients as well as in the mdx Duchenne mouse model. Dystrophin and utrophin can co‐localise in human foetal muscle, in the dystrophin‐competent fibres from DMD/BMD carriers, and revertant fibre clusters in biopsies from DMD patients. These findings suggest that utrophin overexpression could act as a surrogate, compensating for the lack of dystrophin, and, as such, it could be used in combination with dystrophin restoration therapies. Different strategies to overexpress utrophin are currently under investigation. In recent years, many compounds have been reported to modulate utrophin expression efficiently in preclinical studies and ameliorate the dystrophic phenotype in animal models of the disease. In this manuscript, we discuss the current knowledge on utrophin protein and the different mechanisms that modulate its expression in skeletal muscle. We also include a comprehensive review of compounds proposed as utrophin regulators and, as such, potential therapeutic candidates for these muscular dystrophies.

PMO-based let-7c site blocking oligonucleotide (SBO) mediated utrophin upregulation in mdx mice, a therapeutic approach for Duchenne muscular dystrophy (DMD)

Upregulation of utrophin, a dystrophin related protein, is considered a promising therapeutic approach for Duchenne muscular dystrophy (DMD). Utrophin expression is repressed at the post-transcriptional level by a set of miRNAs, among which let-7c is evolutionarily highly conserved. We designed PMO-based SBOs complementary to the let-7c binding site in UTRN 3′UTR, with the goal of inhibiting let-7c interaction with UTRN mRNA and thus upregulating utrophin. We used the C2C12UTRN5′luc3′ reporter cell line in which the 5′- and 3′-UTRs of human UTRN sequences flank luciferase, for reporter assays and the C2C12 cell line for utrophin western blots, to independently evaluate the site blocking efficiency of a series of let-7c PMOs in vitro. Treatment of one-month old mdx mice with the most effective let-7c PMO (i.e. S56) resulted in ca. two-fold higher utrophin protein expression in skeletal muscles and the improvement in dystrophic pathophysiology in mdx mice, in vivo. In summary, we show that PMO-based let-7c SBO has potential applicability for upregulating utrophin expression as a therapeutic approach for DMD.

Tiny Regulators of Massive Tissue: MicroRNAs in Skeletal Muscle Development, Myopathies, and Cancer Cachexia

Skeletal muscles are the largest tissues in our body and the physiological function of muscle is essential to every aspect of life. The regulation of development, homeostasis, and metabolism is critical for the proper functioning of skeletal muscle. Consequently, understanding the processes involved in the regulation of myogenesis is of great interest. Non-coding RNAs especially microRNAs (miRNAs) are important regulators of gene expression and function. MiRNAs are small (~22 nucleotides long) noncoding RNAs known to negatively regulate target gene expression post-transcriptionally and are abundantly expressed in skeletal muscle. Gain- and loss-of function studies have revealed important roles of this class of small molecules in muscle biology and disease. In this review, we summarize the latest research that explores the role of miRNAs in skeletal muscle development, gene expression, and function as well as in muscle disorders like sarcopenia and Duchenne muscular dystrophy (DMD). Continuing with the theme of the current review series, we also briefly discuss the role of miRNAs in cancer cachexia.

Circulating Coding and Long Non-Coding RNAs as Potential Biomarkers of Idiopathic Pulmonary Fibrosis

BACKGROUND

Idiopathic Pulmonary Fibrosis (IPF) is a chronic degenerative disease with a median survival of 2-5 years after diagnosis. Therefore, IPF patient identification represents an important and challenging clinical issue. Current research is still searching for novel reliable non-invasive biomarkers. Therefore, we explored the potential use of long non-coding RNAs (lncRNAs) and mRNAs as biomarkers for IPF.

METHODS

We first performed a whole transcriptome analysis using microarray (n = 14: 7 Control, 7 IPF), followed by the validation of selected transcripts through qPCRs in an independent cohort of 95 subjects (n = 95: 45 Control, 50 IPF). Diagnostic performance and transcript correlation with functional/clinical data were also analyzed.

RESULTS

1059 differentially expressed transcripts were identified. We confirmed the downregulation of FOXF1 adjacent non-coding developmental regulatory RNA (FENDRR) lncRNA, hsa_circ_0001924 circularRNA, utrophin (UTRN) and Y-box binding protein 3 (YBX3) mRNAs. The two analyzed non-coding RNAs correlated with Forced Vital Capacity (FVC)% and Diffusing Capacity of the Lung for carbon monoxide (DLCO)% functional data, while coding RNAs correlated with smock exposure. All analyzed transcripts showed excellent performance in IPF identification with Area Under the Curve values above 0.87; the most outstanding one was YBX3: AUROC 0.944, CI 95% = 0.895-0.992, sensitivity = 90%, specificity = 88.9%, p-value = 1.02 × 10^-13.

CONCLUSIONS

This study has identified specific transcript signatures in IPF suggesting that validated transcripts and microarray data could be useful for the potential future identification of RNA molecules as non-invasive biomarkers for IPF.

Long Non-coding RNAs Are Differentially Expressed After Different Exercise Training Programs

Background

Molecular regulation related to the health benefits of different exercise modes remains unclear. Long non-coding RNAs (lncRNAs) have emerged as an RNA class with regulatory functions in health and diseases. Here, we analyzed the expression of lncRNAs after different exercise training programs and their possible modes of action related to physical exercise adaptations.

Methods

Public high-throughput RNA-seq data (skeletal muscle biopsies) were downloaded, and bioinformatics analysis was performed. We primarily analyzed data reports of 12 weeks of resistance training (RT), high-intensity interval training (HIIT), and combined (CT) exercise training. In addition, we analyzed data from 8 weeks of endurance training (ET). Differential expression analysis of lncRNAs was performed, and an adjusted P-value < 0.1 and log2 (fold change) ≥0.5 or ≤-0.5 were set as the cutoff values to identify differentially expressed lncRNAs (DELs).

Results

We identified 204 DELs after 12 weeks of HIIT, 43 DELs after RT, and 15 DELs after CT. Moreover, 52 lncRNAs were differentially expressed after 8 weeks of ET. The lncRNA expression pattern after physical exercise was very specific, with distinct expression profiles for the different training programs, where few lncRNAs were common among the exercise types. LncRNAs may regulate molecular responses to exercise, such as collagen fibril organization, extracellular matrix organization, myoblast and plasma membrane fusion, skeletal muscle contraction, synaptic transmission, PI3K and TORC regulation, autophagy, and angiogenesis.

Conclusion

For the first time, we show that lncRNAs are differentially expressed in skeletal muscle after different physical exercise programs, and these lncRNAs may act in various biological processes related to physical activity adaptations.

Genome Editing-Mediated Utrophin Upregulation in Duchenne Muscular Dystrophy Stem Cells

Utrophin upregulation is considered a promising therapeutic strategy for Duchenne muscular dystrophy (DMD). A number of microRNAs (miRNAs) post-transcriptionally regulate utrophin expression by binding their cognate sites in the 3′ UTR. Previously we have shown that miRNA: UTRN repression can be alleviated using miRNA let-7c site blocking oligonucleotides (SBOs) to achieve utrophin upregulation and functional improvement in mdx mice. Here, we used CRISPR/Cas9-mediated genome editing to delete five miRNA binding sites (miR-150, miR-296-5p, miR-133b, let-7c, miR-196b) clustered in a 500 bp inhibitory miRNA target region (IMTR) within the UTRN 3′ UTR, for achieving higher expression of endogenous utrophin. Deleting the UTRN IMTR in DMD patient-derived human induced pluripotent stem cells (DMD-hiPSCs) resulted in ca. 2-fold higher levels of utrophin protein. Differentiation of the UTRN edited DMD-hiPSCs (UTRNΔIMTR) by MyoD overexpression resulted in increased sarcolemmal α-sarcoglycan staining consistent with improved dystrophin glycoprotein complex (DGC) restoration. These results demonstrate that CRISPR/Cas9-based UTRN genome editing offers a novel utrophin upregulation therapeutic strategy applicable to all DMD patients, irrespective of the dystrophin mutation status.

Long noncoding RNA HULC accelerates the growth of human liver cancer stem cells by upregulating CyclinD1 through miR675-PKM2 pathway via autophagy

BACKGROUND

The functions of HULC have been demonstrated in several cancers. However, its mechanism has not been elucidated in human liver cancer stem cells.

METHODS

Liver cancer stem cells were isolated from Huh7 cells; gene infection and tumorigenesis test in vitro and in vivo were performed.

RESULTS

We demonstrate that HULC promotes growth of liver cancer stem cells in vitro and in vivo. Mechanistically, HULC enhances the expression of Sirt1 dependent on miR675 and then induces the cellular autophagy through Sirt1. HULC enhances CyclinD1 and thereby increases pRB and inhibited P21 WAF1/CIP 1 via autophagy-miR675-PKM2 pathway in human liver cancer stem cells. Ultimately, our results demonstrate that CyclinD1 is required for the oncogenic functions of HULC in liver cancer stem cells.

CONCLUSIONS

It reveals the key molecular signaling pathways for HULC and provides important basic information for finding effective tumor therapeutic targets based on HULC.

Comprehensive analysis of the expression profile of circRNAs and their predicted protein-coding ability in the muscle of mdx mice

Duchenne muscular dystrophy (DMD) is an X-linked genetic neuromuscular disease that is characterized by progressive muscle wasting and by defects in the regenerative capacity and inflammatory infiltration of muscle. Many noncoding RNAs (ncRNAs) participate in the pathophysiological mechanisms of this disease. To explore the role of circular RNAs (circRNAs), a type of ncRNAs, in DMD, microarray analysis was performed to explore the expression patterns of circRNAs in the gastrocnemius muscles in mdx mice, a DMD animal model, and C57 mice. The microarray data were validated by qRT-PCR. Further, gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed to predict the function of the differentially expressed circRNAs (DEcRNAs). A circRNA/microRNA (miRNA) interaction network was predicted by bioinformatics. We also predicted the protein-coding ability of the circRNAs based on their N⁶-methyladenosine motifs and open-reading frames. We identified 197 differentially expressed circRNAs between mdx mice and C57 mice. Of the 197 DEcRNAs, 6 circRNAs were randomly selected to validate the microarray data, and twenty-two circRNAs were randomly selected to construct a circRNA/miRNA interaction network. Bioinformatics analysis showed that the linear counterparts of the DEcRNAs were mainly associated with muscle structure, nervous system development, and the cAMP signaling pathway. A total of 189 circRNAs were predicted to have protein-coding potential, and there were 98 circRNAs that could potentially be translated into polypeptides with 150 or more amino acids. This work described the expression pattern of circRNAs in mdx mice and indicated that circRNAs may play pivotal roles in the pathophysiological mechanisms of DMD.

Long non coding RNA H19: An emerging therapeutic target in fibrosing diseases

Fibrosis is characterised by excessive deposition of the extracellular matrix (ECM) and develops because of fibroblast differentiation during the process of inflammation. There are few effective treatment options for this diseases due to the aetiology of fibrosis is not completely clarified. Long non-coding RNAs (lncRNAs), a type of ncRNA with a length of greater than 200 nucleotides without evident protein coding function, are important regulators of most biological and pathological processes, including participation, regulation or mediation of disease development. Among them, H19 is recently discovered as a class of lncRNAs which is related to fibrotic disease and inflammation. These observations implied a potential role for H19 as a promising therapeutic targets for treatment of fibrotic diseases. In this review, we will describe the characteristics of H19 and summarise recent advances in the mechanisms of H19 in the process of fibrosis. Finally, we will succinctly discuss the recent progress of the involvement of H19 in the development and pathogenesis of fibrosis diseases.

miRNA Profiling for Early Detection and Treatment of Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is an X-linked recessive genetic disorder caused by out of frame mutations in the dystrophin gene. The hallmark symptoms of the condition include progressive degeneration of skeletal muscle, cardiomyopathy, and respiratory dysfunction. The most recent advances in therapeutic strategies for the treatment of DMD involve exon skipping or administration of minidystrophin, but these strategies are not yet universally available, nor have they proven to be a definitive cure for all DMD patients. Early diagnosis and tracking of symptom progression of DMD usually relies on creatine kinase tests, evaluation of patient performance in various ambulatory assessments, and detection of dystrophin from muscle biopsies, which are invasive and painful for the patient. While the current research focuses primarily on restoring functional dystrophin, accurate and minimally invasive methods to detect and track both symptom progression and the success of early DMD treatments are not yet available. In recent years, several groups have identified miRNA signature changes in DMD tissue samples, and a number of promising studies consistently detected changes in circulating miRNAs in blood samples of DMD patients. These results could potentially lead to non-invasive detection methods, new molecular approaches to treating DMD symptoms, and new methods to monitor of the efficacy of the therapy. In this review, we focus on the role of circulating miRNAs in DMD and highlight their potential both as a biomarker in the early detection of disease and as a therapeutic target in the prevention and treatment of DMD symptoms.

Non-Coding RNA Regulates the Myogenesis of Skeletal Muscle Satellite Cells, Injury Repair and Diseases

Skeletal muscle myogenesis and injury-induced muscle regeneration contribute to muscle formation and maintenance. As myogenic stem cells, skeletal muscle satellite cells have the ability to proliferate, differentiate and self-renew, and are involved in muscle formation and muscle injury repair. Accumulating evidence suggests that non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), are widely involved in the regulation of gene expression during skeletal muscle myogenesis, and their abnormal expression is associated with a variety of muscle diseases. From the perspective of the molecular mechanism and mode of action of ncRNAs in myogenesis, this review aims to summarize the role of ncRNAs in skeletal muscle satellite cells’ myogenic differentiation and in muscle disease, and systematically analyze the mechanism of ncRNAs in skeletal muscle development. This work will systematically summarize the role of ncRNAs in myogenesis and provide reference targets for the treatment of various muscle diseases, such as muscle dystrophy, atrophy and aberrant hypertrophy.