Long noncoding RNA DANCR regulates miR-1305-Smad 4 axis to promote chondrogenic differentiation of human synovium-derived mesenchymal stem cells. Biosci Rep. 2017;37:pii: BSR20170347. [PMID: 28674107 PMCID: PMC5520215 DOI: 10.1042/bsr20170347]

N6-Methyladenosine in Cell-Fate Determination of BMSCs: From Mechanism to Applications

The methylation of adenosine base at the nitrogen-6 position is referred to as "N6-methyladenosine (m6A)" and is one of the most prevalent epigenetic modifications in eukaryotic mRNA and noncoding RNA (ncRNA). Various m6A complex components known as "writers," "erasers," and "readers" are involved in the function of m6A. Numerous studies have demonstrated that m6A plays a crucial role in facilitating communication between different cell types, hence influencing the progression of diverse physiological and pathological phenomena. In recent years, a multitude of functions and molecular pathways linked to m6A have been identified in the osteogenic, adipogenic, and chondrogenic differentiation of bone mesenchymal stem cells (BMSCs). Nevertheless, a comprehensive summary of these findings has yet to be provided. In this review, we primarily examined the m6A alteration of transcripts associated with transcription factors (TFs), as well as other crucial genes and pathways that are involved in the differentiation of BMSCs. Meanwhile, the mutual interactive network between m6A modification, miRNAs, and lncRNAs was intensively elucidated. In the last section, given the beneficial effect of m6A modification in osteogenesis and chondrogenesis of BMSCs, we expounded upon the potential utility of m6A-related therapeutic interventions in the identification and management of human musculoskeletal disorders manifesting bone and cartilage destruction, such as osteoporosis, osteomyelitis, osteoarthritis, and bone defect.

Unveiling Mesenchymal Stem Cells' Regenerative Potential in Clinical Applications: Insights in miRNA and lncRNA Implications

It is now widely recognized that mesenchymal stem cells (MSCs) possess the capacity to differentiate into a wide array of cell types. Numerous studies have identified the role of lncRNA in the regulation of MSC differentiation. It is important to elucidate the role and interplay of microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) in the regulation of signalling pathways that govern MSC function. Furthermore, miRNAs and lncRNAs are important clinical for innovative strategies aimed at addressing a wide spectrum of existing and emerging disease. Hence it is important to consider their impact on MSC function and differentiation. Examining the data available in public databases, we have collected the literature containing the latest discoveries pertaining to human stem cells and their potential in both fundamental research and clinical applications. Furthermore, we have compiled completed clinical studies that revolve around the application of MSCs, shedding light on the opportunities presented by harnessing the regulatory potential of miRNAs and lncRNAs. This exploration of the therapeutic possibilities offered by miRNAs and lncRNAs within MSCs unveils exciting prospects for the development of precision therapies and personalized treatment approaches. Ultimately, these advancements promise to augment the efficacy of regenerative strategies and produce positive outcomes for patients. As research in this field continues to evolve, it is imperative to explore and exploit the vast potential of miRNAs and lncRNAs as therapeutic agents. The findings provide a solid basis for ongoing investigations, fuelling the quest to fully unlock the regenerative potential of MSCs.

The emerging role of lncRNAs in osteoarthritis development and potential therapy

Osteoarthritis impairs the functions of various joints, such as knees, hips, hands and spine, which causes pain, swelling, stiffness and reduced mobility in joints. Multiple factors, including age, joint injuries, obesity, and mechanical stress, could contribute to osteoarthritis development and progression. Evidence has demonstrated that genetics and epigenetics play a critical role in osteoarthritis initiation and progression. Noncoding RNAs (ncRNAs) have been revealed to participate in osteoarthritis development. In this review, we describe the pivotal functions and molecular mechanisms of numerous lncRNAs in osteoarthritis progression. We mention that long noncoding RNAs (lncRNAs) could be biomarkers for osteoarthritis diagnosis, prognosis and therapeutic targets. Moreover, we highlight the several compounds that alleviate osteoarthritis progression in part via targeting lncRNAs. Furthermore, we provide the future perspectives regarding the potential application of lncRNAs in diagnosis, treatment and prognosis of osteoarthritis.

MiR-145-5p restrains chondrogenic differentiation of synovium-derived mesenchymal stem cells by suppressing TLR4

Osteoarthritis (OA) is a progressive degeneration of articular cartilage with involvement of synovial membrane, and subchondral bone. Recently, cell-based therapies, including the application of stem cells such as mesenchymal stem cells (MSCs), have been introduced for restoration of the articular cartilage. Toll-like receptors (TLRs) were reported to participate in OA progression and MSC chondrogenesis. Here, the role and molecular mechanism of toll like receptor 4 (TLR4) in chondrogenic differentiation of synovium-derived MSCs (SMSCs) were investigated. Molecular markers (CD44, CD90, CD45 and CD14) on SMSC surfaces were identified by flow cytometry. Multi-potential differentiation capacities of SMSCs for chondrogenesis, adipogenesis and osteogenesis were examined by Alcian blue, oil red O and Alizarin red staining, respectively. TLR4 and miR-145-5p levels in SMSCs were assessed using RT-qPCR. The protein expression of TGFB3, Col II, SOX9 and Aggrecan in SMSCs was tested by western blotting. Cytokine secretions were analyzed with ELISA for IL-1β and IL-6. Intracellular NAD⁺ content and NAD⁺/NADH ratio were assessed. The interaction between miR-145-5p and TLR4 was confirmed by RNA pulldown and luciferase reporter assays. In this study, SMSCs were identified to have immunophenotypic characteristics of MSCs. TLR4 knockdown inhibited chondrogenic and osteogenic differentiation of SMSCs. Mechanistically, TLR4 was targeted by miR-145-5p in SMSCs. Moreover, TLR4 elevation offset the inhibitory impact of miR-145-5p upregulation on chondrogenic differentiation of SMSCs. Overall, miR-145-5p restrains chondrogenesis of SMSCs by suppressing TLR4.

Integrated regulation of chondrogenic differentiation in mesenchymal stem cells and differentiation of cancer cells

Chondrogenesis is the formation of chondrocytes and cartilage tissues and starts with mesenchymal stem cell (MSC) recruitment and migration, condensation of progenitors, chondrocyte differentiation, and maturation. The chondrogenic differentiation of MSCs depends on co-regulation of many exogenous and endogenous factors including specific microenvironmental signals, non-coding RNAs, physical factors existed in culture condition, etc. Cancer stem cells (CSCs) exhibit self-renewal capacity, pluripotency and cellular plasticity, which have the potential to differentiate into post-mitotic and benign cells. Accumulating evidence has shown that CSCs can be induced to differentiate into various benign cells including adipocytes, fibrocytes, osteoblast, and so on. Retinoic acid has been widely used in the treatment of acute promyelocytic leukemia. Previous study confirmed that polyploid giant cancer cells, a type of cancer stem-like cells, could differentiate into adipocytes, osteocytes, and chondrocytes. In this review, we will summarize signaling pathways and cytokines in chondrogenic differentiation of MSCs. Understanding the molecular mechanism of chondrogenic differentiation of CSCs and cancer cells may provide new strategies for cancer treatment.

Role of lncRNAs into Mesenchymal Stromal Cell Differentiation

Currently, findings support that 75% of the human genome is actively transcribed, but only 2% is translated into a protein, according to databases such as ENCODE (Encyclopedia of DNA Elements) [1]. The development of high-throughput sequencing technologies, computational methods for genome assembly and biological models have led to the realization of the importance of the previously unconsidered non-coding fraction of the genome. Along with this, noncoding RNAs have been shown to be epigenetic, transcriptional and post-transcriptional regulators in a large number of cellular processes [2]. Within the group of non-coding RNAs, lncRNAs represent a fascinating field of study, given the functional versatility in their mode of action on their molecular targets. In recent years, there has been an interest in learning about lncRNAs in MSC differentiation. The aim of this review is to address the signaling mechanisms where lncRNAs are involved, emphasizing their role in either stimulating or inhibiting the transition to differentiated cell. Specifically, the main types of MSC differentiation are discussed: myogenesis, osteogenesis, adipogenesis and chondrogenesis. The description of increasingly new lncRNAs reinforces their role as players in the well-studied field of MSC differentiation, allowing a step towards a better understanding of their biology and their potential application in the clinic.

SMAD4 contributes to chondrocyte and osteocyte development

Different cellular and molecular mechanisms contribute to chondrocyte and osteocyte development. Although vital roles of the mothers against decapentaplegic homolog 4 (also called 'SMAD4') have been discussed in different cancers and stem cell-related studies, there are a few reviews summarizing the roles of this protein in the skeletal development and bone homeostasis. In order to fill this gap, we discuss the critical roles of SMAD4 in the skeletal development. To this end, we review the different signalling pathways and also how SMAD4 defines stem cell features. We also elaborate how the epigenetic factors-ie DNA methylation, histone modifications and noncoding RNAs-make a contribution to the chondrocyte and osteocyte development. To better grasp the important roles of SMAD4 in the cartilage and bone development, we also review the genotype-phenotype correlation in animal models. This review helps us to understand the importance of the SMAD4 in the chondrocyte and bone development and the potential applications for therapeutic goals.

The Role of Long Non-Coding RNAs and Circular RNAs in Bone Regeneration: Modulating MiRNAs Function

Although bone is a self-healing organ and is able to repair and restore most fractures, large bone fractures, about 10%, are not repairable. Bone grafting, as a gold standard, and bone tissue engineering using biomaterials, growth factors, and stem cells have been developed to restore large bone defects. Since bone regeneration is a complex and multiple-step process and the majority of the human genome, about 98%, is composed of the non-protein-coding regions, non-coding RNAs (ncRNAs) play essential roles in bone regeneration. Recent studies demonstrated that long ncRNAs (lncRNAs) and circular RNAs (circRNAs), as members of ncRNAs, are widely involved in bone regeneration by interaction with microRNAs (miRNAs) and constructing a lncRNA or circRNA/miRNA/mRNA regulatory network. The constructed network regulates the differentiation of stem cells into osteoblasts and their commitment to osteogenesis. This review will present the structure and biogenesis of lncRNAs and circRNAs, the mechanism of bone repair, and the bone tissue engineering in bone defects. Finally, we will discuss the role of lncRNAs and circRNAs in osteogenesis and bone fracture healing through constructing various lncRNA or circRNA/miRNA/mRNA networks and the involved pathways. This article is protected by copyright. All rights reserved.

LncRNA NONHSAT030515 promotes the chondrogenic differentiation of human adipose-derived stem cells via regulating the miR-490-5p/BMPR2 axis

BACKGROUND

Chondrogenic differentiation of human adipose-derived stem cells (hADSCs) is important for cartilage generation and degradation. LncRNAs play an essential role in stem cell differentiation. However, the role and mechanism of lncRNA in hADSCs remain unclear. Our previous study showed that miR-490-5p was downregulated during chondrogenic differentiation of hADSCs. In this study, we investigated the effect and mechanism of lncRNA NONHSAT030515 interacting with miR-490-5p on chondrogenic differentiation of hADSCs.

METHODS

Alcian blue staining was used to assess the deposition of chondromatrix proteins following chondrogenic differentiation of human adipose stem cells. Immunohistochemistry was used to evaluate the expression of collagenII. TargetScan, miRTarBase and miRDB database analyses were applied to find the miRNA and target genes of lncRNA NONHSAT030515. A dual luciferase experiment was conducted to identify the direct target of NONHSAT030515. pcDNA3.1- NONHSAT030515 transfection and sh- NONHSAT030515 treatment were conducted to verify the role of lncRNA NONHSAT030515 in chondrogenic differentiation. The levels of Aggrecan, SOX9 and COL2A1 were analyzed by qRT-PCR and Western blot assay.

RESULTS

Alcian blue staining, immunocytochemical, qRT-PCR, and Western blot have determined that lncRNA NONHSAT030515 can promote the chondrogenic differentiation of hADSCs. MiR-490- 5p was the direct target of NONHSAT030515, while BMPR2 was the target gene. This result was confirmed by luciferase reporter assay. Up-regulation of NONHSAT030515 promoted BMPR2 protein expression and promoted chondrogenic differentiation, whereas down-regulation of NONHSAT030515 caused completely opposite results.

CONCLUSION

LncRNA NONHSAT030515 promotes the chondrogenic differentiation of hADSCs through increasing BMPR2 expression by regulating miR-490- 5p.

CRISPR activation of long non-coding RNA DANCR promotes bone regeneration

Healing of large calvarial bone defects in adults adopts intramembranous pathway and is difficult. Implantation of adipose-derived stem cells (ASC) that differentiate towards chondrogenic lineage can switch the bone repair pathway and improve calvarial bone healing. Long non-coding RNA DANCR was recently uncovered to promote chondrogenesis, but its roles in rat ASC (rASC) chondrogenesis and bone healing stimulation have yet to be explored. Here we first verified that DANCR expression promoted rASC chondrogenesis, thus we harnessed CRISPR activation (CRISPRa) technology to upregulate endogenous DANCR, stimulate rASC chondrogenesis and improve calvarial bone healing in rats. We generated 4 different dCas9-VPR orthologues by fusing a tripartite transcription activator domain VPR to catalytically dead Cas9 (dCas9) derived from 4 different bacteria, and compared the degree of activation using the 4 different dCas9-VPR. We unveiled surprisingly that the most commonly used dCas9-VPR derived from Streptococcus pyogenes barely activated DANCR. Nonetheless dCas9-VPR from Staphylococcus aureus (SadCas9-VPR) triggered efficient activation of DANCR in rASC. Delivery of SadCas9-VPR and the associated guide RNA into rASC substantially enhanced chondrogenic differentiation of rASC and augmented cartilage formation in vitro. Implantation of the engineered rASC remarkably potentiated the calvarial bone healing in rats. Furthermore, we identified that DANCR improved the rASC chondrogenesis through inhibition of miR-203a and miR-214. These results collectively proved that DANCR activation by SadCas9-VPR-based CRISPRa provides a novel therapeutic approach to improving calvarial bone healing.

Long Non-coding RNA Regulation of Mesenchymal Stem Cell Homeostasis and Differentiation: Advances, Challenges, and Perspectives

Given the self-renewal, multi-differentiation, immunoregulatory, and tissue maintenance properties, mesenchymal stem cells (MSCs) are promising candidates for stem cell-based therapies. Breakthroughs have been made in uncovering MSCs as key contributors to homeostasis and the regenerative repair of tissues and organs derived from three germ layers. MSC differentiation into specialized cell types is sophisticatedly regulated, and accumulating evidence suggests long non-coding RNAs (lncRNAs) as the master regulators of various biological processes including the maintenance of homeostasis and multi-differentiation functions through epigenetic, transcriptional, and post-translational mechanisms. LncRNAs are ubiquitous and generally referred to as non-coding transcripts longer than 200 bp. Most lncRNAs are evolutionary conserved and species-specific; however, the weak conservation of their sequences across species does not affect their diverse biological functions. Although numerous lncRNAs have been annotated and studied, they are nevertheless only the tip of the iceberg; the rest remain to be discovered. In this review, we characterize MSC functions in homeostasis and highlight recent advances on the functions and mechanisms of lncRNAs in regulating MSC homeostasis and differentiation. We also discuss the current challenges and perspectives for understanding the roles of lncRNAs in MSC functions in homeostasis, which could help develop promising targets for MSC-based therapies.

Linc-ROR promotes mesenchymal stem cells chondrogenesis and cartilage formation via regulating SOX9 expression

OBJECTIVE

The present study is to characterize the role of long intergenic non-coding RNA, regulator of reprogramming (linc-ROR) in bone marrow mesenchymal stem cell (BMSCs) chondrogenesis, cartilage formation and OA development.

METHODS

Linc-ROR expression pattern in articular cartilage tissue sample from OA patients were studied by real-time PCR. Linc-ROR lentivirus mediated BMSCs were constructed. In vitro micromass cultured BMSCs chondrogenesis or in vivo MeHA hydrogel encapsulated BMSCs cartilage formation activity were studied. Linc-ROR associating miRNAs which repressed SOX9 expression were characterized by luciferase assay, real-time PCR and Western blot. Linc-ROR was co-transfected with miRNAs into BMSCs to study its rescue effect on SOX9 expression and chondrogenesis activity.

RESULTS

Linc-ROR was down-regulated in articular cartilage tissue from OA patients and was positively correlated with the expression level of SOX9 (R² = 0.43). Linc-ROR expression was upregulated during BMSCs chondrogenesis. Linc-ROR ectopic expression significantly promoted in vitro BMSCs chondrogenesis and in vivo cartilage formation activities as revealed by safranin O, alcian blue and COL II staining. The mRNA expression level of chondrogenesis markers including COL II, SOX9 and ACAN were increased, and the hypertrophy markers MMP13 and COL X were decreased upon linc-ROR overexpression in BMSCs. Linc-ROR functioned as a miRNA sponge for miR-138 and miR-145. Both miR-138 and miR-145 suppressed BMSCs chondrogenesis activity and SOX9 expression, while co-expression of linc-ROR displayed a rescuing effect.

CONCLUSIONS

Taken together, linc-ROR modulated BMSCs chondrogenesis differentiation and cartilage formation by acting as a competing endogenous RNA for miR-138 and miR-145 and activating SOX9 expression. Linc-ROR could be considered as a new diagnostic and therapeutic target for OA treatment.

Involvement of the long noncoding RNA H19 in osteogenic differentiation and bone regeneration

Osteogenic differentiation and bone regeneration are complex processes involving multiple genes and multiple steps. In this review, we summarize the effects of the long noncoding RNA (lncRNA) H19 on osteogenic differentiation.

Osteogenic differentiation includes matrix secretion and calcium mineralization as hallmarks of osteoblast differentiation and the absorption of calcium and phosphorus as hallmarks of osteoclast differentiation. Mesenchymal stem cells (MSCs) form osteoprogenitor cells, pre-osteoblasts, mature osteoblasts, and osteocytes through induction and differentiation. lncRNAs regulate the expression of coding genes and play essential roles in osteogenic differentiation and bone regeneration. The lncRNA H19 is known to have vital roles in osteogenic induction.

This review highlights the role of H19 as a novel target for osteogenic differentiation and the promotion of bone regeneration.

lncRNA-CRNDE regulates BMSC chondrogenic differentiation and promotes cartilage repair in osteoarthritis through SIRT1/SOX9

Osteoarthritis (OA) is the most common chronic and degenerative joint disease. Although traditional OA medications can partially relieve pain, these medications cannot completely cure OA. Therefore, it is particularly important to find an effective treatment for OA. This study explored the function of long non-coding RNA (lncRNA)-colorectal neoplasia differentially expressed gene (CRNDE) in the chondrogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and the underlying molecular mechanism, aiming to develop a new treatment method for osteoarthritis. BMSCs were isolated from rat bone marrow using the gradient centrifugation method. And BMSC chondrogenic differentiation was induced with chondrogenic medium. The expression of lncRNA-CRNDE was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Silent information regulator factor 2-related enzyme 1 (SIRT1) and cartilage marker genes Aggrecan and collagen 2 (α1) protein expression were researched using western blot. Alcian blue staining was employed to examine the content of cartilage matrix proteoglycan glycosaminoglycan (GAG). The interaction between lncRNA-CRNDE and SIRT1 was detected by RNA pull-down and RNA immunoprecipitation (RIP) assay. Ubiquitination experiments were performed to measure the ubiquitination level of SIRT1. The combination between SMAD ubiquitination regulatory factor 2 (SMURF2) and SIRT1, as well as SRY-related high-mobility-group box 9 (SOX9) and collagen 2 (α1) promoter, was detected by Co-immunoprecipitation or ChIP. With the prolongation of induction time, the expression of lncRNA-CRNDE, SIRT1, cartilage marker genes Aggrecan and collagen 2 (α1) in BMSC osteogenic differentiation was gradually increased. Also, the content of cartilage matrix proteoglycan GAG was gradually elevated with the extension of the induction time. Further increase in the expression of SIRT1, cartilage marker genes Aggrecan and collagen 2 (α1) by overexpression of lncRNA-CRNDE also indicated elevated GAG content. RNA pull-down and RIP assay confirmed the binding between lncRNA-CRNDE and SIRT1. qRT-PCR and western blot showed that interference with lncRNA-CRNDE significantly inhibited the protein expression of SIRT1. BMSCs transfected with si-CRNDE increased ubiquitination levels of SIRT1 mediated by the E3 ligase SMURF2, leading to the reduced protein stability of SIRT1. However, overexpression of lncRNA-CRNDE increased the binding ability of SOX9 and collagen 2 (α1) promoter, which was reversed by the simultaneous transfection of CRNDE overexpression (pcDNA-CRNDE) and SIRT1 small interfering RNA (si-SIRT1). lncRNA-CRNDE regulates BMSC chondrogenic differentiation to promote cartilage repair in osteoarthritis through SIRT1/SOX9.

Differentiation Antagonizing Non-protein Coding RNA Knockdown Alleviates Lipopolysaccharide-Induced Inflammatory Injury and Apoptosis in Human Chondrocyte Primary Chondrocyte Cells Through Upregulating miRNA-19a-3p

Objective

To confirm the role of long noncoding RNA differentiation antagonizing non‐protein coding RNA (DANCR) in chondrocyte inflammatory injury in osteoarthritis (OA) in vitro, as well as its molecular mechanism.

Methods

Human primary chondrocytes were treated with lipopolysaccharide (LPS) to construct a chondrocyte inflammatory injury in human OA cell model. Gene expression was detected using real‐time quantitative polymerase chain reaction. Cell inflammatory injury was evaluated by Cell Counting Kit‐8 assay, flow cytometry, and enzyme‐linked immunosorbent assay. The interplay between miRNA‐19a‐3p (miR‐19a) and DANCR was validated by dual‐luciferase reporter assay and RNA immunoprecipitation.

Results

Expression of DANCR was upregulated, and miR‐19a was downregulated in human OA cartilage and LPS‐treated primary chondrocytes in vitro. Moreover, DANCR expression was inversely correlated with miR‐19a in OA patients. LPS reduced cell viability and increased the apoptotic rate and secretion of interleukin (IL)‐1β, IL‐6, IL‐8, as well as tumor necrosis factor (TNF)‐α in primary chondrocyte cells in vitro, suggesting an inflammatory injury model of OA. Functionally, knockdown of DANCR could attenuate LPS‐induced apoptosis and inflammatory response, as evidenced by improved cell viability, and reduced apoptotic rate and products of IL‐1β, IL‐6, IL‐8, and TNF‐α. Notably, DANCR negatively regulated miR‐19a expression, presumably via sponging. Furthermore, miR‐19a deletion eliminated the effect of DANCR knockdown on apoptosis and the inflammatory response of primary chondrocytes under LPS stress.

Conclusion

Differentiation antagonizing non‐protein coding RNA silencing could protect human chondrocyte cells against LPS‐induced inflammatory injury and apoptosis through targeting miR‐19a, suggesting a vital role of the DANCR/miR‐19a axis in OA.

ACE2 Interaction Networks in COVID-19: A Physiological Framework for Prediction of Outcome in Patients with Cardiovascular Risk Factors

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (coronavirus disease 2019; COVID-19) is associated with adverse outcomes in patients with cardiovascular disease (CVD). The aim of the study was to characterize the interaction between SARS-CoV-2 and Angiotensin-Converting Enzyme 2 (ACE2) functional networks with a focus on CVD.

METHODS

Using the network medicine approach and publicly available datasets, we investigated ACE2 tissue expression and described ACE2 interaction networks that could be affected by SARS-CoV-2 infection in the heart, lungs and nervous system. We compared them with changes in ACE-2 networks following SARS-CoV-2 infection by analyzing public data of human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). This analysis was performed using the Network by Relative Importance (NERI) algorithm, which integrates protein-protein interaction with co-expression networks. We also performed miRNA-target predictions to identify which miRNAs regulate ACE2-related networks and could play a role in the COVID19 outcome. Finally, we performed enrichment analysis for identifying the main COVID-19 risk groups.

RESULTS

We found similar ACE2 expression confidence levels in respiratory and cardiovascular systems, supporting that heart tissue is a potential target of SARS-CoV-2. Analysis of ACE2 interaction networks in infected hiPSC-CMs identified multiple hub genes with corrupted signaling which can be responsible for cardiovascular symptoms. The most affected genes were EGFR (Epidermal Growth Factor Receptor), FN1 (Fibronectin 1), TP53, HSP90AA1, and APP (Amyloid Beta Precursor Protein), while the most affected interactions were associated with MAST2 and CALM1 (Calmodulin 1). Enrichment analysis revealed multiple diseases associated with the interaction networks of ACE2, especially cancerous diseases, obesity, hypertensive disease, Alzheimer's disease, non-insulin-dependent diabetes mellitus, and congestive heart failure. Among affected ACE2-network components connected with the SARS-Cov-2 interactome, we identified AGT (Angiotensinogen), CAT (Catalase), DPP4 (Dipeptidyl Peptidase 4), CCL2 (C-C Motif Chemokine Ligand 2), TFRC (Transferrin Receptor) and CAV1 (Caveolin-1), associated with cardiovascular risk factors. We described for the first time miRNAs which were common regulators of ACE2 networks and virus-related proteins in all analyzed datasets. The top miRNAs regulating ACE2 networks were miR-27a-3p, miR-26b-5p, miR-10b-5p, miR-302c-5p, hsa-miR-587, hsa-miR-1305, hsa-miR-200b-3p, hsa-miR-124-3p, and hsa-miR-16-5p.

CONCLUSION

Our study provides a complete mechanistic framework for investigating the ACE2 network which was validated by expression data. This framework predicted risk groups, including the established ones, thus providing reliable novel information regarding the complexity of signaling pathways affected by SARS-CoV-2. It also identified miRNAs that could be used in personalized diagnosis in COVID-19.

Long non-coding RNA XIST regulates chondrogenic differentiation of synovium-derived mesenchymal stem cells from temporomandibular joint via miR-27b-3p/ADAMTS-5 axis

OBJECTIVE

Temporomandibular joint osteoarthritis (TMJOA) is a common degenerative disease in jaw joint, accompanied by articular cartilage destruction. Differentiation of stem cells to cartilage has important therapeutic implications in TMJ cartilage repair. Previous studies revealed that lncRNA XIST participated in various biological processes. However, the effect of XIST on chondrogenic differentiation of synovium-derived mesenchymal stem cells (SMSCs) remains unclear. Our study aimed to investigate the function of XIST in chondrogenic differentiation of human SMSCs from TMJ.

METHODS

Alcian blue staining was performed to determine proteoglycan in SMSCs. qPCR, western blotting and immunofluorescence assays were allowed to assess sex determining region Y-box 9 (SOX9), Collagen type II alpha 1 chain (COL2A1) and Aggrecan (ACAN) expression. The direct interaction between miR-27b-3p and XIST or ADAMTS-5 was confirmed by dual luciferase reporter assay or RNA immunoprecipitation (RIP) assay.

RESULTS

XIST was remarkably down-regulated in chondrogenic differentiation of SMSCs. Functional analysis demonstrated that XIST silencing promoted chondrogenic differentiation of SMSCs. Dual luciferase reporter and RIP assays identified that XIST acted as a sponge for miR-27b-3p. Moreover, XIST regulated ADAMTS-5 expression by directly binding miR-27b-3p. More importantly, miR-27b-3p/ADAMTS-5 rescued the effects of XIST on chondrogenic differentiation of SMSCs.

CONCLUSION

The results suggest that XIST modulates SMSCs chondrogenic differentiation via the miR-27b-3p/ADAMTS-5 axis, which provides new targets for TMJOA treatment.

Pathogenesis of Osteoarthritis: Risk Factors, Regulatory Pathways in Chondrocytes, and Experimental Models

As the most common chronic degenerative joint disease, osteoarthritis (OA) is the leading cause of pain and physical disability, affecting millions of people worldwide. Mainly characterized by articular cartilage degradation, osteophyte formation, subchondral bone remodeling, and synovial inflammation, OA is a heterogeneous disease that impacts all component tissues of the articular joint organ. Pathological changes, and thus symptoms, vary from person to person, underscoring the critical need of personalized therapies. However, there has only been limited progress towards the prevention and treatment of OA, and there are no approved effective disease-modifying osteoarthritis drugs (DMOADs). Conventional treatments, including non-steroidal anti-inflammatory drugs (NSAIDs) and physical therapy, are still the major remedies to manage the symptoms until the need for total joint replacement. In this review, we provide an update of the known OA risk factors and relevant mechanisms of action. In addition, given that the lack of biologically relevant models to recapitulate human OA pathogenesis represents one of the major roadblocks in developing DMOADs, we discuss current in vivo and in vitro experimental OA models, with special emphasis on recent development and application potential of human cell-derived microphysiological tissue chip platforms.

The Emerging Roles of Long Noncoding RNAs in Bone Homeostasis and Their Potential Application in Bone-Related Diseases

Increasing evidence has announced the emerging roles of long noncoding RNAs (lncRNAs) in modulating bone homeostasis due to their potential regulating effects on bone-related cells' proliferation, migration, differentiation and apoptosis. Thus, lncRNAs have been considered as a promising gene tool to facilitate the bone regeneration process and then to predict and cure bone-related diseases such as osteosarcoma, osteoporosis, and osteoarthritis. In this review, we first enumerated several kinds of dysregulated lncRNAs and concisely summarized their regulating role in bone formation as well as resorption process. The related mechanisms were also discussed, respectively. Then, the positive or negative behavior of these lncRNAs in bone-related diseases was elucidated. This review provides an in-depth sight about the lncRNA's clinical values and limitations, which is conducive to explore new gene targets and further establish new therapeutic strategies for bone-related disease.

Downregulation of lncRNA DANCR promotes osteogenic differentiation of periodontal ligament stem cells

BACKGROUND

Long non-coding RNAs (lncRNAs) have been widely known to have an appreciable effect in physiology and pathology. In tooth regeneration, periodontal ligament stem cells (PDLSCs) are regarded as a key effector, whereas, how lncRNA acts in the osteogenic differentiation of PDLSCs have not been completely understood. This study aims to find out the relationship between lncRNA DANCR and the proliferation and osteogenic differentiation of PDLSCs.

METHODS

Microarray was used to observe the different expression of lncRNAs in differentiated and undifferentiated PDLSCs. And then osteogenic-related lncRNA, DANCR was screened out. Its effects on proliferation and osteogenic differentiation was explored by constructing an overexpression and inhibition model. qRT-PCR was used to detect the mRNA expression of osteogenesis related genes. MTT assay was performed to assess the effects of DANCR on cell growth curve. To quantify the effects of DANCR on osteogenic differentiation of PDLSCs, ALP staining and alizarin red was performed in basic culture medium and osteogenic medium. Data were statistically processed.

RESULTS

Compared with the undifferentiated PDLSCs, the alizarin red staining level was higher in differentiated PDLSCs. And the expressions of osteogenic differentiation marker genes Runt-related transcription factor 2 (Runx2), osteocalcin (OCN) and bone morphogenetic protein (BMP-2) were significantly increased in the differentiated PDLSCs. Furthermore, we noticed that comparing with control groups, the expression of lncRNA DANCR decreases markedly in osteogenically induced PDLSCs. DANCR promoted proliferation of PDLSCs, as evidenced by cell viability. Further investigation has proven that the downregulation of DANCR shows in the calcium sediment forming, alkaline phosphatase (ALP) activation and some osteogenic-related gene markers' upregulation including Runx2, OCN and BMP-2, which finally results in the osteogenic differentiation of PDLSCs following the transfection and induction. Conversely, DANCR upregulation was shown to repress the osteogenic differentiation potential of PDLSCs.

CONCLUSIONS

The osteogenic differentiation of PDLSCs has proven to related to the down regulation of lncRNA DANCR. And this paper throws light on the effects of DANCR in the process of PDLSCs' osteogenic differentiation.

LncRNA DANCR sponges miR-216a to inhibit odontoblast differentiation through upregulating c-Cbl

Enhanced odontoblast differentiation of human dental pulp cells (hDPCs) is considered a keystone in dentin-pulp complex formation. We have revealed lncRNA DANCR was implicated in this differentiation program, however, its mechanism in odontoblast differentiation of hDPCs remains further explored. In this study, by employing loss-of-function approach, we identified downregulation of DANCR drived odontoblast differentiaion of hDPCs. Bioinformatics analysis was utilized to show that DANCR contained binding site for miR-216a and an inverse correlation between DANCR and miR-216a was obtained. Dual luciferase reporter assay and RNA-binding protein immunoprecipitation (RIP) were applied to further confirm that DANCR conferred its functions by directly binding to miR-216a. Notably, miR-216a was able to bind to the 3'-UTR of c-Cbl and repressed its expression. In addition, the protein level of c-CBL was significantly downregulated during hDPCs differentiation, while c-Cbl overexpression inhibited odontoblast differentiation of hDPCs. Moreover, downregulation of miR-216a efficiently reversed the suppression of c-Cbl level and odontoblast differentiation induced by knockdown of DANCR. Taken together, these analyses indicated that DANCR positively regulated the expression of c-Cbl, through sponging miR-216a, and inhibited odontoblast differentiation of hDPCs. Our results will extend the field of clinical application for cell-based therapy in regenerative medicine.

Non-Coding RNAs in Cartilage Development: An Updated Review

In the development of the skeleton, the long bones are arising from the process of endochondral ossification (EO) in which cartilage is replaced by bone. This complex process is regulated by various factors including genetic, epigenetic, and environmental elements. It is recognized that DNA methylation, higher-order chromatin structure, and post-translational modifications of histones regulate the EO. With emerging understanding, non-coding RNAs (ncRNAs) have been identified as another mode of EO regulation, which is consist of microRNAs (miRNAs or miRs) and long non-coding RNAs (lncRNAs). There is expanding experimental evidence to unlock the role of ncRNAs in the differentiation of cartilage cells, as well as the pathogenesis of several skeletal disorders including osteoarthritis. Cutting-edge technologies such as epigenome-wide association studies have been employed to reveal disease-specific patterns regarding ncRNAs. This opens a new avenue of our understanding of skeletal cell biology, and may also identify potential epigenetic-based biomarkers. In this review, we provide an updated overview of recent advances in the role of ncRNAs especially focus on miRNA and lncRNA in the development of bone from cartilage, as well as their roles in skeletal pathophysiology.

Comprehensive analysis of long noncoding RNAs and mRNAs expression profiles and functional networks during chondrogenic differentiation of murine ATDC5 cells

Chondrogenic differentiation is a coordinated biological process orchestrated by various cell signaling pathways, involving complex pathways regulated at both transcriptional and post-transcriptional levels. Long noncoding RNAs (lncRNAs) are emerging as important regulators in the modulation of multiple cell processes. However, the potential roles of lncRNAs and their regulatory mechanisms in chondrogenic differentiation remain largely unclear. In this study, microarray was performed to detect the expression profiles of lncRNAs and messenger RNAs (mRNAs) during chondrogenic differentiation of murine chondrogenic cell line ATDC5. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed to explore their functions. Coding-noncoding co-expression (CNC) and competing endogenous RNA (ceRNA) networks were also constructed with bioinformatics methods. The results revealed that 1009 lncRNAs and 1206 mRNAs were differentially regulated during chondrogenic differentiation. GO and KEGG pathway analysis indicated that the principal functions of the transcripts were associated with system development and extracellular matrix-receptor interaction, TGF-β signaling, and PI3K-Akt signaling pathways. The CNC network showed that lncRNA AK136902 was positively correlated with prostaglandin F receptor (FP). The ceRNA network covered 3 lncRNAs, 121 miRNAs and 241 edges. The upregulated lncRNA AK136902, AK016344, and ENSMUST00000180767 might promote chondrogenic differentiation by acting as ceRNAs. Knockdown of lncRNA AK136902 could inhibit the mRNA expression of FP and other chondrogenic related genes, including Aggrecan and Col2a1 during chondrogenic differentiation. Our results provide a new perspective on the modulation of lncRNAs during chondrogenic differentiation.

Articular fibrocartilage - Why does hyaline cartilage fail to repair?

Once damaged, articular cartilage has a limited potential to repair. Clinically, a repair tissue is formed, yet, it is often mechanically inferior fibrocartilage. The use of monolayer expanded versus naïve cells may explain one of the biggest discrepancies in mesenchymal stromal/stem cell (MSC) based cartilage regeneration. Namely, studies utilizing monolayer expanded MSCs, as indicated by numerous in vitro studies, report as a main limitation the induction of type X collagen and hypertrophy, a phenotype associated with endochondral bone formation. However, marrow stimulation and transfer studies report a mechanically inferior collagen I/II fibrocartilage as the main outcome. Therefore, this review will highlight the collagen species produced during the different therapeutic approaches. New developments in scaffold design and delivery of therapeutic molecules will be described. Potential future directions towards clinical translation will be discussed. New delivery mechanisms are being developed and they offer new hope in targeted therapeutic delivery.

MicroRNA-29b regulates hypertrophy of murine mesenchymal stem cells induced toward chondrogenesis

OBJECTIVE

Chondrocyte hypertrophy, a terminal stage of chondrocyte differentiation, is essential to the endochondral bone formation and is one of the major pathological factors in osteoarthritis. This study investigated the role of microRNA-29b (miR-29b), which is involved in chondrogenesis, in the regulation of hypertrophy in chondrocytes.

METHODS

miR-29b expression was assessed during murine mesenchymal stem cells (mMSCs) chondrogenesis. To detect whether miR-29b affects chondrocyte hypertrophy, the mMSCs induced toward chondrogenesis were transfected with miR-29b or its antisense inhibitor (antagomiR-29b). Finally, the differential effects of antagomiR-29b on chondrocytes at different differentiation stages were evaluated by loss-of-function experiments.

RESULTS

miR-29b expression was low-level during the early chondrogenic differentiation, however, it was changed to high level during hypertrophy. Subsequently, the gain-of-function and loss-of-function experiments had confirmed that miR-29b promoted hypertrophy in mMSC-derived chondrocytes. In addition, we confirmed that on day 7, when cells were treated with antagomiR-29b, was the optimal intervention time for preventing hypertrophic phenotype of mMSCs in vitro.

CONCLUSION

miR-29b regulated chondrogenesis homeostasis and enhance hypertrophic phenotype. These data suggest that miR-29b is a key regulator of the chondrocyte phenotype derived from mMSCs and it might be a potential target for articular cartilage repair.

MicroRNA-1305 Inhibits the Stemness of LCSCs and Tumorigenesis by Repressing the UBE2T-Dependent Akt-Signaling Pathway

MicroRNAs (miRNAs) are involved in the maintenance of the cancer stem cell (CSC) phenotype by binding to genes and proteins that modulate cell proliferation and/or cell apoptosis. In our study, we aimed to investigate the role of miR-1305 in the proliferation and self-renewal of liver CSCs (LCSCs) via the ubiquitin-conjugating enzyme E2T (UBE2T)-mediated Akt-signaling pathway. Differentially expressed genes in human hepatocellular carcinoma (HCC) were obtained by in silico analysis. The relationship between miR-1305 and UBE2T was verified by dual luciferase reporter gene assay. qRT-PCR and western blot analysis were performed to determine the expression of UBE2T, the Akt-signaling pathway, and stemness-related factors in LCSCs. In addition, miR-1305 disrupted the activation of the Akt-signaling pathway by targeting UBE2T, and, ultimately, it repressed the sphere formation, colony formation, and proliferation, as well as tumorigenicity of LCSCs. In summary, miR-1305 targeted UBE2T to inhibit the Akt-signaling pathway, thereby suppressing the self-renewal and tumorigenicity of LCSCs. Those findings may provide an enhanced understanding of miR-1305 as a therapeutic target to limit the progression of LCSCs.

Differentiation antagonizing non-protein coding RNA modulates the proliferation, migration, and angiogenesis of glioma cells by targeting the miR-216a/LGR5 axis and the PI3K/AKT signaling pathway

Purpose: DANCR plays an important role in various types of cancer. However, its role in gliomas remains unclear. In the present study, we aimed to investigate the mechanism underlying the role of DANCR in gliomas.

Methods: DANCR expression was measured by qRT-PCR, and expression of LGR5, PI3K, AKT, and phosphorylated AKT (p-AKT) was detected by western blotting. The combination of miR-216a and DANCR was quantified by Luciferase reporter assays. Proliferation, apoptosis and cell cycle, migration and invasion, and angiogenesis of glioma cells were measured by MTT, flow cytometry, Transwell, and Tube formation assays, respectively.

Results: DANCR expression was significantly higher in glioma cells than in normal human astrocytes. Silencing of DANCR inhibited proliferation, migration, invasion, and angiogenesis of glioma cells, promoted apoptosis, blocked the cell cycle at the G1/S transition, and reduced LGR5, PI3K, and p-AKT expression. We identified miR-216a as a direct target of DANCR. Silencing of DANCR in glioma cells increased miR-216a expression. Further, miR-216a suppression increased proliferation, migration, invasion, and angiogenesis and inhibited apoptosis of glioma cells transfected with DANCR-targeting siRNA. In addition, miR-216a suppression compromised inhibition of the G1/S transition caused by DANCR silencing. Furthermore, suppression of miR-216a increased accumulation of LGR5, PI3K, AKT, and p-AKT in glioma cells transfected with DANCR-targeting siRNA.

Conclusion: DANCR modulates growth and metastasis by targeting the miR-216a/LGR5 axis and PI3K/AKT signaling pathway.

Long non-coding RNA: The functional regulator of mesenchymal stem cells

Mesenchymal stem cells (MSCs) are a subset of multipotent stroma cells residing in various tissues of the body. Apart from supporting the hematopoietic stem cell niche, MSCs possess strong immunoregulatory ability and multiple differentiation potentials. These powerful capacities allow the extensive application of MSCs in clinical practice as an effective treatment for diseases. Therefore, illuminating the functional mechanism of MSCs will help to improve their curative effect and promote their clinical use. Long noncoding RNA (LncRNA) is a novel class of noncoding RNA longer than 200 nt. Recently, multiple studies have demonstrated that LncRNA is widely involved in growth and development through controlling the fate of cells, including MSCs. In this review, we highlight the role of LncRNA in regulating the functions of MSCs and discuss their participation in the pathogenesis of diseases and clinical use in diagnosis and treatment.

Emerging roles of long noncoding RNA in chondrogenesis, osteogenesis, and osteoarthritis

Osteoarthritis (OA) is the most prevalent age-related debilitating joint disease, and is characterized primarily by articular cartilage degradation and subchondral bone lesions. It is also the leading cause of chronic morbidity in older populations. The etiology of OA is multifactorial, with the underlying regulatory mechanisms remaining largely unknown. Long noncoding RNA (lncRNA) is a group of noncoding RNAs defined as being >200 nucleotides in length. Increasing evidence demonstrates that many lncRNAs serve as critical regulators of chondrogenesis and bone and cartilage homeostasis, thereby influencing OA development. In this review, we highlight the current understanding concerning lncRNAs, including their physical features, biological functions, and potential roles in chondrogenesis, osteogenesis, and OA. This information may shed new light on the epigenetic regulation of cartilage and substantiate lncRNAs as novel therapeutic targets in OA.

Long non-coding RNA DANCR promotes the progression of non-small-cell lung cancer by inhibiting p21 expression

Background

Long non-coding RNAs (lncRNAs) play important roles in human cancers. However, the functional roles of lncRNAs in non-small-cell lung cancer (NSCLC) and the underlying mechanisms are not well understood.

Methods

We examined the expression of lncRNA DANCR in NSCLC by qRT-PCR and explored its biological roles in NSCLC progression by cell and molecular biology studies.

Results

DANCR expression level was increased in human NSCLC. The knockdown of DANCR inhibited NSCLC cell proliferation by inducing cell apoptosis and cell cycle arrest. In addition, DANCR knockdown suppressed NSCLC cell migration and invasion via inhibition of epithelial-mesenchymal transition (EMT). On the contrary, DANCR overexpression had the opposite effects. DANCR knockdown inhibited EZH-2-mediated epigenetic silencing of p21 promoter and increased p21 expression. Moreover, DANCR knockdown inhibited NSCLC cell proliferation, migration, and invasion in a p21-dependent manner.

Conclusion

DANCR plays oncogenic roles in NSCLC and may provide a novel biomarker for NSCLC diagnosis and prognosis.

Rs1894720 polymorphism in MIAT increased susceptibility to age-related hearing loss by modulating the activation of miR-29b/SIRT1/PGC-1α signaling

BACKGROUND

MIAT may be implicated in the pathogenesis of age-related hearing loss (AHL). This study aimed to clarify the effect of a MIAT signaling pathway on the risk of AHL.

METHODS

Terminal deoxynucleotidyl transferase dUTP nick-end labeling assay, auditory brainstem response (ABR) and quantitative hair cell counts were used to compare the hearing functions in different groups of mice. 5,5,6,6-Tetrachloro-1,1,3,3-tetraethylbenzimidazolylcarbocyanine iodide (JC-1) dye method was used to establish the potential association between mitochondrial dysfunction and aging. Real-time polymerase chain reaction, Western blot analysis, computational analysis, and luciferase assay were conducted to establish a myocardial infarction associated transcript (MIAT) signaling pathway, whose role in the pathogenesis of AHL was further validated by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay and flow cytometry.

RESULTS

Aged C57BL/6 mice were associated with a more severe level of hair cell loss, while exhibiting a higher ABR threshold at various frequencies as well as a lower percentage of inner/outer hair cells. A reduced mitochondrial membrane potential in the cochleae of aged C57BL/6 mice indicated the presence of mitochondrial dysfunction in these mice. Relative expression of MIAT, Sirtuin1 (SIRT1), and peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) was downregulated in aged mice, with microRNA-29b (miR-29b) being highly expressed. Also, MIAT binds to miR-29b, an inhibitor of SIRT1 expression. The regulatory relationship among MIAT, miR-29b, and SIRT1 was further validated by comparing the differentiated expression of these factors in cells treated with phosphate-buffered saline + H₂ O_2, a negative control + H₂ O_2, MIAT + H₂ O₂ , or H₂ O₂  + anti-miR-29b.

CONCLUSION

MIAT could elevate the expression of SIRT1/PGC-1α via downregulating miR-29b. And the downregulated SIRT/PGC-1α increased the incidence of AHL via promoting the apoptosis of cochlear hair cells.

Long non-coding RNA DANCR regulates proliferation and apoptosis of chondrocytes in osteoarthritis via miR-216a-5p-JAK2-STAT3 axis

Osteoarthritis (OA) is one of the most common chronic joint disease. Long non-coding RNAs (lncRNAs) have been confirmed to play important roles in a variety of diseases including OA. However, the underlying mechanism of lncRNA differentiation antagonizing non-protein coding RNA (DANCR) in OA has not been well elucidated. The expression of DANCR in cartilage tissues from OA patients was detected using quantitative real-time PCR. After cell transfection, the effects of DANCR inhibition on the proliferation, apoptosis and inflammatory factors of OA chondrocytes were detected using Cell Counting Kit-8 assay and flow cytometry assay. Novel target of DANCR was then identified through bioinformatics analysis and confirmed by luciferase reporter assay and RNA immunoprecipitation assay. The expression of DANCR was significantly increased in OA patients. Function assays demonstrated that DANCR suppression inhibited the proliferation, inflammation, and promoted apoptosis of chondrocytes cells. Additionally, DANCR regulated survival of OA chondrocytes through acting as a competitive endogenous RNA for miR-216a-5p. Furthermore, JAK2 was a direct target of miR-216a-5p, and DANCR regulated the JAK2/STAT3 signal pathway through miR-216a-5p in OA chondrocytes. In the present study, we concluded that DANCR promoted the proliferation, inflammation, and reduced cell apoptosis in OA chondrocytes through regulating miR-216a-5p/JAK2/STAT3 signaling pathway, indicating DANCR might be a useful biomarker and potential therapeutic target for OA treatment.

Long non-coding RNA DANCR promotes malignant phenotypes of bladder cancer cells by modulating the miR-149/MSI2 axis as a ceRNA

BACKGROUND

Accumulating evidences have indicated that long non-coding RNAs (lncRNAs) are potential biomarkers that play key roles in tumor development and progression. Differentiation antagonizing non-protein noding RNA (DANCR) is a novel lncRNA that acts as a potential biomarker and is involved in the development of cancers. However, the clinical significance and molecular mechanism of DANCR in bladder cancer is still unknown.

METHODS

The relative expression level of DANCR was determined by Real-Time qPCR in a total of 106 patients with urothelial bladder cancer and in different bladder cancer cell lines. Loss-of-function experiments were performed to investigate the biological roles of DANCR on bladder cancer cell proliferation, migration, invasion and tumorigenicity. Comprehensive transcriptional analysis, RNA-FISH, dual-luciferase reporter assay and western blot were performed to explore the molecular mechanisms underlying the functions of DANCR.

RESULTS

In this study, we found that DANCR was significantly up-regulated in bladder cancer. Moreover, increased DANCR expression was positively correlated with higher histological grade and advanced TNM stage. Further experiments demonstrated that knockdown of DANCR inhibited malignant phenotypes and epithelial-mesenchymal transition (EMT) of bladder cancer cells. Mechanistically, we found that DANCR was distributed mostly in the cytoplasm and DANCR functioned as a miRNA sponge to positively regulate the expression of musashi RNA binding protein 2 (MSI2) through sponging miR-149 and subsequently promoted malignant phenotypes of bladder cancer cells, thus playing an oncogenic role in bladder cancer pathogenesis.

CONCLUSION

This study is the first to demonstrate that DANCR plays a critical regulatory role in bladder cancer cell and DANCR may serve as a potential diagnostic biomarker and therapeutic target of bladder cancer.

LncRNA DANCR Promotes Lung Cancer by Sequestering miR-216a

BACKGROUND

Long noncoding RNAs (lncRNAs) are a new class of cancer regulators. Here, we aimed to investigate the diagnostic and therapeutic values of an lncRNA, differentiation antagonizing noncoding RNA (DANCR), in lung cancer.

METHODS

Real-time polymerase chain reaction was used to compare DANCR levels in normal and cancerous lung tissues as well as lung cancer cells. Lentiviral transduction was used to induce DANCR overexpression or silencing in vitro, followed by monitoring cell proliferation, colony formation, and changes in microRNA-216a (miR-216a) expression. DANCR-specific small hairpin RNA transduction was used to establish cells with stable DANCR knockdown, and silenced cells were used to initiate lung tumor xenografts, followed by monitoring tumor growth.

RESULTS

DANCR upregulation was seen in lung cancer, particularly in high-grade lung cancer tissues and aggressive cancer cells. Ectopic DANCR expression induced lung cancer cell proliferation and colony formation, whereas DANCR silencing induced opposing effects. The miR-216a level in cancer cells was negatively correlated with DANCR expression. The DANCR knockdown reduced the growth of tumor xenografts in vivo.

CONCLUSION

DANCR upregulation is a potential indicator of aggressive lung cancer. Silencing of DANCR has great potential as a potent therapeutic strategy in lung cancer.

Silencing long non-coding RNA, differentiation antagonizing non-protein coding RNA promotes apoptosis and inhibits tumor growth in colon cancer

The long non-coding RNA (lncRNA) differentiation antagonizing non-protein coding RNA (DANCR) has been reported to be a novel potential biomarker for colon cancer prognosis. However, its functional role in colon cancer remains unknown. In the present study, DANCR expression in colon cancer cell lines was determined by reverse transcription-quantitative polymerase chain reaction. Cell Counting kit-8 assay, colony formation assay, flow cytometry, Hoechst 33258 staining and western blotting were utilized to investigate the effect and mechanism of DANCR in the regulation of colon cancer growth. Establishment of a xenograft tumor model followed by terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling assay and immunohistochemical staining were performed to confirm the findings in vitro. DANCR was revealed to be overexpressed in all human colon cancer cell lines. Silencing DANCR by small interfering RNA significantly inhibited cell proliferation and colony formation. Flow cytometry analyses and Hoechst 33258 staining revealed that apoptosis was induced upon DANCR-knockdown. Silencing DANCR was revealed to efficiently impair colon tumor growth by promoting caspase 3 expression and tumor apoptosis. In summary, the results of the present study demonstrated that DANCR is a potential therapeutic target in colon cancer.

Long noncoding RNA DANCR promotes colorectal cancer proliferation and metastasis via miR-577 sponging

Long non-coding RNAs (lncRNAs) play key roles in various malignant tumors, including colorectal cancer (CRC). Long non-coding RNA differentiation antagonizing non-protein coding RNA (DANCR) is overexpressed in CRC patients, but whether it affects CRC proliferation and metastasis via regulation of heat shock protein 27 (HSP27) remains unclear. In the present study, we found that DANCR was highly expressed and correlated with proliferation and metastasis in CRC. In addition, we demonstrated that DANCR and HSP27 were both targets of microRNA-577 (miR-577) and shared the same binding site. Furthermore, we revealed that DANCR promoted HSP27 expression and its mediation of proliferation/metastasis via miR-577 sponging. Finally, using an in vivo study, we confirmed that overexpression of DANCR promoted CRC tumor growth and liver metastasis. The present study demonstrated the function of DANCR in CRC and might provide a new target in the treatment of CRC.

LncRNA-DANCR: A valuable cancer related long non-coding RNA for human cancers

OBJECTIVES

Long noncoding RNAs (lncRNA) are a type of noncoding RNA that comprise of longer than 200 nucleotides sequences. They can regulate chromosome structure, gene expression and play an essential role in the pathophysiology of human diseases, especially in tumorigenesis and progression. Nowadays, they are being targeted as potential biomarkers for various cancer types. And many research studies have proven that lncRNAs might bring a new era to cancer diagnosis and support treatment management. The purpose of this review was to inspect the molecular mechanism and clinical significance of long non-coding RNA- differentiation antagonizing nonprotein coding RNA(DANCR) in various types of human cancers.

MATERIALS AND METHODS

In this review, we summarize and figure out recent research studies concerning the expression and biological mechanisms of lncRNA-DANCR in tumour development. The related studies were obtained through a systematic search of PubMed, Embase and Cochrane Library.

RESULTS

Long non-coding RNAs-DANCR is a valuable cancer-related lncRNA that its dysregulated expression was found in a variety of malignancies, including hepatocellular carcinoma, breast cancer, glioma, colorectal cancer, gastric cancer, and lung cancer. The aberrant expressions of DANCR have been shown to contribute to proliferation, migration and invasion of cancer cells.

CONCLUSIONS

Long non-coding RNAs-DANCR likely serves as a useful disease biomarker or therapeutic cancer target.

An Overview of Long Noncoding RNAs Involved in Bone Regeneration from Mesenchymal Stem Cells

Bone regeneration is very important for the recovery of some diseases including osteoporosis and bone fracture trauma. It is a multiple-step- and multiple-gene-involved complex process, including the matrix secretion and calcium mineralization by osteoblasts differentiated from mesenchymal stem cells (MSCs) and the absorption of calcium and phosphorus by osteoclasts differentiated from hematopoietic stem cells. Long noncoding RNAs (lncRNAs) are a family of transcripts longer than 200 nt without or with very low protein-coding potential. Recent studies have demonstrated that lncRNAs are widely involved in the regulation of lineage commitment and differentiation of stem cells through multiple mechanisms. In this review, we will summarize the roles and molecular mechanism of lncRNAs including H19, MALAT1, MODR, HOTAIR, DANCR, MEG3, HoxA-AS3, and MIAT in osteogenesis ossification; lncRNA ZBED3-AS1 and CTA-941F9.9, DANCR, and HIT in chondrogenic differentiation; and lncRNA DANCR in osteoclast differentiation. These findings will facilitate the development and application of novel molecular drugs which regulate the balance of bone formation and absorption.

LncRNA DANCR involved osteolysis after total hip arthroplasty by regulating FOXO1 expression to inhibit osteoblast differentiation

Background

Aseptic loosening of artificial hip joint is a major complication affecting the long-term use of the artificial hip joint, and is the main cause of joint replacement failure. However, the mechanism of aseptic loosening of THR has not yet cleared. The aim of this study was to investigate the underlying mechanism of DANCR in osteoblast differentiation (OD).

Methods

We detected the expressions of DANCR and FOXO1 in clinical samples and mesenchymal stem cells (MSCs) by qRT-PCR and western blotting. The effects of polymethylmethacrylate (PMMA) on OD of MSCs were examined by alkaline phosphatase (ALP) activity and Alizarin Red S (ARS) staining. The expressions of OD markers were measured by qRT-PCR and western blotting. The mechanism of DANCR in OD was detected by RNA pull-down, RNA immunoprecipitation (RIP) assay and ubiquitination assays.

Results

Compared with the surrounding normal tissues, DANCR expression was up-regulated and FOXO1 expression was down-regulated in periprosthetic tissues. PMMA suppressed ALP activity, increased DANCR expression, and decreased the expressions of FOXO1, Runx2, Osterix (Ostx) and osteocalcin (OCN). ARS staining showed that PMMA inhibited the OD of MSCs. Knockdown of DANCR attenuated the inhibitory effect of PMMA on OD. Knockdown of FOXO1 could reverse the effect of si-DANC. RNA pull-down and RIP assay implicated that DANCR bound to FOXO1. Ubiquitination assay indicated that si-DANCR could repress Skp2-mediated ubiquitination of FOXO1.

Conclusion

LncRNA DANCR could inhibit OD by regulating FOXO1 expression.

Noncoding RNAs Carried by Extracellular Vesicles in Endocrine Diseases

RNA molecules are essential and fine regulators of important biological processes. Their role is well documented also in the endocrine system, both in physiological and pathological conditions. Increasing interest is arising about the function and the importance of noncoding RNAs shuttled by extracellular vesicles (EVs). In fact, EV membrane protects nucleic acids from enzyme degradation. Nowadays, the research on EVs and their cargoes, as well as their biological functions, faces the lack of standardization in EV purification. Here, the main techniques for EV isolation are discussed and compared for their advantages and vulnerabilities. Despite the possible discrepancy due to methodological variability, EVs and their RNA content are reported to be key mediators of intercellular communication in pathologies of main endocrine organs, including the pancreas, thyroid, and reproductive system. In particular, the present work describes the role of RNAs contained in EVs in pathogenesis and progression of several metabolic dysfunctions, including obesity and diabetes, and their related manifestations. Their importance in the establishment and progression of thyroid autoimmunity disorders and complicated pregnancy is also discussed. Preliminary studies highlight the attractive possibility to use RNAs contained in EVs as biomarkers suggesting their exploitation for new diagnostic approaches in endocrinology.

Microarray analysis of lung long non-coding RNAs in cigarette smoke-exposed mouse model

Several studies have demonstrated the function of long non‑coding RNAs (lncRNAs) in various biological processes, yet their role underlying the susceptibility to cigarette smoke (CS)-induced airway inflammation remains limited. In the present study, we aimed to profile the expression of lncRNAs and mRNAs in CS-exposed mice. C57BL/6 mice were assigned into a single cigarette-smoking machine with or without CS exposure for 4 weeks, followed by lung tissue harvest and RNA isolation. Microarray analysis identified 108 lncRNAs and 119 mRNAs with differential expression levels in CS-exposed mouse lung tissue compared with those in control mice. The expression patterns of several lncRNAs were further confirmed by qRT-PCR. GO and pathway analyses showed that the altered mRNAs were mainly related to the processes of immune response, defense response and cell chemotaxis, cytokine-cytokine receptor interaction and chemokine signaling pathway. Moreover, a single lncRNA may co-expressed with several mRNAs, and so was the mRNA. Our findings uncovered the expression profile of lncRNAs and mRNAs in the lungs of CS-exposed mice, which may offer new insights into pathogenesis of CS-associated airway inflammatory disorders.