Recent studies indicate important roles for long noncoding RNAs (lncRNAs) as essential regulators of myogenesis and adult skeletal muscle regeneration. However, the specific roles of lncRNAs in myogenic differentiation of adult skeletal muscle stem cells and myogenesis are still largely unknown. Here we identify a lncRNA that is specifically enriched in skeletal muscle (myogenesis-associated lncRNA, in short, lnc-mg). In mice, conditional knockout of lnc-mg in skeletal muscle results in muscle atrophy and the loss of muscular endurance during exercise. Alternatively, skeletal muscle-specific overexpression of lnc-mg promotes muscle hypertrophy. In vitro analysis of primary skeletal muscle cells shows that lnc-mg increases gradually during myogenic differentiation and its overexpression improves cell differentiation. Mechanistically, lnc-mg promotes myogenesis, by functioning as a competing endogenous RNA (ceRNA) for microRNA-125b to control protein abundance of insulin-like growth factor 2. These findings identify lnc-mg as a novel noncoding regulator for muscle cell differentiation and skeletal muscle development.

Antiosteoporosis gene-based drug development strategies are presently focused on targeting osteoblasts to either suppress bone loss or increase bone mass. Although siRNA/microRNA-based gene therapy has enormous potential, it is severely limited by the lack of specific cell-targeting delivery systems. We report an osteoblast-targeting peptide (SDSSD) that selectively binds to osteoblasts via periostin. We developed SDSSD-modified polyurethane (PU) nanomicelles encapsulating siRNA/microRNA that delivers drugs to osteoblasts; the data showed that SDSSD-PU could selectively target not only bone-formation surfaces but also osteoblasts without overt toxicity or eliciting an immune response in vivo. We used the SDSSD-PU delivery system to deliver anti-miR-214 to osteoblasts and our results showed increased bone formation, improved bone microarchitecture, and increased bone mass in an ovariectomized osteoporosis mouse model. SDSSD-PU may be a useful osteoblast-targeting small nucleic acid delivery system that could be used as an anabolic strategy to treat osteoblast-induced bone diseases.

With increasing fracture risks due to fragility, osteoporosis is a global health problem threatening postmenopausal women. In these patients, osteoclasts play leading roles in bone loss and fracture. How to inhibit osteoclast activity is the key issue for osteoporosis treatment. In recent years, miRNA-based gene therapy through gene regulation has been considered a potential therapeutic method. However, in light of the side effects, the use of therapeutic miRNAs in osteoporosis treatment is still limited by the lack of tissue/cell-specific delivery systems. Here, we developed polyurethane (PU) nanomicelles modified by the acidic peptide Asp 8 . Our data showed that without overt toxicity or eliciting an immune response, this delivery system encapsulated and selectively deliver miRNAs to OSCAR + osteoclasts at bone-resorption surface in vivo. With the Asp 8 -PU delivery system, anti-miR214 was delivered to osteoclasts, and bone microarchitecture and bone mass were improved in ovariectomized osteoporosis mice. Therefore, Asp 8 -PU could be a useful bone-resorption surface-targeting delivery system for treatment of osteoclast-induced bone diseases and aging-related osteoporosis.

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Increasing evidence supports that microRNA (miRNA) plays a significant functional role in cancer progression by directly regulating respective targets. In this study, the expression levels of miR-105-1 and its target gene were analyzed using genes microarray and hierarchical clustering analysis followed by validation with quantitative RT-PCR in hepatocellular carcinoma (HCC) and normal liver tissues. We examined the expression of nuclear receptor coactivator 1 (NCOA1), the potential target gene of miR-105-1, following the transfection of miR-105-1 mimics or inhibitors. Our results showed that miR-105-1 was downregulated in HCC tissues when compared with normal liver tissues and patients with lower miR-105-1 expression had shorter overall survival (OS) and progression free survival (PFS). Moreover, NCOA1 was confirmed to be a direct target of miR-105-1. Furthermore, concomitant high expression of NCOA1 and low expression of miR-105-1 correlated with a shorter median OS and PFS in HCC patients. In conclusion, our results provide the first evidence that NCOA1 is a direct target of miR-105-1 suggesting that NCOA1 and miR-105-1 may have potential prognostic value and may be useful as tumor biomarkers for the diagnosis of HCC patients.

ObjectiveThis study aims to explore the expression pattern and prognostic significance of miR-33a in non-small cell lung cancer (NSCLC) treated with adjuvant chemotherapy.MethodsMiR-33aexpression in NSCLC was analyzed in silico using the GEO database and was subsequently confirmed by quantitative RT-PCR in 147 NSCLC biopsies. Among these, 32 of these biopsies were paired with adjacent non-neoplastic tissues. The survival analysis of NSCLC by Kaplan-Meier estimates was stratified based on miR-33a expression. In addition, multivariate survival analysis in corresponding groups of NSCLC patients was conducted by Cox proportional hazards regression model.ResultsThe in silico analysis of miR-33a expression in NSCLC resulted to its down-regulation in different tumor types. The expression level of miR-33a was lower in each grade of NSCLC tumor biopsies than in normal lung tissues. Univariate and multivariate survival analysis further established that low miR-33a expression was an important risk factor for overall survival and disease free survival in NSCLC patients.ConclusionOur study implied that miR-33a expression levels may have an essential role in NSCLC progression, and could act as a specific and sensitive biomarker for NSCLC patients who have undergone adjuvant chemotherapy.

BackgroundGlucokinase (GCK) is the key glucose phosphorylation enzyme which has attracted considerable attention as a candidate gene for type 2 diabetes (T2D) based on its enzyme function as the first rate-limiting step in the glycolysis pathway and regulates glucose-stimulated insulin secretion. In the past decade, the relationship between GCK and T2D has been reported in various ethnic groups. To derive a more precise estimation of the relationship and the effect of factors that might modify the risk, we performed this meta-analysis.MethodsDatabases including Pubmed, EMBASE, Web of Science and China National Knowledge Infrastructure (CNKI) were searched to find relevant studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association.ResultsA total of 24 articles involving 88, 229 cases and 210, 239 controls were included. An overall random-effects per-allele OR of 1.06 (95% CI: 1.03–1.09; P<10−4) was found for the GCK −30G>A polymorphism. Significant results were also observed using dominant or recessive genetic models. In the subgroup analyses by ethnicity, significant results were found in Caucasians; whereas no significant associations were found among Asians. In addition, we found that the −30G>A polymorphism is a risk factor associated with increased impaired glucose regulation susceptibility. Besides, −30G>A homozygous was found to be significantly associated with increased fasting plasma glucose level with weighted mean difference (WMD) of 0.15 (95%: 0.05–0.24, P = 0.001) compared with G/G genotype.ConclusionsThis meta-analysis demonstrated that the −30G>A polymorphism of GCK is a risk factor associated with increased T2D susceptibility, but these associations vary in different ethnic populations.

Long noncoding RNAs are widely implicated in diverse disease processes. Nonetheless, their regulatory roles in bone resorption are undefined. Here, we identify lncRNA Nron as a critical suppressor of bone resorption. We demonstrate that osteoclastic Nron knockout mice exhibit an osteopenia phenotype with elevated bone resorption activity. Conversely, osteoclastic Nron transgenic mice exhibit lower bone resorption and higher bone mass. Furthermore, the pharmacological overexpression of Nron inhibits bone resorption, while caused apparent side effects in mice. To minimize the side effects, we further identify a functional motif of Nron. The delivery of Nron functional motif to osteoclasts effectively reverses bone loss without obvious side effects. Mechanistically, the functional motif of Nron interacts with E3 ubiquitin ligase CUL4B to regulate ERα stability. These results indicate that Nron is a key bone resorption suppressor, and the lncRNA functional motif could potentially be utilized to treat diseases with less risk of side effects.