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Oxidized low-density lipoprotein (ox-LDL)-induced endothelial dysfunction is an initial step toward atherosclerosis development. Mitochondria damage correlates with ox-LDL-induced endothelial injury through an undefined mechanism. We explored the role of optic atrophy 1 (Opa1)-related mitochondrial fusion and mitophagy in ox-LDL-treated endothelial cells, focusing on mitochondrial damage and cell apoptosis. Oxidized low-density lipoprotein treatment reduced endothelial cell viability by increasing apoptosis. Endothelial cell proliferation and migration were also impaired by ox-LDL. At the molecular level, mitochondrial dysfunction was induced by ox-LDL, as demonstrated by decreased mitochondrial membrane potential, increased mitochondrial reactive oxygen species production, augmented mitochondrial permeability transition pore openings, and elevated caspase-3/9 activity. Mitophagy and mitochondrial fusion were also impaired by ox-LDL. Opa1 overexpression reversed this effect by increasing endothelial cell viability and decreasing apoptosis. Interestingly, inhibition of mitophagy or mitochondrial fusion through transfection of siRNAs against Atg5 or Mfn2, respectively, abolished the protective effects of Opa1. Our results illustrate the role of Opa1-related mitochondrial fusion and mitophagy in sustaining endothelial cell viability and mitochondrial homeostasis under ox-LDL stress., (Copyright © 2020 Zheng and Lu.)

Metastasis, is a development of secondary tumor growths at a distance from the primary site, and closely related to poor prognosis and mortality. However, there is still no effective treatment for metastatic cancer. Therefore, there is an urgent need to find an effective therapy for cancer metastasis. Plenty of evidence indicates that miR-9 can function as a promoter or suppressor in cancer metastasis and coordinate multistep of metastatic process. In this review, we summarize the different roles of miR-9 with the corresponding molecular mechanisms in metastasis of twelve common cancers and the multiple mechanisms underlying miR-9-mediated regulation of metastasis, benefiting the further research of miR-9 and metastasis, and hoping to bridge it with clinical applications., Competing Interests: The authors promise no potential conflicts of interest., (© 2020 Chongqing Medical University. Production and hosting by Elsevier B.V.)

Neural stem cell populations generate a wide spectrum of neuronal and glial cell types in a highly ordered fashion. MicroRNAs are essential regulators of this process. T-UCstem1 is a long non-coding RNA containing an ultraconserved element, and in vitro analyses in pluripotent stem cells provided evidence that it regulates the balance between proliferation and differentiation. Here we investigate the in vivo function of T-UCstem1. We show that T-UCstem1 is expressed in the forebrain neurogenic lineage that generates interneurons for the postnatal olfactory bulb. Gain of function in neural stem cells increased progenitor proliferation at the expense of neuron production, whereas knockdown had the opposite effect. This regulatory function is mediated by its interaction with miR-9-3p and miR-9-5p. Based thereon, we propose a mechanistic model for the role of T-UCstem1 in the dynamic regulation of neural progenitor proliferation during neurogenesis., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

We previously demonstrated that vascular endothelial cells released VEGF-enriched exosomes to promote the tumor vasculogenesis and progression after anti-angiogenic therapies (AATs). To clarify how microRNA (miR)-9 promoted the angiogenesis of tumor-associated endothelial cells, in the present study, we investigated the association between miR-9 and sphingosine-1-phosphate (S1P) receptors in angiogenesis. The levels of miR-9 and S1P receptors in normal and tumor endothelial cells were compared with EndoDB database and their correlations were analyzed. The levels of S1P 1 , S1P 2 , and S1P 3 were detected in miR-9 overexpressing endothelial cells by qRT-PCR and western blot. The binding sites of miR-9 on S1P 1 and S1P 3 were predicted and tested by dual-luciferase reporter assays. Then, angiogenesis in endothelial cells overexpressing both S1P 1 and miR-9 was detected. The results showed that miR-9 is overexpressed in ECs from medulloblastoma and glioblastoma xenograft, which is negatively associated with S1P 1 and S1P 3 . Overexpression of miR-9 significantly inhibited S1P 1 and S1P 3 in both mRNA and protein levels. We predicted that binding sites exist between miR-9 and S1P 1 , S1P 3 , but only S1P 1 was directly targeted by miR-9. Overexpression of S1P 1 significantly suppressed the miR-9-induced angiogenesis. Therefore, miR-9 induces angiogenesis via targeting on S1P 1 ., (Copyright © 2020 Yao, Xie and Zeng.)

Mud crab Scylla paramamosain is one of the most important economic crabs in China. The molecular regulatory mechanism of ovarian development has received considerable attention in recent years. Some studies found that ERK (extracellular signal-regulated protein kinase) signaling pathway plays an important role in ovarian development and is negatively regulated by microRNAs (miRNAs). However, the study about the regulation of miRNA on the ERK pathway in crustacean's ovary remains unknown. In this study, the target genes of the ERK signaling pathway regulated by selected miRNAs identified from the ovary of mud crab in our previous research were predicted by using bioinformatics tools. The results showed that the ERK2 might be a target gene of miR-9c, miR-263a, and miR-263b; MEK2 may be a target gene of miR-263a; and Rap-1b may be a target gene of miR-9, miR-9c, and miR-263a. Results of in vitro dual-luciferase reporter assay showed that the relative luciferase activities were significantly lower in HEK293T cells co-transfected with the combination of miRNA mimics and pmir-RB-REPORTTM-target gene-3'UTR than those with the combination of mimics NC and pmir-RB-REPORTTM-target gene-3'UTR. In contrast, the relative luciferase activities were significantly higher in HEK293T cells co-transfected with miRNA inhibitor than those with inhibitor NC. To further validate in vitro results, the miRNA reagents were injected into the living female mud crabs, and the expression levels of miRNAs and target genes after the injection were analyzed by quantitative real-time PCR. The in vivo experimental results showed that miRNAs (miR-9c/miR-263a) agomir (enhancers)/antagomir (inhibitors) can enhance/decrease the expression of two miRNAs, respectively, and the expression of target genes in the ovary was declined/increased after injection of agomir/antagomir reagent. In conclusion, miR-9/miR-263 can negatively regulate the expression of the ERK pathway genes (ERK2, MEK2, and Rap-1b) in the ovary of mud crab.

Introduction and Objectives: Long non-coding RNAs (lncRNAs) have garnered interest because of their roles in cancer progression. We aimed to explore the role of the lncRNA embigin pseudogene 1 (EMBP1)-miR-9-5p axis in renal cell carcinoma (RCC)., Materials and Methods: Expression profiling of miR-9-5p and EMBP1 were performed in RCC cell lines and tumor samples. To evaluate miR-9-5p and EMBP1's role in proliferation, invasion, migration, and colony formation, we performed in vitro assays along with studies in a xenograft tumor model. In silico binding site analysis using the RNA22 algorithm, RNA-immunoprecipitation (RIP), and luciferase reporter assays were used to validate a direct interaction between EMBP1 and miR-9-5p. Changes in key proteins were also analyzed., Results: miR-9-5p was significantly down-regulated, and EMBP1 was significantly up-regulated, in RCC cell lines and tumor tissue. The clinicopathological characteristics of RCC patients significantly correlated with their expression. Overexpression of miR-9-5p or EMBP1 suppression in RCC cell lines significantly retarded their proliferative, migratory, and invasive behavior, in addition to promoting apoptosis and cell-cycle arrest. EMBP1 directly binds to and negatively regulates miR-9-5p. The EMBP1-miR-9-5p axis dysregulated the expression of the epithelial-to-mesenchymal transition (EMT) markers E-cadherin, claudin, and vimentin, the stemness markers KLF4 and Nanog, and the cell cycle checkpoint gene cyclin E2 (CCNE2) and its downstream mediator E2F1. miR-9-5p overexpression or EMBP1 suppression inhibited xenograft tumor growth in vivo, effects that were abrogated by CCNE2 overexpression., Conclusions: Our findings suggest an important role of the EMBP1/miR-9-5p axis dysregulation in RCC tumor progression., (Copyright © 2020 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.)

Background: The incidence of thyroid cancer is increasing worldwide. This study investigated the association of B-type RAF kinase (BRAF) V600E mutation status, the expression of BRAF-activated long non-coding RNA (BANCR) and microRNA miR-9, and the clinicopathological features of papillary thyroid carcinoma (PTC)., Methods: Clinicopathological data for PTC patients (n = 51) diagnosed and treated between 2018 and 2019 were collected. Carcinoma and adjacent normal tissue samples were analyzed for the presence of the BRAF V600E mutation and/or expression of BANCR and miR-9., Results: Larger tumor, higher rate of bilateral tumors and multifocality, extracapsular invasion, and lateral lymph node metastasis (LNM) were observed in PTC patients with BRAF V600E mutation. Patients with higher BANCR expression had a higher rate of extracapsular invasion and lateral LNM in carcinoma tissue and a lower frequency of bilateral tumors and multifocality in normal adjacent tissue. Patients with higher miR-9 expression had a lower rate of central and lateral LNM in carcinoma tissue and higher rates of bilateral tumor location and multifocality in normal adjacent tissue. Patients with BRAF V600E mutation have a higher rate of BANCR overexpression and tended to have a lower rate of miR-9 overexpression (P = 0.057), and a negative association was observed between BANCR and miR-9 expression in carcinoma tissue., Conclusions: BRAF V600E mutation and the BANCR and miR-9 expression were closely associated with the tumor size, bilateral tumor location, multifocality, extracapsular invasion, and lateral LNM. PTC patients with these clinicopathological characteristics, BRAFV600E mutation, and high BANCR expression and low miR-9 expression needed earlier surgical treatment and are recommended for total thyroidectomy in primary surgery for reducing the risk of recurrence. These findings provide new insight into the molecular basis for PTC and can inform strategies for the management of PTC.

Noise is prevalent in biology and has been widely quantified using snapshot measurements. This static view obscures our understanding of dynamic noise properties and how these affect gene expression and cell state transitions. Using a CRISPR/Cas9 Zebrafish her6::Venus reporter combined with mathematical and in vivo experimentation, we explore how noise affects the protein dynamics of Her6, a basic helix-loop-helix transcriptional repressor. During neurogenesis, Her6 expression transitions from fluctuating to oscillatory at single-cell level. We identify that absence of miR-9 input generates high-frequency noise in Her6 traces, inhibits the transition to oscillatory protein expression and prevents the downregulation of Her6. Together, these impair the upregulation of downstream targets and cells accumulate in a normally transitory state where progenitor and early differentiation markers are co-expressed. Computational modelling and double smFISH of her6 and the early neurogenesis marker, elavl3, suggest that the change in Her6 dynamics precedes the downregulation in Her6 levels. This sheds light onto the order of events at the moment of cell state transition and how this is influenced by the dynamic properties of noise. Our results suggest that Her/Hes oscillations, facilitated by dynamic noise optimization by miR-9, endow progenitor cells with the ability to make a cell state transition., (© 2020 The Authors. Published under the terms of the CC BY 4.0 license.)

Dendritic cells, cells of the innate immune system, are found in a steady state poised to respond to activating stimuli. Once stimulated, they rapidly undergo dynamic changes in gene expression to adopt an activated phenotype capable of stimulating immune responses. We find that the microRNA miR-9 is upregulated in both bone marrow-derived DCs and conventional DC1s but not in conventional DC2s following stimulation. miR-9 expression in BMDCs and conventional DC1s promotes enhanced DC activation and function, including the ability to stimulate T cell activation and control tumor growth. We find that miR-9 regulated the expression of several negative regulators of transcription, including the transcriptional repressor Polycomb group factor 6 (Pcgf6). These findings demonstrate that miR-9 facilitates the transition of DCs from steady state to mature state by regulating the expression of several negative regulators of DC function in a cell-type-specific manner., Competing Interests: Declaration of Interests The authors declare no competing interests., (Copyright © 2020 The Author(s). Published by Elsevier Inc. All rights reserved.)

Long non‑coding RNAs (lncRNAs) are important mediators of the initiation and progression of tumors, including breast cancer (BC). The exact role of long intergenic non‑coding RNA 00312 (LINC00312) in BC and its mechanism of action have not been reported to date. In the present study, LINC00312 was found to be downregulated in human BC tissues and cell lines by RT‑qPCR. The findings of a functional study indicated that overexpression of LINC00312 suppressed the proliferation, colony forming ability, migration and invasiveness of BC cell lines. Mechanistically, LINC00312 was found to induce suppression of cell migration and invasion by directly binding to miR‑9. Overexpression of LINC00312 increased the expression of cadherin 1 (CDH1), a direct target of miR‑9, and decreased the expression of vimentin (VIM), a major cytoskeletal component of mesenchymal cells as determined by western blot analysis. miR‑9 partly abrogated the upregulation of CDH1 and downregulation of VIM induced by LINC00312. Taken together, the results of the present study indicate a role for the LINC00312/miR‑9/CDH1 axis in the progression of BC, and suggest a novel lncRNA‑based diagnostic biomarker or therapeutic target for BC.

The aim of the current study was to explore the role of Resveratrol (Res) in osteoarthritis (OA) and its underlying mechanism. Reverse transcription-quantitative polymerase chain reaction and western blot analysis were used to determine the relative expression levels of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), microRNA-9 (miR-9), nuclear factor kappa B subunit 1 (NF-κB1), interleukin (IL)-6, matrix metallopeptidase 13 (MMP-13) and caspase-3 in vitro and in the in vivo model of OA, as well as examining the effect of Res on MALAT1, miR-9 and NF-κB1, IL-6, MMP-13 and caspase-3 expression levels. Immunohistochemical analysis was performed to examine NF-κB1 and MMP-13 protein levels in the in vivo model of OA. Dual-luciferase reporter assays were used to confirm the regulatory relationship between miR-9 and MALAT1 and NF-κB1, as well as examining the effect of Res on the transcriptional activation of MALAT1 promoter. Furthermore, the effect of Res on cell proliferation in vitro was examined by MTT assay. The relative mRNA expression levels of MALAT1 and NF-κB1 were significantly increased, while miR-9 expression was significantly decreased in the OA group compared with the sham group. Treatment with Res partially reversed the effects of OA on MALAT1, NF-κB1 and miR-9 expression. Similarly, the relative protein expression levels of NF-κB1, IL-6, MMP-13 and caspase-3 were significantly increased in the OA group compared with the sham group; however, treatment with Res partially reversed the effects of OA on the protein expression levels of NF-κB1, IL-6, MMP-13 and caspase-3. MALAT1 and NF-κB1 were identified as potential target genes of miR-9, and dual-luciferase assays were used to examine the effect of miR-9 on the luciferase activity of 3'UTR MALAT1 and NF-κB1. Treatment with Res suppressed the transcriptional activation of the MALAT1 promoter, thereby inhibiting MALAT1 expression. Additionally, the relative expression level of miR-9 significantly increased following treatment with Res in a dose-dependent manner, while the relative protein expression levels of NF-κB1, IL-6, MMP-13 and caspase-3 significantly decreased following treatment with Res compared with the control. Furthermore, treatment with Res significantly increased the growth rate of chondrocytes in a dose-dependent manner compared with the control. Taken together, these results suggest that direct targeting of the MALAT1/miR-9/NF-κB1/IL-6, MMP-13/caspase-3 axis may be a novel therapeutic strategy for the treatment of OA., (Copyright: © Zhang et al.)

DNA vaccine provides a promising method for preventing and treating diseases. However, the low immunogenicity restricts its application. New approaches are urgent to be explored to enhance the immune response of DNA vaccine. MicroRNAs are endogenous, small non-coding RNAs which play parts in gene expression inhibition. In this study, microRNA-9 (miR-9) was found to inhibit the expression of the GLU-A-P antigen protein encoded by the anti-caries DNA vaccine. Mutation of miR-9 binding sites in the gene fragment encoding GLU-A-P antigen protein significantly increased the expression of antigen protein. Moreover, miR-9 sponge can improve the expression of the GLU-A-P antigen protein. The co-immunization with miR-9 sponge and anti-caries DNA vaccine significantly enhanced the specific immune response in vivo. In conclusion, attenuating the inhibition of endogenous miR-9 enhanced the antigen expression and immunogenicity of the anti-caries DNA vaccine., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

T cell acute lymphoblastic leukemia (T-ALL) was a malignant lymphoma. Therefore, the development of novel therapeutic agents against T-ALL is imperative. Previous studies have shown that chrysophanol (CHL), an anthraquinone compound isolated from the Rheum palmatum L., exerts anti-proliferative and anti-metastatic effects in multiple malignant tumors. However, the effect of CHL on the progression of TALL is poorly understood. The aim of this study was to explore the role of CHL in the biological behavior of T-ALL cells and determine its underlying mechanism. Both T-ALL cell lines (Jurkat and TALL-104) were treated with CHL. The proliferation, apoptosis, migration, and invasion of T-ALL cells were determined by CCK-8, flow cytometry, wound healing, and Transwell assay, respectively. Western blot and RT-qPCR were applied to examine gene expression. The dual-luciferase reporter gene assay was employed to examine the regulation mechanism of miR-9 and PD-L1. A T-ALL xenograft model also was used to examine the effect of CHL on the tumor growth and metastasis in vivo. CHL treatment significantly inhibited the proliferation, migration, and invasion ability of both Jurkat and TALL-104 cells and induced cell apoptosis and the expression of miR-9. Moreover, miR-9 was proved to target PD-L1 by binding to its 3'-untranslated region (UTR). Mechanically, pretreated with PD-L1 inhibitor could augment the anti-proliferation and anti-metastatic effect of CHL, while miR-9-silenced alleviated this effect. Consistent with in vitro studies, CHL significantly suppressed the growth and metastasis of tumor in vivo. Our finding uncovers the antitumorigenic effect of CHL in T-ALL progression through upregulating the expression of miR-9 and suppressing PD-L1 expression, which may provide a new potential strategy for T-ALL clinical treatment.

We investigated the role of microRNA (miR)-9 in modulating chemoresistance in hepatocellular carcinoma (HCC) cells. MiR-9 was overexpressed or knocked down in HCC cell lines. Cell viability, cell proliferation, the expression of EIF5A2 and the epithelial-mesenchymal transition (EMT)-related proteins were examined. HCC cells overexpressing miR-9 were more sensitive to cisplatin; miR-9 knockdown yielded the opposite result. The in vivo nude mouse HCC xenograft tumors yielded the same results. EIF5A2 was identified as a potential target of miR-9, where miR-9 regulated EIF5A2 expression at mRNA and protein level. EIF5A2 knockdown reversed miR-9 inhibition-mediated cisplatin resistance. Altering miR-9 and EIF5A2 expression changed E-cadherin and vimentin expression. Furthermore, EIF5A2 mediated miR-9 EMT pathway regulation, indicating that miR-9 can enhance cisplatin sensitivity by targeting EIF5A2 and inhibiting the EMT pathway. Targeting miR-9 may be useful for overcoming drug resistance in HCC., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Effects of micro ribonucleic acid (miR)-9 on neuronal apoptosis and expression levels of apoptosis genes B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein (Bax) in depression model rats, as well as its regulatory mechanism, were investigated. Thirty Sprague-Dawley rats were randomly divided into control group (n=10), model group (n=10) and miR-9 inhibitor group (n=10). The rat model of depression was established using the chronic stress method. The learning and memory abilities of rats were detected via water maze test, the neuronal morphology of the brain was detected using hematoxylin and eosin (H&E) staining, and the levels of serum Bcl-2 and Bax were determined using the enzyme-linked immunosorbent assay (ELISA) kits. Moreover, the neuronal apoptosis in the brain was determined through terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay, and the protein levels of Notch1 and Hes1 in brain tissues were measured via western blot analysis. Compared with the control group, the rats in the model group presented significantly decreased learning and memory abilities, poor neuronal morphology of the brain, significantly higher neuronal apoptosis rate in the brain, decreased level of serum Bcl-2, increased level of serum Bax, and significantly decreased protein levels of Notch1 and Hes1 in brain tissues. Compared with the model group, the rats in miR-9 inhibitor group showed obviously improved learning and memory abilities, improved neuronal morphology of the brain, an obviously lower neuronal apoptosis rate in the brain, increased level of serum Bcl-2, decreased level of serum Bax, and obviously increased protein levels of Notch1 and Hes1 in brain tissues. In conclusion, miR-9 inhibitor can promote the neurological function recovery and inhibit the neuronal apoptosis of depression model rats through activating the Notch signaling pathway, suggesting that miR-9 can be an important therapeutic target for depression., (Copyright: © Xiao et al.)

Given the global outbreak of breast cancer and its debilitating effect on women's health, it is not surprising that tremendous efforts have been made with an aim of shedding more light on the mechanisms involved in the pathogenesis of this type of cancer. Among the long list of risk factors associated with this malignancy, recently, the role of microRNAs (miRNAs or miRs) has turned into a hotspot for breast cancer investigations. miRNAs approximately 20 nucleotides in length and are located in either an exon or an intron, playing a role in the regulation of gene expression. In the present study, we extracted RNA from both the serum and cancerous tissue of breast cancer patients and after synthesizing the cDNA, we performed quantitative PCR to determine the expression levels of miR-9 and miR-192. The resulting data revealed that while the mRNA expression level of miR-9 was significantly decreased in the breast cancer tissues, there was no noticeable change in the expression level of this miRNA in the serum samples. Likewise, we found that the marked downregulation of miR-192 was only restricted to the cancerous tissues, but was not found in the serum of patients. Based on the meaningful downregulation of the expression of miR-9 and miR-192, this study provides a plausible framework for these miRNAs as effective biomarkers for breast cancer patients., (Copyright © 2019, Spandidos Publications.)

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease with poor prognosis. Insights into the roles of MicroRNAs (miRNAs) in diseases, particularly in cancer, have made miRNAs attractive tools and targets for novel therapeutic approaches. Methods: Here, we employed a novel chimeric peptide supramolecular nanoparticle delivery system for plectin-1 (PL-1)-targeted PDAC-specific miR-9 delivery in vitro and in pancreatic cancer patient-derived xenograft (PDX) model. RT-PCR and immunohistochemistry (IHC) were conducted to detect the expression pattern of eIF5A2. mRFP-GFP-LC3 fluorescence microscopy and Western blot were carried out to determine autophagy. Luciferase reporter assays were performed to elucidate the regulatory role of miR-9/eIF5A2 axis. Results: PL-1/miR-9 nanocomplexes dramatically improve the anticancer effect of doxorubicin through downregulating eIF5A2 expression to inhibit autophagy and induce apoptosis in PDAC therapy in vivo . Mechanistically, miR-9 directly targets the eIF5A2 transcript by binding to its 3'-untranslated region (3'-UTR) to reduce the expression levels and the secreted protein of eIF5A2 in PDAC cells. Conclusion: PL-1/miR-9 nanoparticles can be used as a novel promising anti-cancer strategy with tumor targeting and miR-9/eIF5A2 may serve as a new potential therapeutic target for future synergic therapy against human PDAC., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Purpose: High expression of ecotropic viral integration site 1 (EVI1) has been associated with a poor prognosis in leukemia patients, but the underlying mechanism remains unclear. Aberrant expression of microRNAs plays critical roles in leukemia development. MiR-9 is a putative potential target of EVI1. We have investigated the regulating mechanism of miR-9 by EVI1 in leukemia cells., Methods: We first examined the relationship between miR-9 and EVI1 expression levels in nine leukemia cell lines by RT-PCR. Then we forced high expression of EVI1 in UoCM1 and K562 cells to confirm the downregulation of miR-9 by EVI1. Methylation of the miR-9 promoter region was detected by DNA bisulfite sequencing. We treated the EVI1-overexpressing cells with the hypomethylating agent 5-aza-2'-deoxycytidine (5-AZA) to reverse EVI1-induced hypermethylation of miR-9., Results: EVI1 and miR-9 expression was negative related. Forced expression of EVI1 downregulated miR-9 by inducing hypermethylation of the miR-9 promoter. 5-AZA reversed high EVI1-induced hypermethylation of the miR-9 promoter and restored the expression of miR-9. 5-AZA induced extensive apoptosis and inhibited proliferation through cell cycle arrest in EVI1-overexpressing leukemia cells., Conclusions: Our results suggest that EVI1 may be involved in leukemia cell proliferation and apoptosis via the regulation of miR-9 promoter methylation. 5-AZA may represent a promising therapeutic option for EVI1-high leukemia patients.

We have previously reported that miR-9 promotes the homing, proliferation, and angiogenesis of endothelial progenitor cells (EPCs) by targeting transient receptor potential melastatin 7 via the AKT autophagy pathway. In this way, miR-9 promotes thrombolysis and recanalization following deep vein thrombosis (DVT). However, the influence of miR-9 on messenger RNA (mRNA) expression profiles of EPCs remains unclear. The current study comprises a comprehensive exploration of the mechanisms underlying the miR-9-regulated angiogenesis of EPCs and highlights potential treatment strategies for DVT. We performed RNA sequence analysis, which revealed that 4068 mRNAs were differentially expressed between EPCs overexpressing miR-9 and the negative control group, of which 1894 were upregulated and 2174 were downregulated. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses indicated that these mRNAs were mainly involved in regulating cell proliferation/migration processes/pathways and the autophagy pathway, both of which represent potential EPC-based treatment strategies for DVT. Reverse transcriptase quantitative polymerase chain reaction confirmed the changes in mRNA expression related to EPC angiogenesis, migration, and autophagy. We also demonstrate that miR-9 promotes EPC migration and angiogenesis by regulating FGF5 directly or indirectly. In summary, miR-9 enhances the expression of VEGFA, FGF5, FGF12, MMP2, MMP7, MMP10, MMP11, MMP24, and ATG7, which influences EPC migration, angiogenesis, and autophagy. We provide a comprehensive evaluation of the miR-9-regulated mRNA expression in EPCs and highlight potential targets for the development of new therapeutic interventions for DVT.

The decreased adhesion ability of melanocytes to the neighboring keratinocytes prompts melanocytes to lose from the epidermis, comprising the critical step in vitiligo pathogenesis. The repigmentation process involves the migration of melanocytes to the lesional area. This study aims to investigate the role and mechanism of microRNA (miR)-9 in the adhesion and migration of melanocytes during vitiligo repigmentation induced by UVB treatment. The HaCaT keratinocytes were used to mimic lesional condition and the PIG1 melanocytes as perilesional condition. Human lesional vitiligo specimens showed increased miR-9 and decreased adhesion molecules such as E-cadherin and β1 integrin. Furthermore, UVB exposure upregulated IL-10, E-cadherin, and β1 integrin, downregulated miR-9 in HaCaT cells. Moreover, the increased IL-10 by UVB exposure decreased miR-9 level by inducing miR-9 methylation via methyltransferase DNMT3A in HaCaT cells. Additionally, miR-9 targeted and inhibited E-cadherin and β1 integrin in HaCaT cells, and suppressed migration of PIG1 cells to UVB-exposed HaCaT cells. In conclusion, miR-9 was suppressed by IL-10 and inhibited migration of PIG1 cells to HaCaT cells during UVB-mediated vitiligo repigmentation. • Human lesional vitiligo specimens showed increased miR-9 expression. • UVB exposure upregulated IL-10 and downregulated miR-9 in HaCaT cells. • The UVB-increased IL-10 decreased miR-9 level by inducing miR-9 methylation. • miR-9 targeted and inhibited E-cadherin and β1 integrin in HaCaT cells. • miR-9 suppressed migration of PIG1 cells to UVB-exposed HaCaT cells. [ABSTRACT FROM AUTHOR]

Podocytes injury is a major contributor to the progression of diabetic nephropathy (DN). This study aims to investigate the role of long non-coding RNA SOX2OT in the high glucose (HG)-induced injury of human podocytes cells (HPCs) and the underlying mechanism. HPCs proliferation and apoptosis were examined using MTT assay and flow cytometry assay, respectively. The protein levels of SIRT1 and autophagy-associated proteins (Beclin-1, LC3-II, Atg7, and p62) were determined using western blot. The interactions among SOX2OT, miR-9, and SIRT1 were investigated using luciferase activity assay. SOX2OT overexpression significantly alleviated the HG-induced HPCs injury and induced autophagy, which was abrogated by the autophagy inhibitor 3-MA and SIRT1 knockdown. Mechanistically, SOX2OT acted as a ceRNA by sponging miR-9 to facilitate SIRT1, and thus induce autophagy. SOX2OT overexpression alleviates the HG-induced podocytes injury through autophagy induction by the miR-9/SIRT1 axis. [ABSTRACT FROM AUTHOR]

The roles of miR-9 in tumor progression are well-defined, however, its roles and the mechanisms in sepsis are still unclear. This work aims to explore miR-9 roles and related mechanism in LPS-induced sepsis. We found that miR-9 level was significantly upregulated in septic patients and RAW264.7 cells with LPS treatment, knockdown of miR-9 attenuated the induced effects of LPS on IL-6 and TNF-α secretion. In vivo experiments showed that miR-9 expression was increased in septic mice and knockdown of miR-9 partially reversed the upregulation of IL-6 and TNF-α levels in septic mice and prolonged the survival of septic mice. Mechanistic studies revealed that miR-9 could target ANO1, which inactivates the TGF-β/Smad2 signaling. Conversely, Smad2 could bind to the promoter of miR-9 and promote miR-9 expression. Notably, ANO1 overexpression or Smad2 knockdown attenuated miR-9 knockdown-mediated inhibition on LPS-induced sepsis. Therefore, these results suggest that the negative Smad2/miR-9/ANO1 regulatory loop is responsible for LPS-induced sepsis. [ABSTRACT FROM AUTHOR]

Summary MicroRNA (miRNA) processing begins with Drosha cleavage, the fidelity of which is critical for downstream processing and mature miRNA target specificity. To understand how pri-miRNA sequence and structure influence Drosha cleavage, we studied the maturation of three pri-miR-9 paralogs, which encode the same mature miRNA but differ in the surrounding scaffold. We show that pri-miR-9-1 has a unique Drosha cleavage profile due to its distorted and flexible stem structure. Cleavage of pri-miR-9-1, but not pri-miR-9-2 or pri-miR-9-3, generates an alternative miR-9 with a shifted seed sequence that expands the scope of its target RNAs. Analyses of low-grade glioma patient samples indicate that the alternative-miR-9 has a potential role in tumor progression. Furthermore, we provide evidence that distortion of pri-miRNA stems induced by asymmetric internal loops correlates with Drosha cleavage at non-canonical sites. Our studies reveal that pri-miRNA paralogs can have distinct functions via differential Drosha processing. Graphical Abstract Highlights • Pri-miRNA paralogs can adopt new functions due to distinct Drosha processing • A pri-miR-9-1-derived isomiR regulates a novel set of targets in low-grade glioma • The 3D structure of pri-miR-9-1 triggers Drosha cleavage at an alternative position • Structure-induced alternative Drosha cleavage is a general way to produce isomiRs By studying the processing of pri-miR-9 family, Bofill-De Ros et al. demonstrate that the tertiary structure of pri-miRNA triggers alternative biogenesis. Drosha cleaves pri-miR-9-1 at an additional site because of its distorted and flexible lower stem, generating a 5′ isomiR that regulates a distinct set of genes in low-grade glioma. [ABSTRACT FROM AUTHOR]

The aberrant scar is a challenging problem. Baicalein has effects in attenuating hypertrophic scar formation. Herein, the roles of baicalein in NIH-3T3 were obtained. Cells were treated by baicalein. CCK-8 method and western blot were used to detect cell viability and proliferation-related factors. Furthermore, collagen 1, collagen 3 and α-SMA expression were detected by qRT-PCR and western blot. Besides, total soluble collagen was detected by Sircol assay. In addition, the levels of NF-κB and Wnt/β-catenin signal pathways related factors were determined by western blot. The relationship between miR-9 and insulin-like growth factor (IGF)-1 were tested by luciferase reporter assay, qRT-PCR and western blot. We found baicalein cell restrained proliferation and collagen production. Besides, baicalein increased expression of miR-9 and further experiments validated that transfection with miR-9 inhibitor reversed the results led by baicalein. Moreover, baicalein decreased the phosphorylation of pathway-related proteins while transfection with miR-9 inhibitor revised this result. Otherwise, IGF-1 was authenticated as a target of miR-9 and si-IGF-1 reversed the miR-9 inhibitor-induced change in cell proliferation and collagen production. In conclusion, baicalein restrained cell proliferation and collagen production by regulating miR-9/IGF-1 axis through NF-κB and Wnt/β-catenin signal pathways. Highlights: Baicalein restrains NIH/3T3 cell proliferation and collagen production. Baicalein restrains NF-κB and Wnt/β-catenin signal pathways. IGF-1 is a target of miR-9. Baicalein exerts its functions by regulating miR-9/IGF-1 axis.

miR-9 has been reported to play a pivotal role in multiple human cancers by acting as an oncogene or tumor suppressor. In this study, we explored the possible role and molecular mechanism of miR-9 in multiple myeloma (MM). The miR-9 expression was examined by quantitative real-time polymerase chain reaction assay. Transfection with miR-9-mimics, miR-9-inhibitor, pcDNA-TRIM56, or si-TRIM56 into cells was used to change the expression levels of miR-9 and TRIM56. Western blot analysis was used to detect the expression of TRIM56, p65, p-p65, IκBα, and p-IκBα. The potential target of miR-9 was confirmed by luciferase reporter assay. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay, colony formation assay, and flow cytometry were used to assess the abilities of cell proliferation and apoptosis. miR-9 was upregulated in MM patients and cell lines, and miR-9 overexpression promoted proliferation and repressed apoptosis in MM cell lines. TRIM56 was confirmed as a target of miR-9. Moreover, TRIM56 reversed miR-9-mediated pro-proliferation and anti-apoptosis effect on MM cell lines. Furthermore, nuclear factor-κB (NF-κB) pathway was involved in miR-9/TRIM56-mediated regulation on MM cell lines. miR-9 promoted the development and progression of MM by regulating TRIM56/NF-κB pathway, thereby providing a potential microRNA-based target for MM therapy., (© 2019 International Federation for Cell Biology.)

Melatonin is a pleiotropic molecule that, after a short-term sleep deprivation, promotes the proliferation of neural stem cells in the adult hippocampus. However, this effect has not been observed in long-term sleep deprivation. The precise mechanism exerted by melatonin on the modulation of neural stem cells is not entirely elucidated, but evidence indicates that epigenetic regulators may be involved in this process. In this study, we investigated the effect of melatonin treatment during a 96-hour sleep deprivation and analyzed the expression of epigenetic modulators predicted by computational text mining and keyword clusterization. Our results showed that the administration of melatonin under sleep-deprived conditions increased the MECP2 expression and reduced the SIRT1 expression in the dentate gyrus. We observed that let-7b, mir-132, and mir-124 were highly expressed in the dentate gyrus after melatonin administration, but they were not modified by sleep deprivation. In addition, we found more Sox2 + /5-bromo-2'-deoxyuridine (BrdU) + cells in the subgranular zone of the sleep-deprived group treated with melatonin than in the untreated group. These findings may support the notion that melatonin modifies the expression of epigenetic mediators that, in turn, regulate the proliferation of neural progenitor cells in the adult dentate gyrus under long-term sleep-deprived conditions. All procedures performed in this study were approved by the Animal Ethics Committee of the University of Guadalajara, Mexico (approval No. CI-16610) on January 2, 2016., Competing Interests: None

Accumulating evidence has demonstrated that the aberrant expression of microRNAs (miRs or miRNAs) may contribute to the initiation and progression of various types of human cancer and may also constitute biomarkers for cancer diagnosis and therapy. However, the specific function of miR-9 in hepatocellular carcinoma (HCC) remains unclear, and the mechanisms that underlie HCC are incompletely understood. Here, we report that miR-9 expression was significantly decreased in clinical tumor tissue samples, as well as in a cohort of HCC cell lines. In addition, it was demonstrated that overexpression of miR-9 suppressed the proliferative and migratory capacity of HCC cells and impaired cell cycle progression. Furthermore, high mobility group AT-hook 2 (HMGA2) was verified as a downstream target gene of miR-9 using a luciferase reporter assay. Quantitative RT-PCR and western blotting implicated HMGA2 in the miR-9-mediated reduction of HCC cell growth. In vivo, transfection with miR-9 mimics down-regulated the expression of HMGA2, thus leading to a dramatic reduction in tumor growth in a mouse xenograft model. These results suggest that miR-9 may exert critical antitumor effects on HCC by directly targeting HMGA2, and the miR9/HMGA2 signaling pathway may be of use for the diagnosis and prognosis of patients with HCC., (© 2019 The Authors. Published by FEBS Press and John Wiley & Sons Ltd.)

Glioma, the most common primary malignancy in the brain, has high recurrence and lethality rates, and thus, elucidation of the molecular mechanisms of this incurable disease is urgently needed. Poly-pyrimidine tract binding protein (PTBP1, also known as hnRNP I), an RNA-binding protein, has various mechanisms to promote gliomagenesis. However, the mechanisms regulating PTBP1 expression are unclear. Herein, we report a novel natural antisense noncoding RNA, PTB-AS, whose expression correlated positively with PTBP1 mRNA. We found that PTB-AS significantly promoted the proliferation and migration in vivo and in vitro of glioma cells. PTB-AS substantially increased the PTBP1 level by directly binding to its 3' UTR and stabilizing the mRNA. Furthermore, staphylococcal nuclease domain-containing 1 (SND1) dramatically increased the binding capacity between PTB-AS and PTBP1 mRNA. Mechanistically, PTB-AS could mask the binding site of miR-9 in the PTBP1-3' UTR; miR-9 negatively regulates PTBP1. To summarize, we revealed that PTB-AS, which maintains the PTBP1 level through extended base pairing to the PTBP1 3' UTR with the assistance of SND1, could significantly promote gliomagenesis., (Copyright © 2019 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.)

Malignant neoplasms are regarded as the main cause of death around the world; hence, many research studies were conducted to further perceive molecular mechanisms, treatment, and cancer prognosis. Cancer is known as a major factor for health-related problems in the world. The main challenges associated with these diseases are prompt diagnosis, disease remission classification and treatment status forecast. Therefore, progressing in such areas by developing new and optimized methods with the help of minimally invasive biological markers such as circular microRNAs (miRNAs) can be considered important. miRNA interactions with target genes have specified their role in development, apoptosis, differentiation, and proliferation and also, confirm direct miRNA function in cancer. Different miRNAs expression levels in various types of malignant neoplasms have been observed to be associated with prognosis of various carcinomas. miR-9 seems to implement opposite practices in different tissues or under various cancer incidences by influencing different genes. Aberrant miR-9 levels have been observed in many cancer types. Therefore, we intended to investigate the precise role of miR-9 in patients with malignant neoplasms. To this end, in this study, we attempted to examine different studies to clarify the overall role of miR-9 as a prognostic marker in several human tumors. The presented data in this study can help us to find the novel therapeutic avenues for treatment of human cancers., (© 2019 Wiley Periodicals, Inc.)

LncRNA SRA1 plays important roles in several types of human diseases. The present study aimed to explore the role of SRA1 in cervical squamous cell carcinoma (CSCC). In the present study, we showed that plasma SRA1 was down-regulated in human papillomavirus (HPV)-negative CSCC patients but not in HPV-positive CSCC patients compared with healthy females. Down-regulated SRA1 distinguished HPV-negative CSCC patients from HPV-positive CSCC patients and healthy females. In HPV-negative CSCC patients, miR-9 was up-regulated and inversely correlated with SRA1. In HPV-negative CSCC cells, SRA1 overexpression caused the down-regulated miR-9, while miR-9 overexpression failed to affect SRA1. Moreover, SRA1 overexpression caused decreased, while miR-9 overexpression caused increased proliferation, migration and invasion rates of cancer cells. In addition, miR-9 overexpression attenuated the effects of SRA1 overexpression. Therefore, SRA1 is down-regulated in HPV-negative CSCC and regulates cancer cell behaviors possibly by down-regulating miR-9., (© 2019 The Author(s).)

Background: Invasion and metastasis of synovial sarcoma is the leading cause of death in patients. Epithelial mesenchymal transition (EMT) accelerates tumor cell invasion and metastasis. MiR-9 promotes tumor metastasis by inducing EMT. However, the role of miR-9 in synovial sarcoma is still not clear., Methods: Overexpression or knockdown of miR-9 in human synovial sarcoma (HSS) cell lines was carried out by miR-9 mimics or miR-9 inhibitors transfection. Cell proliferation, apoptosis, migration and invasion were detected using MTS and colony formation assays, flow cytometry, wound healing and transwell assays, respectively. Luciferase reporter assay was applied to study the interaction between miR-9 and CDH1. Nude mice xenograft model was established, and immunohistochemistry staining assessed Ki-67 level. The related mRNA and protein expression levels were evaluated by qRT-PCR and Western blotting., Results: The bioinformatics analyses and luciferase reporter assay showed that miR-9 can target CDH1 3'-UTR. Moreover, miR-9 could induce EMT of HSS cells via targeting CDH1. The negative regulation of miR-9 on CDH1 expression was also confirmed in a mouse xenograft model of synovial sarcoma. Furthermore, miR-9 was observed to induce HSS cell proliferation, migration and invasion and inhibit apoptosis. MAPK/ERK and Wnt/β-catenin signal pathways were activated by the miR-9 overexpression in HSS cells, and then further enhancing tumorigenesis of HSS, which was further confirmed in the mouse model., Conclusion: MiR-9 induces EMT by targeting CDH1, and activates MAPK/ERK and Wnt/β-catenin signal pathways, thus promoting HSS tumorigenesis., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background/aim: Diabetic vascular smooth muscle cells (VSMCs) are characterized by increased proliferation and migration. Small noncoding microRNAs (miRNAs) have been considered critical modulators of the VSMC phenotypic switch after an environmental stimulus. However, microRNA in high glucose-induced proinflammation and its atherogenic effect is still ambiguous., Materials and Methods: The technique of qRT-PCR was used to examine the expression of miR-9 in VSMCs. The downstream signaling protein relative to miR-9 regulation, Krüppel-like factor 5, and some marker genes of contractile VSMCs were analyzed by western blotting and qRT-PCR. Luciferase reporter assay was used to detect the expression of KLF5, which is regulated by miR-9. To examine the function of a miR-9 inhibitor in VSMC proliferation and migration, VSMC proliferation and migration assays were performed., Results: Reduced transcriptional levels of miR-9 and expression of specific genes of contractile VSMCs were observed in the SMC cell line C-12511 treated with high glucose and SMCs, which were isolated from db/db mice. Moreover, the activity of KLF5 3′-UTR was dramatically reduced by a miR-9 mimic and increased by a miR-9 inhibitor. The proliferation and migration of SMCs were reduced by the miR-9 mimic., Conclusion: miR-9 inhibits the proliferation and migration of SMC by targeting KLF5 in db/db mice., (This work is licensed under a Creative Commons Attribution 4.0 International License.)

Healing of damaged tissue results in scar development, which can be difficult to manage. The present study was performed to determine the effects of inhibition of the microRNA (miR), miR-9, on the proliferation of fibroblasts in human hyperplastic scar (HS) formation. Samples of HS tissue and normal tissue were isolated from 20 patients, and the fibroblasts were transfected with small-interfering RNA (siRNA) for transforming growth factor beta 1 (TGF-β1), miR-9 mimic, and miR-9 inhibition. TGF-β1 protein and mRNA expression were examined in the fibroblasts and HS tissue samples by Western blotting and RT-PCR, respectively. Moreover, the effects of miR-9 inhibitor and mimic on cell proliferation and apoptosis were also examined in the HS tissue. Protein and mRNA expression levels of TGF-β1 were increased in the HS tissue compared to adjacent normal tissues. The levels of TGF-β1 mRNA and protein expression were reduced in siRNA-transfected cells. The miR-9 and TGF-β1 mRNA expression levels were reduced in the miR-9 inhibitor treatment group compared to both the negative control (NC) and control groups. Reduced levels of miR-9 and TGF-β1 mRNA expression were observed in the miR-9 inhibitor treatment group compared to the NC and control groups. Moreover, miR-9 inhibitor increased the percentage of apoptotic cells and decreased cell proliferation compared to the NC and control groups. In conclusion, this study showed that miR-9 plays an important role in the proliferation of fibroblasts by regulating TGF-β1 expression in HS tissue., Competing Interests: None.

Proper growth of the mammalian cerebral cortex, which is determined by expansion and survival of neural progenitors and mature neurons, is crucial for cognitive functions. Here, we show a role of the dosage of microRNA miR-9 in controlling brain size. Cortical-specific upregulation of miR-9 causes microcephalic defects in mice, due to apoptosis, reduced neural progenitor pool, and decreased neurogenesis. Glial cell-derived neurotrophic factor (GDNF) is a target of miR-9, and protects neural progenitors from miR-9-induced apoptosis. Furthermore, Zika virus (ZIKV) infection in embryonic mouse cortex causes reduced numbers in neural progenitors and newborn neurons, and results in upregulation of miR-9, downregulation of its target GDNF. Our studies indicate an association of altered levels of miR-9 and its target GDNF with microcephaly and ZIKV infection in mice.

MicroRNAs (miRNAs) exert a critical influence on physiological and pathological processes through posttranscriptional modification of their mRNA targets. They play important roles in tumorigenesis and are considered to be potential diagnostic and prognostic biomarkers with various cancers. MiR-200c and miR-9 are regulatory elements that can have dual impacts as oncogenes and/or tumor suppressor genes. MiR-200c regulates two transcription factors, ZEB1 and ZEB2, while miR-9 is a regulatory factor for the E-cadherin protein which has a critical function in cell-cell junctions and is inhibited by two transcription factors ZEB1 and ZEB2. In this study, expression levels of miR-200c and miR-9, ZEB-1, ZEB-2 and E-cadherin were assessed in 30 non-small cell lung cancers (NSCLCs) by real-time qPCR. MiR-9 was down-regulated significantly in tumor tissues compared to normal adjacent tissues, while there was no significant change in expression level of miR-200c. On the other hand, ZEB1 demonstrated significant increase and ZEB2a decrease at the mRNA level. These results indicate roles for miR-9 and ZEB1 in genesis of lung cancer, although clinico-pathological associations were not evident. Further studies are necessary to assess implications for treatment of lung cancer.

Radiation therapy is the mainstay of salvage therapy for nasopharyngeal carcinoma (NPC). However, radiation therapy efficacy is limited by radioresistance that can cause local recurrence and distant metastases. Circular RNAs (circRNAs) have been involved in radioresistant esophageal cancer cells. In this study, we aim to investigate the role of circRNAs in the radioresistant NPC. Human circRNA array was performed in radioresistant and radiosensitive NPC samples to screen the differentially expressed circRNAs. We found that circRNA_000543 expression was upregulated in NPC tissues compared adjacent tissues, and was higher in radioresistant samples than in radiosensitive NPC samples. NPC patients with high circRNA_000543 expression displayed poorer overall survival compared with the patients with low circRNA_000543. Further investigations demonstrated that circRNA_000543 knockdown sensitized NPC cells by targeting miR-9/platelet-derived growth factor receptor B (PDGFRB) axis. CircRNA_000543 may be a potential therapeutic target for radioresistant NPC., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Aims: Severe acute pancreatitis (SAP) is an acute disease of the digestive system accompanied by pancreatic necrosis. We have found that bone marrow-derived mesenchymal stem cells (BMSCs) can attenuate SAP, but the underlying mechanism remains unclear. The present study was conducted to explore the possible mechanisms by which BMSCs alleviate SAP., Main Methods: BMSCs and BMSCs engineered to overexpress microRNA (miR)-9 (miR-9-BMSCs) were transplanted into rat models of SAP via the tail vein. Pancreatic acinar cells (PACs) were isolated from rat pancreatic tissues and induced by tumor necrosis factor-α (TNF-α) in vitro., Key Findings: miR-9-BMSCs significantly reduced the systemic inflammatory response, impeded the necroptosis signaling pathway and promoted regeneration of damaged pancreas in vivo. miR-9-BMSCs secreted miR-9, which targeted the gene encoding receptor interacting protein kinase 1 in PACs induced by TNF-α, to inhibit necroptosis and ameliorate SAP., Significance: miR-9-BMSCs can reduce SAP-induced injury to pancreatic tissues and PACs by regulating miR-9 to suppress necroptosis., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Axon guidance helps growing neural axons to follow precise paths to reach their target locations. It is a critical step for both the formation and regeneration of neuronal circuitry. Netrin-1 (Ntn1) and its receptor, deleted in colorectal carcinoma (Dcc) are essential factors for axon guidance, but their regulation in this process is incompletely understood. In this study, using quantitative real-time RT-PCR (qRT-PCR) and biochemical and reporter gene assays, we found that the Ntn1 and Dcc genes are both robustly up-regulated in the sciatic nerve stump after peripheral nerve injury. Moreover, we found that the microRNA (miR) let-7 directly targets the Ntn1 transcript by binding to its 3'-untranslated region (3'-UTR), represses Ntn1 expression, and reduces the secretion of Ntn1 protein in Schwann cells. We also identified miR-9 as the regulatory miRNA that directly targets Dcc and found that miR-9 down-regulates Dcc expression and suppresses the migration ability of Schwann cells by regulating Dcc abundance. Functional examination in dorsal root ganglion neurons disclosed that let-7 and miR-9 decrease the protein levels of Ntn1 and Dcc in these neurons, respectively, and reduce axon outgrowth. Moreover, we identified a potential regulatory network comprising let-7, miR-9 , Ntn1, Dcc, and related molecules, including the RNA-binding protein Lin-28 homolog A (Lin28), SRC proto-oncogene nonreceptor tyrosine kinase (Src), and the transcription factor NF-κB. In summary, our findings reveal that the miRs let-7 and miR-9 are involved in regulating neuron pathfinding and extend our understanding of the regulatory pathways active during peripheral nerve regeneration., (© 2019 Wang et al.)

Chemotherapy resistance is one of the major challenges for the treatment of osteosarcoma (OS). The potential roles of oestrogenic signals in the chemoresistance of OS cells were investigated. As compare to the parental cells, the doxorubicin and cisplatin (CDDP) resistant OS cells had greater levels of oestrogen-related receptors alpha (ERRα). Targeted inhibition of ERRα by its specific siRNAs or inverse agonist XCT-790 can restore the sensitivity of OS resistant cells to chemotherapy. This might be due to that si-ERRα can decrease the expression of P-glycoprotein (P-gp, encoded by ABCB1), one important ABC membrane transporter for drug efflux. XCT-790 can decrease the transcription and mRNA stability of ABCB1, while had no effect on protein stability of P-gp. ERRα can bind to the transcription factor of SP3 to increase the transcription of ABCB1. Furthermore, XCT-790 treatment decreased the expression of miR-9, which can bind to the 3'UTR of ABCB1 and trigger its decay. Collectively, we found that ERRα can regulate the chemoresistance of OS cells via regulating the transcription and mRNA stability of ABCB1. Targeted inhibition of ERRα might be a potential approach for OS therapy., (© 2019 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Fracture is the most common disease in the orthopedics. Long non-coding small nucleolar RNA host gene 7 (SNHG7) has been confirmed to enhance cell proliferation and decrease cell apoptosis in many cancers. However, the role of SNHG7 in skeletal fracture remains largely to be elucidated. In the current study, we observed SNHG7 was down-regulated in femoral neck fracture tissues. In addition, SNHG7 knockdown inhibited proliferation and migration, induced apoptosis, reduced activity in osteoblast cells in vitro. Bioinformatics analysis revealed SNHG7 acts as a molecular sponge for miR-9 and MiR-9 directly targets with 3'-UTR of TGFBR2. Furthermore, SNHG7 knockdown repressed the TGF-β signaling pathway. Taken together, this study manifested SNHG7 promotes bone repair in femoral neck fracture, and may serve as a potential target for enhancing bone formation., Competing Interests: None.

Aims: Aberrantly expressed miRNAs are demonstrated to be involved in the development of congenital heart disease (CHD). miR-9 was proposed to be upregulated in cardiac tissues from CHD cases. However, the role of miR-9 in hypoxia-induced cardiomyocytes and the potential mechanism are far from being addressed., Main Methods: qRT-PCR and western blot analysis were performed to detect miR-9 and Yes-associated protein 1 (Yap1) expressions in hypoxic H9c2 cells. CCK-8, flow cytometry analysis, caspase-3/7 activity assay were applied to evaluate cell proliferation, apoptosis, and caspase-3/7 activity, respectively. The interaction between miR-9 and Yap1 was explored by luciferase reporter assay, qRT-PCR and western blot., Key Findings: miR-9 was upregulated and Yap1 was downregulated in H9c2 cells in response to hypoxia in a time-dependent manner. Knockdown of miR-9 promoted cell proliferation, and inhibited apoptosis and caspase-3/7 activity in hypoxic H9c2 cells, while miR-9 overexpression exerted the opposite effects on hypoxic H9c2 cells. In addition, Yap1 was a direct target of miR-9 in H9c2 cells. Yap1 knockdown suppressed cell proliferation and promoted apoptosis in hypoxia-exposed H9c2 cells. Yap1 knockdown attenuated the effect of anti-miR-9 on cell proliferation and apoptosis in hypoxia-exposed H9c2 cells., Significance: miR-9 knockdown inhibited hypoxia-induced cardiomyocyte apoptosis by targeting Yap1. Our study provided a novel insight into the mechanism of the adaptation of cardiomyocytes to chronic hypoxia., (Copyright © 2019 Elsevier Inc. All rights reserved.)