MicroRNA-506-3p regulates neural stem cell proliferation and differentiation through targeting TCF3

Genetically engineered neural stem cells (NSCs) therapy for neurological diseases; state-of-the-art

Neural stem cells (NSCs) are multipotent stem cells with remarkable self-renewal potential and also unique competencies to differentiate into neurons, astrocytes, and oligodendrocytes (ODCs) and improve the cellular microenvironment. In addition, NSCs secret diversity of mediators, including neurotrophic factors (e.g., BDNF, NGF, GDNF, CNTF, and NT-3), pro-angiogenic mediators (e.g., FGF-2 and VEGF), and anti-inflammatory biomolecules. Thereby, NSCs transplantation has become a reasonable and effective treatment for various neurodegenerative disorders by their capacity to induce neurogenesis and vasculogenesis and dampen neuroinflammation and oxidative stress. Nonetheless, various drawbacks such as lower migration and survival and less differential capacity to a particular cell lineage concerning the disease pathogenesis hinder their application. Thus, genetic engineering of NSCs before transplantation is recently regarded as an innovative strategy to bypass these hurdles. Indeed, genetically modified NSCs could bring about more favored therapeutic influences post-transplantation in vivo, making them an excellent option for neurological disease therapy. This review for the first time offers a comprehensive review of the therapeutic capability of genetically modified NSCs rather than naïve NSCs in neurological disease beyond brain tumors and sheds light on the recent progress and prospect in this context.

miR-153-3p suppresses the differentiation and proliferation of neural stem cells via targeting GPR55

Alzheimer's disease is the most frequent neurodegenerative disease and is characterized by progressive cognitive impairment and decline. NSCs (neural stem cells) serve as beneficial and promising adjuncts to treat Alzheimer's disease. This study aimed to determine the role of miR-153-3p expression in NSC differentiation and proliferation. We illustrated that miR-153-3p was decreased and GPR55 was upregulated during NSC differentiation. IL-1β can induce miR-153-3p expression. Luciferase reporter analysis noted that elevated expression of miR-153-3p significantly inhibited the luciferase value of the WT reporter plasmid but did not change the luciferase value of the mut reporter plasmid. Ectopic miR-153-3p expression suppressed GPR55 expression in NSCs and identified GPR55 as a direct target gene of miR-153-3p. Ectopic expression of miR-153-3p inhibited NSC growth and differentiation into astrocytes and neurons. Elevated expression of miR-153-3p induced the release of proinflammatory cytokines, such as TNF-α, IL-1β and IL-6, in NSCs. Furthermore, miR-153-3p inhibited NSC differentiation and proliferation by targeting GPR55 expression. These data suggested that miR-153-3p may act as a clinical target for the therapeutics of neurodegenerative diseases.

Identification and verification of microRNA signature and key genes in the development of osteosarcoma with lung metastasis

BACKGROUND

Osteosarcoma (OS) is a heterogeneous malignant spindle cell tumor in children under the age of 20. This study aims to research the association between Solute Carrier Family 7 Member 8 (SLC7A8) as well as related genes and OS.

METHOD

OS and normal samples (GSE38698 and GSE85537) were downloaded from Gene Expression Omnibus dataset. The bioinformatics analysis was performed to distinguish 2 differentially expressed genes, prognostic candidate genes and functional enrichment pathway. Immunohistochemistry and quantitative real-time PCR were utilized for further study.

RESULTS

There were 5 DEMs and 10 differentially expressed genes in cancer tissues compared to normal tissues. According to the km-plot software, ARHGEF3, BSN, PQLC3, and SLC7A8 were significantly related to the overall survival of patients with OS. Furthermore, Multivariate analysis included that SLC7A8 was independent risk factors for OS patients. Furthermore, immunohistochemistry and quantitative real-time PCR outcomes indicated that the expression level of SLC7A8 and hsa-miR-506 was differentially expressed in lung metastasis OS tissues and non-metastasis tissues.

CONCLUSION

The prognostic model based on the miRNA-mRNA network could provide predictive significance for prognosis of OS patients, which would be worthy of clinical application. Our results concluded that SLC7A8 may play a key role in the development of OS.

Sevoflurane induces microRNA-18a to delay rat neurodevelopment via suppression of the RUNX1/Wnt/β-catenin axis

Sevoflurane anesthesia is reported to repress neurogenesis of neural stem cells (NSCs), thereby affecting the brain development, but the underlying mechanism of sevoflurane on the proliferation of NSCs remains unclear. Thus, this study aims to discern the relationship between sevoflurane and NSC proliferation. Bioinformatics tools were employed to predict the expression of microRNA-18a (miR-18a) in 9-day-old neonatal rat hippocampal tissues after sevoflurane treatment and the downstream genes of miR-18a, followed by a series of assays to explore the relationship among miR-18a, runt related transcription factor 1 (RUNX1), and β-catenin in the hippocampal tissues. NSCs were isolated from the hippocampal tissues and subjected to gain-/loss-of-function assays to investigate the interactions among miR-18a, RUNX1, and β-catenin in NSCs and their roles in NSC development. Bioinformatics analysis and experimental results confirmed high expression of miR-18a in rat hippocampal tissues and NSCs after sevoflurane treatment. Next, we found that miR-18a downregulated RUNX1 expression, while RUNX1 promoted NSC proliferation by activating the Wnt/β-catenin signaling pathway. The behavioral experiments also showed that sevoflurane caused nerve injury in rats, whilst RUNX1 overexpression protected rat neurodevelopment. Our findings uncovered that sevoflurane attenuated NSC proliferation via the miR-18a-meidated RUNX1/Wnt/β-catenin pathway, thereby impairing rat neurodevelopment.

Wnt-Signaling Regulated by Glucocorticoid-Induced miRNAs

Glucocorticoids (GCs) are pleiotropic hormones which regulate innumerable physiological processes. Their comprehensive effects are due to the diversity of signaling mechanism networks. MiRNAs, small, non-coding RNAs contribute to the fine tuning of signaling pathways and reciprocal regulation between GCs and miRNAs has been suggested. Our aim was to investigate the expressional change and potential function of GC mediated miRNAs. The miRNA expression profile was measured in three models: human adrenocortical adenoma vs. normal tissue, steroid-producing H295R cells and in hormonally inactive HeLa cells before and after dexamethasone treatment. The gene expression profile in 82 control and 57 GC-affected samples was evaluated in GC producing and six different GC target tissue types. Tissue-specific target prediction (TSTP) was applied to identify the most relevant miRNA-mRNA interactions. Glucocorticoid treatment resulted in cell type-dependent miRNA expression changes. However, 19.5% of the influenced signaling pathways were common in all three experiments, of which the Wnt-signaling pathway seemed to be the most affected. Transcriptome data and TSTP showed similar results, as the Wnt pathway was significantly altered in both the GC-producing adrenal gland and all investigated GC target tissue types. In different cell types, different miRNAs led to the regulation of similar pathways. Wnt signaling may be one of the most important signaling pathways affected by hypercortisolism. It is, at least in part, regulated by miRNAs that mediate the glucocorticoid effect. Our findings on GC producing and GC target tissues suggest that the alteration of Wnt signaling (together with other pathways) may be responsible for the leading symptoms observed in Cushing's syndrome.

miR-506-3p regulates TGF- 1 and affects dermal fibroblast proliferation, migration and collagen formation after thermal injury

Dermal fibroblasts are a promising candidate for cellular-based therapies for thermal wound healing because of their capacity of producing extracellular matrix (ECM), promoting wound contraction and the synthesis of type I collagen, and secreting growth factors. miRNAs (MicroRNAs) might mediate the role of TGF-β1(Transforming Growth Factor-beta 1), one of the major profibrotic cytokines, in improving thermal injury repair. In the present study, we observed the abnormal downregulation of TGF-β1 following thermal injury in the burnt dermis (in vivo) and heat-stimulated human dermal fibroblasts (in vitro). TGF-β1 overexpression reversed heat stimulation-induced repression on fibroblast viability, migration, and ECM synthesis. As demonstrated by online tool prediction and experimental analysis, miR-506-3p downregulated TGF-β1 levels via directly targeting TGFB1. In heat-stimulated human dermal fibroblasts, miR-506-3p expression showed to be significantly upregulated. miR-506-3p inhibition also reversed heat stimulation-induced repression on fibroblast viability, migration, and ECM synthesis; more importantly, TGF-β1 silencing aggravated the thermal injury in vitro and significantly reversed the effects of miR-506-3p inhibition on heat-stimulated dermal fibroblasts. In conclusion, miR-506-3p and its downstream target TGF-β1 form a regulatory axis, modulating the cell viability, migration, and ECM synthesis in human dermal fibroblasts following burn injury.

The Role of microRNAs in Pulp Inflammation

The dental pulp can be affected by thermal, physical, chemical, and bacterial phenomena that stimulate the inflammatory response. The pulp tissue produces an immunological, cellular, and vascular reaction in an attempt to defend itself and resolve the affected tissue. The expression of different microRNAs during pulp inflammation has been previously documented. MicroRNAs (miRNAs) are endogenous small molecules involved in the transcription of genes that regulate the immune system and the inflammatory response. They are present in cellular and physiological functions, as well as in the pathogenesis of human diseases, becoming potential biomarkers for diagnosis, prognosis, monitoring, and safety. Previous studies have evidenced the different roles played by miRNAs in proinflammatory, anti-inflammatory, and immunological phenomena in the dental pulp, highlighting specific key functions of pulp pathology. This systematized review aims to provide an understanding of the role of the different microRNAs detected in the pulp and their effects on the expression of the different target genes that are involved during pulp inflammation.

miR-299-3p suppresses cell progression and induces apoptosis by downregulating PAX3 in gastric cancer

Gastric cancer (GC) is ranked the fourth leading cause of cancer-related death, with an over 75% mortality rate worldwide. In recent years, miR-299-3p has been identified as a biomarker in multiple cancers, such as acute promyelocytic leukemia, thyroid cancer, and lung cancer. However, the regulatory mechanism of miR-299-3p in GC cell progression is still largely unclear. Cell viability and apoptosis tests were performed by CCK8 and flow cytometry assay, respectively. Transwell assay was recruited to examine cell invasion ability. The interaction between miR-299-3p and PAX3 was determined by the luciferase reporter system. PAX3 protein level was evaluated by western blot assay. The expression of miR-299-3p was downregulated in GC tissues and cell lines (MKN-45, AGS, and MGC-803) compared with the normal tissues and cells. Besides, overexpression of miR-299-3p significantly suppressed proliferation and invasion and promoted apoptosis in GC. Next, we clarified that PAX3 expression was regulated by miR-299-3p using a luciferase reporter system, qRT-PCR, and western blot assay. Additionally, downregulation of PAX3 repressed GC cell progression. The rescue experiments indicated that restoration of PAX3 inversed miR-299-3p-mediated inhibition on cell proliferation and invasion. miR-299-3p suppresses cell proliferation and invasion as well as induces apoptosis by regulating PAX3 expression in GC, representing desirable biomarkers for GC diagnosis and therapy.

Studies on the Regulatory Roles and Related Mechanisms of lncRNAs in the Nervous System

Long noncoding RNAs (lncRNAs) have attracted extensive attention due to their regulatory role in various cellular processes. Emerging studies have indicated that lncRNAs are expressed to varying degrees after the growth and development of the nervous system as well as injury and degeneration, thus affecting various physiological processes of the nervous system. In this review, we have compiled various reported lncRNAs related to the growth and development of central and peripheral nerves and pathophysiology (including advanced nerve centers, spinal cord, and peripheral nervous system) and explained how these lncRNAs play regulatory roles through their interactions with target-coding genes. We believe that a full understanding of the regulatory function of lncRNAs in the nervous system will contribute to understand the molecular mechanism of changes after nerve injury and will contribute to discover new diagnostic markers and therapeutic targets for nerve injury diseases.

Regulation of breast cancer metastasis signaling by miRNAs

Despite the decline in death rate from breast cancer and recent advances in targeted therapies and combinations for the treatment of metastatic disease, metastatic breast cancer remains the second leading cause of cancer-associated death in U.S. women. The invasion-metastasis cascade involves a number of steps and multitudes of proteins and signaling molecules. The pathways include invasion, intravasation, circulation, extravasation, infiltration into a distant site to form a metastatic niche, and micrometastasis formation in a new environment. Each of these processes is regulated by changes in gene expression. Noncoding RNAs including microRNAs (miRNAs) are involved in breast cancer tumorigenesis, progression, and metastasis by post-transcriptional regulation of target gene expression. miRNAs can stimulate oncogenesis (oncomiRs), inhibit tumor growth (tumor suppressors or miRsupps), and regulate gene targets in metastasis (metastamiRs). The goal of this review is to summarize some of the key miRNAs that regulate genes and pathways involved in metastatic breast cancer with an emphasis on estrogen receptor α (ERα+) breast cancer. We reviewed the identity, regulation, human breast tumor expression, and reported prognostic significance of miRNAs that have been documented to directly target key genes in pathways, including epithelial-to-mesenchymal transition (EMT) contributing to the metastatic cascade. We critically evaluated the evidence for metastamiRs and their targets and miRNA regulation of metastasis suppressor genes in breast cancer progression and metastasis. It is clear that our understanding of miRNA regulation of targets in metastasis is incomplete.

High expression of miR-374a-5p inhibits the proliferation and promotes differentiation of Rencell VM cells by targeting Hes1

The proliferation and differentiation of NSCs are regulated by miRNAs. This study investigated the role of miR-374a-5p in the proliferation and differentiation of ReNcell VM cells. ReNcell VM cells were transfected with miR-374a-5p mimic, miR-374a-5p inhibitor and Hes1, respectively. Cell proliferation was detected by clone formation assay. Target gene for miR-374a-5p was predicted by TargetScan and confirmed by dual-luciferase reporter. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were performed to detect the expressions of relative genes. After culturing the cells in differentiation medium, the ReNcell VM cells differentiated into βIII-tubulin (Tuj1)-positive neurons and GFAP-positive astrocytes. The miR-374a-5p expression was increased as the cells continued to differentiate. Hes1, which was predicted to be the target gene for miR-374a-5p, was low-expressed during cell differentiation. The miR-374a-5p mimic decreased cell clones, inhibited the expressions of ki-67 and Nestin, but increased those of Tuj1 and GFAP. However, miR-374a-5p inhibitor produced the opposite effects to miR-374a-5p mimic. Hes1 increased the expressions of ki-67 and Nestin, but decreased those of Tuj1 and GFAP, moreover, Hes1 reversed the role of miR-374a-5p mimic. MiR-374a-5p inhibited the proliferation of Rencell VM cells and promoted the differentiation of NSCs by reducing the Hes1 expression.

ADNCR modulates neural stem cell differentiation and proliferation through the regulation of TCF3 expression

Background

Neural stem cells (NSCs) are undifferentiated precursor cells that have the ability to self-renew and proliferate and have the capacity to become either glia (oligodendrocytes and astrocytes) or neurons. NSCs can act as beneficial adjuncts for many neurological disorders, such as cerebral infarction, spinal cord injuries, Alzheimer's disease, and Parkinson's disease. Long noncoding RNAs (lncRNAs) play essential roles during cell differentiation, proliferation, and metabolism. This study aimed to explore the role played by adipocyte differentiation-associated long noncoding RNA (ADNCR) in the self-renewal and multipotency of NSCs.

Methods

In this study, we identified NSCs and verified that these cells were able to regenerate and differentiate into both astrocytes and neurons. Then we studied the relation between expression of ADNCR and transcription factor 3 (TCF3) and proliferation of NSCs.

Results

ADNCR and TCF3 expression have been shown to decrease during the differentiation of NSCs into both neurons and astrocyte induction cells. However, the expression of the microRNA miR-204-5p increased over time during the differentiation of NSCs into both neurons and astrocyte induction cells. ADNCR acts as a competing endogenous RNA (ceRNA) for miR-204-5p, and the overexpression of ADNCR suppressed miR-204-5p expression and enhanced TCF3 expression in NSCs, which resulted in enhanced proliferation and suppressed neural differentiation.

Conclusions

These data suggested that the use of ADNCR may represent a new strategy for expanding the interventions used to treat neurological disorders.

Long Noncoding RNA HOTAIR Contributes to Progression in Hepatocellular Carcinoma by Sponging miR-217-5p

Background: Hepatocellular carcinoma (HCC) is an aggressive primary hepatic cancer with high malignancy and poor prognosis. Long noncoding RNA HOTAIR has been classified as an oncogene to accelerate cell proliferation, migration, and invasion in many cancer types by interacting with the miRNA. Therefore, we assumed that HOTAIR might participate in HCC cell progression by interacting with miR-217-5p expression. Materials and Methods: The expression of HOTAIR and miR-217-5p in 35 HCC patients and HCC cells was measured by quantitative real-time polymerase chain reaction. Cell transfection was conducted using Lipofectamine 2000 transfection reagent. CCK8 and flow cytometry was applied for the measurement of cell proliferation and apoptosis. Cell migration and invasion capacities were carried out by transwell assay. Xenograft mice were constructed by subcutaneously injecting of stably transfected Huh-7 cells in mice. The interaction between HOTAIR and miR-217-5p was determined by luciferase reporter system. Protein expression of P13K, p-P13K, AKT, p-AKT, MMP-2, and MMP-9 was analyzed using Western blot assay. Results: The expression of HOTAIR was upregulated, whereas miR-217-5p was downregulated in HCC tumor tissues and cell lines (Hep3B and Huh-7) compared with normal tissues and human normal liver cell line MIHA. In addition, HOTAIR expression was negatively correlated with miR-217-5p expression in HCC (r² = 0.1867, p = 0.0171). More importantly, HOTAIR knockdown induced apoptosis and inhibited cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT). In vivo experiments revealed that the interference of HOTAIR inhibited tumor growth. Subsequently, luciferase reporter system confirmed the interaction between HOTAIR and miR-217-5p. The rescue experiments clarified that miR-217-5p inhibitor attenuated the suppression of HOTAIR silencing on HCC cell proliferation, migration, invasion, and EMT. Furthermore, miR-217-5p inhibitor restored the inhibition of HOTAIR silencing mediated p-PI3K/p-AKT/MMP-2/9 protein expression. Conclusions: HOTAIR contributes to cell progression in HCC by sponging miR-217-5p, representing promising biomarkers for HCC treatment.

MicroRNA-489 suppresses isoproterenol-induced cardiac fibrosis by downregulating histone deacetylase 2

Cardiac fibrosis is a hallmark of cardiovascular diseases. Several studies have indicated that microRNAs (miRs) are associated with the development of cardiac fibrosis. However, to date, the underlying molecular mechanisms of miR-489 in cardiac fibrosis have not been studied. The present study investigated the biological function of miR-489 in isoproterenol (ISO)-induced cardiac fibrosis. It was observed that miR-489 was downregulated in the heart tissue and cardiac fibroblasts (CFs) obtained from rats with ISO-induced cardiac fibrosis, as compared with the levels in the control group. By contrast, the expression levels of histone deacetylase 2 (HDAC2), collagen I (Col1A1) and α-smooth muscle actin (α-SMA) were increased in the heart tissue and CFs obtained from ISO-treated rats compared with the control group. Furthermore, ISO-treated CFs were transfected with a miR-489 mimic, which resulted in decreased viability and differentiation of CFs compared with the control group. Bioinformatics analysis and a dual-luciferase reporter assay further revealed that HDAC2 is a downstream target of miR-489. Subsequently, a loss-of-function experiment demonstrated that depletion of HDAC2 decreased the expression levels of Col1A1 and α-SMA in CFs. Taken together, the results obtained in the present study revealed that the miR-489/HDAC2 signaling pathway may serve as a novel regulatory mechanism in ISO-induced cardiac fibrosis and may increase the understanding on cardiac fibrosis.

MicroRNA-506 Is Involved in Regulation of the Occurrence of Lipopolysaccharides (LPS)-Induced Pulpitis by Sirtuin 1 (SIRT1)

Background

Toothache often occurs with pulpitis. Lipopolysaccharide (LPS) is produced by gram-negative bacteria, and its accumulation is related to clinical symptoms of pain. MicroRNAs (miRNAs) display anti-inflammatory potential due to their direct regulation of cellular protein expression, which can promote inflammatory changes in dental pulp tissues. However, the mechanism of LPS-induced pulpitis is still unclear.

Material/Methods

In this study, dental pulp stem cells (DPSCs) were separated and cultured from rat dental pulp tissues; then, LPS was administered to induce inflammation and activate the TLR4 pathway.

Results

It was found that miR-506 was upregulated following LPS treatment in DPSCs. The inhibition of miR-506 in LPS-treated DPSCs led to attenuated inflammation and deactivation of the TLR4 pathway. Furthermore, the bioinformatic analysis and dual-luciferase reporter gene assay indicated that miR-506 could target the 3′-UTR of sirtuin 1 (SIRT1). Additionally, SIRT1 decreased in LPS-treated DPSCs, and miR-506 transfection resulted in SIRT1 upregulation. SIRT1 overexpression showed a similar inhibitory effect as that of miR-506 downregulation on inflammation and TLR4 activation in DPSCs.

Conclusions

In brief, miR-506 can protect dental pulp in LPS-induced inflammation by inhibiting the SIRT1-mediated TLR4 pathway.

miR‑329‑3p regulates neural stem cell proliferation by targeting E2F1

Neural stem cells (NSCs) are a class of self‑renewing and undifferentiated progenitor cells that retain the ability to differentiate to neurons, astrocytes and oligodendrocytes. MicroRNAs (miRNAs) are small noncoding RNAs that serve crucial roles in regulating a number of cellular processes, including cell proliferation, differentiation and apoptosis. Our previous GeneChip data indicated that the expression of miR‑329‑3p was increased in neurons compared with NSCs. However, whether miRNA‑329‑3p participates in regulating NSC function remains to be elucidated. In the present study, it was identified that the expression of miR‑329‑3p was upregulated in NSCs during neuronal differentiation, whereas expression of transcription factor E2F1 (E2F1), a putative target gene of miR‑329‑3p, was downregulated. Using luciferase reporter assays, it was confirmed that miR‑329‑3p regulated E2F1 expression. As differentiation has been demonstrated to limit the proliferative capacity of NSCs, the effects of miR‑329‑3p and E2F1 modulation on NSC proliferation were examined. Forced overexpression of miR‑329‑3p or RNA‑mediated silencing of E2F1 inhibited NSC proliferation, and overexpression of miR‑329‑3p also inhibited E2F1 expression. Notably, ectopic expression of E2F1 reversed the inhibition of NSC proliferation induced by miR‑329‑3p overexpression. These results indicated that miR‑329‑3p may serve crucial roles in regulating the proliferation of NSCs, at least in part via inhibition of E2F1 expression. These data improve the understanding of the microRNA‑mRNA regulatory network that controls NSC proliferation.

MiR-506 Suppresses Colorectal Cancer Development by Inhibiting Orphan Nuclear Receptor NR4A1 Expression

NR4A1 acts as an oncogene and plays an important role in colorectal cancer development and progression, but little is known about the regulatory mechanism of NR4A1 expression. MicroRNA (miRNA) is involved in the progression of various tumors, affecting proliferation, apoptosis or migration. We aimed to elucidate whether miRNA regulates NR4A1 expression and determine its underlying significance in colorectal cancer. By using the TargetScan database, we identified a miR-506 binding site in the NR4A1 3'-UTR. Examination of colorectal cancer tissues and cells revealed that NR4A1 mRNA and protein were up-regulated, while miR-506 expression was down-regulated. Spearman correlation analysis revealed that expression of NR4A1 mRNA was negatively correlated with miR-506 levels in colorectal cancer tissue. Further studies indicated that miR-506 decreased NR4A1 expression through directly targeting the NR4A1 mRNA 3'-UTR. Functional experiments showed that rescue of NR4A1 expression in cells reversed the inhibitory effects of miR-506 on proliferation, migration and invasion of colorectal cancer cells. In conclusion, miR-506 acts as a tumor suppressor and inhibits proliferation, migration and invasion in colorectal cancer cells partly through decreasing NR4A1 expression.

MicroRNA-135a-5p promotes neuronal differentiation of pluripotent embryonal carcinoma cells by repressing Sox6/CD44 pathway

MicroRNA-135a-5p has been reported to play a potential role in the generation of new neurons. However, the underlying targets of miR-135a-5p in regulating neuronal differentiation have been poorly understood. Our study recently has uncovered that Sox6 and CD44 genes were significantly downregulated during neuronal differentiation of P19 cells, a multipotent cell type. We then found that Sox6 directly bound to the promoter of CD44. Importantly, we identified Sox6 as a direct target of miR-135a-5p. Additionally, we demonstrated that miR-135a-5p is crucial for the neuronal differentiation of P19 cells. More significantly, we found that Sox6 overexpression could overturn miR-135a-5p-mediated neuronal differentiation and dendrite development. In conclusion, these findings indicated that miR-135a-5p/Sox6/CD44 axis provides an important molecular target mechanism for neurodifferentiation.

DDN-AS1-miR-15a/16-TCF3 feedback loop regulates tumor progression in cervical cancer

Cervical cancer (CC) is known as one of the most common gynecological tumors. Long noncoding RNAs (lncRNAs) are a group of regulators that have been widely reported in human malignant tumors including CC. On the basis of the data of The Cancer Genome Atlas, lncRNA DDN and PRKAG1 antisense RNA 1 ( DDN-AS1) that is overexpressed in CC tissues predicted poor prognosis for patients with CC. Moreover, quantitative reverse transcription PCR analysis further identified the upregulation of DDN-AS1 in CC tissues and cell lines. Loss-of-function assays revealed that knockdown of DDN-AS1 suppressed CC progression by efficiently inhibiting cell proliferation, migration, and invasion. Mechanism investigations revealed that DDN-AS1 was upregulated by its upstream transcription activator transcription factor 3 ( TCF3). Moreover, DDN-AS1 increased the expression of  TCF3 by competitively binding miR-15a and miR-16. In conclusion, DDN-AS1-miR-15a/16-TCF3 feedback loop contributes to cell proliferation, migration, and invasion in CC.

miR-124 promotes proliferation and differentiation of neuronal stem cells through inactivating Notch pathway

Background

Neural stem cells (NSCs) are able to differentiate into neurons and astroglia. miRNAs have been demonstrated to be involved in NSC self-renewal, proliferation and differentiation. However, the exact role of miR-124 in the development of NSCs and its underlying mechanism remain to be explored.

Methods

Primary NSCs were isolated from embryos of Wistar rats. Immunocytochemistry was used to stain purified NSCs. miR-124, Delta-like 4 (DLL4), ki-67, Nestin, β-tubulin III, glial fibrillary acidic protein (GFAP), HES1, HEY2, and cyclin D1 (CCND1) expressions were detected by qRT-PCR and western blot. The interaction between miR-124 and DLL4 was confirmed by luciferase reporter assay. Cell proliferation was assessed by MTT assay.

Results

NSCs could self-proliferate and differentiate into neurons and astrocyte. miR-124 was up-regulated and DLL4 was down-regulated during NSC differentiation. DLL4 was identified as a target of miR-124 in NSCs. Ectopic expression of miR-124 or knockdown of DLL4 promoted the proliferation and the formation of NSCs to neurospheres. Moreover, miR-124 overexpression or DLL4 down-regulation improved β-tubulin III expression but decreased GFAP expression in NSCs. Furthermore, enforced expression of DLL4 partially reversed the effects of miR-124 on NSCs proliferation and differentiation. Elevated expression of miR-124 suppressed the expressions of HES1, HEY2, and CCND1 in NSCs, while these effects were attenuated following the enhancement of DLL4 expression.

Conclusion

miR-124 promoted proliferation and differentiation of NSCs through inactivating Notch pathway.

Reprogramming of somatic cells to induced neural stem cells

Recent investigations have demonstrated that defined sets of exogenous factors (chemical and/or biochemical) can convert human and mouse somatic cells into induced neural stem cells (iNSCs). Considering the self-renewal and multi-potential differentiation capabilities of iNSCs, generation of these cells has considerably enhanced cell therapy for treatment of neurodegenerative disorders. These cells can also serve as models for investigation of the mechanism(s) underlying neurodegenerative diseases and as an asset in drug discovery. Meanwhile, using the process of direct conversion/transdifferentiation, by bypassing pluripotent state and consequently reducing tumorigenesis and genetic instability risks, establishment of several desired cells are feasible. In this review, we describe the pros and cons of different methods employed to directly reprogram somatic cells to iNSCs along with the progress of iNSCs applications and the future challenges.

Combination of RNA Interference and Stem Cells for Treatment of Central Nervous System Diseases

RNA interference (RNAi), including microRNAs, is an important player in the mediation of differentiation and migration of stem cells via target genes. It is used as a potential strategy for gene therapy for central nervous system (CNS) diseases. Stem cells are considered vectors of RNAi due to their capacity to deliver RNAi to other cells. In this review, we discuss the recent advances in studies of RNAi pathways in controlling neuronal differentiation and migration of stem cells. We also highlight the utilization of a combination of RNAi and stem cells in treatment of CNS diseases.

miR-1297 regulates neural stem cell differentiation and viability through controlling Hes1 expression

OBJECTIVES

Neural stem cells (NSCs) are self-renewing, undifferentiated and multipotent precursors that can generate neuronal and glial lineages. MicroRNAs (miRNAs) are small non-coding RNAs that act crucial roles in cell proliferation, differentiation and migration. However, the role of miR-1297 in the development of NSCs is still unknown.

MATERIALS AND METHODS

Primary NSCs were isolated from rat's embryos. The expression of miR-1297 and Hes1 were measured by qRT-PCR. Western blot was performed to detect the protein expression of Hes1, β-tubulin-III and GFAP.

RESULTS

We showed that miR-1297 expression was upregulated during NSC differentiation, while the expression of Hes1 was decreased during NSC differentiation. Elevated expression of miR-1297 promoted the NSCs viability and increased the formation of NSCs to neurospheres. Ecoptic expression of miR-1297 promoted β-tubulin-III expression in the NSCs. Overexpression of miR-1297 decreased GFAP expression in the NSCs. Furthermore, we demonstrated that miR-1297 regulated NSCs viability and differentiation by directly targeting Hes1. Overexpression of miR-1297 suppressed Hes1 expression in the NSCs.

CONCLUSIONS

These results suggested that miR-1297 played an important role in NSCs viability and differentiation through inhibiting Hes1 expression.