Bioinformatics and microarray analysis of microRNA expression profiles of murine embryonic stem cells, neural stem cells induced from ESCs and isolated from E8·5 mouse neural tube
ABSTRACT To better understand whether microRNAs (miRNAs) are involved in the self-renewal of stem cells and fate determination of neural stem cells and to identify the miRNA expression patterns of different neural stem cells (NSC) in vitro and in vivo, we examined miRNA expression profiles of murine embryonic stem cells (ESC), NSC induced from ESC and isolated from E8.5 mouse neural tube (E8.5-NSC) using microarray technique. It was found that a total of 40 miRNAs had similar expression level in all the three cells [false discovery rate (FDR)=0, fold change <3.0]. Moreover, q-PCR showed that some members of miR-106b and miR-17-92 families were expressed in the ESC, NSC induced from ESC (ESC-NSC) and hematopoietic stem cells (HSC). Bioinformatical analysis showed that 'stemness genes' (p21/CDKN1A, p57/CDKN1C and PTEN) were putative targets of miR-106b and miR-17-92 families. A total of 95 miRNAs were found to experience significant change (FDR=0, fold change >5.0) when the ESC differentiated into NSC. On the basis of miRNA, mRNA expression variance and predicted target genes of miRNA, we formulated a bioinformatical model for miRNA control of ESC-NSC differentiation. Then, the miRNA expression pattern was compared between NSC obtained in vitro and in vivo, and it was found that only 8% of miRNAs were different between the two NSCs. This study suggested that miR-106b and miR-17-92 families may promote the renewal of stem cells by targeting PTEN, p21/CDKN1A and p57/CDKN1C. Some miRNAs may play a key role in gene re-programming during ESC-NSC differentiation, and a substantial homogeneity exists between NSCs derived in vitro and those in vivo.
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ABSTRACT: Background MicroRNAs are short (∼22 nt) non-coding regulatory RNAs that control gene expression at the post-transcriptional level. Here the functional impact of microRNAs on cell cycle arrest during neuronal lineage differentiation of unrestricted somatic stem cells from human cord blood (USSC) was analyzed.Methodology/Principal FindingsExpression profiling revealed downregulation of microRNAs miR-17, -20a, and -106b in USSC differentiated into neuronal lineage but not in USSC differentiated into osteogenic lineage. Transfection experiments followed by Ki67 immunostainings demonstrated that each of these microRNAs was able to promote proliferation of native USSC and to prevent in part cell cycle arrest during neuronal lineage differentiation of USSC. Bioinformatic target gene predictions followed by experimental target gene validations revealed that miR-17, -20a, and -106b act in a common manner by downregulating an overlapping set of target genes mostly involved in regulation and execution of G1/S transition. Pro-proliferative target genes cyclinD1 (CCND1) and E2F1 as well as anti-proliferative targets CDKN1A (p21), PTEN, RB1, RBL1 (p107), RBL2 (p130) were shown as common targets for miR-17, -20a, and -106b. Furthermore, these microRNAs also downregulate WEE1 which is involved in G2/M transition. Most strikingly, miR-17, -20a, and -106b were found to promote cell proliferation by increasing the intracellular activity of E2F transcription factors, despite the fact that miR-17, -20a, and -106b directly target the transcripts that encode for this protein family.Conclusions/SignificanceMir-17, -20a, and -106b downregulate a common set of pro- and anti-proliferative target genes to impact cell cycle progression of USSC and increase intracellular activity of E2F transcription factors to govern G1/S transition.PLoS ONE 01/2011; 6(1). · 3.53 Impact Factor
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ABSTRACT: This study investigated the possible involvement of microRNAs in the regulation of genes that participate in peripheral neural regeneration. A microRNA microarray analysis was conducted and 23 microRNAs were identified whose expression was significantly changed in rat dorsal root ganglia after sciatic nerve transection. The expression of one of the downregulated microRNAs, microRNA-214, was validated using quantitative reverse transcriptase-PCR. MicroRNA-214 was predicted to target the 3'-untranslated region of Slit-Robo GTPase-activating protein 3. In situ hybridization verified that microRNA-214 was located in the cytoplasm of dorsal root ganglia primary neurons and was downregulated following sciatic nerve transection. Moreover, a combination of in situ hybridization and immunohistochemistry revealed that microRNA-214 and Slit-Robo GTPase-activating protein 3 were co-localized in dorsal root ganglion primary neurons. Western blot analysis suggested that Slit-Robo GTPase-activating protein 3 was upregulated in dorsal root ganglion neurons after sciatic nerve transection. These data demonstrate that microRNA-214 is located and differentially expressed in dorsal root ganglion primary neurons and may participate in regulating the gene expression of Slit-Robo GTPase-activating protein 3 after sciatic nerve transection.Neural Regeneration Research 05/2014; 9(10):1031-40. DOI:10.4103/1673-5374.133164 · 0.23 Impact Factor
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ABSTRACT: Bone morphogenetic protein (BMP) signaling is active in many tissues including the central nervous system, in which it regulates cell proliferation, differentiation and maturation. The modulation of BMP pathway is crucial since abnormality of BMP signaling may cause cellular malfunction such as apoptosis. There are evidences indicating that miR-17 family is involved in the BMP signaling. In the present study, we demonstrated that BMP2 stimulation directly increased the transcription of miR-17-92 and miR-106b-25 cluster via Smad activation, which leads to the up-regulation of mature miR-17/20a/93. In addition, we provided evidence that BMP2 activation repressed BMPRII expression through modulating miR-17 family in primary neurons. Furthermore, we proved that such negative regulation protected neurons from apoptosis induced by abnormal BMP signaling. Taken together, these results suggest a regulatory pathway of BMP-miR-17 family-BMPRII, which consist a negative feedback loop that balances BMP signaling and maintains cell homeostasis in neurons.PLoS ONE 12/2013; 8(12):e83067. DOI:10.1371/journal.pone.0083067 · 3.53 Impact Factor