MicroRNA-378 regulates neural stem cell proliferation and differentiation in vitro by modulating Tailless expression.

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Huang, Yanxia; Liu, Xiaoguai; Wang, Yaping

2015-10-16

Previous studies have suggested that microRNAs (miRNAs) play an important role in regulating neural stem cell (NSC) proliferation and differentiation. However, the precise role of miRNAs in NSC remains largely unexplored. In this study, we showed that miR-378 can target Tailless (TLX), a critical regulator of NSC, to regulate NSC proliferation and differentiation. By bioinformatic algorithms, miR-378 was found to have a predicted target site in the 3'-untranslated region of TLX, which was verified by a dual-luciferase reporter assay. The expression of miR-378 was increased during NSC differentiation and inversely correlated with TLX expression. qPCR and Western blot analysis also showed that miR-378 negatively regulated TLX mRNA and protein expression in neural stem cells (NSCs). Intriguingly, overexpression of miR-378 increased NSC differentiation and reduced NSC proliferation, whereas suppression of miR-378 led to decreased NSC differentiation and increased NSC proliferation. Moreover, the downstream targets of TLX, including p21, PTEN and Wnt/β-catenin were also found to be regulated by miR-378. Additionally, overexpression of TLX rescued the NSC proliferation deficiency induced by miR-378 overexpression and abolished miR-378-promoted NSC differentiation. Taken together, our data suggest that miR-378 is a novel miRNA that regulates NSC proliferation and differentiation via targeting TLX. Therefore, manipulating miR-378 in NSCs could be a novel strategy to develop novel interventions for the treatment of relevant neurological disorders. Copyright © 2015 Elsevier Inc. All rights reserved.

Fibroblasts maintained in 3 dimensions show a better differentiation state and higher sensitivity to estrogens

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Montani, Claudia [Laboratory of Biotechnology, Department of Laboratory Medicine, Civic Hospital of Brescia (Italy); Steimberg, Nathalie; Boniotti, Jennifer [Laboratory of Tissue Engineering, Anatomy and Physiopathology Unit, Department of Clinical and Experimental Sciences, School of Medicine, University of Brescia (Italy); Biasiotto, Giorgio; Zanella, Isabella [Laboratory of Biotechnology, Department of Laboratory Medicine, Civic Hospital of Brescia (Italy); Department of Molecular and Translational Medicine, University of Brescia, Brescia (Italy); Diafera, Giuseppe [Integrated Systems Engineering (ISE), Milan (Italy); Biunno, Ida [IRGB-CNR, Milan (Italy); IRCCS-Multimedica, Milan (Italy); Caimi, Luigi [Laboratory of Biotechnology, Department of Laboratory Medicine, Civic Hospital of Brescia (Italy); Department of Molecular and Translational Medicine, University of Brescia, Brescia (Italy); Mazzoleni, Giovanna [Laboratory of Tissue Engineering, Anatomy and Physiopathology Unit, Department of Clinical and Experimental Sciences, School of Medicine, University of Brescia (Italy); Di Lorenzo, Diego, E-mail: diego.dilorenzo@yahoo.it [Laboratory of Biotechnology, Department of Laboratory Medicine, Civic Hospital of Brescia (Italy)

2014-11-01

Cell differentiation and response to hormonal signals were studied in a 3D environment on an in-house generated mouse fibroblast cell line expressing a reporter gene under the control of estrogen responsive sequences (EREs). 3D cell culture conditions were obtained in a Rotary Cell Culture System; (RCCS™), a microgravity based bioreactor that promotes the aggregation of cells into multicellular spheroids (MCS). In this bioreactor the cells maintained a better differentiated phenotype and more closely resembled in vivo tissue. The RCCS™ cultured fibroblasts showed higher expression of genes regulating cell assembly, differentiation and hormonal functions. Microarray analysis showed that genes related to cell cycle, proliferation, cytoskeleton, migration, adhesion and motility were all down-regulated in 3D as compared to 2D conditions, as well as oncogene expression and inflammatory cytokines. Controlled remodeling of ECM, which is an essential aspect of cell organization, homeostasis and tissue was affected by the culture method as assessed by immunolocalization of β-tubulin. Markers of cell organization, homeostasis and tissue repair, metalloproteinase 2 (MMP2) and its physiological inhibitor (TIMP4) changed expression in association with the relative formation of cell aggregates. The fibroblasts cultured in the RCCS™ maintain a better responsiveness to estrogens, measured as expression of ERα and regulation of an ERE-dependent reporter and of the endogenous target genes CBP, Rarb, MMP1 and Dbp. Our data highlight the interest of this 3D culture model for its potential application in the field of cell response to hormonal signals and the pharmaco-toxicological analyses of chemicals and natural molecules endowed of estrogenic potential. - Highlights: • We here characterized the first cell line derived from an estrogen reporter mouse. • In the RCCS cells express an immortalized behavior but not a transformed phenotype. • The RCCS provides a system for

Negative regulation of neuronal cell differentiation by INHAT subunit SET/TAF-Iβ.

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Kim, Dong-Wook; Kim, Kee-Beom; Kim, Ji-Young; Lee, Kyu-Sun; Seo, Sang-Beom

2010-09-24

Epigenetic modification plays an important role in transcriptional regulation. As a subunit of the INHAT (inhibitor of histone acetyltransferases) complex, SET/TAF-Iβ evidences transcriptional repression activity. In this study, we demonstrate that SET/TAF-Iβ is abundantly expressed in neuronal tissues of Drosophila embryos. It is expressed at high levels prior to and in early stages of neuronal development, and gradually reduced as differentiation proceeds. SET/TAF-Iβ binds to the promoters of a subset of neuronal development markers and negatively regulates the transcription of these genes. The results of this study show that the knockdown of SET/TAF-Iβ by si-RNA induces neuronal cell differentiation, thus implicating SET/TAF-Iβ as a negative regulator of neuronal development. Copyright © 2010 Elsevier Inc. All rights reserved.

N-Myc Differentially Regulates Expression of MXI1 Isoforms in Neuroblastoma

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Michael B. Armstrong

2013-12-01

Full Text Available Amplification of the MYCN proto-oncogene is associated with a poor prognosis in patients with metastatic neuroblastoma (NB. MYCN encodes the N-Myc protein, a transcriptional regulator that dimerizes with the Max transcription factor, binds to E-box DNA sequences, and regulates genes involved in cell growth and apoptosis. Overexpression of N-Myc leads to transcriptional activation and an increase in NB cell proliferation. Mxi1, a member of the Myc family of transcriptional regulators, also binds to Max. However, Mxi1 is a transcriptional repressor and inhibits proliferation of NB cells, suggesting that Mxi1 functions as an N-Myc antagonist. Our laboratory previously identified Mxi1-0, an alternatively transcribed Mxi1 isoform. Mxi1-0 has properties distinct from those of Mxi1; in contrast to Mxi1, Mxi1-0 is unable to suppress c-Myc-dependent transcription. We now show that Mxi1-0 expression increases in response to MYCN overexpression in NB cells, with a positive correlation between MYCN and MXI1-0 RNA levels. We also show that N-Myc expression differentially regulates the MXI1 and MXI1-0 promoters: Increased MYCN expression suppresses MXI1 promoter activity while enhancing transcription through the MXI1-0 promoter. Finally, induction of Mxi1-0 leads to increased proliferation, whereas expression of Mxi1 inhibits cell growth, indicating differential roles for these two proteins. These data suggest that N-Myc differentially regulates the expression of MXI1 and MXI1-0 and can alter the balance between the two transcription factors. Furthermore, MXI1-0 appears to be a downstream target of MYCN-dependent signaling pathways and may contribute to N-Myc-dependent cell growth and proliferation.

Withaferin A Associated Differential Regulation of Inflammatory Cytokines

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Seema Dubey

2018-02-01

Full Text Available A role of inflammation-associated cytokines/chemokines has been implicated in a wide variety of human diseases. Here, we investigated the regulation of inflammatory cytokines released by monocyte-derived THP-1 cells following treatment with the dietary agent withaferin A (WFA. Membrane-based cytokine array profiling of the culture supernatant from adenosine triphosphate-stimulated WFA-treated THP-1 cells showed differential regulation of multiple cytokines/chemokines. A selected group of cytokines/chemokines [interleukin-1 beta (IL-1β, CCL2/MCP-1, granulocyte-macrophage colony stimulating factor, PDGF-AA, PTX3, cystatin-3, relaxin-2, TNFRSF8/CD30, and ACRP30] was validated at the transcription level using qPCR. In silico analysis for transcriptional binding factors revealed the presence of nuclear factor-kappa B (NF-κB in a group of downregulated cytokine gene promoters. WFA treatment of THP-1 cells blocks the nuclear translocation of NF-kB and corresponds with the reduced levels of cytokine secretion. To further understand the differential expression of cytokines/chemokines, we showed that WFA alters the nigericin-induced co-localization of NLRP3 and ASC proteins, thereby inhibiting caspase-1 activation, which is responsible for the cleavage and maturation of pro-inflammatory cytokines IL-1β and IL-18. These data suggest that dietary agent WFA concurrently targets NF-κB and the inflammasome complex, leading to inhibition of IL-1β and IL-18, respectively, in addition to differential expression of multiple cytokines/chemokines. Taken together, these results provide a rationale for using WFA to further explore the anti-inflammatory mechanism of cytokines/chemokines associated with inflammatory diseases.

Global regulator SATB1 recruits beta-catenin and regulates T(H2 differentiation in Wnt-dependent manner.

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Dimple Notani

2010-01-01

Full Text Available In vertebrates, the conserved Wnt signalling cascade promotes the stabilization and nuclear accumulation of beta-catenin, which then associates with the lymphoid enhancer factor/T cell factor proteins (LEF/TCFs to activate target genes. Wnt/beta -catenin signalling is essential for T cell development and differentiation. Here we show that special AT-rich binding protein 1 (SATB1, the T lineage-enriched chromatin organizer and global regulator, interacts with beta-catenin and recruits it to SATB1's genomic binding sites. Gene expression profiling revealed that the genes repressed by SATB1 are upregulated upon Wnt signalling. Competition between SATB1 and TCF affects the transcription of TCF-regulated genes upon beta-catenin signalling. GATA-3 is a T helper type 2 (T(H2 specific transcription factor that regulates production of T(H2 cytokines and functions as T(H2 lineage determinant. SATB1 positively regulated GATA-3 and siRNA-mediated knockdown of SATB1 downregulated GATA-3 expression in differentiating human CD4(+ T cells, suggesting that SATB1 influences T(H2 lineage commitment by reprogramming gene expression. In the presence of Dickkopf 1 (Dkk1, an inhibitor of Wnt signalling, GATA-3 is downregulated and the expression of signature T(H2 cytokines such as IL-4, IL-10, and IL-13 is reduced, indicating that Wnt signalling is essential for T(H2 differentiation. Knockdown of beta-catenin also produced similar results, confirming the role of Wnt/beta-catenin signalling in T(H2 differentiation. Furthermore, chromatin immunoprecipitation analysis revealed that SATB1 recruits beta-catenin and p300 acetyltransferase on GATA-3 promoter in differentiating T(H2 cells in a Wnt-dependent manner. SATB1 coordinates T(H2 lineage commitment by reprogramming gene expression. The SATB1:beta-catenin complex activates a number of SATB1 regulated genes, and hence this study has potential to find novel Wnt responsive genes. These results demonstrate that SATB1

Biophysical Regulation of Vascular Differentiation and Assembly

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Gerecht, Sharon

2011-01-01

The ability to grow stem cells in the laboratory and to guide their maturation to functional cells allows us to study the underlying mechanisms that govern vasculature differentiation and assembly in health and disease. Accumulating evidence suggests that early stages of vascular growth are exquisitely tuned by biophysical cues from the microenvironment, yet the scientific understanding of such cellular environments is still in its infancy. Comprehending these processes sufficiently to manipulate them would pave the way to controlling blood vessel growth in therapeutic applications. This book assembles the works and views of experts from various disciplines to provide a unique perspective on how different aspects of its microenvironment regulate the differentiation and assembly of the vasculature. In particular, it describes recent efforts to exploit modern engineering techniques to study and manipulate various biophysical cues. Biophysical Regulation of Vascular Differentiation and Assembly provides an inter...

Plant GSK3 proteins regulate xylem cell differentiation downstream of TDIF-TDR signalling

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Kondo, Yuki; Ito, Tasuku; Nakagami, Hirofumi; Hirakawa, Yuki; Saito, Masato; Tamaki, Takayuki; Shirasu, Ken; Fukuda, Hiroo

2014-03-01

During plant radial growth typically seen in trees, procambial and cambial cells act as meristematic cells in the vascular system to self-proliferate and differentiate into xylem cells. These two processes are regulated by a signalling pathway composed of a peptide ligand and its receptor; tracheary element differentiation inhibitory factor (TDIF) and TDIF RECEPTOR (TDR). Here we show that glycogen synthase kinase 3 proteins (GSK3s) are crucial downstream components of the TDIF signalling pathway suppressing xylem differentiation from procambial cells. TDR interacts with GSK3s at the plasma membrane and activates GSK3s in a TDIF-dependent fashion. Consistently, a specific inhibitor of plant GSK3s strongly induces xylem cell differentiation through BRI1-EMS SUPPRESSOR 1 (BES1), a well-known target transcription factor of GSK3s. Our findings provide insight into the regulation of cell fate determination in meristem maintenance.

Myostatin acts as an autocrine/paracrine negative regulator in myoblast differentiation from human induced pluripotent stem cells.

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Gao, Fei; Kishida, Tsunao; Ejima, Akika; Gojo, Satoshi; Mazda, Osam

2013-02-08

Myostatin, also known as growth differentiation factor (GDF-8), regulates proliferation of muscle satellite cells, and suppresses differentiation of myoblasts into myotubes via down-regulation of key myogenic differentiation factors including MyoD. Recent advances in stem cell biology have enabled generation of myoblasts from pluripotent stem cells, but it remains to be clarified whether myostatin is also involved in regulation of artificial differentiation of myoblasts from pluripotent stem cells. Here we show that the human induced pluripotent stem (iPS) cell-derived cells that were induced to differentiate into myoblasts expressed myostatin and its receptor during the differentiation. An addition of recombinant human myostatin (rhMyostatin) suppressed induction of MyoD and Myo5a, resulting in significant suppression of myoblast differentiation. The rhMyostatin treatment also inhibited proliferation of the cells at a later phase of differentiation. RNAi-mediated silencing of myostatin promoted differentiation of human iPS-derived embryoid body (EB) cells into myoblasts. These results strongly suggest that myostatin plays an important role in regulation of myoblast differentiation from iPS cells of human origin. The present findings also have significant implications for potential regenerative medicine for muscular diseases. Copyright © 2013 Elsevier Inc. All rights reserved.

The regulation of health care providers' payments when horizontal and vertical differentiation matter.

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Bardey, David; Canta, Chiara; Lozachmeur, Jean-Marie

2012-09-01

This paper analyzes the regulation of payment schemes for health care providers competing in both quality and product differentiation of their services. The regulator uses two instruments: a prospective payment per patient and a cost reimbursement rate. When the regulator can only use a prospective payment, the optimal price involves a trade-off between the level of quality provision and the level of horizontal differentiation. If this pure prospective payment leads to underprovision of quality and overdifferentiation, a mixed reimbursement scheme allows the regulator to improve the allocation efficiency. This is true for a relatively low level of patients' transportation costs. We also show that if the regulator cannot commit to the level of the cost reimbursement rate, the resulting allocation can dominate the one with full commitment. This occurs when the transportation cost is low or high enough, and the full commitment solution either implies full or zero cost reimbursement. Copyright © 2012 Elsevier B.V. All rights reserved.

Ubx regulates differential enlargement and diversification of insect hind legs.

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Najmus Mahfooz

2007-09-01

Full Text Available Differential enlargement of hind (T3 legs represents one of the hallmarks of insect evolution. However, the actual mechanism(s responsible are yet to be determined. To address this issue, we have now studied the molecular basis of T3 leg enlargement in Oncopeltus fasciatus (milkweed bug and Acheta domesticus (house cricket. In Oncopeltus, the T3 tibia displays a moderate increase in size, whereas in Acheta, the T3 femur, tibia, and tarsus are all greatly enlarged. Here, we show that the hox gene Ultrabithorax (Ubx is expressed in the enlarged segments of hind legs. Furthermore, we demonstrate that depletion of Ubx during embryogenesis has a primary effect in T3 legs and causes shortening of leg segments that are enlarged in a wild type. This result shows that Ubx is regulating the differential growth and enlargement of T3 legs in both Oncopeltus and Acheta. The emerging view suggests that Ubx was co-opted for a novel role in regulating leg growth and that the transcriptional modification of its expression may be a universal mechanism for the evolutionary diversification of insect hind legs.

Myostatin acts as an autocrine/paracrine negative regulator in myoblast differentiation from human induced pluripotent stem cells

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Gao, Fei; Kishida, Tsunao; Ejima, Akika [Department of Immunology, Kyoto Prefectural University of Medicine, Kyoto (Japan); Gojo, Satoshi [Department of Cardiac Support, Kyoto Prefectural University of Medicine, Kyoto (Japan); Mazda, Osam, E-mail: mazda@koto.kpu-m.ac.jp [Department of Immunology, Kyoto Prefectural University of Medicine, Kyoto (Japan)

2013-02-08

Highlights: ► iPS-derived cells express myostatin and its receptor upon myoblast differentiation. ► Myostatin inhibits myoblast differentiation by inhibiting MyoD and Myo5a induction. ► Silencing of myostatin promotes differentiation of human iPS cells into myoblasts. -- Abstract: Myostatin, also known as growth differentiation factor (GDF-8), regulates proliferation of muscle satellite cells, and suppresses differentiation of myoblasts into myotubes via down-regulation of key myogenic differentiation factors including MyoD. Recent advances in stem cell biology have enabled generation of myoblasts from pluripotent stem cells, but it remains to be clarified whether myostatin is also involved in regulation of artificial differentiation of myoblasts from pluripotent stem cells. Here we show that the human induced pluripotent stem (iPS) cell-derived cells that were induced to differentiate into myoblasts expressed myostatin and its receptor during the differentiation. An addition of recombinant human myostatin (rhMyostatin) suppressed induction of MyoD and Myo5a, resulting in significant suppression of myoblast differentiation. The rhMyostatin treatment also inhibited proliferation of the cells at a later phase of differentiation. RNAi-mediated silencing of myostatin promoted differentiation of human iPS-derived embryoid body (EB) cells into myoblasts. These results strongly suggest that myostatin plays an important role in regulation of myoblast differentiation from iPS cells of human origin. The present findings also have significant implications for potential regenerative medicine for muscular diseases.

Myostatin acts as an autocrine/paracrine negative regulator in myoblast differentiation from human induced pluripotent stem cells

International Nuclear Information System (INIS)

Gao, Fei; Kishida, Tsunao; Ejima, Akika; Gojo, Satoshi; Mazda, Osam

2013-01-01

Highlights: ► iPS-derived cells express myostatin and its receptor upon myoblast differentiation. ► Myostatin inhibits myoblast differentiation by inhibiting MyoD and Myo5a induction. ► Silencing of myostatin promotes differentiation of human iPS cells into myoblasts. -- Abstract: Myostatin, also known as growth differentiation factor (GDF-8), regulates proliferation of muscle satellite cells, and suppresses differentiation of myoblasts into myotubes via down-regulation of key myogenic differentiation factors including MyoD. Recent advances in stem cell biology have enabled generation of myoblasts from pluripotent stem cells, but it remains to be clarified whether myostatin is also involved in regulation of artificial differentiation of myoblasts from pluripotent stem cells. Here we show that the human induced pluripotent stem (iPS) cell-derived cells that were induced to differentiate into myoblasts expressed myostatin and its receptor during the differentiation. An addition of recombinant human myostatin (rhMyostatin) suppressed induction of MyoD and Myo5a, resulting in significant suppression of myoblast differentiation. The rhMyostatin treatment also inhibited proliferation of the cells at a later phase of differentiation. RNAi-mediated silencing of myostatin promoted differentiation of human iPS-derived embryoid body (EB) cells into myoblasts. These results strongly suggest that myostatin plays an important role in regulation of myoblast differentiation from iPS cells of human origin. The present findings also have significant implications for potential regenerative medicine for muscular diseases

N-Myc Differentially Regulates Expression of MXI1 Isoforms in Neuroblastoma1

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Armstrong, Michael B; Mody, Rajen J; Ellis, D Christian; Hill, Adam B; Erichsen, David A; Wechsler, Daniel S

2013-01-01

Amplification of the MYCN proto-oncogene is associated with a poor prognosis in patients with metastatic neuroblastoma (NB). MYCN encodes the N-Myc protein, a transcriptional regulator that dimerizes with the Max transcription factor, binds to E-box DNA sequences, and regulates genes involved in cell growth and apoptosis. Overexpression of N-Myc leads to transcriptional activation and an increase in NB cell proliferation. Mxi1, a member of the Myc family of transcriptional regulators, also binds to Max. However, Mxi1 is a transcriptional repressor and inhibits proliferation of NB cells, suggesting that Mxi1 functions as an N-Myc antagonist. Our laboratory previously identified Mxi1-0, an alternatively transcribed Mxi1 isoform. Mxi1-0 has properties distinct from those of Mxi1; in contrast to Mxi1, Mxi1-0 is unable to suppress c-Myc-dependent transcription. We now show that Mxi1-0 expression increases in response to MYCN overexpression in NB cells, with a positive correlation between MYCN and MXI1-0 RNA levels. We also show that N-Myc expression differentially regulates the MXI1 and MXI1-0 promoters: Increased MYCN expression suppresses MXI1 promoter activity while enhancing transcription through the MXI1-0 promoter. Finally, induction of Mxi1-0 leads to increased proliferation, whereas expression of Mxi1 inhibits cell growth, indicating differential roles for these two proteins. These data suggest that N-Myc differentially regulates the expression of MXI1 and MXI1-0 and can alter the balance between the two transcription factors. Furthermore, MXI1-0 appears to be a downstream target of MYCN-dependent signaling pathways and may contribute to N-Myc-dependent cell growth and proliferation. PMID:24403858

FGF signalling regulates chromatin organisation during neural differentiation via mechanisms that can be uncoupled from transcription.

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Nishal S Patel

Full Text Available Changes in higher order chromatin organisation have been linked to transcriptional regulation; however, little is known about how such organisation alters during embryonic development or how it is regulated by extrinsic signals. Here we analyse changes in chromatin organisation as neural differentiation progresses, exploiting the clear spatial separation of the temporal events of differentiation along the elongating body axis of the mouse embryo. Combining fluorescence in situ hybridisation with super-resolution structured illumination microscopy, we show that chromatin around key differentiation gene loci Pax6 and Irx3 undergoes both decompaction and displacement towards the nuclear centre coincident with transcriptional onset. Conversely, down-regulation of Fgf8 as neural differentiation commences correlates with a more peripheral nuclear position of this locus. During normal neural differentiation, fibroblast growth factor (FGF signalling is repressed by retinoic acid, and this vitamin A derivative is further required for transcription of neural genes. We show here that exposure to retinoic acid or inhibition of FGF signalling promotes precocious decompaction and central nuclear positioning of differentiation gene loci. Using the Raldh2 mutant as a model for retinoid deficiency, we further find that such changes in higher order chromatin organisation are dependent on retinoid signalling. In this retinoid deficient condition, FGF signalling persists ectopically in the elongating body, and importantly, we find that inhibiting FGF receptor (FGFR signalling in Raldh2-/- embryos does not rescue differentiation gene transcription, but does elicit both chromatin decompaction and nuclear position change. These findings demonstrate that regulation of higher order chromatin organisation during differentiation in the embryo can be uncoupled from the machinery that promotes transcription and, for the first time, identify FGF as an extrinsic signal that

New insights into redox regulation of stem cell self-renewal and differentiation.

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Ren, Fenglian; Wang, Kui; Zhang, Tao; Jiang, Jingwen; Nice, Edouard Collins; Huang, Canhua

2015-08-01

Reactive oxygen species (ROS), the natural byproducts of aerobic metabolism, are precisely orchestrated to evoke diverse signaling pathways. To date, studies have focused mainly on the detrimental effects of ROS in stem cells. Recently, accumulating evidence has suggested that ROS also function as second messengers that modulate stem cell self-renewal and differentiation by regulating intricate signaling networks. Although many efforts have been made to clarify the general effects of ROS on signal transduction in stem cells, less is known about the initial and direct executors of ROS signaling, which are known as 'redox sensors'. Modifications of cysteine residues in redox sensors are of significant importance in the modulation of protein function in response to different redox conditions. Intriguingly, most key molecules in ROS signaling and cell cycle regulation (including transcriptional factors and kinases) that are crucial in the regulation of stem cell self-renewal and differentiation have the potential to be redox sensors. We highlight herein the importance of redox regulation of these key regulators in stem cell self-renewal and differentiation. Understanding the mechanisms of redox regulation in stem cell self-renewal and differentiation will open exciting new perspectives for stem cell biology. This article is part of a Special Issue entitled Redox regulation of differentiation and de-differentiation. Copyright © 2015 Elsevier B.V. All rights reserved.

CCAAT/Enhancer Binding Protein β Regulates Expression of Indian Hedgehog during Chondrocytes Differentiation

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Ushijima, Takahiro; Okazaki, Ken; Tsushima, Hidetoshi; Ishihara, Kohei; Doi, Toshio; Iwamoto, Yukihide

2014-01-01

Background CCAAT/enhancer binding protein β (C/EBPβ) is a transcription factor that promotes hypertrophic differentiation of chondrocytes. Indian hedgehog (Ihh) also stimulates the hypertrophic transition of chondrocytes. Furthermore, runt-related transcription factor-2 (RUNX2) was reported to regulate chondrocyte maturation during skeletal development and to directly regulate transcriptional activity of Ihh. In this study, we investigated whether the interaction of C/EBPβ and RUNX2 regulates the expression of Ihh during chondrocyte differentiation. Methodology/Results Immunohistochemistry of embryonic growth plate revealed that both C/EBPβ and Ihh were strongly expressed in pre-hypertrophic and hypertrophic chondrocytes. Overexpression of C/EBPβ by adenovirus vector in ATDC5 cells caused marked stimulation of Ihh and Runx2. Conversely, knockdown of C/EBPβ by lentivirus expressing shRNA significantly repressed Ihh and Runx2 in ATDC5 cells. A reporter assay revealed that C/EBPβ stimulated transcriptional activity of Ihh. Deletion and mutation analysis showed that the C/EBPβ responsive element was located between −214 and −210 bp in the Ihh promoter. An electrophoretic mobility shift assay (EMSA) and a chromatin immunoprecipitation (ChIP) assay also revealed the direct binding of C/EBPβ to this region. Moreover, reporter assays demonstrated that RUNX2 failed to stimulate the transcriptional activity of the Ihh promoter harboring a mutation at the C/EBPβ binding site. EMSA and ChIP assays showed that RUNX2 interacted to this element with C/EBPβ. Immunoprecipitation revealed that RUNX2 and C/EBPβ formed heterodimer complex with each other in the nuclei of chondrocytes. These data suggested that the C/EBPβ binding element is also important for RUNX2 to regulate the expression of Ihh. Ex vivo organ culture of mouse limbs transfected with C/EBPβ showed that the expression of Ihh and RUNX2 was increased upon ectopic C/EBPβ expression. Conclusions C

CCAAT/enhancer binding protein β regulates expression of Indian hedgehog during chondrocytes differentiation.

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Takahiro Ushijima

Full Text Available CCAAT/enhancer binding protein β (C/EBPβ is a transcription factor that promotes hypertrophic differentiation of chondrocytes. Indian hedgehog (Ihh also stimulates the hypertrophic transition of chondrocytes. Furthermore, runt-related transcription factor-2 (RUNX2 was reported to regulate chondrocyte maturation during skeletal development and to directly regulate transcriptional activity of Ihh. In this study, we investigated whether the interaction of C/EBPβ and RUNX2 regulates the expression of Ihh during chondrocyte differentiation.Immunohistochemistry of embryonic growth plate revealed that both C/EBPβ and Ihh were strongly expressed in pre-hypertrophic and hypertrophic chondrocytes. Overexpression of C/EBPβ by adenovirus vector in ATDC5 cells caused marked stimulation of Ihh and Runx2. Conversely, knockdown of C/EBPβ by lentivirus expressing shRNA significantly repressed Ihh and Runx2 in ATDC5 cells. A reporter assay revealed that C/EBPβ stimulated transcriptional activity of Ihh. Deletion and mutation analysis showed that the C/EBPβ responsive element was located between -214 and -210 bp in the Ihh promoter. An electrophoretic mobility shift assay (EMSA and a chromatin immunoprecipitation (ChIP assay also revealed the direct binding of C/EBPβ to this region. Moreover, reporter assays demonstrated that RUNX2 failed to stimulate the transcriptional activity of the Ihh promoter harboring a mutation at the C/EBPβ binding site. EMSA and ChIP assays showed that RUNX2 interacted to this element with C/EBPβ. Immunoprecipitation revealed that RUNX2 and C/EBPβ formed heterodimer complex with each other in the nuclei of chondrocytes. These data suggested that the C/EBPβ binding element is also important for RUNX2 to regulate the expression of Ihh. Ex vivo organ culture of mouse limbs transfected with C/EBPβ showed that the expression of Ihh and RUNX2 was increased upon ectopic C/EBPβ expression.C/EBPβ and RUNX2 cooperatively stimulate

MicroRNA-138 regulates osteogenic differentiation of human stromal (mesenchymal) stem cells in vivo

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Eskildsen, Tilde; Taipaleenmäki, Hanna; Stenvang, Jan; Abdallah, Basem M.; Ditzel, Nicholas; Nossent, Anne Yael; Bak, Mads; Kauppinen, Sakari; Kassem, Moustapha

2011-01-01

Elucidating the molecular mechanisms that regulate human stromal (mesenchymal) stem cell (hMSC) differentiation into osteogenic lineage is important for the development of anabolic therapies for treatment of osteoporosis. MicroRNAs (miRNAs) are short, noncoding RNAs that act as key regulators of diverse biological processes by mediating translational repression or mRNA degradation of their target genes. Here, we show that miRNA-138 (miR-138) modulates osteogenic differentiation of hMSCs. miRNA array profiling and further validation by quantitative RT-PCR (qRT-PCR) revealed that miR-138 was down-regulated during osteoblast differentiation of hMSCs. Overexpression of miR-138 inhibited osteoblast differentiation of hMSCs in vitro, whereas inhibition of miR-138 function by antimiR-138 promoted expression of osteoblast-specific genes, alkaline phosphatase (ALP) activity, and matrix mineralization. Furthermore, overexpression of miR-138 reduced ectopic bone formation in vivo by 85%, and conversely, in vivo bone formation was enhanced by 60% when miR-138 was antagonized. Target prediction analysis and experimental validation by luciferase 3′ UTR reporter assay confirmed focal adhesion kinase, a kinase playing a central role in promoting osteoblast differentiation, as a bona fide target of miR-138. We show that miR-138 attenuates bone formation in vivo, at least in part by inhibiting the focal adhesion kinase signaling pathway. Our findings suggest that pharmacological inhibition of miR-138 by antimiR-138 could represent a therapeutic strategy for enhancing bone formation in vivo. PMID:21444814

Regulators of Tfh cell differentiation

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Gajendra Motiram Jogdand

2016-11-01

Full Text Available The follicular helper T (Tfh cells help is critical for activation of B cells, antibody class switching and germinal center formation. The Tfh cells are characterized by the expression of CXCR5, ICOS, PD-1, Bcl-6, and IL-21. They are involved in clearing infections and are adversely linked with autoimmune diseases and also have a role in viral replication as well as clearance. Tfh cells are generated from naïve CD4 T cells with sequential steps involving cytokine signaling (IL-21, IL-6, IL-12, activin A, migration and positioning in the germinal center by CXCR5, surface receptors (ICOS/ICOSL, SAP/SLAM as well as transcription factor (Bcl-6, c-Maf, STAT3 signaling and repressor miR155. On the other hand Tfh generation is negatively regulated at specific steps of Tfh generation by specific cytokine (IL-2, IL-7, surface receptor (PD-1, CTLA-4, transcription factors Blimp-1, STAT5, T-bet, KLF-2 signaling and repressor miR 146a. Interestingly, miR 17-92 and FOXO1 acts as a positive as well as a negative regulator of Tfh differentiation depending on the time of expression and disease specificity. Tfh cells are also generated from the conversion of other effector T cells as exemplified by Th1 cells converting into Tfh during viral infection. The mechanistic details of effector T cells conversion into Tfh are yet to be clear. To manipulate Tfh cells for therapeutic implication and or for effective vaccination strategies, it is important to know positive and negative regulators of Tfh generation. Hence, in this review we have highlighted and interlinked molecular signaling from cytokines, surface receptors, transcription factors, ubiquitin Ligase and miRNA as positive and negative regulators for Tfh differentiation.

Unkempt is negatively regulated by mTOR and uncouples neuronal differentiation from growth control.

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Amélie Avet-Rochex

2014-09-01

Full Text Available Neuronal differentiation is exquisitely controlled both spatially and temporally during nervous system development. Defects in the spatiotemporal control of neurogenesis cause incorrect formation of neural networks and lead to neurological disorders such as epilepsy and autism. The mTOR kinase integrates signals from mitogens, nutrients and energy levels to regulate growth, autophagy and metabolism. We previously identified the insulin receptor (InR/mTOR pathway as a critical regulator of the timing of neuronal differentiation in the Drosophila melanogaster eye. Subsequently, this pathway has been shown to play a conserved role in regulating neurogenesis in vertebrates. However, the factors that mediate the neurogenic role of this pathway are completely unknown. To identify downstream effectors of the InR/mTOR pathway we screened transcriptional targets of mTOR for neuronal differentiation phenotypes in photoreceptor neurons. We identified the conserved gene unkempt (unk, which encodes a zinc finger/RING domain containing protein, as a negative regulator of the timing of photoreceptor differentiation. Loss of unk phenocopies InR/mTOR pathway activation and unk acts downstream of this pathway to regulate neurogenesis. In contrast to InR/mTOR signalling, unk does not regulate growth. unk therefore uncouples the role of the InR/mTOR pathway in neurogenesis from its role in growth control. We also identified the gene headcase (hdc as a second downstream regulator of the InR/mTOR pathway controlling the timing of neurogenesis. Unk forms a complex with Hdc, and Hdc expression is regulated by unk and InR/mTOR signalling. Co-overexpression of unk and hdc completely suppresses the precocious neuronal differentiation phenotype caused by loss of Tsc1. Thus, Unk and Hdc are the first neurogenic components of the InR/mTOR pathway to be identified. Finally, we show that Unkempt-like is expressed in the developing mouse retina and in neural stem

EZH2: a pivotal regulator in controlling cell differentiation.

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Chen, Ya-Huey; Hung, Mien-Chie; Li, Long-Yuan

2012-01-01

Epigenetic regulation plays an important role in stem cell self-renewal, maintenance and lineage differentiation. The epigenetic profiles of stem cells are related to their transcriptional signature. Enhancer of Zeste homlog 2 (EZH2), a catalytic subunit of epigenetic regulator Polycomb repressive complex 2 (PRC2), has been shown to be a key regulator in controlling cellular differentiation. EZH2 is a histone methyltransferase that not only methylates histone H3 on Lys 27 (H3K27me3) but also interacts with and recruits DNA methyltransferases to methylate CpG at certain EZH2 target genes to establish firm repressive chromatin structures, contributing to tumor progression and the regulation of development and lineage commitment both in embryonic stem cells (ESCs) and adult stem cells. In addition to its well-recognized epigenetic gene silencing function, EZH2 also directly methylates nonhistone targets such as the cardiac transcription factor, GATA4, resulting in attenuated GATA4 transcriptional activity and gene repression. This review addresses recent progress toward the understanding of the biological functions and regulatory mechanisms of EZH2 and its targets as well as their roles in stem cell maintenance and cell differentiation.

DISC1 (disrupted-in-schizophrenia-1 regulates differentiation of oligodendrocytes.

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Tsuyoshi Hattori

Full Text Available Disrupted-in-schizophrenia 1 (DISC1 is a gene disrupted by a translocation, t(1;11 (q42.1;q14.3, that segregates with major psychiatric disorders, including schizophrenia, recurrent major depression and bipolar affective disorder, in a Scottish family. Here we report that mammalian DISC1 endogenously expressed in oligodendroglial lineage cells negatively regulates differentiation of oligodendrocyte precursor cells into oligodendrocytes. DISC1 expression was detected in oligodendrocytes of the mouse corpus callosum at P14 and P70. DISC1 mRNA was expressed in primary cultured rat cortical oligodendrocyte precursor cells and decreased when oligodendrocyte precursor cells were induced to differentiate by PDGF deprivation. Immunocytochemical analysis showed that overexpressed DISC1 was localized in the cell bodies and processes of oligodendrocyte precursor cells and oligodendrocytes. We show that expression of the myelin related markers, CNPase and MBP, as well as the number of cells with a matured oligodendrocyte morphology, were decreased following full length DISC1 overexpression. Conversely, both expression of CNPase and the number of oligodendrocytes with a mature morphology were increased following knockdown of endogenous DISC1 by RNA interference. Overexpression of a truncated form of DISC1 also resulted in an increase in expression of myelin related proteins and the number of mature oligodendrocytes, potentially acting via a dominant negative mechanism. We also identified involvement of Sox10 and Nkx2.2 in the DISC1 regulatory pathway of oligodendrocyte differentiation, both well-known transcription factors involved in the regulation of myelin genes.

Mitochondrial activity in the regulation of stem cell self-renewal and differentiation.

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Khacho, Mireille; Slack, Ruth S

2017-12-01

Mitochondria are classically known as the essential energy producers in cells. As such, the activation of mitochondrial metabolism upon cellular differentiation was deemed a necessity to fuel the high metabolic needs of differentiated cells. However, recent studies have revealed a direct role for mitochondrial activity in the regulation of stem cell fate and differentiation. Several components of mitochondrial metabolism and respiration have now been shown to regulate different aspects of stem cell differentiation through signaling, transcriptional, proteomic and epigenetic modulations. In light of these findings mitochondrial metabolism is no longer considered a consequence of cellular differentiation, but rather a key regulatory mechanism of this process. This review will focus on recent progress that defines mitochondria as the epicenters for the regulation of stem cell fate decisions. Copyright © 2017 Elsevier Ltd. All rights reserved.

TET2 Regulates Mast Cell Differentiation and Proliferation through Catalytic and Non-catalytic Activities

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Sara Montagner

2016-05-01

Full Text Available Summary: Dioxygenases of the TET family impact genome functions by converting 5-methylcytosine (5mC in DNA to 5-hydroxymethylcytosine (5hmC. Here, we identified TET2 as a crucial regulator of mast cell differentiation and proliferation. In the absence of TET2, mast cells showed disrupted gene expression and altered genome-wide 5hmC deposition, especially at enhancers and in the proximity of downregulated genes. Impaired differentiation of Tet2-ablated cells could be relieved or further exacerbated by modulating the activity of other TET family members, and mechanistically it could be linked to the dysregulated expression of C/EBP family transcription factors. Conversely, the marked increase in proliferation induced by the loss of TET2 could be rescued exclusively by re-expression of wild-type or catalytically inactive TET2. Our data indicate that, in the absence of TET2, mast cell differentiation is under the control of compensatory mechanisms mediated by other TET family members, while proliferation is strictly dependent on TET2 expression. : The impact of TET enzymes on gene expression and cell function is incompletely understood. Montagner et al. investigate the TET-mediated regulation of mast cell differentiation and function, uncover transcriptional pathways regulated by TET2, and identify both enzymatic activity-dependent and -independent functions of TET2. Keywords: differentiation, DNA hydroxymethylation, epigenetics, mast cells, proliferation, TET

LIX1 regulates YAP1 activity and controls the proliferation and differentiation of stomach mesenchymal progenitors.

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McKey, Jennifer; Martire, Delphine; de Santa Barbara, Pascal; Faure, Sandrine

2016-04-28

Smooth muscle cell (SMC) plasticity maintains the balance between differentiated SMCs and proliferative mesenchymal progenitors, crucial for muscular tissue homeostasis. Studies on the development of mesenchymal progenitors into SMCs have proven useful in identifying molecular mechanisms involved in digestive musculature plasticity in physiological and pathological conditions. Here, we show that Limb Expression 1 (LIX1) molecularly defines the population of mesenchymal progenitors in the developing stomach. Using in vivo functional approaches in the chick embryo, we demonstrate that LIX1 is a key regulator of stomach SMC development. We show that LIX1 is required for stomach SMC determination to regulate the expression of the pro-proliferative gene YAP1 and mesenchymal cell proliferation. However, as stomach development proceeds, sustained LIX1 expression has a negative impact on further SMC differentiation and this is associated with a decrease in YAP1 activity. We demonstrate that expression of LIX1 must be tightly regulated to allow fine-tuning of the transcript levels and state of activation of the pro-proliferative transcriptional coactivator YAP1 to regulate proliferation rates of stomach mesenchymal progenitors and their differentiation. Our data highlight dual roles for LIX1 and YAP1 and provide new insights into the regulation of cell density-dependent proliferation, which is essential for the development and homeostasis of organs.

MiRNA-20a promotes osteogenic differentiation of human mesenchymal stem cells by co-regulating BMP signaling.

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Zhang, Jin-fang; Fu, Wei-ming; He, Ming-liang; Xie, Wei-dong; Lv, Qing; Wan, Gang; Li, Guo; Wang, Hua; Lu, Gang; Hu, Xiang; Jiang, Su; Li, Jian-na; Lin, Marie C M; Zhang, Ya-ou; Kung, Hsiang-fu

2011-01-01

Osteogenic differentiation of mesenchymal stem cells (MSCs) is a complex process, which is regulated by various factors including microRNAs. Our preliminary data showed that the expression of endogenous miR-20a was increased during the course of osteogenic differentiation. Simultaneously, the expression of osteoblast markers and regulators BMP2, BMP4, Runx2, Osx, OCN and OPN was also elevated whereas adipocyte markers PPARγ and osteoblast antagonist, Bambi and Crim1, were downregulated, thereby suggesting that miR-20a plays an important role in regulating osteoblast differentiation. To validate this hypothesis, we tested its effects on osteogenic differentiation by introducing miR-20a mimics and lentiviral-miR20a-expression vectors into hMSCs. We showed that miR-20a promoted osteogenic differentiation by the upregulation of BMP/Runx2 signaling. We performed bioinformatics analysis and predicted that PPARγ, Bambi and Crim1 would be potential targets of miR-20a. PPARγ is a negative regulator of BMP/Runx2 signaling whereas Bambi or Crim1 are antagonists of the BMP pathway. Furthermore, we confirmed that all these molecules were indeed the targets of miR-20a by luciferase reporter, quantitative RT-PCR and western blot assays. Similarly to miR-20a overexpression, the osteogenesis was enhanced by the silence of PPARγ, Bambi or Crim1 by specific siRNAs. Taken together, for the first time, we demonstrated that miR-20a promoted the osteogenesis of hMSCs in a co-regulatory pattern by targeting PPARγ, Bambi and Crim1, the negative regulators of BMP signaling.

Syndecan-4 Regulates Muscle Differentiation and Is Internalized from the Plasma Membrane during Myogenesis.

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Rønning, Sissel B; Carlson, Cathrine R; Stang, Espen; Kolset, Svein O; Hollung, Kristin; Pedersen, Mona E

2015-01-01

The cell surface proteoglycan syndecan-4 has been reported to be crucial for muscle differentiation, but the molecular mechanisms still remain to be fully understood. During in vitro differentiation of bovine muscle cells immunocytochemical analyses showed strong labelling of syndecan-4 intracellularly, in close proximity with Golgi structures, in membranes of intracellular vesicles and finally, in the nuclear area including the nuclear envelope. Chase experiments showed that syndecan-4 was internalized from the plasma membrane during this process. Furthermore, when syndecan-4 was knocked down by siRNA more myotubes were formed, and the expression of myogenic transcription factors, β1-integrin and actin was influenced. However, when bovine muscle cells were treated with a cell-penetrating peptide containing the cytoplasmic region of syndecan-4, myoblast fusion and thus myotube formation was blocked, both in normal cells and in syndecan-4 knock down cells. Altogether this suggests that the cytoplasmic domain of syndecan-4 is important in regulation of myogenesis. The internalization of syndecan-4 from the plasma membrane during muscle differentiation and the nuclear localization of syndecan-4 in differentiated muscle cells may be part of this regulation, and is a novel aspect of syndecan biology which merits further studies.

Syndecan-4 Regulates Muscle Differentiation and Is Internalized from the Plasma Membrane during Myogenesis.

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Sissel B Rønning

Full Text Available The cell surface proteoglycan syndecan-4 has been reported to be crucial for muscle differentiation, but the molecular mechanisms still remain to be fully understood. During in vitro differentiation of bovine muscle cells immunocytochemical analyses showed strong labelling of syndecan-4 intracellularly, in close proximity with Golgi structures, in membranes of intracellular vesicles and finally, in the nuclear area including the nuclear envelope. Chase experiments showed that syndecan-4 was internalized from the plasma membrane during this process. Furthermore, when syndecan-4 was knocked down by siRNA more myotubes were formed, and the expression of myogenic transcription factors, β1-integrin and actin was influenced. However, when bovine muscle cells were treated with a cell-penetrating peptide containing the cytoplasmic region of syndecan-4, myoblast fusion and thus myotube formation was blocked, both in normal cells and in syndecan-4 knock down cells. Altogether this suggests that the cytoplasmic domain of syndecan-4 is important in regulation of myogenesis. The internalization of syndecan-4 from the plasma membrane during muscle differentiation and the nuclear localization of syndecan-4 in differentiated muscle cells may be part of this regulation, and is a novel aspect of syndecan biology which merits further studies.

Towards spatially differentiated regulation of nitrogen

DEFF Research Database (Denmark)

Lajer Højberg, Anker; Refsgaard, Jens Christian; Jørgensen, Lisbeth Flindt

EU member states are challenged by nitrogen loads to estuaries and inland freshwater systems impeding the achievement of good ecological status as required by the Water Framework Directive (WFD). In Denmark nitrate leaching from the root zone has been reduced by 50% since 1987, but additional...... reductions of 30-50% are required to meet the objectives of the WFD. Achieving such abatements by uniform restrictions for all areas, would be very costly and inefficient as studies have shown that reduction varies spatially depending on the local hydrogeological conditions, the presence and dynamics...... of drains and hydro-biogeochemical conditions in associated riparian lowlands. Hence, a shift of paradigm in regulation practice is needed, whit a cost-effective regulation accounting for this variability and differentiate the regulations/restrictions between resilient and vulnerable areas. However...

Roquin Paralogs Differentially Regulate Functional NKT Cell Subsets.

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Drees, Christoph; Vahl, J Christoph; Bortoluzzi, Sabrina; Heger, Klaus D; Fischer, Julius C; Wunderlich, F Thomas; Peschel, Christian; Schmidt-Supprian, Marc

2017-04-01

NKT cells represent a small subset of glycolipid-recognizing T cells that are heavily implicated in human allergic, autoimmune, and malignant diseases. In the thymus, precursor cells recognize self-glycolipids by virtue of their semi-invariant TCR, which triggers NKT cell lineage commitment and maturation. During their development, NKT cells are polarized into the NKT1, NKT2, and NKT17 subsets, defined through their cytokine-secretion patterns and the expression of key transcription factors. However, we have largely ignored how the differentiation into the NKT cell subsets is regulated. In this article, we describe the mRNA-binding Roquin-1 and -2 proteins as central regulators of murine NKT cell fate decisions. In the thymus, T cell-specific ablation of the Roquin paralogs leads to a dramatic expansion of NKT17 cells, whereas peripheral mature NKT cells are essentially absent. Roquin-1/2-deficient NKT17 cells show exaggerated lineage-specific expression of nearly all NKT17-defining proteins tested. We show through mixed bone marrow chimera experiments that NKT17 polarization is mediated through cell-intrinsic mechanisms early during NKT cell development. In contrast, the loss of peripheral NKT cells is due to cell-extrinsic factors. Surprisingly, Roquin paralog-deficient NKT cells are, in striking contrast to conventional T cells, compromised in their ability to secrete cytokines. Altogether, we show that Roquin paralogs regulate the development and function of NKT cell subsets in the thymus and periphery. Copyright © 2017 by The American Association of Immunologists, Inc.

Regulation of mat responses by a differentiation MAPK pathway in Saccharomyces cerevisiae.

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Sheelarani Karunanithi

Full Text Available Fungal species exhibit diverse behaviors when presented with extracellular challenges. Pathogenic fungi can undergo cell differentiation and biofilm formation in response to fluctuating nutrient levels, and these responses are required for virulence. In the model fungal eukaryote Saccharomyces cerevisiae, nutrient limitation induces filamentous growth and biofilm/mat formation. Both responses require the same signal transduction (MAPK pathway and the same cell adhesion molecule (Flo11 but have been studied under different conditions. We found that filamentous growth and mat formation are aspects of a related response that is regulated by the MAPK pathway. Cells in yeast-form mats differentiated into pseudohyphae in response to nutrient limitation. The MAPK pathway regulated mat expansion (in the plane of the XY-axis and substrate invasion (downward in the plane of the Z-axis, which optimized the mat's response to extracellular nutrient levels. The MAPK pathway also regulated an upward growth pattern (in the plane of the Z-axis in response to nutrient limitation and changes in surface rigidity. Upward growth allowed for another level of mat responsiveness and resembled a type of colonial chemorepulsion. Together our results show that signaling pathways play critical roles in regulating social behaviors in which fungal cells participate. Signaling pathways may regulate similar processes in pathogens, whose highly nuanced responses are required for virulence.

MicroRNA let-7b regulates neural stem cell proliferation and differentiation by targeting nuclear receptor TLX signaling.

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Zhao, Chunnian; Sun, GuoQiang; Li, Shengxiu; Lang, Ming-Fei; Yang, Su; Li, Wendong; Shi, Yanhong

2010-02-02

Neural stem cell self-renewal and differentiation is orchestrated by precise control of gene expression involving nuclear receptor TLX. Let-7b, a member of the let-7 microRNA family, is expressed in mammalian brains and exhibits increased expression during neural differentiation. However, the role of let-7b in neural stem cell proliferation and differentiation remains unknown. Here we show that let-7b regulates neural stem cell proliferation and differentiation by targeting the stem cell regulator TLX and the cell cycle regulator cyclin D1. Overexpression of let-7b led to reduced neural stem cell proliferation and increased neural differentiation, whereas antisense knockdown of let-7b resulted in enhanced proliferation of neural stem cells. Moreover, in utero electroporation of let-7b to embryonic mouse brains led to reduced cell cycle progression in neural stem cells. Introducing an expression vector of Tlx or cyclin D1 that lacks the let-7b recognition site rescued let-7b-induced proliferation deficiency, suggesting that both TLX and cyclin D1 are important targets for let-7b-mediated regulation of neural stem cell proliferation. Let-7b, by targeting TLX and cyclin D1, establishes an efficient strategy to control neural stem cell proliferation and differentiation.

The T-ALL related gene BCL11B regulates the initial stages of human T-cell differentiation.

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Ha, V L; Luong, A; Li, F; Casero, D; Malvar, J; Kim, Y M; Bhatia, R; Crooks, G M; Parekh, C

2017-11-01

The initial stages of T-cell differentiation are characterized by a progressive commitment to the T-cell lineage, a process that involves the loss of alternative (myelo-erythroid, NK, B) lineage potentials. Aberrant differentiation during these stages can result in T-cell acute lymphoblastic leukemia (T-ALL). However, the mechanisms regulating the initial stages of human T-cell differentiation are obscure. Through loss of function studies, we showed BCL11B, a transcription factor recurrently mutated T-ALL, is essential for T-lineage commitment, particularly the repression of NK and myeloid potentials, and the induction of T-lineage genes, during the initial stages of human T-cell differentiation. In gain of function studies, BCL11B inhibited growth of and induced a T-lineage transcriptional program in T-ALL cells. We found previously unknown differentiation stage-specific DNA binding of BCL11B at multiple T-lineage genes; target genes showed BCL11B-dependent expression, suggesting a transcriptional activator role for BCL11B at these genes. Transcriptional analyses revealed differences in the regulatory actions of BCL11B between human and murine thymopoiesis. Our studies show BCL11B is a key regulator of the initial stages of human T-cell differentiation and delineate the BCL11B transcriptional program, enabling the dissection of the underpinnings of normal T-cell differentiation and providing a resource for understanding dysregulations in T-ALL.

Convergent differential regulation of parvalbumin in the brains of vocal learners.

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Erina Hara

Full Text Available Spoken language and learned song are complex communication behaviors found in only a few species, including humans and three groups of distantly related birds--songbirds, parrots, and hummingbirds. Despite their large phylogenetic distances, these vocal learners show convergent behaviors and associated brain pathways for vocal communication. However, it is not clear whether this behavioral and anatomical convergence is associated with molecular convergence. Here we used oligo microarrays to screen for genes differentially regulated in brain nuclei necessary for producing learned vocalizations relative to adjacent brain areas that control other behaviors in avian vocal learners versus vocal non-learners. A top candidate gene in our screen was a calcium-binding protein, parvalbumin (PV. In situ hybridization verification revealed that PV was expressed significantly higher throughout the song motor pathway, including brainstem vocal motor neurons relative to the surrounding brain regions of all distantly related avian vocal learners. This differential expression was specific to PV and vocal learners, as it was not found in avian vocal non-learners nor for control genes in learners and non-learners. Similar to the vocal learning birds, higher PV up-regulation was found in the brainstem tongue motor neurons used for speech production in humans relative to a non-human primate, macaques. These results suggest repeated convergent evolution of differential PV up-regulation in the brains of vocal learners separated by more than 65-300 million years from a common ancestor and that the specialized behaviors of learned song and speech may require extra calcium buffering and signaling.

Interplay between H1 and HMGN epigenetically regulates OLIG1&2 expression and oligodendrocyte differentiation.

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Deng, Tao; Postnikov, Yuri; Zhang, Shaofei; Garrett, Lillian; Becker, Lore; Rácz, Ildikó; Hölter, Sabine M; Wurst, Wolfgang; Fuchs, Helmut; Gailus-Durner, Valerie; de Angelis, Martin Hrabe; Bustin, Michael

2017-04-07

An interplay between the nucleosome binding proteins H1 and HMGN is known to affect chromatin dynamics, but the biological significance of this interplay is still not clear. We find that during embryonic stem cell differentiation loss of HMGNs leads to down regulation of genes involved in neural differentiation, and that the transcription factor OLIG2 is a central node in the affected pathway. Loss of HMGNs affects the expression of OLIG2 as well as that of OLIG1, two transcription factors that are crucial for oligodendrocyte lineage specification and nerve myelination. Loss of HMGNs increases the chromatin binding of histone H1, thereby recruiting the histone methyltransferase EZH2 and elevating H3K27me3 levels, thus conferring a repressive epigenetic signature at Olig1&2 sites. Embryonic stem cells lacking HMGNs show reduced ability to differentiate towards the oligodendrocyte lineage, and mice lacking HMGNs show reduced oligodendrocyte count and decreased spinal cord myelination, and display related neurological phenotypes. Thus, the presence of HMGN proteins is required for proper expression of neural differentiation genes during embryonic stem cell differentiation. Specifically, we demonstrate that the dynamic interplay between HMGNs and H1 in chromatin epigenetically regulates the expression of OLIG1&2, thereby affecting oligodendrocyte development and myelination, and mouse behavior. Published by Oxford University Press on behalf of Nucleic Acids Research 2016.

Human Long Noncoding RNA Regulation of Stem Cell Potency and Differentiation

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Seahyoung Lee

2017-01-01

Full Text Available Because of their capability of differentiation into lineage-specific cells, stem cells are an attractive therapeutic modality in regenerative medicine. To develop an effective stem cell-based therapeutic strategy with predictable results, deeper understanding of the underlying molecular mechanisms of stem cell differentiation and/or pluripotency maintenance is required. Thus, reviewing the key factors involved in the transcriptional and epigenetic regulation of stem cell differentiation and maintenance is important. Accumulating data indicate that long noncoding RNAs (lncRNAs mediate numerous biological processes, including stem cell differentiation and maintenance. Here, we review recent findings on the human lncRNA regulation of stem cell potency and differentiation. Although the clinical implication of these lncRNAs is only beginning to be elucidated, it is anticipated that lncRNAs will become important therapeutic targets in the near future.

Regulation of T Cell Differentiation and Function by EZH2

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Karantanos, Theodoros; Christofides, Anthos; Bardhan, Kankana; Li, Lequn; Boussiotis, Vassiliki A.

2016-01-01

The enhancer of zeste homolog 2 (EZH2), one of the polycomb-group proteins, is the catalytic subunit of Polycomb-repressive complex 2 (PRC2) and induces the trimethylation of the histone H3 lysine 27 (H3K27me3) promoting epigenetic gene silencing. EZH2 contains a SET domain promoting the methyltransferase activity, while the three other protein components of PRC2, namely EED, SUZ12, and RpAp46/48, induce compaction of the chromatin permitting EZH2 enzymatic activity. Numerous studies highlight the role of this evolutionary conserved protein as a master regulator of differentiation in humans involved in the repression of the homeotic gene and the inactivation of X-chromosome. Through its effects in the epigenetic regulation of critical genes, EZH2 has been strongly linked to cell cycle progression, stem cell pluripotency, and cancer biology, being currently at the cutting edge of research. Most recently, EZH2 has been associated with hematopoietic stem cell proliferation and differentiation, thymopoiesis and lymphopoiesis. Several studies have evaluated the role of EZH2 in the regulation of T cell differentiation and plasticity as well as its implications in the development of autoimmune diseases and graft-versus-host disease (GVHD). The aim of this review is to summarize the current knowledge regarding the role of EZH2 in the regulation of the differentiation and function of T cells focusing on possible applications in various immune-mediated conditions, including autoimmune disorders and GVHD. PMID:27199994

NAD+ protects against EAE by regulating CD4+ T-cell differentiation

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Tullius, Stefan G.; Biefer, Hector Rodriguez Cetina; Li, Suyan; Trachtenberg, Alexander J.; Edtinger, Karoline; Quante, Markus; Krenzien, Felix; Uehara, Hirofumi; Yang, Xiaoyong; Kissick, Haydn T.; Kuo, Winston P.; Ghiran, Ionita; de la Fuente, Miguel A.; Arredouani, Mohamed S.; Camacho, Virginia; Tigges, John C.; Toxavidis, Vasilis; El Fatimy, Rachid; Smith, Brian D.; Vasudevan, Anju; ElKhal, Abdallah

2014-01-01

CD4+ T cells are involved in the development of autoimmunity, including multiple sclerosis (MS). Here we show that nicotinamide adenine dinucleotide (NAD+) blocks experimental autoimmune encephalomyelitis (EAE), a mouse model of MS, by inducing immune homeostasis through CD4+IFNγ+IL-10+ T cells and reverses disease progression by restoring tissue integrity via remyelination and neuroregeneration. We show that NAD+ regulates CD4+ T-cell differentiation through tryptophan hydroxylase-1 (Tph1), independently of well-established transcription factors. In the presence of NAD+, the frequency of T-bet−/− CD4+IFNγ+ T cells was twofold higher than wild-type CD4+ T cells cultured in conventional T helper 1 polarizing conditions. Our findings unravel a new pathway orchestrating CD4+ T-cell differentiation and demonstrate that NAD+ may serve as a powerful therapeutic agent for the treatment of autoimmune and other diseases. PMID:25290058

Expression of POEM, a positive regulator of osteoblast differentiation, is suppressed by TNF-α

International Nuclear Information System (INIS)

Tsukasaki, Masayuki; Yamada, Atsushi; Suzuki, Dai; Aizawa, Ryo; Miyazono, Agasa; Miyamoto, Yoichi; Suzawa, Tetsuo; Takami, Masamichi; Yoshimura, Kentaro; Morimura, Naoko; Yamamoto, Matsuo; Kamijo, Ryutaro

2011-01-01

Highlights: → TNF-α inhibits POEM gene expression. → Inhibition of POEM gene expression is caused by NF-κB activation by TNF-α. → Over-expression of POEM recovers inhibition of osteoblast differentiation by TNF-α. -- Abstract: POEM, also known as nephronectin, is an extracellular matrix protein considered to be a positive regulator of osteoblast differentiation. In the present study, we found that tumor necrosis factor-α (TNF-α), a key regulator of bone matrix properties and composition that also inhibits terminal osteoblast differentiation, strongly inhibited POEM expression in the mouse osteoblastic cell line MC3T3-E1. TNF-α-induced down-regulation of POEM gene expression occurred in both time- and dose-dependent manners through the nuclear factor kappa B (NF-κB) pathway. In addition, expressions of marker genes in differentiated osteoblasts were down-regulated by TNF-α in a manner consistent with our findings for POEM, while over-expression of POEM recovered TNF-α-induced inhibition of osteoblast differentiation. These results suggest that TNF-α inhibits POEM expression through the NF-κB signaling pathway and down-regulation of POEM influences the inhibition of osteoblast differentiation by TNF-α.

Expression of POEM, a positive regulator of osteoblast differentiation, is suppressed by TNF-{alpha}

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Tsukasaki, Masayuki [Department of Biochemistry, School of Dentistry, Showa University, 1-5-8 Hatanodai, Shinagawa, Tokyo 142-8555 (Japan); Yamada, Atsushi, E-mail: yamadaa@dent.showa-u.ac.jp [Department of Biochemistry, School of Dentistry, Showa University, 1-5-8 Hatanodai, Shinagawa, Tokyo 142-8555 (Japan); Suzuki, Dai [Department of Biochemistry, School of Dentistry, Showa University, 1-5-8 Hatanodai, Shinagawa, Tokyo 142-8555 (Japan); Aizawa, Ryo [Department of Biochemistry, School of Dentistry, Showa University, 1-5-8 Hatanodai, Shinagawa, Tokyo 142-8555 (Japan); Department of Periodontology, School of Dentistry, Showa University, 2-1-1 Kitasenzoku, Ohta, Tokyo 145-8515 (Japan); Miyazono, Agasa [Department of Periodontology, School of Dentistry, Showa University, 2-1-1 Kitasenzoku, Ohta, Tokyo 145-8515 (Japan); Miyamoto, Yoichi; Suzawa, Tetsuo; Takami, Masamichi; Yoshimura, Kentaro [Department of Biochemistry, School of Dentistry, Showa University, 1-5-8 Hatanodai, Shinagawa, Tokyo 142-8555 (Japan); Morimura, Naoko [Laboratory for Comparative Neurogenesis, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Yamamoto, Matsuo [Department of Periodontology, School of Dentistry, Showa University, 2-1-1 Kitasenzoku, Ohta, Tokyo 145-8515 (Japan); Kamijo, Ryutaro [Department of Biochemistry, School of Dentistry, Showa University, 1-5-8 Hatanodai, Shinagawa, Tokyo 142-8555 (Japan)

2011-07-15

Highlights: {yields} TNF-{alpha} inhibits POEM gene expression. {yields} Inhibition of POEM gene expression is caused by NF-{kappa}B activation by TNF-{alpha}. {yields} Over-expression of POEM recovers inhibition of osteoblast differentiation by TNF-{alpha}. -- Abstract: POEM, also known as nephronectin, is an extracellular matrix protein considered to be a positive regulator of osteoblast differentiation. In the present study, we found that tumor necrosis factor-{alpha} (TNF-{alpha}), a key regulator of bone matrix properties and composition that also inhibits terminal osteoblast differentiation, strongly inhibited POEM expression in the mouse osteoblastic cell line MC3T3-E1. TNF-{alpha}-induced down-regulation of POEM gene expression occurred in both time- and dose-dependent manners through the nuclear factor kappa B (NF-{kappa}B) pathway. In addition, expressions of marker genes in differentiated osteoblasts were down-regulated by TNF-{alpha} in a manner consistent with our findings for POEM, while over-expression of POEM recovered TNF-{alpha}-induced inhibition of osteoblast differentiation. These results suggest that TNF-{alpha} inhibits POEM expression through the NF-{kappa}B signaling pathway and down-regulation of POEM influences the inhibition of osteoblast differentiation by TNF-{alpha}.

Expression profiling of genes regulated by TGF-beta: Differential regulation in normal and tumour cells

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Takahashi Takashi

2007-04-01

Full Text Available Abstract Background TGF-beta is one of the key cytokines implicated in various disease processes including cancer. TGF-beta inhibits growth and promotes apoptosis in normal epithelial cells and in contrast, acts as a pro-tumour cytokine by promoting tumour angiogenesis, immune-escape and metastasis. It is not clear if various actions of TGF-beta on normal and tumour cells are due to differential gene regulations. Hence we studied the regulation of gene expression by TGF-beta in normal and cancer cells. Results Using human 19 K cDNA microarrays, we show that 1757 genes are exclusively regulated by TGF-beta in A549 cells in contrast to 733 genes exclusively regulated in HPL1D cells. In addition, 267 genes are commonly regulated in both the cell-lines. Semi-quantitative and real-time qRT-PCR analysis of some genes agrees with the microarray data. In order to identify the signalling pathways that influence TGF-beta mediated gene regulation, we used specific inhibitors of p38 MAP kinase, ERK kinase, JNK kinase and integrin signalling pathways. The data suggest that regulation of majority of the selected genes is dependent on at least one of these pathways and this dependence is cell-type specific. Interestingly, an integrin pathway inhibitor, RGD peptide, significantly affected TGF-beta regulation of Thrombospondin 1 in A549 cells. Conclusion These data suggest major differences with respect to TGF-beta mediated gene regulation in normal and transformed cells and significant role of non-canonical TGF-beta pathways in the regulation of many genes by TGF-beta.

Cell recognition molecule L1 promotes embryonic stem cell differentiation through the regulation of cell surface glycosylation

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Li, Ying [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Department of Clinical Laboratory, Second Affiliated Hospital of Dalian Medical University, Dalian 116023 (China); Huang, Xiaohua [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Department of Clinical Biochemistry, College of Laboratory Medicine, Dalian Medical University, Dalian 116044 (China); An, Yue [Department of Clinical Laboratory, Second Affiliated Hospital of Dalian Medical University, Dalian 116023 (China); Ren, Feng [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Yang, Zara Zhuyun; Zhu, Hongmei; Zhou, Lei [The Key Laboratory of Stem Cell and Regenerative Medicine, Institute of Molecular and Clinical Medicine, Kunming Medical University, Kunming 650228 (China); Department of Anatomy and Developmental Biology, Monash University, Clayton 3800 (Australia); He, Xiaowen; Schachner, Melitta [Keck Center for Collaborative Neuroscience and Department of Cell Biology and Neuroscience, Rutgers University, New Brunswick, NJ (United States); Xiao, Zhicheng, E-mail: zhicheng.xiao@monash.edu [The Key Laboratory of Stem Cell and Regenerative Medicine, Institute of Molecular and Clinical Medicine, Kunming Medical University, Kunming 650228 (China); Department of Anatomy and Developmental Biology, Monash University, Clayton 3800 (Australia); Ma, Keli, E-mail: makeli666@aliyun.com [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Li, Yali, E-mail: yalilipaper@gmail.com [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Department of Anatomy, National University of Singapore, Singapore 119078 (Singapore)

2013-10-25

Highlights: •Down-regulating FUT9 and ST3Gal4 expression blocks L1-induced neuronal differentiation of ESCs. •Up-regulating FUT9 and ST3Gal4 expression in L1-ESCs depends on the activation of PLCγ. •L1 promotes ESCs to differentiate into neuron through regulating cell surface glycosylation. -- Abstract: Cell recognition molecule L1 (CD171) plays an important role in neuronal survival, migration, differentiation, neurite outgrowth, myelination, synaptic plasticity and regeneration after injury. Our previous study has demonstrated that overexpressing L1 enhances cell survival and proliferation of mouse embryonic stem cells (ESCs) through promoting the expression of FUT9 and ST3Gal4, which upregulates cell surface sialylation and fucosylation. In the present study, we examined whether sialylation and fucosylation are involved in ESC differentiation through L1 signaling. RNA interference analysis showed that L1 enhanced differentiation of ESCs into neurons through the upregulation of FUT9 and ST3Gal4. Furthermore, blocking the phospholipase Cγ (PLCγ) signaling pathway with either a specific PLCγ inhibitor or knockdown PLCγ reduced the expression levels of both FUT9 and ST3Gal4 mRNAs and inhibited L1-mediated neuronal differentiation. These results demonstrate that L1 promotes neuronal differentiation from ESCs through the L1-mediated enhancement of FUT9 and ST3Gal4 expression.

Cell recognition molecule L1 promotes embryonic stem cell differentiation through the regulation of cell surface glycosylation

International Nuclear Information System (INIS)

Li, Ying; Huang, Xiaohua; An, Yue; Ren, Feng; Yang, Zara Zhuyun; Zhu, Hongmei; Zhou, Lei; He, Xiaowen; Schachner, Melitta; Xiao, Zhicheng; Ma, Keli; Li, Yali

2013-01-01

Highlights: •Down-regulating FUT9 and ST3Gal4 expression blocks L1-induced neuronal differentiation of ESCs. •Up-regulating FUT9 and ST3Gal4 expression in L1-ESCs depends on the activation of PLCγ. •L1 promotes ESCs to differentiate into neuron through regulating cell surface glycosylation. -- Abstract: Cell recognition molecule L1 (CD171) plays an important role in neuronal survival, migration, differentiation, neurite outgrowth, myelination, synaptic plasticity and regeneration after injury. Our previous study has demonstrated that overexpressing L1 enhances cell survival and proliferation of mouse embryonic stem cells (ESCs) through promoting the expression of FUT9 and ST3Gal4, which upregulates cell surface sialylation and fucosylation. In the present study, we examined whether sialylation and fucosylation are involved in ESC differentiation through L1 signaling. RNA interference analysis showed that L1 enhanced differentiation of ESCs into neurons through the upregulation of FUT9 and ST3Gal4. Furthermore, blocking the phospholipase Cγ (PLCγ) signaling pathway with either a specific PLCγ inhibitor or knockdown PLCγ reduced the expression levels of both FUT9 and ST3Gal4 mRNAs and inhibited L1-mediated neuronal differentiation. These results demonstrate that L1 promotes neuronal differentiation from ESCs through the L1-mediated enhancement of FUT9 and ST3Gal4 expression

PDK1 Is a Regulator of Epidermal Differentiation that Activates and Organizes Asymmetric Cell Division

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Teruki Dainichi

2016-05-01

Full Text Available Asymmetric cell division (ACD in a perpendicular orientation promotes cell differentiation and organizes the stratified epithelium. However, the upstream cues regulating ACD have not been identified. Here, we report that phosphoinositide-dependent kinase 1 (PDK1 plays a critical role in establishing ACD in the epithelium. Production of phosphatidyl inositol triphosphate (PIP3 is localized to the apical side of basal cells. Asymmetric recruitment of atypical protein kinase C (aPKC and partitioning defective (PAR 3 is impaired in PDK1 conditional knockout (CKO epidermis. PDK1CKO keratinocytes do not undergo calcium-induced activation of aPKC or IGF1-induced activation of AKT and fail to differentiate. PDK1CKO epidermis shows decreased expression of Notch, a downstream effector of ACD, and restoration of Notch rescues defective expression of differentiation-induced Notch targets in vitro. We therefore propose that PDK1 signaling regulates the basal-to-suprabasal switch in developing epidermis by acting as both an activator and organizer of ACD and the Notch-dependent differentiation program.

Regulation of T cell differentiation and function by EZH2

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THEODOROS KARANTANOS

2016-05-01

Full Text Available The enhancer of zeste homologue 2 (EZH2, one of the polycomb group (PcG proteins, is the catalytic subunit of Polycomb-repressive complex 2 (PRC2 and induces the trimethylation of the histone H3 lysine 27 (H3K27me3 promoting epigenetic gene silencing. EZH2 contains a SET domain promoting the methyltransferase activity while the three other protein components of PRC2, namely EED, SUZ12 and RpAp46/48 induce compaction of the chromatin permitting EZH2 enzymatic activity. Numerous studies highlight the role of this evolutionary conserved protein as a master regulator of differentiation in humans involved in the repression of the homeotic (Hox gene and the inactivation of X-chromosome. Through its effects in the epigenetic regulation of critical genes, EZH2 has been strongly linked to cell cycle progression, stem cell pluripotency and cancer biology. Most recently, EZH2 has been associated with hematopoietic stem cell proliferation and differentiation, thymopoiesis and lymphopoiesis. Several studies have evaluated the role of EZH2 in the regulation of T cell differentiation and plasticity as well as its implications in the development of autoimmune diseases and graft versus host disease (GvHD. In this review we will briefly summarize the current knowledge regarding the role of EZH2 in the regulation of T cell differentiation, effector function and homing in the tumor microenvironment and we will discuss possible therapeutic targeting of EZH2 in order to alter T cell immune functions.

MicroRNA, miR-374b, directly targets Myf6 and negatively regulates C2C12 myoblasts differentiation

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Ma, Zhiyuan; Sun, Xiaorui; Xu, Dequan; Xiong, Yuanzhu; Zuo, Bo, E-mail: zuobo@mail.hzau.edu.cn

2015-11-27

Myogenesis is a complex process including myoblast proliferation, differentiation and myotube formation and is controlled by myogenic regulatory factors (MRFs), MyoD, MyoG, Myf5 and Myf6 (also known as MRF4). MicroRNA is a kind of ∼22 nt-long non-coding small RNAs, and act as key transcriptional or post-transcriptional regulators of gene expression. Identification of miRNAs involved in the regulation of muscle genes could improve our understanding of myogenesis process. In this study, we investigated the regulation of Myf6 gene by miRNAs. We showed that miR-374b specifically bound to the 3'untranslated region (UTR) of Myf6 and down-regulated the expression of Myf6 gene at both mRNA and protein level. Furthermore, miR-374b is ubiquitously expressed in the tissues of adult C57BL6 mouse, and the mRNA abundance increases first and then decreases during C2C12 myoblasts differentiation. Over-expression of miR-374b impaired C2C12 cell differentiation, while inhibiting miR-374b expression by 2′-O-methyl antisense oligonucleotides promoted C2C12 cell differentiation. Taken together, our findings identified miR-374b directly targets Myf6 and negatively regulates myogenesis. - Highlights: • MiR-374b directly targets 3′UTR of Myf6. • MiR-374b negatively regulates Myf6 in C2C12 cells. • MiR-374b abundance significiently changes during C2C12 cells differentiation. • MiR-374b negatively regulates C2C12 cells differentiation.

MicroRNA-138 regulates osteogenic differentiation of human stromal (mesenchymal) stem cells in vivo

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Eskildsen, Tilde; Taipaleenmäki, Hanna; Stenvang, Jan

2011-01-01

Elucidating the molecular mechanisms that regulate human stromal (mesenchymal) stem cell (hMSC) differentiation into osteogenic lineage is important for the development of anabolic therapies for treatment of osteoporosis. MicroRNAs (miRNAs) are short, noncoding RNAs that act as key regulators......-regulated during osteoblast differentiation of hMSCs. Overexpression of miR-138 inhibited osteoblast differentiation of hMSCs in vitro, whereas inhibition of miR-138 function by antimiR-138 promoted expression of osteoblast-specific genes, alkaline phosphatase (ALP) activity, and matrix mineralization. Furthermore...

TRPV4 Regulates Tight Junctions and Affects Differentiation in a Cell Culture Model of the Corneal Epithelium.

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Martínez-Rendón, Jacqueline; Sánchez-Guzmán, Erika; Rueda, Angélica; González, James; Gulias-Cañizo, Rosario; Aquino-Jarquín, Guillermo; Castro-Muñozledo, Federico; García-Villegas, Refugio

2017-07-01

TRPV4 (transient receptor potential vanilloid 4) is a cation channel activated by hypotonicity, moderate heat, or shear stress. We describe the expression of TRPV4 during the differentiation of a corneal epithelial cell model, RCE1(5T5) cells. TRPV4 is a late differentiation feature that is concentrated in the apical membrane of the outmost cell layer of the stratified epithelia. Ca 2+ imaging experiments showed that TRPV4 activation with GSK1016790A produced an influx of calcium that was blunted by the specific TRPV4 blocker RN-1734. We analyzed the involvement of TRPV4 in RCE1(5T5) epithelial differentiation by measuring the development of transepithelial electrical resistance (TER) as an indicator of the tight junction (TJ) assembly. We showed that TRPV4 activity was necessary to establish the TJ. In differentiated epithelia, activation of TRPV4 increases the TER and the accumulation of claudin-4 in cell-cell contacts. Epidermal Growth Factor (EGF) up-regulates the TER of corneal epithelial cultures, and we show here that TRPV4 activation mimicked this EGF effect. Conversely, TRPV4 inhibition or knock down by specific shRNA prevented the increase in TER. Moreover, TRPP2, an EGF-activated channel that forms heteromeric complexes with TRPV4, is also concentrated in the outmost cell layer of differentiated RCE1(5T5) sheets. This suggests that the EGF regulation of the TJ may involve a heterotetrameric TRPV4-TRPP2 channel. These results demonstrated TRPV4 activity was necessary for the correct establishment of TJ in corneal epithelia and as well as the regulation of both the barrier function of TJ and its ability to respond to EGF. J. Cell. Physiol. 232: 1794-1807, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Gene profile analysis of osteoblast genes differentially regulated by histone deacetylase inhibitors

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Lamblin Anne-Francoise

2007-10-01

Full Text Available Abstract Background Osteoblast differentiation requires the coordinated stepwise expression of multiple genes. Histone deacetylase inhibitors (HDIs accelerate the osteoblast differentiation process by blocking the activity of histone deacetylases (HDACs, which alter gene expression by modifying chromatin structure. We previously demonstrated that HDIs and HDAC3 shRNAs accelerate matrix mineralization and the expression of osteoblast maturation genes (e.g. alkaline phosphatase, osteocalcin. Identifying other genes that are differentially regulated by HDIs might identify new pathways that contribute to osteoblast differentiation. Results To identify other osteoblast genes that are altered early by HDIs, we incubated MC3T3-E1 preosteoblasts with HDIs (trichostatin A, MS-275, or valproic acid for 18 hours in osteogenic conditions. The promotion of osteoblast differentiation by HDIs in this experiment was confirmed by osteogenic assays. Gene expression profiles relative to vehicle-treated cells were assessed by microarray analysis with Affymetrix GeneChip 430 2.0 arrays. The regulation of several genes by HDIs in MC3T3-E1 cells and primary osteoblasts was verified by quantitative real-time PCR. Nine genes were differentially regulated by at least two-fold after exposure to each of the three HDIs and six were verified by PCR in osteoblasts. Four of the verified genes (solute carrier family 9 isoform 3 regulator 1 (Slc9a3r1, sorbitol dehydrogenase 1, a kinase anchor protein, and glutathione S-transferase alpha 4 were induced. Two genes (proteasome subunit, beta type 10 and adaptor-related protein complex AP-4 sigma 1 were suppressed. We also identified eight growth factors and growth factor receptor genes that are significantly altered by each of the HDIs, including Frizzled related proteins 1 and 4, which modulate the Wnt signaling pathway. Conclusion This study identifies osteoblast genes that are regulated early by HDIs and indicates pathways that

Regulation of B cell differentiation by intracellular membrane associated proteins and microRNAs: role in the antibody response

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Zheng eLou

2015-10-01

Full Text Available B cells are central to adaptive immunity and their functions in antibody responses are exquisitely regulated. As suggested by recent findings, B cell differentiation is mediated by intracellular membrane structures (including endosomes, lysosomes and autophagosomes and protein factors specifically associated with these membranes, including Rab7, Atg5 and Atg7. These factors participate in vesicle formation/trafficking, signal transduction and induction of gene expression to promote antigen presentation, CSR/SHM, and generation/maintenance of plasma cells and memory B cells. Their expression is induced in B cells activated to differentiate and further fine-tuned by immune-modulating microRNAs, which coordinates CSR/SHM, plasma cell differentiation and memory B cell differentiation. These short non-coding RNAs would individually target multiple factors associated with the same intracellular membrane compartments and collaboratively target a single factor in addition to regulate AID and Blimp-1. These, together with regulation of microRNA biogenesis and activities by endosomes and autophagosomes, show that intracellular membranes and microRNAs, two broadly relevant cell constituents, play important roles in balancing gene expression to specify B cell differentiation processes for optimal antibody responses.

UVA and UVB Irradiation Differentially Regulate microRNA Expression in Human Primary Keratinocytes

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Kraemer, Anne; Chen, I-Peng; Henning, Stefan; Faust, Alexandra; Volkmer, Beate; Atkinson, Michael J.; Moertl, Simone; Greinert, Ruediger

2013-01-01

MicroRNA (miRNA)-mediated regulation of the cellular transcriptome is an important epigenetic mechanism for fine-tuning regulatory pathways. These include processes related to skin cancer development, progression and metastasis. However, little is known about the role of microRNA as an intermediary in the carcinogenic processes following exposure to UV-radiation. We now show that UV irradiation of human primary keratinocytes modulates the expression of several cellular miRNAs. A common set of miRNAs was influenced by exposure to both UVA and UVB. However, each wavelength band also activated a distinct subset of miRNAs. Common sets of UVA- and UVB-regulated miRNAs harbor the regulatory elements GLYCA-nTRE, GATA-1-undefined-site-13 or Hox-2.3-undefined-site-2 in their promoters. In silico analysis indicates that the differentially expressed miRNAs responding to UV have potential functions in the cellular pathways of cell growth and proliferation. Interestingly, the expression of miR-23b, which is a differentiation marker of human keratinocytes, is remarkably up-regulated after UVA irradiation. Studying the interaction between miR-23b and its putative skin-relevant targets using a Luciferase reporter assay revealed that RRAS2 (related RAS viral oncogene homolog 2), which is strongly expressed in highly aggressive malignant skin cancer, to be a direct target of miR-23b. This study demonstrates for the first time a differential miRNA response to UVA and UVB in human primary keratinocytes. This suggests that selective regulation of signaling pathways occurs in response to different UV energies. This may shed new light on miRNA-regulated carcinogenic processes involved in UV-induced skin carcinogenesis. PMID:24391759

UVA and UVB irradiation differentially regulate microRNA expression in human primary keratinocytes.

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Anne Kraemer

Full Text Available MicroRNA (miRNA-mediated regulation of the cellular transcriptome is an important epigenetic mechanism for fine-tuning regulatory pathways. These include processes related to skin cancer development, progression and metastasis. However, little is known about the role of microRNA as an intermediary in the carcinogenic processes following exposure to UV-radiation. We now show that UV irradiation of human primary keratinocytes modulates the expression of several cellular miRNAs. A common set of miRNAs was influenced by exposure to both UVA and UVB. However, each wavelength band also activated a distinct subset of miRNAs. Common sets of UVA- and UVB-regulated miRNAs harbor the regulatory elements GLYCA-nTRE, GATA-1-undefined-site-13 or Hox-2.3-undefined-site-2 in their promoters. In silico analysis indicates that the differentially expressed miRNAs responding to UV have potential functions in the cellular pathways of cell growth and proliferation. Interestingly, the expression of miR-23b, which is a differentiation marker of human keratinocytes, is remarkably up-regulated after UVA irradiation. Studying the interaction between miR-23b and its putative skin-relevant targets using a Luciferase reporter assay revealed that RRAS2 (related RAS viral oncogene homolog 2, which is strongly expressed in highly aggressive malignant skin cancer, to be a direct target of miR-23b. This study demonstrates for the first time a differential miRNA response to UVA and UVB in human primary keratinocytes. This suggests that selective regulation of signaling pathways occurs in response to different UV energies. This may shed new light on miRNA-regulated carcinogenic processes involved in UV-induced skin carcinogenesis.

Uhrf1 controls the self-renewal versus differentiation of hematopoietic stem cells by epigenetically regulating the cell-division modes.

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Zhao, Jingyao; Chen, Xufeng; Song, Guangrong; Zhang, Jiali; Liu, Haifeng; Liu, Xiaolong

2017-01-10

Hematopoietic stem cells (HSCs) are able to both self-renew and differentiate. However, how individual HSC makes the decision between self-renewal and differentiation remains largely unknown. Here we report that ablation of the key epigenetic regulator Uhrf1 in the hematopoietic system depletes the HSC pool, leading to hematopoietic failure and lethality. Uhrf1-deficient HSCs display normal survival and proliferation, yet undergo erythroid-biased differentiation at the expense of self-renewal capacity. Notably, Uhrf1 is required for the establishment of DNA methylation patterns of erythroid-specific genes during HSC division. The expression of these genes is enhanced in the absence of Uhrf1, which disrupts the HSC-division modes by promoting the symmetric differentiation and suppressing the symmetric self-renewal. Moreover, overexpression of one of the up-regulated genes, Gata1, in HSCs is sufficient to phenocopy Uhrf1-deficient HSCs, which show impaired HSC symmetric self-renewal and increased differentiation commitment. Taken together, our findings suggest that Uhrf1 controls the self-renewal versus differentiation of HSC through epigenetically regulating the cell-division modes, thus providing unique insights into the relationship among Uhrf1-mediated DNA methylation, cell-division mode, and HSC fate decision.

BMP-2 Induced Expression of Alx3 That Is a Positive Regulator of Osteoblast Differentiation.

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Takashi Matsumoto

Full Text Available Bone morphogenetic proteins (BMPs regulate many aspects of skeletal development, including osteoblast and chondrocyte differentiation, cartilage and bone formation, and cranial and limb development. Among them, BMP-2, one of the most potent osteogenic signaling molecules, stimulates osteoblast differentiation, while it inhibits myogenic differentiation in C2C12 cells. To evaluate genes involved in BMP-2-induced osteoblast differentiation, we performed cDNA microarray analyses to compare BMP-2-treated and -untreated C2C12 cells. We focused on Alx3 (aristaless-like homeobox 3 which was clearly induced during osteoblast differentiation. Alx3, a homeobox gene related to the Drosophilaaristaless gene, has been linked to developmental functions in craniofacial structures and limb development. However, little is known about its direct relationship with bone formation. In the present study, we focused on the mechanisms of Alx3 gene expression and function during osteoblast differentiation induced by BMP-2. In C2C12 cells, BMP-2 induced increase of Alx3 gene expression in both time- and dose-dependent manners through the BMP receptors-mediated SMAD signaling pathway. In addition, silencing of Alx3 by siRNA inhibited osteoblast differentiation induced by BMP-2, as showed by the expressions of alkaline phosphatase (Alp, Osteocalcin, and Osterix, while over-expression of Alx3 enhanced osteoblast differentiation induced by BMP-2. These results indicate that Alx3 expression is enhanced by BMP-2 via the BMP receptors mediated-Smad signaling and that Alx3 is a positive regulator of osteoblast differentiation induced by BMP-2.

miR-150-Mediated Foxo1 Regulation Programs CD8+ T Cell Differentiation.

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Ban, Young Ho; Oh, Se-Chan; Seo, Sang-Hwan; Kim, Seok-Min; Choi, In-Pyo; Greenberg, Philip D; Chang, Jun; Kim, Tae-Don; Ha, Sang-Jun

2017-09-12

MicroRNA (miR)-150 is a developmental regulator of several immune-cell types, but its role in CD8 + T cells is largely unexplored. Here, we show that miR-150 regulates the generation of memory CD8 + T cells. After acute virus infection, miR-150 knockout (KO) mice exhibited an accelerated differentiation of CD8 + T cells into memory cells and improved production of effector cytokines. Additionally, miR-150 KO CD8 + T cells displayed an enhanced recall response and improved protection against infections with another virus and bacteria. We found that forkhead box O1 (Foxo1) and T cell-specific transcription factor 1 (TCF1) are upregulated during the early activation phase in miR-150 KO CD8 + T cells and that miR-150 directly targets and suppresses Foxo1. These results suggest that miR-150-mediated suppression of Foxo1 regulates the balance between effector and memory cell differentiation, which might aid in the development of improved vaccines and T cell therapeutics. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

LncRNA Dum interacts with Dnmts to regulate Dppa2 expression during myogenic differentiation and muscle regeneration

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Wang, Lijun; Zhao, Yu; Bao, Xichen; Zhu, Xihua; Kwok, Yvonne Ka-yin; Sun, Kun; Chen, Xiaona; Huang, Yongheng; Jauch, Ralf; Esteban, Miguel A; Sun, Hao; Wang, Huating

2015-01-01

Emerging studies document the roles of long non-coding RNAs (LncRNAs) in regulating gene expression at chromatin level but relatively less is known how they regulate DNA methylation. Here we identify an lncRNA, Dum (developmental pluripotency-associated 2 (Dppa2) Upstream binding Muscle lncRNA) in skeletal myoblast cells. The expression of Dum is dynamically regulated during myogenesis in vitro and in vivo. It is also transcriptionally induced by MyoD binding upon myoblast differentiation. Functional analyses show that it promotes myoblast differentiation and damage-induced muscle regeneration. Mechanistically, Dum was found to silence its neighboring gene, Dppa2, in cis through recruiting Dnmt1, Dnmt3a and Dnmt3b. Furthermore, intrachromosomal looping between Dum locus and Dppa2 promoter is necessary for Dum/Dppa2 interaction. Collectively, we have identified a novel lncRNA that interacts with Dnmts to regulate myogenesis. PMID:25686699

Lysophosphatidylcholine Regulates Sexual Stage Differentiation in the Human Malaria Parasite Plasmodium falciparum.

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Brancucci, Nicolas M B; Gerdt, Joseph P; Wang, ChengQi; De Niz, Mariana; Philip, Nisha; Adapa, Swamy R; Zhang, Min; Hitz, Eva; Niederwieser, Igor; Boltryk, Sylwia D; Laffitte, Marie-Claude; Clark, Martha A; Grüring, Christof; Ravel, Deepali; Blancke Soares, Alexandra; Demas, Allison; Bopp, Selina; Rubio-Ruiz, Belén; Conejo-Garcia, Ana; Wirth, Dyann F; Gendaszewska-Darmach, Edyta; Duraisingh, Manoj T; Adams, John H; Voss, Till S; Waters, Andrew P; Jiang, Rays H Y; Clardy, Jon; Marti, Matthias

2017-12-14

Transmission represents a population bottleneck in the Plasmodium life cycle and a key intervention target of ongoing efforts to eradicate malaria. Sexual differentiation is essential for this process, as only sexual parasites, called gametocytes, are infective to the mosquito vector. Gametocyte production rates vary depending on environmental conditions, but external stimuli remain obscure. Here, we show that the host-derived lipid lysophosphatidylcholine (LysoPC) controls P. falciparum cell fate by repressing parasite sexual differentiation. We demonstrate that exogenous LysoPC drives biosynthesis of the essential membrane component phosphatidylcholine. LysoPC restriction induces a compensatory response, linking parasite metabolism to the activation of sexual-stage-specific transcription and gametocyte formation. Our results reveal that malaria parasites can sense and process host-derived physiological signals to regulate differentiation. These data close a critical knowledge gap in parasite biology and introduce a major component of the sexual differentiation pathway in Plasmodium that may provide new approaches for blocking malaria transmission. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

[Comprehensive regulation effect of traditional Chinese medicine on proliferation and differentiation of neural stem cells].

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Wang, Hong-Jin; Li, Jing-Jing; Ke, Hui; Xu, Xiao-Yu

2017-11-01

Since the discovery of neural stem cells(NSCs) in embryonic and adult mammalian central nervous systems, new approaches for proliferation and differentiation of NSCs have been put forward. One of the approaches to promote the clinical application of NSCs is to search effective methods to regulate the proliferation and differentiation. This problem is urgently to be solved in the medical field. Previous studies have shown that traditional Chinese medicine could promote the proliferation and differentiation of NSCs by regulating the relevant signaling pathway in vivo and in vitro. Domestic and foreign literatures for regulating the proliferation and differentiation of neural stem cells in recent 10 years and the reports for their target and signaling pathways were analyzed in this paper. Traditional Chinese medicine could regulate the proliferation and differentiation of NSCs through signaling pathways of Notch, PI3K/Akt, Wnt/β-catenin and GFs. However, studies about NSCs and traditional Chinese medicine should be further deepened; the mechanism of multiple targets and the comprehensive regulation function of traditional Chinese medicine should be clarified. Copyright© by the Chinese Pharmaceutical Association.

Invariant NKT cells regulate experimental autoimmune uveitis through inhibition of Th17 differentiation.

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Oh, Keunhee; Byoun, Ok-Jin; Ham, Don-Il; Kim, Yon Su; Lee, Dong-Sup

2011-02-01

Although NKT cells have been implicated in diverse immunomodulatory responses, the effector mechanisms underlying the NKT cell-mediated regulation of pathogenic T helper cells are not well understood. Here, we show that invariant NKT cells inhibited the differentiation of CD4(+) T cells into Th17 cells both in vitro and in vivo. The number of IL-17-producing CD4(+) T cells was reduced following co-culture with purified NK1.1(+) TCR(+) cells from WT, but not from CD1d(-/-) or Jα18(-/-) , mice. Co-cultured NKT cells from either cytokine-deficient (IL-4(-/-) , IL-10(-/-) , or IFN-γ(-/-) ) or WT mice efficiently inhibited Th17 differentiation. The contact-dependent mechanisms of NKT cell-mediated regulation of Th17 differentiation were confirmed using transwell co-culture experiments. On the contrary, the suppression of Th1 differentiation was dependent on IL-4 derived from the NKT cells. The in vivo regulatory capacity of NKT cells on Th17 cells was confirmed using an experimental autoimmune uveitis model induced with human IRBP(1-20) (IRBP, interphotoreceptor retinoid-binding protein) peptide. NKT cell-deficient mice (CD1d(-/-) or Jα18(-/-) ) demonstrated an increased disease severity, which was reversed by the transfer of WT or cytokine-deficient (IL-4(-/-) , IL-10(-/-) , or IFN-γ(-/-) ) NKT cells. Our results indicate that invariant NKT cells inhibited autoimmune uveitis predominantly through the cytokine-independent inhibition of Th17 differentiation. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The regulation and role of c-FLIP in human Th cell differentiation.

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Kyläniemi, Minna K; Kaukonen, Riina; Myllyviita, Johanna; Rasool, Omid; Lahesmaa, Riitta

2014-01-01

The early differentiation of T helper (Th) cells is a tightly controlled and finely balanced process, which involves several factors including cytokines, transcription factors and co-stimulatory molecules. Recent studies have shown that in addition to the regulation of apoptosis, caspase activity is also needed for Th cell proliferation and activation and it might play a role in Th cell differentiation. The isoforms of the cellular FLICE inhibitory protein (c-FLIP) are regulators of CASPASE-8 activity and the short isoform, c-FLIPS, has been shown to be up-regulated by IL-4, the Th2 driving cytokine. In this work, we have studied the expression and functional role of three c-FLIP isoforms during the early Th cell differentiation. Only two of the isoforms, c-FLIPS and c-FLIPL, were detected at the protein level although c-FLIPR was expressed at the mRNA level. The knockdown of c-FLIPL led to enhanced Th1 differentiation and elevated IL-4 production by Th2 cells, whereas the knockdown of c-FLIPS diminished GATA3 expression and IL-4 production by Th2 cells. In summary, our results provide new insight into the role of c-FLIP proteins in the early differentiation of human Th cells.

17β-estradiol regulates the differentiation of cementoblasts via Notch signaling cascade

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Liao, Jing; Zhou, Zeyuan; Huang, Li; Li, Yuyu [Department of Orthodontics, The State Key Laboratory of Oral Disease, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan Province (China); Li, Jingtao [Department of Oral and Maxillofacial Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan Province (China); Zou, Shujuan, E-mail: drzsj@scu.edu.cn [Department of Orthodontics, The State Key Laboratory of Oral Disease, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan Province (China)

2016-08-12

Estrogen has been well recognized as a key factor in the homeostasis of bone and periodontal tissue, but the way it regulates the activities of cementoblasts, the cell population maintaining cementum has not been fully understood. In this study, we examined the expression of estrogen receptor in OCCM-30 cells and the effect of 17β-estradiol (E2) on the proliferation and differentiation of OCCM-30 cells. We found that both estrogen receptor α and β were expressed in OCCM-30 cells. E2 exerted no significant influence on the proliferation of OCCM-30 cells, but inhibited the transcription and translation of BSP and Runx2 in the early phase of osteogenic induction except the BSP mRNA. Afterwards in the late phase of osteogenic induction, E2 enhanced the transcription and translation of BSP and Runx2 and promoted the calcium deposition. In addition, the expression level of Notch1, NICD and Hey1 mRNAs responded to exogenous E2 in a pattern similar to that of the osteoblastic markers. DAPT could attenuate the effect of E2 on the expression of osteoblastic markers. These findings indicated that E2 might regulate the differentiation of cementoblasts via Notch signaling. - Highlights: • 17β-estradiol showed no significant effect on the proliferation of cementoblasts. • 17β-estradiol promoted the osteoblastic differentiation of cementoblasts despite of an early transient inhibition. • Notch signaling was regulated by 17β-estradiol and was responsible for mediating the effect of E2 on cementoblasts. • Hey1 might display an opposite expression pattern to Notch signaling in certain circumstances.

CUDC-907 Promotes Bone Marrow Adipocytic Differentiation Through Inhibition of Histone Deacetylase and Regulation of Cell Cycle.

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Ali, Dalia; Alshammari, Hassan; Vishnubalaji, Radhakrishnan; Chalisserry, Elna Paul; Hamam, Rimi; Alfayez, Musaad; Kassem, Moustapha; Aldahmash, Abdullah; Alajez, Nehad M

2017-03-01

The role of bone marrow adipocytes (BMAs) in overall energy metabolism and their effects on bone mass are currently areas of intensive investigation. BMAs differentiate from bone marrow stromal cells (BMSCs); however, the molecular mechanisms regulating BMA differentiation are not fully understood. In this study, we investigated the effect of CUDC-907, identified by screening an epigenetic small-molecule library, on adipocytic differentiation of human BMSCs (hBMSCs) and determined its molecular mechanism of action. Human bone marrow stromal cells exposed to CUDC-907 (500 nM) exhibited enhanced adipocytic differentiation (∼2.9-fold increase, P < 0.005) compared with that of control cells. Global gene expression and signaling pathway analyses of differentially expressed genes revealed a strong enrichment of genes involved in adipogenesis, cell cycle, and DNA replication. Chromatin immune precipitation combined with quantitative polymerase chain reaction showed significant increase in H3K9ac epigenetic marker in the promoter regions of AdipoQ, FABP4, PPARγ, KLF15, and CEBPA in CUDC-907-treated hBMSCs. Follow-up experiments corroborated that the inhibition of histone deacetylase (HDAC) activity enhanced adipocytic differentiation, while the inhibition of PI3K decreased adipocytic differentiation. In addition, CUDC-907 arrested hBMSCs in the G0-G1 phase of the cell cycle and reduced the number of S-phase cells. Our data reveal that HDAC, PI3K, and cell cycle genes are important regulators of BMA formation and demonstrate that adipocyte differentiation of hBMSCs is associated with complex changes in a number of epigenetic and genetic pathways, which can be targeted to regulate BMA formation.

The regulation of autophagy differentially affects Trypanosoma cruzi metacyclogenesis.

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María Cristina Vanrell

2017-11-01

Full Text Available Autophagy is a cellular process required for the removal of aged organelles and cytosolic components through lysosomal degradation. All types of eukaryotic cells from yeasts to mammalian cells have the machinery to activate autophagy as a result of many physiological and pathological situations. The most frequent stimulus of autophagy is starvation and the result, in this case, is the fast generation of utilizable food (e.g. amino acids and basic nutrients to maintain the vital biological processes. In some organisms, starvation also triggers other associated processes such as differentiation. The protozoan parasite Trypanosoma cruzi undergoes a series of differentiation processes throughout its complex life cycle. Although not all autophagic genes have been identified in the T. cruzi genome, previous works have demonstrated the presence of essential autophagic-related proteins. Under starvation conditions, TcAtg8, which is the parasite homolog of Atg8/LC3 in other organisms, is located in autophagosome-like vesicles. In this work, we have characterized the autophagic pathway during T. cruzi differentiation from the epimastigote to metacyclic trypomastigote form, a process called metacyclogenesis. We demonstrated that autophagy is stimulated during metacyclogenesis and that the induction of autophagy promotes this process. Moreover, with exception of bafilomycin, other classical autophagy modulators have similar effects on T. cruzi autophagy. We also showed that spermidine and related polyamines can positively regulate parasite autophagy and differentiation. We concluded that both polyamine metabolism and autophagy are key processes during T. cruzi metacyclogenesis that could be exploited as drug targets to avoid the parasite cycle progression.

Gastrointestinal differentiation marker Cytokeratin 20 is regulated by homeobox gene CDX1

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Chan, Carol W M; Wong, Newton A; Liu, Ying

2009-01-01

colorectal cancer cell lines. Deletion and mutation analysis of the KRT20 promoter showed that the minimum regulatory region for the control of KRT20 expression by CDX1 is within 246 bp upstream of the KRT20 transcription start site. ChIP analysis confirmed that CDX1 binds to the predicted CDX elements...... in this region of the KRT20 promoter in vivo. In addition, immunohistochemistry showed expression of CDX1 parallels that of KRT20 in the normal crypt, which further supports their close relationship. In summary, our observations strongly imply that KRT20 is directly regulated by CDX1, and therefore suggest...... a role for CDX1 in maintaining differentiation in intestinal epithelial cells. Because a key feature of the development of a cancer is an unbalanced program of proliferation and differentiation, dysregulation of CDX1 may be an advantage for the development of a colorectal carcinoma. This could, therefore...

Ihh/Gli2 signaling promotes osteoblast differentiation by regulating Runx2 expression and function.

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Shimoyama, Atsuko; Wada, Masahiro; Ikeda, Fumiyo; Hata, Kenji; Matsubara, Takuma; Nifuji, Akira; Noda, Masaki; Amano, Katsuhiko; Yamaguchi, Akira; Nishimura, Riko; Yoneda, Toshiyuki

2007-07-01

Genetic and cell biological studies have indicated that Indian hedgehog (Ihh) plays an important role in bone development and osteoblast differentiation. However, the molecular mechanism by which Ihh regulates osteoblast differentiation is complex and remains to be fully elucidated. In this study, we investigated the role of Ihh signaling in osteoblast differentiation using mesenchymal cells and primary osteoblasts. We observed that Ihh stimulated alkaline phosphatase (ALP) activity, osteocalcin expression, and calcification. Overexpression of Gli2- but not Gli3-induced ALP, osteocalcin expression, and calcification of these cells. In contrast, dominant-negative Gli2 markedly inhibited Ihh-dependent osteoblast differentiation. Ihh treatment or Gli2 overexpression also up-regulated the expression of Runx2, an essential transcription factor for osteoblastogenesis, and enhanced the transcriptional activity and osteogenic action of Runx2. Coimmunoprecipitation analysis demonstrated a physical interaction between Gli2 and Runx2. Moreover, Ihh or Gli2 overexpression failed to increase ALP activity in Runx2-deficient mesenchymal cells. Collectively, these results suggest that Ihh regulates osteoblast differentiation of mesenchymal cells through up-regulation of the expression and function of Runx2 by Gli2.

Novel function of the retinoblastoma protein in fat: regulation of white versus brown adipocyte differentiation

DEFF Research Database (Denmark)

Hansen, Jacob B; te Riele, Hein; Kristiansen, Karsten

2004-01-01

the major energy store and brown adipocytes being potent energy-dissipaters through thermogenesis. Yet, little is known about factors differentially regulating the formation of white and brown fat cells. Members of the retinoblastoma protein family (pRB, p107, p130) have been implicated in the regulation...... of adipocyte differentiation, and expression and phosphorylation of the three retinoblastoma family proteins oscillate in a characteristic manner during differentiation of the white preadipocyte cell line 3T3-L1. We have recently demonstrated a surprising function of the retinoblastoma protein...... in the regulation of white versus brown adipocyte differentiation in vitro and possibly in vivo. Here we summarize the current knowledge on the retinoblastoma protein in fat cells, with particular emphasis on its potential role in adipocyte lineage commitment and differentiation....

DNER, an epigenetically modulated gene, regulates glioblastoma-derived neurosphere cell differentiation and tumor propagation.

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Sun, Peng; Xia, Shuli; Lal, Bachchu; Eberhart, Charles G; Quinones-Hinojosa, Alfredo; Maciaczyk, Jarek; Matsui, William; Dimeco, Francesco; Piccirillo, Sara M; Vescovi, Angelo L; Laterra, John

2009-07-01

Neurospheres derived from glioblastoma (GBM) and other solid malignancies contain neoplastic stem-like cells that efficiently propagate tumor growth and resist cytotoxic therapeutics. The primary objective of this study was to use histone-modifying agents to elucidate mechanisms by which the phenotype and tumor-promoting capacity of GBM-derived neoplastic stem-like cells are regulated. Using established GBM-derived neurosphere lines and low passage primary GBM-derived neurospheres, we show that histone deacetylase (HDAC) inhibitors inhibit growth, induce differentiation, and induce apoptosis of neoplastic neurosphere cells. A specific gene product induced by HDAC inhibition, Delta/Notch-like epidermal growth factor-related receptor (DNER), inhibited the growth of GBM-derived neurospheres, induced their differentiation in vivo and in vitro, and inhibited their engraftment and growth as tumor xenografts. The differentiating and tumor suppressive effects of DNER, a noncanonical Notch ligand, contrast with the previously established tumor-promoting effects of canonical Notch signaling in brain cancer stem-like cells. Our findings are the first to implicate noncanonical Notch signaling in the regulation of neoplastic stem-like cells and suggest novel neoplastic stem cell targeting treatment strategies for GBM and potentially other solid malignancies.

Gli3 acts as a repressor downstream of Ihh in regulating two distinct steps of chondrocyte differentiation.

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Koziel, Lydia; Wuelling, Manuela; Schneider, Sabine; Vortkamp, Andrea

2005-12-01

During endochondral ossification, the secreted growth factor Indian hedgehog (Ihh) regulates several differentiation steps. It interacts with a second secreted factor, parathyroid hormone-related protein (PTHrP), to regulate the onset of hypertrophic differentiation, and it regulates chondrocyte proliferation and ossification of the perichondrium independently of PTHrP. To investigate how the Ihh signal is translated in the different target tissues, we analyzed the role of the zinc-finger transcription factor Gli3, which acts downstream of hedgehog signals in other organs. Loss of Gli3 in Ihh mutants restores chondrocyte proliferation and delays the accelerated onset of hypertrophic differentiation observed in Ihh-/- mutants. Furthermore the expression of the Ihh target genes patched (Ptch) and PTHrP is reactivated in Ihh-/-;Gli3-/- mutants. Gli3 seems thus to act as a strong repressor of Ihh signals in regulating chondrocyte differentiation. In addition, loss of Gli3 in mice that overexpress Ihh in chondrocytes accelerates the onset of hypertrophic differentiation by reducing the domain and possibly the level of PTHrP expression. Careful analysis of chondrocyte differentiation in Gli3-/- mutants revealed that Gli3 negatively regulates the differentiation of distal, low proliferating chondrocytes into columnar, high proliferating cells. Our results suggest a model in which the Ihh/Gli3 system regulates two distinct steps of chondrocyte differentiation: (1) the switch from distal into columnar chondrocytes is repressed by Gli3 in a PTHrP-independent mechanism; (2) the transition from proliferating into hypertrophic chondrocytes is regulated by Gli3-dependent expression of PTHrP. Furthermore, by regulating distal chondrocyte differentiation, Gli3 seems to position the domain of PTHrP expression.

EZH2 regulates neuroblastoma cell differentiation via NTRK1 promoter epigenetic modifications.

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Li, Zhenghao; Takenobu, Hisanori; Setyawati, Amallia Nuggetsiana; Akita, Nobuhiro; Haruta, Masayuki; Satoh, Shunpei; Shinno, Yoshitaka; Chikaraishi, Koji; Mukae, Kyosuke; Akter, Jesmin; Sugino, Ryuichi P; Nakazawa, Atsuko; Nakagawara, Akira; Aburatani, Hiroyuki; Ohira, Miki; Kamijo, Takehiko

2018-05-01

The polycomb repressor complex 2 molecule EZH2 is now known to play a role in essential cellular processes, namely, cell fate decisions, cell cycle regulation, senescence, cell differentiation, and cancer development/progression. EZH2 inhibitors have recently been developed; however, their effectiveness and underlying molecular mechanisms in many malignancies have not yet been elucidated in detail. Although the functional role of EZH2 in tumorigenesis in neuroblastoma (NB) has been investigated, mutations of EZH2 have not been reported. A Kaplan-Meier analysis on the event free survival and overall survival of NB patients indicated that the high expression of EZH2 correlated with an unfavorable prognosis. In order to elucidate the functional roles of EZH2 in NB tumorigenesis and its aggressiveness, we knocked down EZH2 in NB cell lines using lentivirus systems. The knockdown of EZH2 significantly induced NB cell differentiation, e.g., neurite extension, and the neuronal differentiation markers, NF68 and GAP43. EZH2 inhibitors also induced NB cell differentiation. We performed a comprehensive transcriptome analysis using Human Gene Expression Microarrays and found that NTRK1 (TrkA) is one of the EZH2-related suppression targets. The depletion of NTRK1 canceled EZH2 knockdown-induced NB cell differentiation. Our integrative methylome, transcriptome, and chromatin immunoprecipitation assays using NB cell lines and clinical samples clarified that the NTRK1 P1 and P2 promoter regions were regulated differently by DNA methylation and EZH2-related histone modifications. The NTRK1 transcript variants 1/2, which were regulated by EZH2-related H3K27me3 modifications at the P1 promoter region, were strongly expressed in favorable, but not unfavorable NB. The depletion and inhibition of EZH2 successfully induced NTRK1 transcripts and functional proteins. Collectively, these results indicate that EZH2 plays important roles in preventing the differentiation of NB cells and also

Developmental regulation of nucleolus size during Drosophila eye differentiation.

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Nicholas E Baker

Full Text Available When cell cycle withdrawal accompanies terminal differentiation, biosynthesis and cellular growth are likely to change also. In this study, nucleolus size was monitored during cell fate specification in the Drosophila eye imaginal disc using fibrillarin antibody labeling. Nucleolus size is an indicator of ribosome biogenesis and can correlate with cellular growth rate. Nucleolar size was reduced significantly during cell fate specification and differentiation, predominantly as eye disc cells entered a cell cycle arrest that preceded cell fate specification. This reduction in nucleolus size required Dpp and Hh signaling. A transient enlargement of the nucleolus accompanied cell division in the Second Mitotic Wave. Nucleoli continued to diminish in postmitotic cells following fate specification. These results suggest that cellular growth is regulated early in the transition from proliferating progenitor cells to terminal cell fate specification, contemporary with regulation of the cell cycle, and requiring the same extracellular signals.

Developmental regulation of nucleolus size during Drosophila eye differentiation.

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Baker, Nicholas E

2013-01-01

When cell cycle withdrawal accompanies terminal differentiation, biosynthesis and cellular growth are likely to change also. In this study, nucleolus size was monitored during cell fate specification in the Drosophila eye imaginal disc using fibrillarin antibody labeling. Nucleolus size is an indicator of ribosome biogenesis and can correlate with cellular growth rate. Nucleolar size was reduced significantly during cell fate specification and differentiation, predominantly as eye disc cells entered a cell cycle arrest that preceded cell fate specification. This reduction in nucleolus size required Dpp and Hh signaling. A transient enlargement of the nucleolus accompanied cell division in the Second Mitotic Wave. Nucleoli continued to diminish in postmitotic cells following fate specification. These results suggest that cellular growth is regulated early in the transition from proliferating progenitor cells to terminal cell fate specification, contemporary with regulation of the cell cycle, and requiring the same extracellular signals.

Semipermeable Capsules Wrapping a Multifunctional and Self-regulated Co-culture Microenvironment for Osteogenic Differentiation

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Correia, Clara R.; Pirraco, Rogério P.; Cerqueira, Mariana T.; Marques, Alexandra P.; Reis, Rui L.; Mano, João F.

2016-02-01

A new concept of semipermeable reservoirs containing co-cultures of cells and supporting microparticles is presented, inspired by the multi-phenotypic cellular environment of bone. Based on the deconstruction of the “stem cell niche”, the developed capsules are designed to drive a self-regulated osteogenesis. PLLA microparticles functionalized with collagen I, and a co-culture of adipose stem (ASCs) and endothelial (ECs) cells are immobilized in spherical liquified capsules. The capsules are coated with multilayers of poly(L-lysine), alginate, and chitosan nano-assembled through layer-by-layer. Capsules encapsulating ASCs alone or in a co-culture with ECs are cultured in endothelial medium with or without osteogenic differentiation factors. Results show that osteogenesis is enhanced by the co-encapsulation, which occurs even in the absence of differentiation factors. These findings are supported by an increased ALP activity and matrix mineralization, osteopontin detection, and the up regulation of BMP-2, RUNX2 and BSP. The liquified co-capsules also act as a VEGF and BMP-2 cytokines release system. The proposed liquified capsules might be a valuable injectable self-regulated system for bone regeneration employing highly translational cell sources.

Biosynthesis of ribosomal RNA in nucleoli regulates pluripotency and differentiation ability of pluripotent stem cells.

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Watanabe-Susaki, Kanako; Takada, Hitomi; Enomoto, Kei; Miwata, Kyoko; Ishimine, Hisako; Intoh, Atsushi; Ohtaka, Manami; Nakanishi, Mahito; Sugino, Hiromu; Asashima, Makoto; Kurisaki, Akira

2014-12-01

Pluripotent stem cells have been shown to have unique nuclear properties, for example, hyperdynamic chromatin and large, condensed nucleoli. However, the contribution of the latter unique nucleolar character to pluripotency has not been well understood. Here, we show that fibrillarin (FBL), a critical methyltransferase for ribosomal RNA (rRNA) processing in nucleoli, is one of the proteins highly expressed in pluripotent embryonic stem (ES) cells. Stable expression of FBL in ES cells prolonged the pluripotent state of mouse ES cells cultured in the absence of leukemia inhibitory factor (LIF). Analyses using deletion mutants and a point mutant revealed that the methyltransferase activity of FBL regulates stem cell pluripotency. Knockdown of this gene led to significant delays in rRNA processing, growth inhibition, and apoptosis in mouse ES cells. Interestingly, both partial knockdown of FBL and treatment with actinomycin D, an inhibitor of rRNA synthesis, induced the expression of differentiation markers in the presence of LIF and promoted stem cell differentiation into neuronal lineages. Moreover, we identified p53 signaling as the regulatory pathway for pluripotency and differentiation of ES cells. These results suggest that proper activity of rRNA production in nucleoli is a novel factor for the regulation of pluripotency and differentiation ability of ES cells. © 2014 AlphaMed Press.

Regulation of TFIIIB during F9 cell differentiation.

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Athineos, Dimitris; Marshall, Lynne; White, Robert J

2010-03-12

Differentiation of F9 embryonal carcinoma (EC) cells into parietal endoderm (PE) provides a tractable model system for studying molecular events during early and inaccessible stages of murine development. PE formation is accompanied by extensive changes in gene expression both in vivo and in culture. One of the most dramatic is the ~10-fold decrease in transcriptional output by RNA polymerase (pol) III. This has been attributed to changes in activity of TFIIIB, a factor that is necessary and sufficient to recruit pol III to promoters. The goal of this study was to identify molecular changes that can account for the low activity of TFIIIB following F9 cell differentiation. Three essential subunits of TFIIIB decrease in abundance as F9 cells differentiate; these are Brf1 and Bdp1, which are pol III-specific, and TBP, which is also used by pols I and II. The decreased levels of Brf1 and Bdp1 proteins can be explained by reduced expression of the corresponding mRNAs. However, this is not the case for TBP, which is regulated post-transcriptionally. In proliferating cells, pol III transcription is stimulated by the proto-oncogene product c-Myc and the mitogen-activated protein kinase Erk, both of which bind to TFIIIB. However, c-Myc levels fall during differentiation and Erk becomes inactive through dephosphorylation. The diminished abundance of TFIIIB is therefore likely to be compounded by changes to these positive regulators that are required for its full activity. In addition, PE cells have elevated levels of the retinoblastoma protein RB, which is known to bind and repress TFIIIB. The low activity of TFIIIB in PE can be attributed to a combination of changes, any one of which could be sufficient to inhibit pol III transcription. Declining levels of essential TFIIIB subunits and of activators that are required for maximal TFIIIB activity are accompanied by an increase in a potent repressor of TFIIIB. These events provide fail-safe guarantees to ensure that pol III

Leptin differentially regulate STAT3 activation in ob/ob mouse adipose mesenchymal stem cells

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Zhou Zhou

2012-12-01

Full Text Available Abstract Background Leptin-deficient ob/ob mice exhibit adipocyte hypertrophy and hyperplasia as well as elevated adipose tissue and systemic inflammation. Multipotent stem cells isolated from adult adipose tissue can differentiate into adipocytes ex vivo and thereby contribute toward increased adipocyte cell numbers, obesity, and inflamm ation. Currently, information is lacking regarding regulation of adipose stem cell numbers as well as leptin-induced inflammation and its signaling pathway in ob/ob mice. Methods Using leptin deficient ob/ob mice, we investigated whether leptin injection into ob/ob mice increases adipose stem cell numbers and adipose tissue inflammatory marker MCP-1 mRNA and secretion levels. We also determined leptin mediated signaling pathways in the adipose stem cells. Results We report here that adipose stem cell number is significantly increased following leptin injection in ob/ob mice and with treatment of isolated stem cells with leptin in vitro. Leptin also up-regulated MCP-1 secretion in a dose- and time-dependent manner. We further showed that increased MCP-1 mRNA levels were due to increased phosphorylation of Signal Transducer and Activator of Transcription 3 (STAT3 Ser727 but not STAT3 Tyr705 phosphorylation, suggesting differential regulation of MCP-1 gene expression under basal and leptin-stimulated conditions in adipose stem cells. Conclusions Taken together, these studies demonstrate that leptin increases adipose stem cell number and differentially activates STAT3 protein resulting in up-regulation of MCP-1 gene expression. Further studies of mechanisms mediating adipose stem cell hyperplasia and leptin signaling in obesity are warranted and may help identify novel anti-obesity target strategies.

Mechanical regulation of stem-cell differentiation by the stretch-activated Piezo channel.

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He, Li; Si, Guangwei; Huang, Jiuhong; Samuel, Aravinthan D T; Perrimon, Norbert

2018-03-01

Somatic stem cells constantly adjust their self-renewal and lineage commitment by integrating various environmental cues to maintain tissue homeostasis. Although numerous chemical and biological signals have been identified that regulate stem-cell behaviour, whether stem cells can directly sense mechanical signals in vivo remains unclear. Here we show that mechanical stress regulates stem-cell differentiation in the adult Drosophila midgut through the stretch-activated ion channel Piezo. We find that Piezo is specifically expressed in previously unidentified enteroendocrine precursor cells, which have reduced proliferation ability and are destined to become enteroendocrine cells. Loss of Piezo activity reduces the generation of enteroendocrine cells in the adult midgut. In addition, ectopic expression of Piezo in all stem cells triggers both cell proliferation and enteroendocrine cell differentiation. Both the Piezo mutant and overexpression phenotypes can be rescued by manipulation of cytosolic Ca 2+ levels, and increases in cytosolic Ca 2+ resemble the Piezo overexpression phenotype, suggesting that Piezo functions through Ca 2+ signalling. Further studies suggest that Ca 2+ signalling promotes stem-cell proliferation and differentiation through separate pathways. Finally, Piezo is required for both mechanical activation of stem cells in a gut expansion assay and the increase of cytosolic Ca 2+ in response to direct mechanical stimulus in a gut compression assay. Thus, our study demonstrates the existence of a specific group of stem cells in the fly midgut that can directly sense mechanical signals through Piezo.

MiR-217 is down-regulated in psoriasis and promotes keratinocyte differentiation via targeting GRHL2

International Nuclear Information System (INIS)

Zhu, Haigang; Hou, Liyue; Liu, Jingjing; Li, Zhiming

2016-01-01

MiR-217 is a well-known tumor suppressor, and its down-regulation has been shown in a wide range of solid and leukaemic cancers. However, the biological role of miR-217 in psoriasis pathogenesis, especially in keratinocyte hyperproliferation and differentiation, is not clearly understood. In this study, we found the expression of miR-217 was markedly down-regulated in psoriasis keratinocytes of psoriatic patients. In addition, overexpression of miR-217 inhibited the proliferation and promoted the differentiation of primary human keratinocytes. On the contrary, inhibition of endogenous miR-217 increased cell proliferation and delayed differentiation. Furthermore, Grainyhead-like 2 (GRHL2) was identified as a direct target of miR-217 by luciferase reporter assay. The expression of miR-217 and GRHL2 was inversely correlated in both transfected keratinocytes and in psoriasis lesional skin. Moreover, knocking down GRHL2 expression by siRNA enhanced keratinocyte differentiation. Taken together, our results demonstrate a role for miR-217 in the regulation of keratinocyte differentiation, partially through the regulation of GRHL2. - Highlights: • miR-217 is down-regulated in psoriasis skin lesions. • miR-217 inhibits the proliferation and promotes differentiation of keratinocytes. • GRHL2 is a novel target of miR-217 in keratinocytes. • GRHL2 is up-regulated and inversely correlated with miR-217 in psoriasis skin lesions.

MiR-217 is down-regulated in psoriasis and promotes keratinocyte differentiation via targeting GRHL2

Energy Technology Data Exchange (ETDEWEB)

Zhu, Haigang; Hou, Liyue; Liu, Jingjing; Li, Zhiming, E-mail: lizm_1001@sina.com

2016-02-26

MiR-217 is a well-known tumor suppressor, and its down-regulation has been shown in a wide range of solid and leukaemic cancers. However, the biological role of miR-217 in psoriasis pathogenesis, especially in keratinocyte hyperproliferation and differentiation, is not clearly understood. In this study, we found the expression of miR-217 was markedly down-regulated in psoriasis keratinocytes of psoriatic patients. In addition, overexpression of miR-217 inhibited the proliferation and promoted the differentiation of primary human keratinocytes. On the contrary, inhibition of endogenous miR-217 increased cell proliferation and delayed differentiation. Furthermore, Grainyhead-like 2 (GRHL2) was identified as a direct target of miR-217 by luciferase reporter assay. The expression of miR-217 and GRHL2 was inversely correlated in both transfected keratinocytes and in psoriasis lesional skin. Moreover, knocking down GRHL2 expression by siRNA enhanced keratinocyte differentiation. Taken together, our results demonstrate a role for miR-217 in the regulation of keratinocyte differentiation, partially through the regulation of GRHL2. - Highlights: • miR-217 is down-regulated in psoriasis skin lesions. • miR-217 inhibits the proliferation and promotes differentiation of keratinocytes. • GRHL2 is a novel target of miR-217 in keratinocytes. • GRHL2 is up-regulated and inversely correlated with miR-217 in psoriasis skin lesions.

Tissue-specific 5' heterogeneity of PPARα transcripts and their differential regulation by leptin.

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Emma S Garratt

Full Text Available The genes encoding nuclear receptors comprise multiple 5'untranslated exons, which give rise to several transcripts encoding the same protein, allowing tissue-specific regulation of expression. Both human and mouse peroxisome proliferator activated receptor (PPAR α genes have multiple promoters, although their function is unknown. Here we have characterised the rat PPARα promoter region and have identified three alternative PPARα transcripts, which have different transcription start sites owing to the utilisation of distinct first exons. Moreover these alternative PPARα transcripts were differentially expressed between adipose tissue and liver. We show that while the major adipose (P1 and liver (P2 transcripts were both induced by dexamethasone, they were differentially regulated by the PPARα agonist, clofibric acid, and leptin. Leptin had no effect on the adipose-specific P1 transcript, but induced liver-specific P2 promoter activity via a STAT3/Sp1 mechanism. Moreover in Wistar rats, leptin treatment between postnatal day 3-13 led to an increase in P2 but not P1 transcription in adipose tissue which was sustained into adulthood. This suggests that the expression of the alternative PPARα transcripts are in part programmed by early life exposure to leptin leading to persistent change in adipose tissue fatty acid metabolism through specific activation of a quiescent PPARα promoter. Such complexity in the regulation of PPARα may allow the expression of PPARα to be finely regulated in response to environmental factors.

SPDEF is required for mouse pulmonary goblet cell differentiation and regulates a network of genes associated with mucus production.

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Chen, Gang; Korfhagen, Thomas R; Xu, Yan; Kitzmiller, Joseph; Wert, Susan E; Maeda, Yutaka; Gregorieff, Alexander; Clevers, Hans; Whitsett, Jeffrey A

2009-10-01

Various acute and chronic inflammatory stimuli increase the number and activity of pulmonary mucus-producing goblet cells, and goblet cell hyperplasia and excess mucus production are central to the pathogenesis of chronic pulmonary diseases. However, little is known about the transcriptional programs that regulate goblet cell differentiation. Here, we show that SAM-pointed domain-containing Ets-like factor (SPDEF) controls a transcriptional program critical for pulmonary goblet cell differentiation in mice. Initial cell-lineage-tracing analysis identified nonciliated secretory epithelial cells, known as Clara cells, as the progenitors of goblet cells induced by pulmonary allergen exposure in vivo. Furthermore, in vivo expression of SPDEF in Clara cells caused rapid and reversible goblet cell differentiation in the absence of cell proliferation. This was associated with enhanced expression of genes regulating goblet cell differentiation and protein glycosylation, including forkhead box A3 (Foxa3), anterior gradient 2 (Agr2), and glucosaminyl (N-acetyl) transferase 3, mucin type (Gcnt3). Consistent with these findings, levels of SPDEF and FOXA3 were increased in mouse goblet cells after sensitization with pulmonary allergen, and the proteins were colocalized in goblet cells lining the airways of patients with chronic lung diseases. Deletion of the mouse Spdef gene resulted in the absence of goblet cells in tracheal/laryngeal submucosal glands and in the conducting airway epithelium after pulmonary allergen exposure in vivo. These data show that SPDEF plays a critical role in regulating a transcriptional network mediating the goblet cell differentiation and mucus hyperproduction associated with chronic pulmonary disorders.

Activated Fps/Fes tyrosine kinase regulates erythroid differentiation and survival.

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Sangrar, Waheed; Gao, Yan; Bates, Barbara; Zirngibl, Ralph; Greer, Peter A

2004-10-01

A substantial body of evidence implicates the cytoplasmic protein tyrosine kinase Fps/Fes in regulation of myeloid differentiation and survival. In this study we wished to determine if Fps/Fes also plays a role in the regulation of erythropoiesis. Mice tissue-specifically expressing a "gain-of-function" mutant fps/fes transgene (fps(MF)) encoding an activated variant of Fps/Fes (MFps), were used to explore the in vivo biological role of Fps/Fes. Erythropoiesis in these mice was assessed by hematological analysis, lineage marker analysis, bone-marrow colony assays, and biochemical approaches. fps(MF) mice displayed reductions in peripheral red cell counts. However, there was an accumulation of immature erythroid precursors, which displayed increased survival. Fps/Fes and the related Fer kinase were both detected in early erythroid progenitors/blasts and in mature red cells. Fps/Fes was also activated in response to erythropoietin (EPO) and stem cell factor (SCF), two critical factors in erythroid development. In addition, increased Stat5A/B activation and reduced Erk1/2 phosphorylation was observed in fps(MF) primary erythroid cells in response to EPO or SCF, respectively. These data support a role for Fps/Fes in regulating the survival and differentiation of erythroid cells through modulation of Stat5A/B and Erk kinase pathways induced by EPO and SCF. The increased numbers and survival of erythroid progenitors from fps(MF) mice, and their differential responsiveness to SCF and EPO, implicates Fps/Fes in the commitment of multilineage progenitors to the erythroid lineage. The anemic phenotype in fps(MF) mice suggests that downregulation of Fps/Fes activity might be required for terminal erythroid differentiation.

Mof-associated complexes have overlapping and unique roles in regulating pluripotency in embryonic stem cells and during differentiation

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Ravens, Sarina; Fournier, Marjorie; Ye, Tao; Stierle, Matthieu; Dembele, Doulaye; Chavant, Virginie; Tora, Làszlò

2014-01-01

The histone acetyltransferase (HAT) Mof is essential for mouse embryonic stem cell (mESC) pluripotency and early development. Mof is the enzymatic subunit of two different HAT complexes, MSL and NSL. The individual contribution of MSL and NSL to transcription regulation in mESCs is not well understood. Our genome-wide analysis show that i) MSL and NSL bind to specific and common sets of expressed genes, ii) NSL binds exclusively at promoters, iii) while MSL binds in gene bodies. Nsl1 regulates proliferation and cellular homeostasis of mESCs. MSL is the main HAT acetylating H4K16 in mESCs, is enriched at many mESC-specific and bivalent genes. MSL is important to keep a subset of bivalent genes silent in mESCs, while developmental genes require MSL for expression during differentiation. Thus, NSL and MSL HAT complexes differentially regulate specific sets of expressed genes in mESCs and during differentiation. DOI: http://dx.doi.org/10.7554/eLife.02104.001 PMID:24898753

Suppression of MicroRNA let-7a Expression by Agmatine Regulates Neural Stem Cell Differentiation.

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Song, Juhyun; Oh, Yumi; Kim, Jong Youl; Cho, Kyoung Joo; Lee, Jong Eun

2016-11-01

Neural stem cells (NSCs) effectively reverse some severe central nervous system (CNS) disorders, due to their ability to differentiate into neurons. Agmatine, a biogenic amine, has cellular protective effects and contributes to cellular proliferation and differentiation in the CNS. Recent studies have elucidated the function of microRNA let-7a (let-7a) as a regulator of cell differentiation with roles in regulating genes associated with CNS neurogenesis. This study aimed to investigate whether agmatine modulates the expression of crucial regulators of NSC differentiation including DCX, TLX, c-Myc, and ERK by controlling let-7a expression. Our data suggest that high levels of let-7a promoted the expression of TLX and c-Myc, as well as repressed DCX and ERK expression. In addition, agmatine attenuated expression of TLX and increased expression of ERK by negatively regulating let-7a. Our study therefore enhances the present understanding of the therapeutic potential of NSCs in CNS disorders.

Flow-regulated versus differential pressure-regulated shunt valves for adult patients with normal pressure hydrocephalus

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Ziebell, Morten; Wetterslev, Jørn; Tisell, Magnus

2013-01-01

Since 1965 many ventriculo-peritoneal shunt systems have been inserted worldwide to treat hydrocephalus. The most frequent indication in adults is normal pressure hydrocephalus (NPH), a condition that can be difficult to diagnose precisely. Surgical intervention with flow-regulated and differential...

Emergence of differentially regulated pathways associated with the development of regional specificity in chicken skin.

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Chang, Kai-Wei; Huang, Nancy A; Liu, I-Hsuan; Wang, Yi-Hui; Wu, Ping; Tseng, Yen-Tzu; Hughes, Michael W; Jiang, Ting Xin; Tsai, Mong-Hsun; Chen, Chien-Yu; Oyang, Yen-Jen; Lin, En-Chung; Chuong, Cheng-Ming; Lin, Shau-Ping

2015-01-23

Regional specificity allows different skin regions to exhibit different characteristics, enabling complementary functions to make effective use of the integumentary surface. Chickens exhibit a high degree of regional specificity in the skin and can serve as a good model for when and how these regional differences begin to emerge. We used developing feather and scale regions in embryonic chickens as a model to gauge the differences in their molecular pathways. We employed cosine similarity analysis to identify the differentially regulated and co-regulated genes. We applied low cell techniques for expression validation and chromatin immunoprecipitation (ChIP)-based enhancer identification to overcome limited cell availabilities from embryonic chicken skin. We identified a specific set of genes demonstrating a high correlation as being differentially expressed during feather and scale development and maturation. Some members of the WNT, TGF-beta/BMP, and Notch family known to be involved in feathering skin differentiation were found to be differentially regulated. Interestingly, we also found genes along calcium channel pathways that are differentially regulated. From the analysis of differentially regulated pathways, we used calcium signaling pathways as an example for further verification. Some voltage-gated calcium channel subunits, particularly CACNA1D, are expressed spatio-temporally in the skin epithelium. These calcium signaling pathway members may be involved in developmental decisions, morphogenesis, or epithelial maturation. We further characterized enhancers associated with histone modifications, including H3K4me1, H3K27ac, and H3K27me3, near calcium channel-related genes and identified signature intensive hotspots that may be correlated with certain voltage-gated calcium channel genes. We demonstrated the applicability of cosine similarity analysis for identifying novel regulatory pathways that are differentially regulated during development. Our study

Regulation of human skeletal stem cells differentiation by Dlk1/Pref-1

DEFF Research Database (Denmark)

Abdallah, Basem M; Jensen, Charlotte H; Gutierrez, Gloria

2004-01-01

Dlk-1/Pref-1 was identified as a novel regulator of human skeletal stem cell differentiation. Dlk1/Pref-1 is expressed in bone and cultured osteoblasts, and its constitutive overexpression led to inhibition of osteoblast and adipocyte differentiation of human marrow stromal cells. INTRODUCTION......: Molecular control of human mesenchymal stem cell (hMSC) differentiation into osteoblasts and adipocytes is not known. In this study, we examined the role of delta-like 1/preadipocyte factor-1 (Dlk1/Pref-1) in regulating the differentiation of hMSCs. MATERIALS AND METHODS: As a model for hMSCs, we have...... was used to confirm the in vitro effect of Dlk/Pref-1 on bone formation. RESULTS: Dlk1/Pref-1 was found to be expressed in fetal and adult bone, hMSCs, and some osteoblastic cell lines. A retroviral vector containing the human Dlk1/Pref-1 cDNA was used to create a cell line (hMSC-dlk1) expressing high...

Characterization of the Methylation Status of Pax7 and Myogenic Regulator Factors in Cell Myogenic Differentiation.

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Chao, Zhe; Zheng, Xin-Li; Sun, Rui-Ping; Liu, Hai-Long; Huang, Li-Li; Cao, Zong-Xi; Deng, Chang-Yan; Wang, Feng

2016-07-01

Epigenetic processes in the development of skeletal muscle have been appreciated for over a decade. DNA methylation is a major epigenetic modification important for regulating gene expression and suppressing spurious transcription. Up to now, the importance of epigenetic marks in the regulation of Pax7 and myogenic regulatory factors (MRFs) expression is far less explored. In the present study, semi-quantitative the real-time polymerase chain reaction (RT-PCR) analyses showed MyoD and Myf5 were expressed in activated and quiescent C2C12 cells. MyoG was expressed in a later stage of myogenesis. Pax7 was weakly expressed in differentiated C2C12 cells. To further understand the regulation of expression of these genes, the DNA methylation status of Pax7, MyoD, and Myf5 was determined by bisulfite sequencing PCR. During the C2C12 myoblasts fusion process, the changes of promoter and exon 1 methylation of Pax7, MyoD, and Myf5 genes were observed. In addition, an inverse relationship of low methylation and high expression was found. These results suggest that DNA methylation may be an important mechanism regulating Pax7 and MRFs transcription in cell myogenic differentiation.

MiR-132 regulates osteogenic differentiation via downregulating Sirtuin1 in a peroxisome proliferator-activated receptor β/δ–dependent manner

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Gong, Kai; Qu, Bo; Liao, Dongfa; Liu, Da; Wang, Cairu; Zhou, Jingsong; Pan, Xianming, E-mail: xianmingpanxj@163.com

2016-09-09

MicroRNAs (miRNAs) play significant roles in multiple diseases by regulating the expression of their target genes. Type 2 diabetes mellitus (T2DM) is a chronic endocrine and metabolic disease with complex mechanisms. T2DM can result in diabetic osteoporosis (DO), which is characterized by bone loss, decreased bone mineral density and increased bone fractures. The promotion of osteogenic differentiation of osteoblasts is an effective way to treat osteoporosis. In the present study, high glucose (HG) and free fatty acids (FFA) were employed to mimic T2DM in MC3T3-E1 cells. To induce osteogenic differentiation, MC3T3-E1 cells were cultured in osteogenic medium. The results showed that osteogenic differentiation was significantly suppressed by HG and FFA. We found that miR-132 expression was significantly upregulated and much higher in HG-FFA–induced cells than other selected miRNAs, indicating that miR-132 might play an important role in DO. Furthermore, overexpression of miR-132 markedly inhibited the expression of key markers of osteogenic differentiation and alkaline phosphatase (ALP) activity. Reciprocally, inhibition of miR-132 restored osteogenic differentiation, even under treatment with HG-FFA. We also showed that Sirtuin 1 (Sirt1) was one of the target genes of miR-132, whose expression was controlled by miR-132. Ectopic expression of Sirt1 reversed the decrease in osteogenic differentiation caused by miR-132 and HG-FFA. These results demonstrated the direct role of miR-132 in suppressing osteogenic differentiation through downregulating Sirt1. Moreover, we demonstrated that peroxisome proliferator-activated receptor β/δ (PPARβ/δ) was a downstream molecule of Sirt1, and its knockout by PPARβ/δ siRNA significantly abolished the promotive effects of Sirt1 on osteogenic differentiation, indicating that Sirt1 functioned in a PPARβ/δ–dependent manner. Taken together, we provide crucial evidence that miR-132 plays a key role in regulating osteogenic

MiR-132 regulates osteogenic differentiation via downregulating Sirtuin1 in a peroxisome proliferator-activated receptor β/δ–dependent manner

International Nuclear Information System (INIS)

Gong, Kai; Qu, Bo; Liao, Dongfa; Liu, Da; Wang, Cairu; Zhou, Jingsong; Pan, Xianming

2016-01-01

MicroRNAs (miRNAs) play significant roles in multiple diseases by regulating the expression of their target genes. Type 2 diabetes mellitus (T2DM) is a chronic endocrine and metabolic disease with complex mechanisms. T2DM can result in diabetic osteoporosis (DO), which is characterized by bone loss, decreased bone mineral density and increased bone fractures. The promotion of osteogenic differentiation of osteoblasts is an effective way to treat osteoporosis. In the present study, high glucose (HG) and free fatty acids (FFA) were employed to mimic T2DM in MC3T3-E1 cells. To induce osteogenic differentiation, MC3T3-E1 cells were cultured in osteogenic medium. The results showed that osteogenic differentiation was significantly suppressed by HG and FFA. We found that miR-132 expression was significantly upregulated and much higher in HG-FFA–induced cells than other selected miRNAs, indicating that miR-132 might play an important role in DO. Furthermore, overexpression of miR-132 markedly inhibited the expression of key markers of osteogenic differentiation and alkaline phosphatase (ALP) activity. Reciprocally, inhibition of miR-132 restored osteogenic differentiation, even under treatment with HG-FFA. We also showed that Sirtuin 1 (Sirt1) was one of the target genes of miR-132, whose expression was controlled by miR-132. Ectopic expression of Sirt1 reversed the decrease in osteogenic differentiation caused by miR-132 and HG-FFA. These results demonstrated the direct role of miR-132 in suppressing osteogenic differentiation through downregulating Sirt1. Moreover, we demonstrated that peroxisome proliferator-activated receptor β/δ (PPARβ/δ) was a downstream molecule of Sirt1, and its knockout by PPARβ/δ siRNA significantly abolished the promotive effects of Sirt1 on osteogenic differentiation, indicating that Sirt1 functioned in a PPARβ/δ–dependent manner. Taken together, we provide crucial evidence that miR-132 plays a key role in regulating osteogenic

NFIX Regulates Neural Progenitor Cell Differentiation During Hippocampal Morphogenesis

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Heng, Yee Hsieh Evelyn; McLeay, Robert C.; Harvey, Tracey J.; Smith, Aaron G.; Barry, Guy; Cato, Kathleen; Plachez, Céline; Little, Erica; Mason, Sharon; Dixon, Chantelle; Gronostajski, Richard M.; Bailey, Timothy L.; Richards, Linda J.; Piper, Michael

2014-01-01

Neural progenitor cells have the ability to give rise to neurons and glia in the embryonic, postnatal and adult brain. During development, the program regulating whether these cells divide and self-renew or exit the cell cycle and differentiate is tightly controlled, and imbalances to the normal trajectory of this process can lead to severe functional consequences. However, our understanding of the molecular regulation of these fundamental events remains limited. Moreover, processes underpinning development of the postnatal neurogenic niches within the cortex remain poorly defined. Here, we demonstrate that Nuclear factor one X (NFIX) is expressed by neural progenitor cells within the embryonic hippocampus, and that progenitor cell differentiation is delayed within Nfix−/− mice. Moreover, we reveal that the morphology of the dentate gyrus in postnatal Nfix−/− mice is abnormal, with fewer subgranular zone neural progenitor cells being generated in the absence of this transcription factor. Mechanistically, we demonstrate that the progenitor cell maintenance factor Sry-related HMG box 9 (SOX9) is upregulated in the hippocampus of Nfix−/− mice and demonstrate that NFIX can repress Sox9 promoter-driven transcription. Collectively, our findings demonstrate that NFIX plays a central role in hippocampal morphogenesis, regulating the formation of neuronal and glial populations within this structure. PMID:23042739

The hippo pathway promotes Notch signaling in regulation of cell differentiation, proliferation, and oocyte polarity.

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Jianzhong Yu

2008-03-01

Full Text Available Specification of the anterior-posterior axis in Drosophila oocytes requires proper communication between the germ-line cells and the somatically derived follicular epithelial cells. Multiple signaling pathways, including Notch, contribute to oocyte polarity formation by controlling the temporal and spatial pattern of follicle cell differentiation and proliferation. Here we show that the newly identified Hippo tumor-suppressor pathway plays a crucial role in the posterior follicle cells in the regulation of oocyte polarity. Disruption of the Hippo pathway, including major components Hippo, Salvador, and Warts, results in aberrant follicle-cell differentiation and proliferation and dramatic disruption of the oocyte anterior-posterior axis. These phenotypes are related to defective Notch signaling in follicle cells, because misexpression of a constitutively active form of Notch alleviates the oocyte polarity defects. We also find that follicle cells defective in Hippo signaling accumulate the Notch receptor and display defects in endocytosis markers. Our findings suggest that the interaction between Hippo and classic developmental pathways such as Notch is critical to spatial and temporal regulation of differentiation and proliferation and is essential for development of the body axes in Drosophila.

microRNAs as regulators of adipogenic differentiation of mesenchymal stem cells.

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Hamam, Dana; Ali, Dalia; Kassem, Moustapha; Aldahmash, Abdullah; Alajez, Nehad M

2015-02-15

microRNAs (miRNAs) constitute complex regulatory network, fine tuning the expression of a myriad of genes involved in different biological and physiological processes, including stem cell differentiation. Mesenchymal stem cells (MSCs) are multipotent stem cells present in the bone marrow stroma, and the stroma of many other tissues, and can give rise to a number of mesoderm-type cells including adipocytes and osteoblasts, which form medullary fat and bone tissues, respectively. The role of bone marrow fat in bone mass homeostasis is an area of intensive investigation with the aim of developing novel approaches for enhancing osteoblastic bone formation through inhibition of bone marrow fat formation. A number of recent studies have reported several miRNAs that enhance or inhibit adipogenic differentiation of MSCs and with potential use in microRNA-based therapy to regulate adipogenesis in the context of treating bone diseases and metabolic disorders. The current review focuses on miRNAs and their role in regulating adipogenic differentiation of MSCs.

Differential regulation of histamine- and bradykinin-stimulated phospholipase C in adrenal chromaffin cells: evidence for involvement of different protein kinase C isoforms.

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Sena, C M; Rosário, L M; Parker, P J; Patel, V; Boarder, M R

1996-03-01

In this report we investigate the isoforms of protein kinase C (PKC) present in cultured adrenal chromaffin cells with respect to their modulation by treatment with phorbol ester and their possible differential involvement in the regulation of responses to histamine and bradykinin. The presence of individual isoforms of PKC was investigated by using eight isoform specific antisera, as a result of which PKC-alpha, epsilon, and zeta were identified. To characterize down-regulation of these enzymes, cells were incubated for 6-48 h with 1 microM phorbol myristate acetate (PMA). PKC-epsilon down-regulated more rapidly than PKC-alpha. At 12 h, PMA pretreatment, for example, PKC-epsilon was maximally down-regulated (23 +/- 4% of controls), whereas PKC-alpha was unchanged. PKC-alpha showed partial down-regulation by 24 h of PMA pretreatment. PKC-zeta did not down-regulate at any of the times tested. Translocation from cytosol to membrane in response to PMA was also more rapid for PKC-epsilon than for PKC-alpha. The accumulation of total 3H-inositol (poly) phosphates in response to bradykinin or histamine was essentially abolished by prior treatment with 10-min PMA treatment (1 microM). However, with 12-h exposure to PMA, the bradykinin response was restored to the level seen with no prior PMA exposure. The histamine response showed no recovery by 12 h of PMA, but showed partial recovery by 24 h of PMA pretreatment. These observations showed that the restoration of the response to bradykinin corresponds to the loss of PKC-epsilon, whereas the restoration of the histamine response corresponds to the loss of PKC-alpha. This picture was confirmed with further studies on cytosolic Ca2+. The results show that chromaffin cells exhibit an unusual pattern of down-regulation of PKC isoforms on prolonged exposure to PMA, and that there is a differential effect of exposure to PMA on the histamine and bradykinin responses, suggesting that different PLC-linked receptors in chromafin

Mediator complex cooperatively regulates transcription of retinoic acid target genes with Polycomb Repressive Complex 2 during neuronal differentiation.

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Fukasawa, Rikiya; Iida, Satoshi; Tsutsui, Taiki; Hirose, Yutaka; Ohkuma, Yoshiaki

2015-11-01

The Mediator complex (Mediator) plays key roles in transcription and functions as the nexus for integration of various transcriptional signals. Previously, we screened for Mediator cyclin-dependent kinase (CDK)-interacting factors and identified three proteins related to chromatin regulation. One of them, SUZ12 is required for both stability and activity of Polycomb Repressive Complex 2 (PRC2). PRC2 primarily suppresses gene expression through histone H3 lysine 27 trimethylation, resulting in stem cell maintenance and differentiation; perturbation of this process leads to oncogenesis. Recent work showed that Mediator contributes to the embryonic stem cell state through DNA loop formation, which is strongly associated with chromatin architecture; however, it remains unclear how Mediator regulates gene expression in cooperation with chromatin regulators (i.e. writers, readers and remodelers). We found that Mediator CDKs interact directly with the PRC2 subunit EZH2, as well as SUZ12. Known PRC2 target genes were deregulated by Mediator CDK knockdown during neuronal differentiation, and both Mediator and PRC2 complexes co-occupied the promoters of developmental genes regulated by retinoic acid. Our results provide a mechanistic link between Mediator and PRC2 during neuronal differentiation. © The Authors 2015. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

Enteric neural crest cells regulate vertebrate stomach patterning and differentiation.

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Faure, Sandrine; McKey, Jennifer; Sagnol, Sébastien; de Santa Barbara, Pascal

2015-01-15

In vertebrates, the digestive tract develops from a uniform structure where reciprocal epithelial-mesenchymal interactions pattern this complex organ into regions with specific morphologies and functions. Concomitant with these early patterning events, the primitive GI tract is colonized by the vagal enteric neural crest cells (vENCCs), a population of cells that will give rise to the enteric nervous system (ENS), the intrinsic innervation of the GI tract. The influence of vENCCs on early patterning and differentiation of the GI tract has never been evaluated. In this study, we report that a crucial number of vENCCs is required for proper chick stomach development, patterning and differentiation. We show that reducing the number of vENCCs by performing vENCC ablations induces sustained activation of the BMP and Notch pathways in the stomach mesenchyme and impairs smooth muscle development. A reduction in vENCCs also leads to the transdifferentiation of the stomach into a stomach-intestinal mixed phenotype. In addition, sustained Notch signaling activity in the stomach mesenchyme phenocopies the defects observed in vENCC-ablated stomachs, indicating that inhibition of the Notch signaling pathway is essential for stomach patterning and differentiation. Finally, we report that a crucial number of vENCCs is also required for maintenance of stomach identity and differentiation through inhibition of the Notch signaling pathway. Altogether, our data reveal that, through the regulation of mesenchyme identity, vENCCs act as a new mediator in the mesenchymal-epithelial interactions that control stomach development. © 2015. Published by The Company of Biologists Ltd.

Gammaherpesvirus-driven plasma cell differentiation regulates virus reactivation from latently infected B lymphocytes.

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Xiaozhen Liang

2009-11-01

Full Text Available Gammaherpesviruses chronically infect their host and are tightly associated with the development of lymphoproliferative diseases and lymphomas, as well as several other types of cancer. Mechanisms involved in maintaining chronic gammaherpesvirus infections are poorly understood and, in particular, little is known about the mechanisms involved in controlling gammaherpesvirus reactivation from latently infected B cells in vivo. Recent evidence has linked plasma cell differentiation with reactivation of the human gammaherpesviruses EBV and KSHV through induction of the immediate-early viral transcriptional activators by the plasma cell-specific transcription factor XBP-1s. We now extend those findings to document a role for a gammaherpesvirus gene product in regulating plasma cell differentiation and thus virus reactivation. We have previously shown that the murine gammaherpesvirus 68 (MHV68 gene product M2 is dispensable for virus replication in permissive cells, but plays a critical role in virus reactivation from latently infected B cells. Here we show that in mice infected with wild type MHV68, virus infected plasma cells (ca. 8% of virus infected splenocytes at the peak of viral latency account for the majority of reactivation observed upon explant of splenocytes. In contrast, there is an absence of virus infected plasma cells at the peak of latency in mice infected with a M2 null MHV68. Furthermore, we show that the M2 protein can drive plasma cell differentiation in a B lymphoma cell line in the absence of any other MHV68 gene products. Thus, the role of M2 in MHV68 reactivation can be attributed to its ability to manipulate plasma cell differentiation, providing a novel viral strategy to regulate gammaherpesvirus reactivation from latently infected B cells. We postulate that M2 represents a new class of herpesvirus gene products (reactivation conditioners that do not directly participate in virus replication, but rather facilitate virus

Gammaherpesvirus-driven plasma cell differentiation regulates virus reactivation from latently infected B lymphocytes.

Science.gov (United States)

Liang, Xiaozhen; Collins, Christopher M; Mendel, Justin B; Iwakoshi, Neal N; Speck, Samuel H

2009-11-01

Gammaherpesviruses chronically infect their host and are tightly associated with the development of lymphoproliferative diseases and lymphomas, as well as several other types of cancer. Mechanisms involved in maintaining chronic gammaherpesvirus infections are poorly understood and, in particular, little is known about the mechanisms involved in controlling gammaherpesvirus reactivation from latently infected B cells in vivo. Recent evidence has linked plasma cell differentiation with reactivation of the human gammaherpesviruses EBV and KSHV through induction of the immediate-early viral transcriptional activators by the plasma cell-specific transcription factor XBP-1s. We now extend those findings to document a role for a gammaherpesvirus gene product in regulating plasma cell differentiation and thus virus reactivation. We have previously shown that the murine gammaherpesvirus 68 (MHV68) gene product M2 is dispensable for virus replication in permissive cells, but plays a critical role in virus reactivation from latently infected B cells. Here we show that in mice infected with wild type MHV68, virus infected plasma cells (ca. 8% of virus infected splenocytes at the peak of viral latency) account for the majority of reactivation observed upon explant of splenocytes. In contrast, there is an absence of virus infected plasma cells at the peak of latency in mice infected with a M2 null MHV68. Furthermore, we show that the M2 protein can drive plasma cell differentiation in a B lymphoma cell line in the absence of any other MHV68 gene products. Thus, the role of M2 in MHV68 reactivation can be attributed to its ability to manipulate plasma cell differentiation, providing a novel viral strategy to regulate gammaherpesvirus reactivation from latently infected B cells. We postulate that M2 represents a new class of herpesvirus gene products (reactivation conditioners) that do not directly participate in virus replication, but rather facilitate virus reactivation by

Yeast three-hybrid screen identifies TgBRADIN/GRA24 as a negative regulator of Toxoplasma gondii bradyzoite differentiation.

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Anahi V Odell

Full Text Available Differentiation of the protozoan parasite Toxoplasma gondii into its latent bradyzoite stage is a key event in the parasite's life cycle. Compound 2 is an imidazopyridine that was previously shown to inhibit the parasite lytic cycle, in part through inhibition of parasite cGMP-dependent protein kinase. We show here that Compound 2 can also enhance parasite differentiation, and we use yeast three-hybrid analysis to identify TgBRADIN/GRA24 as a parasite protein that interacts directly or indirectly with the compound. Disruption of the TgBRADIN/GRA24 gene leads to enhanced differentiation of the parasite, and the TgBRADIN/GRA24 knockout parasites show decreased susceptibility to the differentiation-enhancing effects of Compound 2. This study represents the first use of yeast three-hybrid analysis to study small-molecule mechanism of action in any pathogenic microorganism, and it identifies a previously unrecognized inhibitor of differentiation in T. gondii. A better understanding of the proteins and mechanisms regulating T. gondii differentiation will enable new approaches to preventing the establishment of chronic infection in this important human pathogen.

The transition from proliferation to differentiation in colorectal cancer is regulated by the calcium activated chloride channel A1.

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Bo Yang

Full Text Available Breaking the balance between proliferation and differentiation in animal cells can lead to cancer, but the mechanisms maintaining this balance remain largely undefined. The calcium activated chloride channel A1 (CLCA1 is a member of the calcium sensitive chloride conductance family of proteins and is expressed mainly in the colon, small intestine and appendix. We show that CLCA1 plays a functional role in differentiation and proliferation of Caco-2 cells and of intestinal tissue. Caco-2 cells spontaneously differentiate either in confluent culture or when treated with butyrate, a molecule present naturally in the diet. Here, we compared CLCA1 expressional levels between patients with and without colorectal cancer (CRC and determined the functional role of CLCA1 in differentiation and proliferation of Caco-2 cells. We showed that: 1 CLCA1 and CLCA4 expression were down-regulated significantly in CRC patients; 2 CLCA1 expression was up-regulated in Caco-2 cells induced to differentiate by confluent culture or by treatment with sodium butyrate (NaBT; 3 Knockdown of CLCA1 with siRNA significantly inhibited cell differentiation and promoted cell proliferation in Caco-2 confluent cultures, and 4 In Caco-2 3D culture, suppression of CLCA1 significantly increased cell proliferation and compromised NaBT-induced inhibition of proliferation. In conclusion, CLCA1 may contribute to promoting spontaneous differentiation and reducing proliferation of Caco-2 cells and may be a target of NaBT-induced inhibition of proliferation and therefore a potential diagnostic marker for CRC prognosis.

Gαq Regulates the Development of Rheumatoid Arthritis by Modulating Th1 Differentiation.

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Wang, Dashan; Liu, Yuan; Li, Yan; He, Yan; Zhang, Jiyun; Shi, Guixiu

2017-01-01

The G α q-containing G protein, an important member of G q/11 class, is ubiquitously expressed in mammalian cells. G α q has been found to play an important role in immune regulation and development of autoimmune disease such as rheumatoid arthritis (RA). However, how G α q participates in the pathogenesis of RA is still not fully understood. In the present study, we aimed to find out whether G α q controls RA via regulation of Th1 differentiation. We observed that the expression of G α q was negatively correlated with the expression of signature Th1 cytokine (IFN- γ ) in RA patients, which suggests a negative role of G α q in differentiation of Th1 cells. By using G α q knockout ( Gnaq-/- ) mice, we demonstrated that loss of G α q led to enhanced Th1 cell differentiation. G α q negative regulated the differentiation of Th1 cell by modulating the expression of T-bet and the activity of STAT4. Furthermore, we detected the increased ratio of Th1 cells in Gnaq-/- bone marrow (BM) chimeras spontaneously developing inflammatory arthritis. In conclusion, results presented in the study demonstrate that loss of G α q promotes the differentiation of Th1 cells and contributes to the pathogenesis of RA.

Calcium imaging shows differential sensitivity to cooling and communication in luminous transgenic plants.

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Campbell, A K; Trewavas, A J; Knight, M R

1996-03-01

Imaging of a recombinant bioluminescent Ca2+ indicator, aequorin, in an entire organism showed three novel features of Ca2+ signals in plants. First, cooling the plant from 25 degrees C to 2 degrees C demonstrated differential sensitivities between organs, the roots firing a Ca2+ signal at some 8-10 degrees C higher than the cotyledons. Secondly, prolonged cooling provoked Ca2+ oscillations, but only in the cotyledons. These oscillations occurred with a frequency of 100 s and damped down within 800 s. Thirdly, cooling the roots of mature plants triggered a Ca2+ signal in the leaves, as a result of organ-organ communication. However, warming and then recooling the roots did not generate a second Ca2+ signal in these leaves. This desensitisation was not due to down-regulation in the leaf since this was able to generate a Ca2+ signal of its own when cooled directly. Thus a combination of a recombinant bioluminescent indicator with photon counting imaging reveals startling new aspects of signalling in intact organs and whole organisms.

Hyperthyroidism differentially regulates neuropeptide S system in the rat brain.

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González, Carmen R; Martínez de Morentin, Pablo B; Martínez-Sánchez, Noelia; Gómez-Díaz, Consuelo; Lage, Ricardo; Varela, Luis; Diéguez, Carlos; Nogueiras, Rubén; Castaño, Justo P; López, Miguel

2012-04-23

Thyroid hormones play an important role in the regulation of energy balance, sleep and emotional behaviors. Neuropeptide S (NPS) is a recently discovered neuropeptide, regulating feeding, sleep and anxiety. Here, we examined the effect of hyperthyroidism on the gene and protein expression of neuropeptide S and its receptor (NPS-R) in the hypothalamus, brainstem and amygdala of rats. Our results showed that the expression of NPS and NPS-R was differentially modulated by hyperthyroidism in the rat brain. NPS and NPS-R mRNA and protein levels were decreased in the hypothalamus of hyperthyroid rats. Conversely NPS-R expression was highly increased in the brainstem and NPS and NPS-R expression were unchanged in the amygdala of these rats. These data suggest that changes in anxiety and food intake patterns observed in hyperthyroidism could be associated with changes in the expression of NPS and NPS-R. Thus, the NPS/NPS-R system may be involved in several hyperthyroidism-associated comorbidities. Copyright © 2012 Elsevier B.V. All rights reserved.

Substrate stiffness and oxygen as regulators of stem cell differentiation during skeletal tissue regeneration: a mechanobiological model.

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Darren Paul Burke

Full Text Available Extrinsic mechanical signals have been implicated as key regulators of mesenchymal stem cell (MSC differentiation. It has been possible to test different hypotheses for mechano-regulated MSC differentiation by attempting to simulate regenerative events such as bone fracture repair, where repeatable spatial and temporal patterns of tissue differentiation occur. More recently, in vitro studies have identified other environmental cues such as substrate stiffness and oxygen tension as key regulators of MSC differentiation; however it remains unclear if and how such cues determine stem cell fate in vivo. As part of this study, a computational model was developed to test the hypothesis that substrate stiffness and oxygen tension regulate stem cell differentiation during fracture healing. Rather than assuming mechanical signals act directly on stem cells to determine their differentiation pathway, it is postulated that they act indirectly to regulate angiogenesis and hence partially determine the local oxygen environment within a regenerating tissue. Chondrogenesis of MSCs was hypothesized to occur in low oxygen regions, while in well vascularised regions of the regenerating tissue a soft local substrate was hypothesised to facilitate adipogenesis while a stiff substrate facilitated osteogenesis. Predictions from the model were compared to both experimental data and to predictions of a well established computational mechanobiological model where tissue differentiation is assumed to be regulated directly by the local mechanical environment. The model predicted all the major events of fracture repair, including cartilaginous bridging, endosteal and periosteal bony bridging and bone remodelling. It therefore provides support for the hypothesis that substrate stiffness and oxygen play a key role in regulating MSC fate during regenerative events such as fracture healing.

The transcription factor Th-POK negatively regulates Th17 differentiation in Vα14i NKT cells

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Engel, Isaac; Zhao, Meng; Kappes, Dietmar; Taniuchi, Ichiro

2012-01-01

The majority of mouse Vα14 invariant natural killer T (Vα14i NKT) cells produce several cytokines, including IFNγ and IL-4, very rapidly after activation. A subset of these cells, known as NKT17 cells, however, differentiates in the thymus to preferentially produce IL-17. Here, we show that the transcription factor—known as T helper, Poxviruses, and Zinc-finger and Krüppel family, (Th-POK)—represses the formation of NKT17 cells. Vα14i NKT cells from Th-POK–mutant helper deficient (hd/hd) mice have increased transcripts of genes normally expressed by Th17 and NKT17 cells, and even heterozygosity for this mutation leads to dramatically increased numbers of Vα14i NKT cells that are poised to express IL-17, especially in the thymus and lymph nodes. In addition, using gene reporter mice, we demonstrate that NKT17 cells from wild-type mice express lower amounts of Th-POK than the majority population of Vα14i NKT cells. We also show that retroviral transduction of Th-POK represses the expression of the Th17 master regulator RORγT in Vα14i NKT-cell lines. Our data suggest that NKT17-cell differentiation is intrinsically regulated by Th-POK activity, with only low levels of Th-POK permissive for the differentiation of NKT17 cells. PMID:23034280

Characterization of a type-A response regulator differentially expressed during adventitious caulogenesis in Pinus pinaster.

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Alvarez, José M; Cortizo, Millán; Ordás, Ricardo J

2012-12-15

The molecular cloning and characterization of PipsRR1, a type-A response regulator in Pinus pinaster, is reported here. Type-A response regulators mediate downstream responses to cytokinin and act as negative feedback regulators of the signal transduction pathway. Some type-A response regulators in Arabidopsis have been related to de novo meristem formation. However, little information exists in Pinus spp. The PipsRR1 gene contains 5 exons, as do all type-A response regulators in Arabidopsis, and the deduced protein contains a receiver domain with the conserved DDK residues and a short C terminal extension. Expression analysis showed that the PipsRR1 gene is differentially expressed during the first phases of adventitious caulogenesis induced by benzyladenine in P. pinaster cotyledons, suggesting that PipsRR1 plays a role in caulogenesis in conifers. Additionally, a binary vector carrying the PipsRR1 promoter driving GFP:GUS expression was constructed to analyze the promoter activity in P. pinaster somatic embryos. The results of genetic transformation showed GUS activity during somatic embryo mass proliferation and embryo maturation. Copyright © 2012 Elsevier GmbH. All rights reserved.

Differential expression of genes regulated in response to drought stress in diploid cotton (Gossypium arboreum) (abstract)

International Nuclear Information System (INIS)

Hussain, T.; Majeed, A.; Maqbool, A.; Hussain, S.S.; Ali, T.; Riazuddin, S.

2005-01-01

Negative effects on the Water status of plants is one of the most common and deleterious stresses experienced by wild and cultivated plants throughout the World. Our project is designed to identify, clone and characterize gene sequences regulated in response to Water stress (e.g., drought). We used the differential-display reverse transcriptase polymerase chain reaction (DD-RT- PCA) methodology to accomplish our Objectives. Structural and functional characterization of environmental stress-induced genes has contributed to a better understanding of how plants respond and adapt to different abiotic stresses. Differential display was used to compare overall difference in gene expression between draught stressed and unstressed (control) plants of diploid Cotton (Gossypium arboreum). DDRT-PCR product from stressed and unstressed samples resolved side by side on 6% PAGE to compare qualitative and quantitative difference in mRNA expression. A total of 81 primer combinations were tested. DDRT -PCR enabled us to identify differentially expressed transcripts between water stressed and non-stressed cotton seedlings. PAGE revealed a total of 347 DNA transcripts in stressed samples (New Transcripts) while 110 down regulated and 209 up regulated DNA transcripts were also recorded. Similarly. 22 DNA transcripts were identified based on the comparative study of PAGE and Agarose gel electrophoresis. These sequences showed various degree homology With draught tolerant genes in the gene bank. (author)

Tissue-Specific 5′ Heterogeneity of PPARα Transcripts and Their Differential Regulation by Leptin

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Garratt, Emma S.; Vickers, Mark H.; Gluckman, Peter D.; Hanson, Mark A.

2013-01-01

The genes encoding nuclear receptors comprise multiple 5′untranslated exons, which give rise to several transcripts encoding the same protein, allowing tissue-specific regulation of expression. Both human and mouse peroxisome proliferator activated receptor (PPAR) α genes have multiple promoters, although their function is unknown. Here we have characterised the rat PPARα promoter region and have identified three alternative PPARα transcripts, which have different transcription start sites owing to the utilisation of distinct first exons. Moreover these alternative PPARα transcripts were differentially expressed between adipose tissue and liver. We show that while the major adipose (P1) and liver (P2) transcripts were both induced by dexamethasone, they were differentially regulated by the PPARα agonist, clofibric acid, and leptin. Leptin had no effect on the adipose-specific P1 transcript, but induced liver-specific P2 promoter activity via a STAT3/Sp1 mechanism. Moreover in Wistar rats, leptin treatment between postnatal day 3–13 led to an increase in P2 but not P1 transcription in adipose tissue which was sustained into adulthood. This suggests that the expression of the alternative PPARα transcripts are in part programmed by early life exposure to leptin leading to persistent change in adipose tissue fatty acid metabolism through specific activation of a quiescent PPARα promoter. Such complexity in the regulation of PPARα may allow the expression of PPARα to be finely regulated in response to environmental factors. PMID:23825665

miR-342-5p Regulates Neural Stem Cell Proliferation and Differentiation Downstream to Notch Signaling in Mice

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Fang Gao

2017-04-01

Full Text Available Summary: Notch signaling is critically involved in neural development, but the downstream effectors remain incompletely understood. In this study, we cultured neurospheres from Nestin-Cre-mediated conditional Rbp-j knockout (Rbp-j cKO and control embryos and compared their miRNA expression profiles using microarray. Among differentially expressed miRNAs, miR-342-5p showed upregulated expression as Notch signaling was genetically or pharmaceutically interrupted. Consistently, the promoter of the miR-342-5p host gene, the Ena-vasodilator stimulated phosphoprotein-like (Evl, was negatively regulated by Notch signaling, probably through HES5. Transfection of miR-342-5p promoted the differentiation of neural stem cells (NSCs into intermediate neural progenitors (INPs in vitro and reduced the stemness of NSCs in vivo. Furthermore, miR-342-5p inhibited the differentiation of neural stem/intermediate progenitor cells into astrocytes, likely mediated by targeting GFAP directly. Our results indicated that miR-342-5p could function as a downstream effector of Notch signaling to regulate the differentiation of NSCs into INPs and astrocytes commitment. : In this article, Han and colleagues show that miR-342-5p acts as a downstream effector of Notch signaling in the mouse CNS. Notch signal inhibits miR-342-5p expression by regulating its host gene Evl. And with attenuated Notch signal in NSCs, miR-342-5p is upregulated to promote NSCs transition into INPs, and to inhibit astrocyte commitment by targeting GFAP. Keywords: neural stem cells, intermediate neural progenitors, Notch, RBP-J, neuron, glia, miR-342-5p

Differential trypanosome surface coat regulation by a CCCH protein that co-associates with procyclin mRNA cis-elements.

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Pegine Walrad

2009-02-01

Full Text Available The genome of Trypanosoma brucei is unusual in being regulated almost entirely at the post-transcriptional level. In terms of regulation, the best-studied genes are procyclins, which encode a family of major surface GPI-anchored glycoproteins (EP1, EP2, EP3, GPEET that show differential expression in the parasite's tsetse-fly vector. Although procyclin mRNA cis-regulatory sequences have provided the paradigm for post-transcriptional control in kinetoplastid parasites, trans-acting regulators of procyclin mRNAs are unidentified, despite intensive effort over 15 years. Here we identify the developmental regulator, TbZFP3, a CCCH-class predicted RNA binding protein, as an isoform-specific regulator of Procyclin surface coat expression in trypanosomes. We demonstrate (i that endogenous TbZFP3 shows sequence-specific co-precipitation of EP1 and GPEET, but not EP2 and EP3, procyclin mRNA isoforms, (ii that ectopic overexpression of TbZFP3 does not perturb the mRNA abundance of procyclin transcripts, but rather that (iii their protein expression is regulated in an isoform-specific manner, as evidenced by mass spectrometric analysis of the Procyclin expression signature in the transgenic cell lines. The TbZFP3 mRNA-protein complex (TbZFP3mRNP is identified as a trans-regulator of differential surface protein expression in trypanosomes. Moreover, its sequence-specific interactions with procyclin mRNAs are compatible with long-established predictions for Procyclin regulation. Combined with the known association of TbZFP3 with the translational apparatus, this study provides a long-sought missing link between surface protein cis-regulatory signals and the gene expression machinery in trypanosomes.

4E-BP1 regulates the differentiation of white adipose tissue.

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Tsukiyama-Kohara, Kyoko; Katsume, Asao; Kimura, Kazuhiro; Saito, Masayuki; Kohara, Michinori

2013-07-01

4E Binding protein 1 (4E-BP1) suppresses translation initiation. The absence of 4E-BP1 drastically reduces the amount of adipose tissue in mice. To address the role of 4E-BP1 in adipocyte differentiation, we characterized 4E-BP1(-/-) mice in this study. The lack of 4E-BP1 decreased the amount of white adipose tissue and increased the amount of brown adipose tissue. In 4E-BP1(-/-) MEF cells, PPARγ coactivator 1 alpha (PGC-1α) expression increased and exogenous 4E-BP1 expression suppressed PGC-1α expression. The level of 4E-BP1 expression was higher in white adipocytes than in brown adipocytes and showed significantly greater up-regulation in white adipocytes than in brown adipocytes during preadipocyte differentiation into mature adipocytes. The amount of PGC-1α was consistently higher in HB cells (a brown preadipocyte cell line) than in HW cells (a white preadipocyte cell line) during differentiation. Moreover, the ectopic over-expression of 4E-BP1 suppressed PGC-1α expression in white adipocytes, but not in brown adipocytes. Thus, the results of our study indicate that 4E-BP1 may suppress brown adipocyte differentiation and PGC-1α expression in white adipose tissues. © 2013 The Authors Genes to Cells © 2013 by the Molecular Biology Society of Japan and Wiley Publishing Asia Pty Ltd.

Tissue transglutaminase (TG2 activity regulates osteoblast differentiation and mineralization in the SAOS-2 cell line

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Xiaoxue Yin

2012-08-01

Full Text Available Tissue transglutaminase (type II, TG2 has long been postulated to directly promote skeletal matrix calcification and play an important role in ossification. However, limited information is available on the expression, function and modulating mechanism of TG2 during osteoblast differentiation and mineralization. To address these issues, we cultured the well-established human osteosarcoma cell line SAOS-2 with osteo-inductive conditioned medium and set up three time points (culture days 4, 7, and 14 to represent different stages of SAOS-2 differentiation. Osteoblast markers, mineralization, as well as TG2 expression and activity, were then assayed in each stage. Furthermore, we inhibited TG activity with cystamine and then checked SAOS-2 differentiation and mineralization in each stage. The results showed that during the progression of osteoblast differentiation SAOS-2 cells presented significantly high levels of osteocalcin (OC mRNA, bone morphogenetic protein-2 (BMP-2 and collagen I, significantly high alkaline phosphatase (ALP activity, and the increased formation of calcified matrix. With the same tendency, TG2 expression and activity were up-regulated. Furthermore, inhibition of TG activity resulted in a significant decrease of OC, collagen I, and BMP-2 mRNA and of ALP activity and mineralization. This study demonstrated that TG2 is involved in osteoblast differentiation and may play a role in the initiation and regulation of the mineralization processes. Moreover, the modulating effects of TG2 on osteoblasts may be related to BMP-2.

Nicotine induces cell proliferation in association with cyclin D1 up-regulation and inhibits cell differentiation in association with p53 regulation in a murine pre-osteoblastic cell line

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Sato, Tsuyoshi; Abe, Takahiro; Nakamoto, Norimichi; Tomaru, Yasuhisa; Koshikiya, Noboru; Nojima, Junya; Kokabu, Shoichiro; Sakata, Yasuaki; Kobayashi, Akio; Yoda, Tetsuya

2008-01-01

Recent studies have suggested that nicotine critically affects bone metabolism. Many studies have examined the effects of nicotine on proliferation and differentiation, but the underlying molecular mechanisms remain unclear. We examined cell cycle regulators involved in the proliferation and differentiation of MC3T3-E1 cells. Nicotine induced cell proliferation in association with p53 down-regulation and cyclin D1 up-regulation. In differentiated cells, nicotine reduced alkaline phosphatase activity and mineralized nodule formation in dose-dependent manners. Furthermore, p53 expression was sustained in nicotine-treated cells during differentiation. These findings indicate that nicotine promotes the cell cycle and inhibits differentiation in association with p53 regulation in pre-osteoblastic cells

YB1/p32, a nuclear Y-box binding protein 1, is a novel regulator of myoblast differentiation that interacts with Msx1 homeoprotein

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Song, Young Joon [Department of Biological Sciences, College of Natural Science, Inha University, 253 Yonghyun-dong, Nam-Gu, Incheon, Korea, 402-751 (Korea, Republic of); Lee, Hansol, E-mail: hlee@inha.ac.kr [Department of Biological Sciences, College of Natural Science, Inha University, 253 Yonghyun-dong, Nam-Gu, Incheon, Korea, 402-751 (Korea, Republic of)

2010-02-15

Precisely controlled cellular differentiation is essential for the proper development of vertebrate embryo and deregulated differentiation is a major cause of many human congenital diseases as well as cancer. Msx1 is a member of the homeoprotein family implicated in these processes, which inhibits the differentiation of skeletal muscle and other cell types, presumably by regulating transcription of target genes through interaction with other cellular factors. We presently show that YB1/p32, a nuclear Y-box binding protein 1, interacts with Msx1 homeoprotein and functions as a regulator of C2C12 myoblast differentiation. We demonstrate that YB1/p32 functionally interacts with Msx1 through its N-terminal region and colocalizes with Msx1 at the nuclear periphery. Moreover, we find that YB1/p32 is competent for inhibition of C2C12 myoblast differentiation, which is correlated with its activity as a negative regulator of MyoD gene expression and binding to the MyoD core enhancer region (CER). Furthermore, YB1/p32 cooperates with Msx1 in transcriptional repression and knocking down the expression of endogenous YB1 attenuates the effects of Msx1. Taken together, our study has uncovered a new function of YB1/p32, a regulator of skeletal muscle differentiation.

YB1/p32, a nuclear Y-box binding protein 1, is a novel regulator of myoblast differentiation that interacts with Msx1 homeoprotein

International Nuclear Information System (INIS)

Song, Young Joon; Lee, Hansol

2010-01-01

Precisely controlled cellular differentiation is essential for the proper development of vertebrate embryo and deregulated differentiation is a major cause of many human congenital diseases as well as cancer. Msx1 is a member of the homeoprotein family implicated in these processes, which inhibits the differentiation of skeletal muscle and other cell types, presumably by regulating transcription of target genes through interaction with other cellular factors. We presently show that YB1/p32, a nuclear Y-box binding protein 1, interacts with Msx1 homeoprotein and functions as a regulator of C2C12 myoblast differentiation. We demonstrate that YB1/p32 functionally interacts with Msx1 through its N-terminal region and colocalizes with Msx1 at the nuclear periphery. Moreover, we find that YB1/p32 is competent for inhibition of C2C12 myoblast differentiation, which is correlated with its activity as a negative regulator of MyoD gene expression and binding to the MyoD core enhancer region (CER). Furthermore, YB1/p32 cooperates with Msx1 in transcriptional repression and knocking down the expression of endogenous YB1 attenuates the effects of Msx1. Taken together, our study has uncovered a new function of YB1/p32, a regulator of skeletal muscle differentiation.

Protein Kinase A Regulatory Subunit Isoforms Regulate Growth and Differentiation in Mucor circinelloides: Essential Role of PKAR4

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Ocampo, J.; McCormack, B.; Navarro, E.; Moreno, S.; Garre, V.

2012-01-01

The protein kinase A (PKA) signaling pathway plays a role in regulating growth and differentiation in the dimorphic fungus Mucor circinelloides. PKA holoenzyme is comprised of two catalytic (C) and two regulatory (R) subunits. In M. circinelloides, four genes encode the PKAR1, PKAR2, PKAR3, and PKAR4 isoforms of R subunits. We have constructed null mutants and demonstrate that each isoform has a different role in growth and differentiation. The most striking finding is that pkaR4 is an essential gene, because only heterokaryons were obtained in knockout experiments. Heterokaryons with low levels of wild-type nuclei showed an impediment in the emission of the germ tube, suggesting a pivotal role of this gene in germ tube emergence. The remaining null strains showed different alterations in germ tube emergence, sporulation, and volume of the mother cell. The pkaR2 null mutant showed an accelerated germ tube emission and was the only mutant that germinated under anaerobic conditions when glycine was used as a nitrogen source, suggesting that pkaR2 participates in germ tube emergence by repressing it. From the measurement of the mRNA and protein levels of each isoform in the wild-type and knockout strains, it can be concluded that the expression of each subunit has its own mechanism of differential regulation. The PKAR1 and PKAR2 isoforms are posttranslationally modified by ubiquitylation, suggesting another regulation point in the specificity of the signal transduction. The results indicate that each R isoform has a different role in M. circinelloides physiology, controlling the dimorphism and contributing to the specificity of cyclic AMP (cAMP)-PKA pathway. PMID:22635921

Transcription factor KLF7 regulates differentiation of neuroectodermal and mesodermal cell lineages

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Caiazzo, Massimiliano; Colucci-D'Amato, Luca; Esposito, Maria T.; Parisi, Silvia; Stifani, Stefano; Ramirez, Francesco; Porzio, Umberto di

2010-01-01

Previous gene targeting studies in mice have implicated the nuclear protein Krueppel-like factor 7 (KLF7) in nervous system development while cell culture assays have documented its involvement in cell cycle regulation. By employing short hairpin RNA (shRNA)-mediated gene silencing, here we demonstrate that murine Klf7 gene expression is required for in vitro differentiation of neuroectodermal and mesodermal cells. Specifically, we show a correlation of Klf7 silencing with down-regulation of the neuronal marker microtubule-associated protein 2 (Map2) and the nerve growth factor (NGF) tyrosine kinase receptor A (TrkA) using the PC12 neuronal cell line. Similarly, KLF7 inactivation in Klf7-null mice decreases the expression of the neurogenic marker brain lipid-binding protein/fatty acid-binding protein 7 (BLBP/FABP7) in neural stem cells (NSCs). We also report that Klf7 silencing is detrimental to neuronal and cardiomyocytic differentiation of embryonic stem cells (ESCs), in addition to altering the adipogenic and osteogenic potential of mouse embryonic fibroblasts (MEFs). Finally, our results suggest that genes that are key for self-renewal of undifferentiated ESCs repress Klf7 expression in ESCs. Together with previous findings, these results provide evidence that KLF7 has a broad spectrum of regulatory functions, which reflect the discrete cellular and molecular contexts in which this transcription factor operates.

Transcription factor KLF7 regulates differentiation of neuroectodermal and mesodermal cell lineages

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Caiazzo, Massimiliano, E-mail: caiazzo@igb.cnr.it [Institute of Genetics and Biophysics ' A. Buzzati-Traverso,' CNR, 80131 Naples (Italy); Istituto di diagnosi e cura ' Hermitage Capodimonte,' 80131 Naples (Italy); Colucci-D' Amato, Luca, E-mail: luca.colucci@unina2.it [Institute of Genetics and Biophysics ' A. Buzzati-Traverso,' CNR, 80131 Naples (Italy); Dipartimento di Scienze della Vita, Seconda Universita di Napoli, 81100 Caserta (Italy); Esposito, Maria T., E-mail: maria_teresa.esposito@kcl.ac.uk [CEINGE Biotecnologie Avanzate, 80145 Naples (Italy); Parisi, Silvia, E-mail: parisi@ceinge.unina.it [CEINGE Biotecnologie Avanzate, 80145 Naples (Italy); Stifani, Stefano, E-mail: stefano.stifani@mcgill.ca [Centre for Neuronal Survival, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada H3A 2B4 (Canada); Ramirez, Francesco, E-mail: francesco.ramirez@mssm.edu [Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, NY 10029 (United States); Porzio, Umberto di, E-mail: diporzio@igb.cnr.it [Institute of Genetics and Biophysics ' A. Buzzati-Traverso,' CNR, 80131 Naples (Italy)

2010-08-15

Previous gene targeting studies in mice have implicated the nuclear protein Krueppel-like factor 7 (KLF7) in nervous system development while cell culture assays have documented its involvement in cell cycle regulation. By employing short hairpin RNA (shRNA)-mediated gene silencing, here we demonstrate that murine Klf7 gene expression is required for in vitro differentiation of neuroectodermal and mesodermal cells. Specifically, we show a correlation of Klf7 silencing with down-regulation of the neuronal marker microtubule-associated protein 2 (Map2) and the nerve growth factor (NGF) tyrosine kinase receptor A (TrkA) using the PC12 neuronal cell line. Similarly, KLF7 inactivation in Klf7-null mice decreases the expression of the neurogenic marker brain lipid-binding protein/fatty acid-binding protein 7 (BLBP/FABP7) in neural stem cells (NSCs). We also report that Klf7 silencing is detrimental to neuronal and cardiomyocytic differentiation of embryonic stem cells (ESCs), in addition to altering the adipogenic and osteogenic potential of mouse embryonic fibroblasts (MEFs). Finally, our results suggest that genes that are key for self-renewal of undifferentiated ESCs repress Klf7 expression in ESCs. Together with previous findings, these results provide evidence that KLF7 has a broad spectrum of regulatory functions, which reflect the discrete cellular and molecular contexts in which this transcription factor operates.

Prion protein expression regulates embryonic stem cell pluripotency and differentiation.

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Alberto Miranda

2011-04-01

Full Text Available Cellular prion protein (PRNP is a glycoprotein involved in the pathogenesis of transmissible spongiform encephalopathies (TSEs. Although the physiological function of PRNP is largely unknown, its key role in prion infection has been extensively documented. This study examines the functionality of PRNP during the course of embryoid body (EB differentiation in mouse Prnp-null (KO and WT embryonic stem cell (ESC lines. The first feature observed was a new population of EBs that only appeared in the KO line after 5 days of differentiation. These EBs were characterized by their expression of several primordial germ cell (PGC markers until Day 13. In a comparative mRNA expression analysis of genes playing an important developmental role during ESC differentiation to EBs, Prnp was found to participate in the transcription of a key pluripotency marker such as Nanog. A clear switching off of this gene on Day 5 was observed in the KO line as opposed to the WT line, in which maximum Prnp and Nanog mRNA levels appeared at this time. Using a specific antibody against PRNP to block PRNP pathways, reduced Nanog expression was confirmed in the WT line. In addition, antibody-mediated inhibition of ITGB5 (integrin αvβ5 in the KO line rescued the low expression of Nanog on Day 5, suggesting the regulation of Nanog transcription by Prnp via this Itgb5. mRNA expression analysis of the PRNP-related proteins PRND (Doppel and SPRN (Shadoo, whose PRNP function is known to be redundant, revealed their incapacity to compensate for the absence of PRNP during early ESC differentiation. Our findings provide strong evidence for a relationship between Prnp and several key pluripotency genes and attribute Prnp a crucial role in regulating self-renewal/differentiation status of ESC, confirming the participation of PRNP during early embryogenesis.

Sox2 Promotes Malignancy in Glioblastoma by Regulating Plasticity and Astrocytic Differentiation

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Artem D. Berezovsky

2014-03-01

Full Text Available The high-mobility group–box transcription factor sex-determining region Y–box 2 (Sox2 is essential for the maintenance of stem cells from early development to adult tissues. Sox2 can reprogram differentiated cells into pluripotent cells in concert with other factors and is overexpressed in various cancers. In glioblastoma (GBM, Sox2 is a marker of cancer stemlike cells (CSCs in neurosphere cultures and is associated with the proneural molecular subtype. Here, we report that Sox2 expression pattern in GBM tumors and patient-derived mouse xenografts is not restricted to a small percentage of cells and is coexpressed with various lineage markers, suggesting that its expression extends beyond CSCs to encompass more differentiated neoplastic cells across molecular subtypes. Employing a CSC derived from a patient with GBM and isogenic differentiated cell model, we show that Sox2 knockdown in the differentiated state abolished dedifferentiation and acquisition of CSC phenotype. Furthermore, Sox2 deficiency specifically impaired the astrocytic component of a biphasic gliosarcoma xenograft model while allowing the formation of tumors with sarcomatous phenotype. The expression of genes associated with stem cells and malignancy were commonly downregulated in both CSCs and serum-differentiated cells on Sox2 knockdown. Genes previously shown to be associated with pluripontency and CSCs were only affected in the CSC state, whereas embryonic stem cell self-renewal genes and cytokine signaling were downregulated, and the Wnt pathway activated in differentiated Sox2-deficient cells. Our results indicate that Sox2 regulates the expression of key genes and pathways involved in GBM malignancy, in both cancer stemlike and differentiated cells, and maintains plasticity for bidirectional conversion between the two states, with significant clinical implications.

A novel crosstalk between Alk7 and cGMP signaling differentially regulates brown adipocyte function

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Aileen Balkow

2015-08-01

Conclusions: We found a so far unknown crosstalk between cGMP and Alk7 signaling pathways. Tight regulation of Alk7 is required for efficient differentiation of brown adipocytes. Alk7 has differential effects on adipogenic differentiation and the development of the thermogenic program in brown adipocytes.

Regulation of proliferation and differentiation of adipocyte precursor cells in rainbow trout (Oncorhynchus mykiss).

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Bouraoui, L; Gutiérrez, J; Navarro, I

2008-09-01

Here, we describe optimal conditions for the culture of rainbow trout (Oncorhynchus mykiss) pre-adipocytes obtained from adipose tissue and their differentiation into mature adipocytes, in order to study the endocrine control of adipogenesis. Pre-adipocytes were isolated by collagenase digestion and cultured on laminin or 1% gelatin substrate. The expression of proliferating cell nuclear antigen was used as a marker of cell proliferation on various days of culture. Insulin growth factor-I stimulated cell proliferation especially on days 5 and 7 of culture. Tumor necrosis factor alpha (TNFalpha) slightly enhanced cell proliferation only at a low dose. We verified the differentiation of cells grown in specific medium into mature adipocytes by oil red O (ORO) staining. Quantification of ORO showed an increase in triglycerides throughout culture. Immunofluorescence staining of cells at day 11 revealed the expression of CCAAT/enhancer-binding protein and peroxisome proliferator-activator receptor gamma, suggesting that these transcriptional factors are involved in adipocyte differentiation in trout. We also examined the effect of TNFalpha on the differentiation of these adipocytes in primary culture. TNFalpha inhibited the differentiation of these cells, as indicated by a decrease in glycerol-3-phosphate dehydrogenase activity, an established marker of adipocyte differentiation. In conclusion, the culture system described here for trout pre-adipocytes is a powerful tool to study the endocrine regulation of adipogenesis in this species.

Tracking differentiating neural progenitors in pluripotent cultures using microRNA-regulated lentiviral vectors.

Science.gov (United States)

Sachdeva, Rohit; Jönsson, Marie E; Nelander, Jenny; Kirkeby, Agnete; Guibentif, Carolina; Gentner, Bernhard; Naldini, Luigi; Björklund, Anders; Parmar, Malin; Jakobsson, Johan

2010-06-22

In this study, we have used a microRNA-regulated lentiviral reporter system to visualize and segregate differentiating neuronal cells in pluripotent cultures. Efficient suppression of transgene expression, specifically in undifferentiated pluripotent cells, was achieved by using a lentiviral vector expressing a fluorescent reporter gene regulated by microRNA-292. Using this strategy, it was possible to track progeny from murine ES, human ES cells, and induced pluripotent stem cells as they differentiated toward the neural lineage. In addition, this strategy was successfully used to FACS purify neuronal progenitors for molecular analysis and transplantation. FACS enrichment reduced tumor formation and increased survival of ES cell-derived neuronal progenitors after transplantation. The properties and versatility of the microRNA-regulated vectors allows broad use of these vectors in stem cell applications.

Carcinoma Showing Thymus-Like Differentiation (CASTLE of Thyroid: A Case Report and Literature Review

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Leong-Perng Chan

2008-11-01

Full Text Available Carcinoma showing thymus-like differentiation (CASTLE is a rare malignant neoplasm that occurs in the thyroid gland, or head and neck. This tumor arises from either ectopic thymus tissue or remnants of branchial pouches, which retain the potential to differentiate along the thymus line. Clinical presentation and imaging can be consistent with a malignant lesion such as thyroid cancer or thymic carcinoma. Immunohistochemical staining with CD5 can differentiate CASTLE from other malignant thyroid neoplasms. A 54-year-old male had initially presented with a painless, left neck mass for 3 months. He underwent left thyroid lobectomy via a median sternotomy approach. Carcinoma showing thymus-like differentiation was the final histopathologic diagnosis. After 36 months of follow-up, no evidence of recurrence was observed. A median sternotomy is an excellent approach for CASTLE with anterior mediastinum involvement. Complete resection is important to improve the long-term survival rate and the locoregional recurrence rate.

DIDO as a Switchboard that Regulates Self-Renewal and Differentiation in Embryonic Stem Cells.

Science.gov (United States)

Fütterer, Agnes; de Celis, Jésus; Navajas, Rosana; Almonacid, Luis; Gutiérrez, Julio; Talavera-Gutiérrez, Amaia; Pacios-Bras, Cristina; Bernascone, Ilenia; Martin-Belmonte, Fernando; Martinéz-A, Carlos

2017-04-11

Transition from symmetric to asymmetric cell division requires precise coordination of differential gene expression. We show that embryonic stem cells (ESCs) mainly express DIDO3 and that their differentiation after leukemia inhibitory factor withdrawal requires DIDO1 expression. C-terminal truncation of DIDO3 (Dido3ΔCT) impedes ESC differentiation while retaining self-renewal; small hairpin RNA-Dido1 ESCs have the same phenotype. Dido3ΔCT ESC differentiation is rescued by ectopic expression of DIDO3, which binds the Dido locus via H3K4me3 and RNA POL II and induces DIDO1 expression. DIDO1, which is exported to cytoplasm, associates with, and is N-terminally phosphorylated by PKCiota. It binds the E3 ubiquitin ligase WWP2, which contributes to cell fate by OCT4 degradation, to allow expression of primitive endoderm (PE) markers. PE formation also depends on phosphorylated DIDO3 localization to centrosomes, which ensures their correct positioning for PE cell polarization. We propose that DIDO isoforms act as a switchboard that regulates genetic programs for ESC transition from pluripotency maintenance to promotion of differentiation. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

MicroRNA-1 Regulates the Differentiation of Adipose-Derived Stem Cells into Cardiomyocyte-Like Cells

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Can Chen

2018-01-01

Full Text Available Stem cell transplantation is one of most valuable methods in the treatment of myocardial infarction, and adipose-derived stem cells (ASCs are becoming a hot topic in medical research. Previous studies have shown that ASCs can be differentiated into cardiomyocyte-like cells, but the efficiency and survival rates are low. We investigated the role and mechanism of microRNA-1 (miR-1 in the differentiation of ASCs into cardiomyocyte-like cells. ASCs and cardiomyocytes were isolated from neonatal rats. We constructed lentivirus for overexpressing miR-1 and used DAPT, an antagonist of the Notch1 pathway, for in vitro analyses. We performed cocultures with ASCs and cardiomyocytes. The differentiation efficiency of ASCs was detected by cell-specific surface antigens. Our results showed that miR-1 can promote the expression of Notch1 and reduce the expression of Hes1, a Notch pathway factor, and overexpression of miR-1 can promote the differentiation of ASCs into cardiomyocyte-like cells, which may occur by regulating Notch1 and Hes1.

Meis1 regulates Foxn4 expression during retinal progenitor cell differentiation

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Mohammed M. Islam

2013-09-01

The transcription factor forkhead box N4 (Foxn4 is a key regulator in a variety of biological processes during development. In particular, Foxn4 plays an essential role in the genesis of horizontal and amacrine neurons from neural progenitors in the vertebrate retina. Although the functions of Foxn4 have been well established, the transcriptional regulation of Foxn4 expression during progenitor cell differentiation remains unclear. Here, we report that an evolutionarily conserved 129 bp noncoding DNA fragment (Foxn4CR4.2 or CR4.2, located ∼26 kb upstream of Foxn4 transcription start site, functions as a cis-element for Foxn4 regulation. CR4.2 directs gene expression in Foxn4-positive cells, primarily in progenitors, differentiating horizontal and amacrine cells. We further determined that the gene regulatory activity of CR4.2 is modulated by Meis1 binding motif, which is bound and activated by Meis1 transcription factor. Deletion of the Meis1 binding motif or knockdown of Meis1 expression abolishes the gene regulatory activity of CR4.2. In addition, knockdown of Meis1 expression diminishes the endogenous Foxn4 expression and affects cell lineage development. Together, we demonstrate that CR4.2 and its interacting Meis1 transcription factor play important roles in regulating Foxn4 expression during early retinogenesis. These findings provide new insights into molecular mechanisms that govern gene regulation in retinal progenitors and specific cell lineage development.

Epigenetic landscapes reveal transcription factors regulating CD8+ T cell differentiation

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Yu, Bingfei; Zhang, Kai; Milner, J. Justin; Toma, Clara; Chen, Runqiang; Scott-Browne, James P.; Pereira, Renata M.; Crotty, Shane; Chang, John T.; Pipkin, Matthew E.; Wang, Wei; Goldrath, Ananda W.

2017-01-01

Dynamic changes in the expression of transcription factors (TFs) can influence specification of distinct CD8+ T cell fates, but the observation of equivalent expression of TF among differentially-fated precursor cells suggests additional underlying mechanisms. Here, we profiled genome-wide histone modifications, open chromatin and gene expression of naive, terminal-effector, memory-precursor and memory CD8+ T cell populations induced during the in vivo response to bacterial infection. Integration of these data suggested that TF expression and binding contributed to establishment of subset-specific enhancers during differentiation. We developed a new bioinformatics method using the PageRank algorithm to reveal novel TFs influencing the generation of effector and memory populations. The TFs YY1 and Nr3c1, both constitutively expressed during CD8+ T cell differentiation, regulated the formation of terminal-effector and memory-precursor cell-fates, respectively. Our data define the epigenetic landscape of differentiation intermediates, facilitating identification of TFs with previously unappreciated roles in CD8+ T cell differentiation. PMID:28288100

MicroRNAs define distinct human neuroblastoma cell phenotypes and regulate their differentiation and tumorigenicity

International Nuclear Information System (INIS)

Samaraweera, Leleesha; Grandinetti, Kathryn B; Huang, Ruojun; Spengler, Barbara A; Ross, Robert A

2014-01-01

Neuroblastoma (NB) is the most common extracranial solid tumor in children. NB tumors and derived cell lines are phenotypically heterogeneous. Cell lines are classified by phenotype, each having distinct differentiation and tumorigenic properties. The neuroblastic phenotype is tumorigenic, has neuronal features and includes stem cells (I-cells) and neuronal cells (N-cells). The non-neuronal phenotype (S-cell) comprises cells that are non-tumorigenic with features of glial/smooth muscle precursor cells. This study identified miRNAs associated with each distinct cell phenotypes and investigated their role in regulating associated differentiation and tumorigenic properties. A miRNA microarray was performed on the three cell phenotypes and expression verified by qRT-PCR. miRNAs specific for certain cell phenotypes were modulated using miRNA inhibitors or stable transfection. Neuronal differentiation was induced by RA; non-neuronal differentiation by BrdU. Changes in tumorigenicity were assayed by soft agar colony forming ability. N-myc binding to miR-375 promoter was assayed by chromatin-immunoprecipitation. Unsupervised hierarchical clustering of miRNA microarray data segregated neuroblastic and non-neuronal cell lines and showed that specific miRNAs define each phenotype. qRT-PCR validation confirmed that increased levels of miR-21, miR-221 and miR-335 are associated with the non-neuronal phenotype, whereas increased levels of miR-124 and miR-375 are exclusive to neuroblastic cells. Downregulation of miR-335 in non-neuronal cells modulates expression levels of HAND1 and JAG1, known modulators of neuronal differentiation. Overexpression of miR-124 in stem cells induces terminal neuronal differentiation with reduced malignancy. Expression of miR-375 is exclusive for N-myc-expressing neuroblastic cells and is regulated by N-myc. Moreover, miR-375 downregulates expression of the neuronal-specific RNA binding protein HuD. Thus, miRNAs define distinct NB cell phenotypes

Human colon cancer profiles show differential microRNA expression depending on mismatch repair status and are characteristic of undifferentiated proliferative states

International Nuclear Information System (INIS)

Sarver, Aaron L; Cunningham, Julie M; Subramanian, Subbaya; Wang, Liang; Smyrk, Tom C; Rodrigues, Cecilia MP; Thibodeau, Stephen N; Steer, Clifford J; French, Amy J; Borralho, Pedro M; Thayanithy, Venugopal; Oberg, Ann L; Silverstein, Kevin AT; Morlan, Bruce W; Riska, Shaun M; Boardman, Lisa A

2009-01-01

Colon cancer arises from the accumulation of multiple genetic and epigenetic alterations to normal colonic tissue. microRNAs (miRNAs) are small, non-coding regulatory RNAs that post-transcriptionally regulate gene expression. Differential miRNA expression in cancer versus normal tissue is a common event and may be pivotal for tumor onset and progression. To identify miRNAs that are differentially expressed in tumors and tumor subtypes, we carried out highly sensitive expression profiling of 735 miRNAs on samples obtained from a statistically powerful set of tumors (n = 80) and normal colon tissue (n = 28) and validated a subset of this data by qRT-PCR. Tumor specimens showed highly significant and large fold change differential expression of the levels of 39 miRNAs including miR-135b, miR-96, miR-182, miR-183, miR-1, and miR-133a, relative to normal colon tissue. Significant differences were also seen in 6 miRNAs including miR-31 and miR-592, in the direct comparison of tumors that were deficient or proficient for mismatch repair. Examination of the genomic regions containing differentially expressed miRNAs revealed that they were also differentially methylated in colon cancer at a far greater rate than would be expected by chance. A network of interactions between these miRNAs and genes associated with colon cancer provided evidence for the role of these miRNAs as oncogenes by attenuation of tumor suppressor genes. Colon tumors show differential expression of miRNAs depending on mismatch repair status. miRNA expression in colon tumors has an epigenetic component and altered expression that may reflect a reversion to regulatory programs characteristic of undifferentiated proliferative developmental states

MxiN Differentially Regulates Monomeric and Oligomeric Species of the Shigella Type Three Secretion System ATPase Spa47.

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Case, Heather B; Dickenson, Nicholas E

2018-04-17

Shigella rely entirely on the action of a single type three secretion system (T3SS) to support cellular invasion of colonic epithelial cells and to circumvent host immune responses. The ATPase Spa47 resides at the base of the Shigella needle-like type three secretion apparatus (T3SA), supporting protein secretion through the apparatus and providing a likely means for native virulence regulation by Shigella and a much needed target for non-antibiotic therapeutics to treat Shigella infections. Here, we show that MxiN is a differential regulator of Spa47 and that its regulatory impact is determined by the oligomeric state of the Spa47 ATPase, with which it interacts. In vitro and in vivo characterization shows that interaction of MxiN with Spa47 requires the six N-terminal residues of Spa47 that are also necessary for stable Spa47 oligomer formation and activation. This interaction with MxiN negatively influences the activity of Spa47 oligomers while upregulating the ATPase activity of monomeric Spa47. Detailed kinetic analyses of monomeric and oligomeric Spa47 in the presence and absence of MxiN uncover additional mechanistic insights into the regulation of Spa47 by MxiN, suggesting that the MxiN/Spa47 species resulting from interaction with monomeric and oligomeric Spa47 are functionally distinct and that both could be involved in Shigella T3SS regulation. Uncovering regulation of Spa47 by MxiN addresses an important gap in the current understanding of how Shigella controls T3SA activity and provides the first description of differential T3SS ATPase regulation by a native T3SS protein.

Pairwise comparisons of ten porcine tissues identify differential transcriptional regulation at the gene, isoform, promoter and transcription start site level

DEFF Research Database (Denmark)

Farajzadeh, Leila; Hornshøj, Henrik; Momeni, Jamal

2013-01-01

, isoform, and transcription start site (TSS), and promoter level showed that several of the genes differed at all four levels. Interestingly, these genes were mainly annotated to the "electron transport chain" and neuronal differentiation, emphasizing that "tissue important" genes are regulated at several...

SEPTIN2 and STATHMIN Regulate CD99-Mediated Cellular Differentiation in Hodgkin's Lymphoma.

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Wenjing Jian

Full Text Available Hodgkin's lymphoma (HL is a lymphoid neoplasm characterized by Hodgkin's and Reed-Sternberg (H/RS cells, which is regulated by CD99. We previously reported that CD99 downregulation led to the transformation of murine B lymphoma cells (A20 into cells with an H/RS phenotype, while CD99 upregulation induced differentiation of classical Hodgkin's lymphoma (cHL cells (L428 into terminal B-cells. However, the molecular mechanism remains unclear. In this study, using fluorescence two-dimensional differential in-gel electrophoresis and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS, we have analyzed the alteration of protein expression following CD99 upregulation in L428 cells as well as downregulation of mouse CD99 antigen-like 2 (mCD99L2 in A20 cells. Bioinformatics analysis showed that SEPTIN2 and STATHMIN, which are cytoskeleton proteins, were significantly differentially expressed, and chosen for further validation and functional analysis. Differential expression of SEPTIN2 was found in both models and was inversely correlated with CD99 expression. STATHMIN was identified in the A20 cell line model and its expression was positively correlated with that of CD99. Importantly, silencing of SEPTIN2 with siRNA substantially altered the cellular cytoskeleton in L428 cells. The downregulation of STATHMIN by siRNA promoted the differentiation of H/RS cells toward terminal B-cells. These results suggest that SEPTIN2-mediated cytoskeletal rearrangement and STATHMIN-mediated differentiation may contribute to changes in cell morphology and differentiation of H/RS cells with CD99 upregulation in HL.

The heterocyst differentiation transcriptional regulator HetR of the filamentous cyanobacterium Anabaena forms tetramers and can be regulated by phosphorylation.

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Valladares, Ana; Flores, Enrique; Herrero, Antonia

2016-02-01

Many filamentous cyanobacteria respond to the external cue of nitrogen scarcity by the differentiation of heterocysts, cells specialized in the fixation of atmospheric nitrogen in oxic environments. Heterocysts follow a spatial pattern along the filament of two heterocysts separated by ca. 10-15 vegetative cells performing oxygenic photosynthesis. HetR is a transcriptional regulator that directs heterocyst differentiation. In the model strain Anabaena sp. PCC 7120, the HetR protein was observed in various oligomeric forms in vivo, including a tetramer that peaked with maximal hetR expression during differentiation. Tetramers were not detected in a hetR point mutant incapable of differentiation, but were conspicuous in an over-differentiating strain lacking the PatS inhibitor. In differentiated filaments the HetR tetramer was restricted to heterocysts, being undetectable in vegetative cells. HetR co-purified with RNA polymerase from Anabaena mainly as a tetramer. In vitro, purified recombinant HetR was distributed between monomers, dimers, trimers and tetramers, and it was phosphorylated when incubated with (γ-(32)P)ATP. Phosphorylation and PatS hampered the accumulation of HetR tetramers and impaired HetR binding to DNA. In summary, tetrameric HetR appears to represent a functionally relevant form of HetR, whose abundance in the Anabaena filament could be negatively regulated by phosphorylation and by PatS. © 2015 John Wiley & Sons Ltd.

MicroRNA-140 Provides Robustness to the Regulation of Hypertrophic Chondrocyte Differentiation by the PTHrP-HDAC4 Pathway.

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Papaioannou, Garyfallia; Mirzamohammadi, Fatemeh; Lisse, Thomas S; Nishimori, Shigeki; Wein, Marc N; Kobayashi, Tatsuya

2015-06-01

Growth plate chondrocytes go through multiple differentiation steps and eventually become hypertrophic chondrocytes. The parathyroid hormone (PTH)-related peptide (PTHrP) signaling pathway plays a central role in regulation of hypertrophic differentiation, at least in part, through enhancing activity of histone deacetylase 4 (HDAC4), a negative regulator of MEF2 transcription factors that drive hypertrophy. We have previously shown that loss of the chondrocyte-specific microRNA (miRNA), miR-140, alters chondrocyte differentiation including mild acceleration of hypertrophic differentiation. Here, we provide evidence that miR-140 interacts with the PTHrP-HDAC4 pathway to control chondrocyte differentiation. Heterozygosity of PTHrP or HDAC4 substantially impaired animal growth in miR-140 deficiency, whereas these mutations had no effect in the presence of miR-140. miR-140-deficient chondrocytes showed increased MEF2C expression with normal levels of total and phosphorylated HDAC4, indicating that the miR-140 pathway merges with the PTHrP-HDAC4 pathway at the level of MEF2C. miR-140 negatively regulated p38 mitogen-activated protein kinase (MAPK) signaling, and inhibition of p38 MAPK signaling reduced MEF2C expression. These results demonstrate that miR-140 ensures the robustness of the PTHrP/HDAC4 regulatory system by suppressing MEF2C-inducing stimuli. © 2014 American Society for Bone and Mineral Research © 2015 American Society for Bone and Mineral Research. © 2014 American Society for Bone and Mineral Research.

Regulation of caste differentiation in the honey bee (Apis mellifera L.)

NARCIS (Netherlands)

Goewie, E.A.

1978-01-01

The nutritional environment of honey-bee larvae affects the juvenile hormone (JH) titre of larval haemolymph and tissues. In this investigation the mechanism for the regulation of caste differentiation has been studied.

Chemo- and mechanoreceptors are found on larval mouthparts.

The Satellite Cell Niche Regulates the Balance between Myoblast Differentiation and Self-Renewal via p53.

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Flamini, Valentina; Ghadiali, Rachel S; Antczak, Philipp; Rothwell, Amy; Turnbull, Jeremy E; Pisconti, Addolorata

2018-03-13

Satellite cells are adult muscle stem cells residing in a specialized niche that regulates their homeostasis. How niche-generated signals integrate to regulate gene expression in satellite cell-derived myoblasts is poorly understood. We undertook an unbiased approach to study the effect of the satellite cell niche on satellite cell-derived myoblast transcriptional regulation and identified the tumor suppressor p53 as a key player in the regulation of myoblast quiescence. After activation and proliferation, a subpopulation of myoblasts cultured in the presence of the niche upregulates p53 and fails to differentiate. When satellite cell self-renewal is modeled ex vivo in a reserve cell assay, myoblasts treated with Nutlin-3, which increases p53 levels in the cell, fail to differentiate and instead become quiescent. Since both these Nutlin-3 effects are rescued by small interfering RNA-mediated p53 knockdown, we conclude that a tight control of p53 levels in myoblasts regulates the balance between differentiation and return to quiescence. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

microRNA-145 promotes differentiation in human urothelial carcinoma through down-regulation of syndecan-1

International Nuclear Information System (INIS)

Fujii, Tomomi; Shimada, Keiji; Tatsumi, Yoshihiro; Hatakeyama, Kinta; Obayashi, Chiho; Fujimoto, Kiyohide; Konishi, Noboru

2015-01-01

A new molecular marker of carcinoma in the urinary bladder is needed as a diagnostic tool or as a therapeutic target. Potential markers include microRNAs (miRNAs), which are short, low molecular weight RNAs 19–24 nt long that regulate genes associated with cell proliferation, differentiation, and development in various cancers. In this study, we investigated the molecular mechanisms by which miR-145 promotes survival of urothelial carcinoma cells and differentiation into multiple lineages. We found miR-145 to regulate expression of syndecan-1, a heparin sulfate proteoglycan. Cell proliferation in the human urothelial carcinoma cell lines T24 and KU7 was assessed by MTS assay. Cellular senescence and apoptosis were measured by senescence-associated β-galactosidase (SA-β-gal) and TUNEL assay, respectively. Quantitative RT-PCR was used to measure mRNA expression of various genes, including syndecan-1, stem cell factors, and markers of differentiation into squamous, glandular, or neuroendocrine cells. Overexpression of miR-145 induced cell senescence, and thus significantly inhibited cell proliferation in T24 and KU7 cells. Syndecan-1 expression diminished, whereas stem cell markers such as SOX2, NANOG, OCT4, and E2F3 increased. miR-145 also up-regulated markers of differentiation into squamous (p63, TP63, and CK5), glandular (MUC-1, MUC-2, and MUC-5 AC), and neuroendocrine cells (NSE and UCHL-1). Finally, expression of miR-145 was down-regulated in high-grade urothelial carcinomas, but not in low-grade tumors. Results indicate that miR-145 suppresses syndecan-1 and, by this mechanism, up-regulates stem cell factors and induces cell senescence and differentiation. We propose that miR-145 may confer stem cell-like properties on urothelial carcinoma cells and thus facilitate differentiation into multiple cell types. The online version of this article (doi:10.1186/s12885-015-1846-0) contains supplementary material, which is available to authorized users

Identification of novel regulators in T-cell differentiation of aplastic anemia patients

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Probst-Kepper Michael

2006-10-01

Full Text Available Abstract Background Aplastic anemia (AA is a bone marrow failure syndrome mostly characterized by an immune-mediated destruction of marrow hematopoietic progenitor/stem cells. The resulting hypocellularity limits a detailed analysis of the cellular immune response. To overcome this technical problem we performed a microarray analysis of CD3+ T-cells derived from bone marrow aspirates and peripheral blood samples of newly diagnosed AA patients and healthy volunteers. Two AA patients were additionally analyzed after achieving a partial remission following immunosuppression. The regulation of selected candidate genes was confirmed by real-time RT-PCR. Results Among more than 22.200 transcripts, 583 genes were differentially expressed in the bone marrow of AA patients compared to healthy controls. Dysregulated genes are involved in T-cell mediated cytotoxicity, immune response of Th1 differentiated T-cells, and major regulators of immune function. In hematological remission the expression levels of several candidate genes tend to normalize, such as immune regulators and genes involved in proinflammatory immune response. Conclusion Our study suggests a pivotal role of Th1/Tc1 differentiated T-cells in immune-mediated marrow destruction of AA patients. Most importantly, immune regulatory genes could be identified, which are likely involved in the recovery of hematopoiesis and may help to design new therapeutic strategies in bone marrow failure syndromes.

Post-Transcriptional Regulation of KLF4 by High-Risk Human Papillomaviruses Is Necessary for the Differentiation-Dependent Viral Life Cycle.

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Vignesh Kumar Gunasekharan

2016-07-01

Full Text Available Human papillomaviruses (HPVs are epithelial tropic viruses that link their productive life cycles to the differentiation of infected host keratinocytes. A subset of the over 200 HPV types, referred to as high-risk, are the causative agents of most anogenital malignancies. HPVs infect cells in the basal layer, but restrict viral genome amplification, late gene expression, and capsid assembly to highly differentiated cells that are active in the cell cycle. In this study, we demonstrate that HPV proteins regulate the expression and activities of a critical cellular transcription factor, KLF4, through post-transcriptional and post-translational mechanisms. Our studies show that KLF4 regulates differentiation as well as cell cycle progression, and binds to sequences in the upstream regulatory region (URR to regulate viral transcription in cooperation with Blimp1. KLF4 levels are increased in HPV-positive cells through a post-transcriptional mechanism involving E7-mediated suppression of cellular miR-145, as well as at the post-translational level by E6-directed inhibition of its sumoylation and phosphorylation. The alterations in KLF4 levels and functions results in activation and suppression of a subset of KLF4 target genes, including TCHHL1, VIM, ACTN1, and POT1, that is distinct from that seen in normal keratinocytes. Knockdown of KLF4 with shRNAs in cells that maintain HPV episomes blocked genome amplification and abolished late gene expression upon differentiation. While KLF4 is indispensable for the proliferation and differentiation of normal keratinocytes, it is necessary only for differentiation-associated functions of HPV-positive keratinocytes. Increases in KLF4 levels alone do not appear to be sufficient to explain the effects on proliferation and differentiation of HPV-positive cells indicating that additional modifications are important. KLF4 has also been shown to be a critical regulator of lytic Epstein Barr virus (EBV replication

SNF5 is an essential executor of epigenetic regulation during differentiation.

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You, Jueng Soo; De Carvalho, Daniel D; Dai, Chao; Liu, Minmin; Pandiyan, Kurinji; Zhou, Xianghong J; Liang, Gangning; Jones, Peter A

2013-04-01

Nucleosome occupancy controls the accessibility of the transcription machinery to DNA regulatory regions and serves an instructive role for gene expression. Chromatin remodelers, such as the BAF complexes, are responsible for establishing nucleosome occupancy patterns, which are key to epigenetic regulation along with DNA methylation and histone modifications. Some reports have assessed the roles of the BAF complex subunits and stemness in murine embryonic stem cells. However, the details of the relationships between remodelers and transcription factors in altering chromatin configuration, which ultimately affects gene expression during cell differentiation, remain unclear. Here for the first time we demonstrate that SNF5, a core subunit of the BAF complex, negatively regulates OCT4 levels in pluripotent cells and is essential for cell survival during differentiation. SNF5 is responsible for generating nucleosome-depleted regions (NDRs) at the regulatory sites of OCT4 repressed target genes such as PAX6 and NEUROG1, which are crucial for cell fate determination. Concurrently, SNF5 closes the NDRs at the regulatory regions of OCT4-activated target genes such as OCT4 itself and NANOG. Furthermore, using loss- and gain-of-function experiments followed by extensive genome-wide analyses including gene expression microarrays and ChIP-sequencing, we highlight that SNF5 plays dual roles during differentiation by antagonizing the expression of genes that were either activated or repressed by OCT4, respectively. Together, we demonstrate that SNF5 executes the switch between pluripotency and differentiation.

SNF5 is an essential executor of epigenetic regulation during differentiation.

Directory of Open Access Journals (Sweden)

Jueng Soo You

2013-04-01

Full Text Available Nucleosome occupancy controls the accessibility of the transcription machinery to DNA regulatory regions and serves an instructive role for gene expression. Chromatin remodelers, such as the BAF complexes, are responsible for establishing nucleosome occupancy patterns, which are key to epigenetic regulation along with DNA methylation and histone modifications. Some reports have assessed the roles of the BAF complex subunits and stemness in murine embryonic stem cells. However, the details of the relationships between remodelers and transcription factors in altering chromatin configuration, which ultimately affects gene expression during cell differentiation, remain unclear. Here for the first time we demonstrate that SNF5, a core subunit of the BAF complex, negatively regulates OCT4 levels in pluripotent cells and is essential for cell survival during differentiation. SNF5 is responsible for generating nucleosome-depleted regions (NDRs at the regulatory sites of OCT4 repressed target genes such as PAX6 and NEUROG1, which are crucial for cell fate determination. Concurrently, SNF5 closes the NDRs at the regulatory regions of OCT4-activated target genes such as OCT4 itself and NANOG. Furthermore, using loss- and gain-of-function experiments followed by extensive genome-wide analyses including gene expression microarrays and ChIP-sequencing, we highlight that SNF5 plays dual roles during differentiation by antagonizing the expression of genes that were either activated or repressed by OCT4, respectively. Together, we demonstrate that SNF5 executes the switch between pluripotency and differentiation.

miR-24-mediated down-regulation of H2AX suppresses DNA repair in terminally differentiated blood cells

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Lal, Ashish; Pan, Yunfeng; Navarro, Francisco; Dykxhoorn, Derek M.; Moreau, Lisa; Meire, Eti; Bentwich, Zvi; Lieberman, Judy; Chowdhury, Dipanjan

2010-01-01

Terminally differentiated cells have reduced capacity to repair double strand breaks (DSB), but the molecular mechanism behind this down-regulation is unclear. Here we find that miR-24 is consistently up-regulated during post-mitotic differentiation of hematopoietic cell lines and regulates the histone variant H2AX, a key DSB repair protein that activates cell cycle checkpoint proteins and retains DSB repair factors at DSB foci. The H2AX 3’UTR contains conserved miR-24 binding sites regulated by miR-24. Both H2AX mRNA and protein are substantially reduced during hematopoietic cell terminal differentiation by miR-24 up-regulation both in in vitro differentiated cells and primary human blood cells. miR-24 suppression of H2AX renders cells hypersensitive to γ-irradiation and genotoxic drugs. Antagonizing miR-24 in differentiating cells protects them from DNA damage-induced cell death, while transfecting miR-24 mimics in dividing cells increases chromosomal breaks and unrepaired DNA damage and reduces viability in response to DNA damage. This DNA repair phenotype can be fully rescued by over-expressing miR-24-insensitive H2AX. Therefore, miR-24 up-regulation in post-replicative cells reduces H2AX and thereby renders them highly vulnerable to DNA damage. PMID:19377482

SIRT3/SOD2 maintains osteoblast differentiation and bone formation by regulating mitochondrial stress

OpenAIRE

Gao, Jing; Feng, Zhihui; Wang, Xueqiang; Zeng, Mengqi; Liu, Jing; Han, Shujun; Xu, Jie; Chen, Lei; Cao, Ke; Long, Jiangang; Li, Zongfang; Shen, Weili; Liu, Jiankang

2017-01-01

Recent studies have revealed robust metabolic changes during cell differentiation. Mitochondria, the organelles where many vital metabolic reactions occur, may play an important role. Here, we report the involvement of SIRT3-regulated mitochondrial stress in osteoblast differentiation and bone formation. In both the osteoblast cell line MC3T3-E1 and primary calvarial osteoblasts, robust mitochondrial biogenesis and supercomplex formation were observed during differentiation, accompanied by in...

Cholesterol and phytosterols differentially regulate the expression of caveolin 1 and a downstream prostate cell growth-suppressor gene

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Ifere, Godwin O.; Equan, Anita; Gordon, Kereen; Nagappan, Peri; Igietseme, Joseph U.; Ananaba, Godwin A.

2010-01-01

Background The purpose of our study was to show the distinction between the apoptotic and anti-proliferative signaling of phytosterols and cholesterol enrichment in prostate cancer cell lines, mediated by the differential transcription of caveolin-1, and N-myc downstream regulated gene1 (NDRG1), a pro-apoptotic androgen-regulated tumor suppressor. Methods PC-3 and DU145 cells were treated with sterols (cholesterol and phytosterols) for 72 h, followed by trypan blue dye exclusion measurement of necrosis and cell growth measured with a Coulter counter. Sterol induction of cell growth-suppressor gene expression was evaluated by mRNA transcription using RT-PCR, while cell cycle analysis was performed by FACS analysis. Altered expression of Ndrg1 protein was confirmed by Western blot analysis. Apoptosis was evaluated by real time RT-PCR amplification of P53, Bcl-2 gene and its related pro- and anti-apoptotic family members. Results Physiological doses (16 µM) of cholesterol and phytosterols were not cytotoxic in these cells. Cholesterol enrichment promoted cell growth (Pphytosterols significantly induced growth-suppression (Pphytosterols decreased mitotic subpopulations. We demonstrated for the first time that cholesterols concertedly attenuated the expression of caveolin-1(cav-1) and NDRG1 genes in both prostate cancer cell lines. Phytosterols had the opposite effect by inducing overexpression of cav-1, a known mediator of androgen-dependent signals that presumably control cell growth or apoptosis. Conclusions Cholesterol and phytosterol treatment differentially regulated the growth of prostate cancer cells and the expression of p53 and cav-1, a gene that regulates androgen-regulated signals. These sterols also differentially regulated cell cycle arrest, downstream pro-apoptotic androgen-regulated tumor-suppressor, NDRG1 suggesting that cav-1 may mediate pro-apoptotic NDRG1 signals. Elucidation of the mechanism for sterol modulation of growth and apoptosis signaling

Down-regulation of Irf8 by Lyz2-cre/loxP accelerates osteoclast differentiation in vitro.

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Saito, Emi; Suzuki, Dai; Kurotaki, Daisuke; Mochizuki, Ayako; Manome, Yoko; Suzawa, Tetsuo; Toyoshima, Yoichi; Ichikawa, Takahiro; Funatsu, Takahiro; Inoue, Tomio; Takami, Masamichi; Tamura, Tomohiko; Inagaki, Katsunori; Kamijo, Ryutaro

2017-06-01

Interferon regulatory factor 8 (Irf8) is a transcription factor that negatively regulates osteoclast differentiation and Irf8 global knockout (Irf8 -/- ) mice have been shown to have reduced bone volume resulting from increased osteoclast numbers. However, detailed analysis of the functions of Irf8 in osteoclast precursors with a monocyte/macrophage linage is difficult, because the population and properties of hematopoietic cells in Irf8 -/- mice are severely altered. Therefore, to clearly elucidate the functions of Irf8 during osteoclastogenesis, we established myeloid cell-specific Irf8 conditional knockout (Irf8 fl/fl ;Lyz2 cre/+ ) mice. We found that trabecular bone volume in the Irf8 fl/fl ;Lyz2 cre/+ mice was not significantly affected, while exposure to M-CSF and RANKL significantly increased TRAP activity in vitro in osteoclasts that underwent osteoclastogenesis from bone marrow-derived macrophages (BMMs) induced from bone marrow cells (BMCs) of those mice by addition of M-CSF. Our results also showed that expression of Irf8 mRNA and protein in BMMs obtained from Irf8 fl/fl ;Lyz2 cre/+ mice and cultured with M-CSF was reduced. These findings predicted that Lyz2/Lyz2-cre expression is induced when BMCs differentiate into BMMs in cultures with M-CSF. In osteoclast differentiation cultures, Lyz2 was gradually increased by M-CSF during the first 3 days of culture, then rapidly decreased by the addition of RANKL with M-CSF during the next 3 days. Furthermore, BMCs differentiated into osteoclasts while maintaining a low level of Lyz2 expression when cultured simultaneously with both M-CSF and RANKL from the initiation of culture. These findings suggest that Lyz2-cre expression is induced along with differentiation to BMMs by BMCs obtained from Irf8 fl/fl ;Lyz2 cre/+ mice and cultured with M-CSF. In addition, Irf8 was down-regulated by activation of the cre/loxP recombination system in BMMs and osteoclastogenesis was accelerated. Based on our results, we propose

Dystroglycan and mitochondrial ribosomal protein L34 regulate differentiation in the Drosophila eye.

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Yougen Zhan

2010-05-01

Full Text Available Mutations that diminish the function of the extracellular matrix receptor Dystroglycan (DG result in muscular dystrophies, with associated neuronal migration defects in the brain and mental retardation e.g. Muscle Eye Brain Disease. To gain insight into the function of DG in the nervous system we initiated a study to examine its contribution to development of the eye of Drosophila melanogaster. Immuno-histochemistry showed that DG is concentrated on the apical surface of photoreceptors (R cells during specification of cell-fate in the third instar larva and is maintained at this location through early pupal stages. In point mutations that are null for DG we see abortive R cell elongation during differentiation that first appears in the pupa and results in stunted R cells in the adult. Overexpression of DG in R cells results in a small but significant increase in their size. R cell differentiation defects appear at the same stage in a deficiency line Df(2RDg(248 that affects Dg and the neighboring mitochondrial ribosomal gene, mRpL34. In the adult, these flies have severely disrupted R cells as well as defects in the lens and ommatidia. Expression of an mRpL34 transgene rescues much of this phenotype. We conclude that DG does not affect neuronal commitment but functions R cell autonomously to regulate neuronal elongation during differentiation in the pupa. We discuss these findings in view of recent work implicating DG as a regulator of cell metabolism and its genetic interaction with mRpL34, a member of a class of mitochondrial genes essential for normal metabolic function.

Glucose metabolism regulates T cell activation, differentiation and functions

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Clovis Steve Palmer

2015-01-01

Full Text Available The adaptive immune system is equipped to eliminate both tumors and pathogenic microorganisms. It requires a series of complex and coordinated signals to drive the activation, proliferation and differentiation of appropriate T cell subsets. It is now established that changes in cellular activation are coupled to profound changes in cellular metabolism. In addition, emerging evidence now suggest that specific metabolic alterations associated with distinct T cell subsets may be ancillary to their differentiation and influential in their immune functions. The Warburg effect originally used to describe a phenomenon in which most cancer cells relied on aerobic glycolysis for their growth is a key process that sustain T cell activation and differentiation. Here we review how different aspects of metabolism in T cells influence their functions, focusing on the emerging role of key regulators of glucose metabolism such as HIF-1α. A thorough understanding of the role of metabolism in T cell function could provide insights into mechanisms involved in inflammatory-mediated conditions, with the potential for developing novel therapeutic approaches to treat these diseases.

Cholesterol negatively regulates IL-9-producing CD8+ T cell differentiation and antitumor activity.

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Ma, Xingzhe; Bi, Enguang; Huang, Chunjian; Lu, Yong; Xue, Gang; Guo, Xing; Wang, Aibo; Yang, Maojie; Qian, Jianfei; Dong, Chen; Yi, Qing

2018-05-09

CD8 + T cells can be polarized into IL-9-secreting (Tc9) cells. We previously showed that adoptive therapy using tumor-specific Tc9 cells generated stronger antitumor responses in mouse melanoma than classical Tc1 cells. To understand why Tc9 cells exert stronger antitumor responses, we used gene profiling to compare Tc9 and Tc1 cells. Tc9 cells expressed different levels of cholesterol synthesis and efflux genes and possessed significantly lower cholesterol content than Tc1 cells. Unique to Tc9, but not other CD8 + or CD4 + T cell subsets, manipulating cholesterol content in polarizing Tc9 cells significantly affected IL-9 expression and Tc9 differentiation and antitumor response in vivo. Mechanistic studies showed that IL-9 was indispensable for Tc9 cell persistence and antitumor effects, and cholesterol or its derivatives inhibited IL-9 expression by activating liver X receptors (LXRs), leading to LXR Sumoylation and reduced p65 binding to Il9 promoter. Our study identifies cholesterol as a critical regulator of Tc9 cell differentiation and function. © 2018 Ma et al.

Tiam1 Regulates the Wnt/Dvl/Rac1 Signaling Pathway and the Differentiation of Midbrain Dopaminergic Neurons

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Čajánek, Lukáš; Ganji, Ranjani Sri; Henriques-Oliveira, Catarina; Theofilopoulos, Spyridon; Koník, Peter

2013-01-01

Understanding the mechanisms that drive the differentiation of dopaminergic (DA) neurons is crucial for successful development of novel therapies for Parkinson's disease, in which DA neurons progressively degenerate. However, the mechanisms underlying the differentiation-promoting effects of Wnt5a on DA precursors are poorly understood. Here, we present the molecular and functional characterization of a signaling pathway downstream of Wnt5a, the Wnt/Dvl/Rac1 pathway. First, we characterize the interaction between Rac1 and Dvl and identify the N-terminal part of Dvl3 as necessary for Rac1 binding. Next, we show that Tiam1, a Rac1 guanosine exchange factor (GEF), is expressed in the ventral midbrain, interacts with Dvl, facilitates Dvl-Rac1 interaction, and is required for Dvl- or Wnt5a-induced activation of Rac1. Moreover, we show that Wnt5a promotes whereas casein kinase 1 (CK1), a negative regulator of the Wnt/Dvl/Rac1 pathway, abolishes the interactions between Dvl and Tiam1. Finally, using ventral midbrain neurosphere cultures, we demonstrate that the generation of DA neurons in culture is impaired after Tiam1 knockdown, indicating that Tiam1 is required for midbrain DA differentiation. In summary, our data identify Tiam1 as a novel regulator of DA neuron development and as a Dvl-associated and Rac1-specific GEF acting in the Wnt/Dvl/Rac1 pathway. PMID:23109420

Pbx and Prdm1a transcription factors differentially regulate subsets of the fast skeletal muscle program in zebrafish

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Zizhen Yao

2013-04-01

The basic helix–loop–helix factor Myod initiates skeletal muscle differentiation by directly and sequentially activating sets of muscle differentiation genes, including those encoding muscle contractile proteins. We hypothesize that Pbx homeodomain proteins direct Myod to a subset of its transcriptional targets, in particular fast-twitch muscle differentiation genes, thereby regulating the competence of muscle precursor cells to differentiate. We have previously shown that Pbx proteins bind with Myod on the promoter of the zebrafish fast muscle gene mylpfa and that Pbx proteins are required for Myod to activate mylpfa expression and the fast-twitch muscle-specific differentiation program in zebrafish embryos. Here we have investigated the interactions of Pbx with another muscle fiber-type regulator, Prdm1a, a SET-domain DNA-binding factor that directly represses mylpfa expression and fast muscle differentiation. The prdm1a mutant phenotype, early and increased fast muscle differentiation, is the opposite of the Pbx-null phenotype, delayed and reduced fast muscle differentiation. To determine whether Pbx and Prdm1a have opposing activities on a common set of genes, we used RNA-seq analysis to globally assess gene expression in zebrafish embryos with single- and double-losses-of-function for Pbx and Prdm1a. We find that the levels of expression of certain fast muscle genes are increased or approximately wild type in pbx2/4-MO;prdm1a−/− embryos, suggesting that Pbx activity normally counters the repressive action of Prdm1a for a subset of the fast muscle program. However, other fast muscle genes require Pbx but are not regulated by Prdm1a. Thus, our findings reveal that subsets of the fast muscle program are differentially regulated by Pbx and Prdm1a. Our findings provide an example of how Pbx homeodomain proteins act in a balance with other transcription factors to regulate subsets of a cellular differentiation program.

Expression of osterix Is Regulated by FGF and Wnt/β-Catenin Signalling during Osteoblast Differentiation.

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Katharina Felber

Full Text Available Osteoblast differentiation from mesenchymal cells is regulated by multiple signalling pathways. Here we have analysed the roles of Fibroblast Growth Factor (FGF and canonical Wingless-type MMTV integration site (Wnt/β-Catenin signalling pathways on zebrafish osteogenesis. We have used transgenic and chemical interference approaches to manipulate these pathways and have found that both pathways are required for osteoblast differentiation in vivo. Our analysis of bone markers suggests that these pathways act at the same stage of differentiation to initiate expression of the osteoblast master regulatory gene osterix (osx. We use two independent approaches that suggest that osx is a direct target of these pathways. Firstly, we manipulate signalling and show that osx gene expression responds with similar kinetics to that of known transcriptional targets of the FGF and Wnt pathways. Secondly, we have performed ChIP with transcription factors for both pathways and our data suggest that a genomic region in the first intron of osx mediates transcriptional activation. Based upon these data, we propose that FGF and Wnt/β-Catenin pathways act in part by directing transcription of osx to promote osteoblast differentiation at sites of bone formation.

Can green consumerism replace environmental regulation? A differentiated-products example

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Eriksson, Clas [Department of Economics, Swedish University of Agricultural Sciences, P.O. Box 7013, S-750 07 Uppsala (Sweden)

2004-09-01

This paper assumes that consumers are willing to pay an extra premium for a good if it has a low impact on the environment. We examine if a little dose of such idealistic behavior has a large impact on the market equilibrium, and to what extent it can replace the environmental regulation. The analysis is carried out in a model with product differentiation, where consumers differ in their preferences for product quality. Consumers' willingness to pay the environmental premium may be uniformly or non-uniformly distributed. Green consumerism will only be modestly influential in both cases, despite the fact that product differentiation leads to relaxed competition and increased profits, and thereby creates leverage.

Can green consumerism replace environmental regulation? A differentiated-products example

International Nuclear Information System (INIS)

Eriksson, Clas

2004-01-01

This paper assumes that consumers are willing to pay an extra premium for a good if it has a low impact on the environment. We examine if a little dose of such idealistic behavior has a large impact on the market equilibrium, and to what extent it can replace the environmental regulation. The analysis is carried out in a model with product differentiation, where consumers differ in their preferences for product quality. Consumers' willingness to pay the environmental premium may be uniformly or non-uniformly distributed. Green consumerism will only be modestly influential in both cases, despite the fact that product differentiation leads to relaxed competition and increased profits, and thereby creates leverage

Low-intensity pulsed ultrasound regulates proliferation and differentiation of osteoblasts through osteocytes

International Nuclear Information System (INIS)

Li, Lei; Yang, Zheng; Zhang, Hai; Chen, Wenchuan; Chen, Mengshi; Zhu, Zhimin

2012-01-01

Highlights: ► CM from LIPUS-stimulated osteocytes inhibits proliferation of osteoblasts. ► CM from LIPUS-stimulated osteocytes enhances differentiation of osteoblasts. ► LIPUS stimulates MLO-Y4 cells to secrete PGE 2 and NO. -- Abstract: Low-intensity pulsed ultrasound (LIPUS) has been used as a safe and effective modality to enhance fracture healing. As the most abundant cells in bone, osteocytes orchestrate biological activities of effector cells via direct cell-to-cell contacts and by soluble factors. In this study, we have used the osteocytic MLO-Y4 cells to study the effects of conditioned medium from LIPUS-stimulated MLO-Y4 cells on proliferation and differentiation of osteoblastic MC3T3-E1 cells. Conditioned media from LIPUS-stimulated MLO-Y4 cells (LIPUS-Osteocyte-CM) were collected and added on MC3T3-E1 cell cultures. MC3T3-E1 cells cultured in LIPUS-Osteocyte-CM demonstrated a significant inhibition of proliferation and an increased alkaline phosphatase activity. The results of PGE 2 and NO assay showed that LIPUS could enhance PGE 2 and NO secretion from MLO-Y4 cells at all time points within 24 h after LIPUS stimulation. We conclude that LIPUS regulates proliferation and differentiation of osteoblasts through osteocytes in vitro. Increased secretion of PGE 2 from osteocytes may play a role in this effect.

Biphasic regulation of intracellular calcium by gemfibrozil contributes to inhibiting L6 myoblast differentiation: implications for clinical myotoxicity.

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Liu, Aiming; Yang, Julin; Gonzalez, Frank J; Cheng, Gary Q; Dai, Renke

2011-02-18

Gemfibrozil is the most myotoxic fibrate drug commonly used for dyslipidemia, but the mechanism is poorly understood. The current study revealed that gemfibrozil inhibits myoblast differentiation through the regulation of intracellular calcium ([Ca(2+)]i) as revealed in L6 myoblasts by use of laser scan confocal microscopy and flow cytometry using Fluo-4 AM as a probe. Gemfibrozil at 20-400 μM, could regulate [Ca(2+)]i in L6 cells in a biphasic manner, and sustained reduction was observed when the concentration reached 200 μM. Inhibition of L6 differentiation by gemfibrozil was concentration-dependent with maximal effect noted between 200 and 400 μM, as indicated by creatine kinase activities and the differentiation index, respectively. In differentiating L6 myoblasts, gemfibrozil at concentrations below 400 μM led to no significant signs of apoptosis or cytotoxicity, whereas differentiation, inhibited by 200 μM gemfibrozil, was only partially recovered. A good correlation was noted between gemfibrozil concentrations that regulate [Ca(2+)]i and inhibit L6 myoblasts differentiation, and both are within the range of total serum concentrations found in the clinic. These data suggest a potential pharmacodynamic effect of gemfibrozil on myogenesis as a warning sign, in addition to the complex pharmacokinetic interactions. It is also noteworthy that mobilization of [Ca(2+)]i by gemfibrozil may trigger complex biological responses besides myocyte differentiation. Information revealed in this study explores the mechanism of gemfibrozil-induced myotoxicity through the regulation of intracellular calcium.

RSPO1/β-catenin signaling pathway regulates oogonia differentiation and entry into meiosis in the mouse fetal ovary.

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Anne-Amandine Chassot

Full Text Available Differentiation of germ cells into male gonocytes or female oocytes is a central event in sexual reproduction. Proliferation and differentiation of fetal germ cells depend on the sex of the embryo. In male mouse embryos, germ cell proliferation is regulated by the RNA helicase Mouse Vasa homolog gene and factors synthesized by the somatic Sertoli cells promote gonocyte differentiation. In the female, ovarian differentiation requires activation of the WNT/β-catenin signaling pathway in the somatic cells by the secreted protein RSPO1. Using mouse models, we now show that Rspo1 also activates the WNT/β-catenin signaling pathway in germ cells. In XX Rspo1(-/- gonads, germ cell proliferation, expression of the early meiotic marker Stra8, and entry into meiosis are all impaired. In these gonads, impaired entry into meiosis and germ cell sex reversal occur prior to detectable Sertoli cell differentiation, suggesting that β-catenin signaling acts within the germ cells to promote oogonial differentiation and entry into meiosis. Our results demonstrate that RSPO1/β-catenin signaling is involved in meiosis in fetal germ cells and contributes to the cellular decision of germ cells to differentiate into oocyte or sperm.

Distinct bone marrow blood vessels differentially regulate haematopoiesis.

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Itkin, Tomer; Gur-Cohen, Shiri; Spencer, Joel A; Schajnovitz, Amir; Ramasamy, Saravana K; Kusumbe, Anjali P; Ledergor, Guy; Jung, Yookyung; Milo, Idan; Poulos, Michael G; Kalinkovich, Alexander; Ludin, Aya; Kollet, Orit; Shakhar, Guy; Butler, Jason M; Rafii, Shahin; Adams, Ralf H; Scadden, David T; Lin, Charles P; Lapidot, Tsvee

2016-04-21

Bone marrow endothelial cells (BMECs) form a network of blood vessels that regulate both leukocyte trafficking and haematopoietic stem and progenitor cell (HSPC) maintenance. However, it is not clear how BMECs balance these dual roles, and whether these events occur at the same vascular site. We found that mammalian bone marrow stem cell maintenance and leukocyte trafficking are regulated by distinct blood vessel types with different permeability properties. Less permeable arterial blood vessels maintain haematopoietic stem cells in a low reactive oxygen species (ROS) state, whereas the more permeable sinusoids promote HSPC activation and are the exclusive site for immature and mature leukocyte trafficking to and from the bone marrow. A functional consequence of high permeability of blood vessels is that exposure to blood plasma increases bone marrow HSPC ROS levels, augmenting their migration and differentiation, while compromising their long-term repopulation and survival. These findings may have relevance for clinical haematopoietic stem cell transplantation and mobilization protocols.

Regulator of differentiation 1 (ROD1) binds to the amphipathic C-terminal peptide of thrombospondin-4 and is involved in its mitogenic activity.

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Sadvakassova, Gulzhakhan; Dobocan, Monica C; Difalco, Marcos R; Congote, Luis F

2009-09-01

The matrix protein thrombospondin-4 has an acidic amphipathic C-terminal peptide (C21) which stimulates erythroid cell proliferation. Here we show that C21 stimulates red cell formation in anemic mice in vivo. In vitro experiments indicated that the peptide-mediated increase of erythroid colony formation in cultures of human CD34+ hematopoietic progenitor cells was possible only under continuous presence of erythropoietin. In the absence of this cytokine, C21 stimulated exclusively myeloid colony formation. Therefore, the peptide is not a specific erythroid differentiation factor. In fact, it is mitogenic in non-erythroid cells, such as skin fibroblasts and kidney epithelial cells. In erythroleukemic TF-1 cells, it actually decreased the production of the erythroid differentiation marker glycophorin A. C21-affinity chromatography revealed regulator of differentiation 1 (ROD1) as a major C21-binding protein. ROD1 is the hematopoietic cell paralog of polypyrimidine tract binding proteins (PTBs), RNA splice regulators which regulate differentiation by repressing tissue-specific exons. ROD1 binding to C21 was strongly inhibited by synthetic RNAs in the order poly A > poly U > poly G = poly C and was weakly inhibited by a synthetic phosphorylated peptide mimicking the C-terminal domain of RNA polymerase II. Cellular overexpression or knockdown experiments of ROD1 suggest a role for this protein in the mitogenic activity of C21. Since the nuclear proteins ROD1 and PTBs regulate differentiation at a posttranscriptional level and there is a fast nuclear uptake of C21, we put forward the idea that the peptide is internalized, goes to the nucleus and maintains cells in a proliferative state by supporting ROD1-mediated inhibition of differentiation.

Role of RHEB in Regulating Differentiation Fate of Mesenchymal Stem Cells for Cartilage and Bone Regeneration

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Sajjad Ashraf

2017-04-01

Full Text Available Advances in mesenchymal stem cells (MSCs and cell replacement therapies are promising approaches to treat cartilage and bone defects since substantial differentiation capacities of MSCs match the demands of tissue regeneration. Our understanding of the dynamic process requiring indispensable differentiation of MSCs remains limited. Herein, we describe the role of RHEB (Ras homolog enriched in brain regulating gene signature for differentiation of human adipose derived mesenchymal stem cells (ASCs into chondrogenic, osteogenic, and adipogenic lineages. RHEB-overexpression increases the proliferation of the ASCs. RHEB enhances the chondrogenic differentiation of ASCs in 3D culture via upregulation of SOX9 with concomitant increase in glycosaminoglycans (GAGs, and type II collagen (COL2. RHEB increases the osteogenesis via upregulation of runt related transcription factor 2 (RUNX2 with an increase in the calcium and phosphate contents. RHEB also increases the expression of osteogenic markers, osteonectin and osteopontin. RHEB knockdown ASCs were incapable of expressing sufficient SRY (Sex determining region Y-box 9 (SOX9 and RUNX2, and therefore had decreased chondrogenic and osteogenic differentiation. RHEB-overexpression impaired ASCs differentiation into adipogenic lineage, through downregulation of CCAAT/enhancer binding protein beta (C/EBPβ. Conversely, RHEB knockdown abolished the negative regulation of adipogenesis. We demonstrate that RHEB is a novel regulator, with a critical role in ASCs lineage determination, and RHEB-modulated ASCs may be useful as a cell therapy for cartilage and bone defect treatments.

Somatic stem cell differentiation is regulated by PI3K/Tor signaling in response to local cues.

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Amoyel, Marc; Hillion, Kenzo-Hugo; Margolis, Shally R; Bach, Erika A

2016-11-01

Stem cells reside in niches that provide signals to maintain self-renewal, and differentiation is viewed as a passive process that depends on loss of access to these signals. Here, we demonstrate that the differentiation of somatic cyst stem cells (CySCs) in the Drosophila testis is actively promoted by PI3K/Tor signaling, as CySCs lacking PI3K/Tor activity cannot differentiate properly. We find that an insulin peptide produced by somatic cells immediately outside of the stem cell niche acts locally to promote somatic differentiation through Insulin-like receptor (InR) activation. These results indicate that there is a local 'differentiation' niche that upregulates PI3K/Tor signaling in the early daughters of CySCs. Finally, we demonstrate that CySCs secrete the Dilp-binding protein ImpL2, the Drosophila homolog of IGFBP7, into the stem cell niche, which blocks InR activation in CySCs. Thus, we show that somatic cell differentiation is controlled by PI3K/Tor signaling downstream of InR and that the local production of positive and negative InR signals regulates the differentiation niche. These results support a model in which leaving the stem cell niche and initiating differentiation are actively induced by signaling. © 2016. Published by The Company of Biologists Ltd.

Differential gene expression of two extreme honey bee (Apis mellifera) colonies showing varroa tolerance and susceptibility.

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Jiang, S; Robertson, T; Mostajeran, M; Robertson, A J; Qiu, X

2016-06-01

Varroa destructor, an ectoparasitic mite of honey bees (Apis mellifera), is the most serious pest threatening the apiculture industry. In our honey bee breeding programme, two honey bee colonies showing extreme phenotypes for varroa tolerance/resistance (S88) and susceptibility (G4) were identified by natural selection from a large gene pool over a 6-year period. To investigate potential defence mechanisms for honey bee tolerance to varroa infestation, we employed DNA microarray and real time quantitative (PCR) analyses to identify differentially expressed genes in the tolerant and susceptible colonies at pupa and adult stages. Our results showed that more differentially expressed genes were identified in the tolerant bees than in bees from the susceptible colony, indicating that the tolerant colony showed an increased genetic capacity to respond to varroa mite infestation. In both colonies, there were more differentially expressed genes identified at the pupa stage than at the adult stage, indicating that pupa bees are more responsive to varroa infestation than adult bees. Genes showing differential expression in the colony phenotypes were categorized into several groups based on their molecular functions, such as olfactory signalling, detoxification processes, exoskeleton formation, protein degradation and long-chain fatty acid metabolism, suggesting that these biological processes play roles in conferring varroa tolerance to naturally selected colonies. Identification of differentially expressed genes between the two colony phenotypes provides potential molecular markers for selecting and breeding varroa-tolerant honey bees. © 2016 The Royal Entomological Society.

Angiotensin II Regulation of Proliferation, Differentiation, and Engraftment of Hematopoietic Stem Cells.

Science.gov (United States)

Kim, Seungbum; Zingler, Michael; Harrison, Jeffrey K; Scott, Edward W; Cogle, Christopher R; Luo, Defang; Raizada, Mohan K

2016-03-01

Emerging evidence indicates that differentiation and mobilization of hematopoietic cell are critical in the development and establishment of hypertension and hypertension-linked vascular pathophysiology. This, coupled with the intimate involvement of the hyperactive renin-angiotensin system in hypertension, led us to investigate the hypothesis that chronic angiotensin II (Ang II) infusion affects hematopoietic stem cell (HSC) regulation at the level of the bone marrow. Ang II infusion resulted in increases in hematopoietic stem/progenitor cells (83%) and long-term HSC (207%) in the bone marrow. Interestingly, increases of HSCs and long-term HSCs were more pronounced in the spleen (228% and 1117%, respectively). Furthermore, we observed higher expression of C-C chemokine receptor type 2 in these HSCs, indicating there was increased myeloid differentiation in Ang II-infused mice. This was associated with accumulation of C-C chemokine receptor type 2(+) proinflammatory monocytes in the spleen. In contrast, decreased engraftment efficiency of GFP(+) HSC was observed after Ang II infusion. Time-lapse in vivo imaging and in vitro Ang II pretreatment demonstrated that Ang II induces untimely proliferation and differentiation of the donor HSC resulting in diminished HSC engraftment and bone marrow reconstitution. We conclude that (1) chronic Ang II infusion regulates HSC proliferation, mediated by angiotensin receptor type 1a, (2) Ang II accelerates HSC to myeloid differentiation resulting in accumulation of C-C chemokine receptor type 2(+) HSCs and inflammatory monocytes in the spleen, and (3) Ang II impairs homing and reconstitution potentials of the donor HSCs. These observations highlight the important regulatory roles of Ang II on HSC proliferation, differentiation, and engraftment. © 2016 American Heart Association, Inc.

SOX17 Regulates Cholangiocyte Differentiation and Acts as a Tumor Suppressor in Cholangiocarcinoma

DEFF Research Database (Denmark)

Merino-Azpitarte, M; Lozano, E; Perugorria, M J

2017-01-01

/function was evaluated along the differentiation of human induced pluripotent stem cells (iPSC) into cholangiocytes, in the dedifferentiation process of normal human cholangiocytes (NHC) in culture and in cholangiocarcinogenesis. Lentiviruses for SOX17 overexpression or knock-down were used. Gene expression and DNA......BACKGROUND & AIMS: Cholangiocarcinoma (CCA) is a biliary malignancy linked to genetic and epigenetic abnormalities, such as hypermethylation of SOX17 promoter. Here, the role of SOX17 in cholangiocyte differentiation and cholangiocarcinogenesis was studied. METHODS: SOX17 expression...... methylation profiling were performed. RESULTS: SOX17 expression is induced in the last stage of cholangiocyte differentiation from iPSC and regulates the acquisition of biliary markers. SOX17 becomes downregulated in NHC undergoing dedifferentiation; experimental SOX17 knock-down in differentiated NHC...

Clinical and pathogenetic interrelation between molecular regulation of apoptosis and cell differentiation in osteoarthritis

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M A Kabalyk

2018-02-01

Full Text Available Aim. To determine clinical and pathogenetic relationship between the levels of apoptosis and growth and differentiation regulation (growth inhibitor 1 induced by oxidative stress, growth/differentiation factor 5 in osteoarthritis. Methods. In a rheumatology office of Vladivostok polyclinic №3 65 patients with knee osteoarthritis Kellgren grade 1-4 aged 66.5±8.0 years were examined. 25 healthy volunteers matched by sex and age without clinical and radiologic manifestations of osteoarthritis were included into control group. To measure concentration of the studied molecules in study patients’ blood, ELISA method was used. Results. Patients with osteoarthritis compared to control group had statistically significantly increased levels of Fas, growth/differentiation factor 5 and ratio of growth/differentiation factor 5/growth inhibitor 1 induced by oxidative stress. Fas levels were significantly lower in late stages 2-4 of osteoarthritis compared to stages 1 and 2. Growth/differentiation factor 5 level was lower in patients with stage 3-4 of osteoarthritis compared to stages 1 and 2. As radiologic signs of osteoarthritis progressed, decrease of the ratio of growth/differentiation factor 5/growth inhibitor 1 induced by oxidative stress, was registered which was significantly lower in stages 2 and 3 compared to stage 1. Conclusion. Extrinsic pathway of apoptosis plays a big role in forming pain syndrome in osteoarthritis, and its maintenance is provided by other mechanisms which include influence of oxidative stress via inhibition of cell cycle mediated by growth inhibitor 1 induced by oxidative stress, reduced involvement of growth/differentiation factor 5 in differentiation processes and regulation of protein synthesis of extracellular cartilaginous tissue matrix.

Sialylation regulates myofibroblast differentiation of human skin fibroblasts.

Science.gov (United States)

Sasaki, Norihiko; Itakura, Yoko; Toyoda, Masashi

2017-04-18

differentiation in LP fibroblasts was restored by a sialidase inhibitor. Desialylation of CD44 with increased sialidase during the process to senescence reduced the localization of CD44 in lipid rafts after TGF-β1 stimulation, leading to the inhibition of myofibroblast differentiation. Thus, regulation of sialylation may be an attractive strategy for the prevention and regenerative therapy of age-related skin diseases, cosmetic skin alterations, and chronic wounds caused by delayed healing in elderly people.

Differential regulation of cyclin-dependent kinase inhibitors in neuroblastoma cells

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Qiao, Lan [Department of Pediatric Surgery, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Department of Pharmaceutical Sciences, Jilin University, Changchun 130021 (China); Paul, Pritha; Lee, Sora [Department of Pediatric Surgery, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Qiao, Jingbo [Department of Pediatric Surgery, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Wang, Yongsheng [Department of Pharmaceutical Sciences, Jilin University, Changchun 130021 (China); Chung, Dai H., E-mail: dai.chung@vanderbilt.edu [Department of Pediatric Surgery, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN 37232 (United States)

2013-05-31

Highlights: •GRP-R signaling differentially regulated the expression of p21 and p27. •Silencing GRP/GRP-R downregulated p21, while p27 expression was upregulated. •Inhibition of GRP/GRP-R signaling enhanced PTEN expression, correlative to the increased expression of p27. •PTEN and p27 co-localized in cytoplasm and silencing PTEN decreased p27 expression. -- Abstract: Gastrin-releasing peptide (GRP) and its receptor (GRP-R) are highly expressed in undifferentiated neuroblastoma, and they play critical roles in oncogenesis. We previously reported that GRP activates the PI3K/AKT signaling pathway to promote DNA synthesis and cell cycle progression in neuroblastoma cells. Conversely, GRP-R silencing induces cell cycle arrest. Here, we speculated that GRP/GRP-R signaling induces neuroblastoma cell proliferation via regulation of cyclin-dependent kinase (CDK) inhibitors. Surprisingly, we found that GRP/GRP-R differentially induced expressions of p21 and p27. Silencing GRP/GRP-R decreased p21, but it increased p27 expressions in neuroblastoma cells. Furthermore, we found that the intracellular localization of p21 and p27 in the nuclear and cytoplasmic compartments, respectively. In addition, we found that GRP/GRP-R silencing increased the expression and accumulation of PTEN in the cytoplasm of neuroblastoma cells where it co-localized with p27, thus suggesting that p27 promotes the function of PTEN as a tumor suppressor by stabilizing PTEN in the cytoplasm. GRP/GRP-R regulation of CDK inhibitors and tumor suppressor PTEN may be critical for tumoriogenesis of neuroblastoma.

Differential regulation of cyclin-dependent kinase inhibitors in neuroblastoma cells

International Nuclear Information System (INIS)

Qiao, Lan; Paul, Pritha; Lee, Sora; Qiao, Jingbo; Wang, Yongsheng; Chung, Dai H.

2013-01-01

Highlights: •GRP-R signaling differentially regulated the expression of p21 and p27. •Silencing GRP/GRP-R downregulated p21, while p27 expression was upregulated. •Inhibition of GRP/GRP-R signaling enhanced PTEN expression, correlative to the increased expression of p27. •PTEN and p27 co-localized in cytoplasm and silencing PTEN decreased p27 expression. -- Abstract: Gastrin-releasing peptide (GRP) and its receptor (GRP-R) are highly expressed in undifferentiated neuroblastoma, and they play critical roles in oncogenesis. We previously reported that GRP activates the PI3K/AKT signaling pathway to promote DNA synthesis and cell cycle progression in neuroblastoma cells. Conversely, GRP-R silencing induces cell cycle arrest. Here, we speculated that GRP/GRP-R signaling induces neuroblastoma cell proliferation via regulation of cyclin-dependent kinase (CDK) inhibitors. Surprisingly, we found that GRP/GRP-R differentially induced expressions of p21 and p27. Silencing GRP/GRP-R decreased p21, but it increased p27 expressions in neuroblastoma cells. Furthermore, we found that the intracellular localization of p21 and p27 in the nuclear and cytoplasmic compartments, respectively. In addition, we found that GRP/GRP-R silencing increased the expression and accumulation of PTEN in the cytoplasm of neuroblastoma cells where it co-localized with p27, thus suggesting that p27 promotes the function of PTEN as a tumor suppressor by stabilizing PTEN in the cytoplasm. GRP/GRP-R regulation of CDK inhibitors and tumor suppressor PTEN may be critical for tumoriogenesis of neuroblastoma

Histone Methylation and microRNA-dependent Regulation of Epigenetic Activities in Neural Progenitor Self-Renewal and Differentiation.

Science.gov (United States)

Cacci, Emanuele; Negri, Rodolfo; Biagioni, Stefano; Lupo, Giuseppe

2017-01-01

Neural stem/progenitor cell (NSPC) self-renewal and differentiation in the developing and the adult brain are controlled by extra-cellular signals and by the inherent competence of NSPCs to produce appropriate responses. Stage-dependent responsiveness of NSPCs to extrinsic cues is orchestrated at the epigenetic level. Epigenetic mechanisms such as DNA methylation, histone modifications and non-coding RNA-mediated regulation control crucial aspects of NSPC development and function, and are also implicated in pathological conditions. While their roles in the regulation of stem cell fate have been largely explored in pluripotent stem cell models, the epigenetic signature of NSPCs is also key to determine their multipotency as well as their progressive bias towards specific differentiation outcomes. Here we review recent developments in this field, focusing on the roles of histone methylation marks and the protein complexes controlling their deposition in NSPCs of the developing cerebral cortex and the adult subventricular zone. In this context, we describe how bivalent promoters, carrying antagonistic epigenetic modifications, feature during multiple steps of neural development, from neural lineage specification to neuronal differentiation. Furthermore, we discuss the emerging cross-talk between epigenetic regulators and microRNAs, and how the interplay between these different layers of regulation can finely tune the expression of genes controlling NSPC maintenance and differentiation. In particular, we highlight recent advances in the identification of astrocyte-enriched microRNAs and their function in cell fate choices of NSPCs differentiating towards glial lineages.

MiRNA-199a-3p Regulates C2C12 Myoblast Differentiation through IGF-1/AKT/mTOR Signal Pathway

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Long Jia

2013-12-01

Full Text Available MicroRNAs constitute a class of ~22-nucleotide non-coding RNAs. They modulate gene expression by associating with the 3' untranslated regions (3' UTRs of messenger RNAs (mRNAs. Although multiple miRNAs are known to be regulated during myoblast differentiation, their individual roles in muscle development are still not fully understood. In this study, we showed that miR-199a-3p was highly expressed in skeletal muscle and was induced during C2C12 myoblasts differentiation. We also identified and confirmed several genes of the IGF-1/AKT/mTOR signal pathway, including IGF-1, mTOR, and RPS6KA6, as important cellular targets of miR-199a-3p in myoblasts. Overexpression of miR-199a-3p partially blocked C2C12 myoblast differentiation and the activation of AKT/mTOR signal pathway, while interference of miR-199a-3p by antisense oligonucleotides promoted C2C12 differentiation and myotube hypertrophy. Thus, our studies have established miR-199a-3p as a potential regulator of myogenesis through the suppression of IGF-1/AKT/mTOR signal pathway.

Proximity-based differential single cell analysis of the niche to identify stem/progenitor cell regulators

Science.gov (United States)

Silberstein, Lev; Goncalves, Kevin A; Kharchenko, Peter V; Turcotte, Raphael; Kfoury, Youmna; Mercier, Francois; Baryawno, Ninib; Severe, Nicolas; Bachand, Jacqueline; Spencer, Joel; Papazian, Ani; Lee, Dongjun; Chitteti, Brahmananda Reddy; Srour, Edward F; Hoggatt, Jonathan; Tate, Tiffany; Celso, Cristina Lo; Ono, Noriaki; Nutt, Stephen; Heino, Jyrki; Sipilä, Kalle; Shioda, Toshihiro; Osawa, Masatake; Lin, Charles P; Hu, Guo-fu; Scadden, David T

2016-01-01

SUMMARY Physiological stem cell function is regulated by secreted factors produced by niche cells. In this study, we describe an unbiased approach based on differential single-cell gene expression analysis of mesenchymal osteolineage cells close to and further removed from hematopoietic stem/progenitor cells to identify candidate niche factors. Mesenchymal cells displayed distinct molecular profiles based on their relative location. Amongst the genes which were preferentially expressed in proximal cells, we functionally examined three secreted or cell surface molecules not previously connected to HSPC biology: the secreted RNase Angiogenin, the cytokine IL18 and the adhesion molecule Embigin and discovered that all of these factors are HSPC quiescence regulators. Our proximity-based differential single cell approach therefore reveals molecular heterogeneity within niche cells and can be used to identify novel extrinsic stem/progenitor cell regulators. Similar approaches could also be applied to other stem cell/niche pairs to advance understanding of microenvironmental regulation of stem cell function. PMID:27524439

Molecular and Genetic Analysis of Hormone-Regulated Differential Cell Elongation in Arabidopsis

Energy Technology Data Exchange (ETDEWEB)

Ecker, Joseph R.

2005-09-15

We have utilized the response of Arabidopsis seedlings to the plant hormone ethylene to identify new genes involved in the regulation of ethylene biosynthesis, perception, signal transduction and differential cell growth. In building a genetic framework for the action of these genes, we have developed a molecular model that has facilitated our understanding of the molecular requirements of ethylene for cell elongation processes. The ethylene response pathway in Arabidopsis appears to be primarily linear and is defined by the genes: ETR1, ETR2, ERS1, ERS2, EIN4, CTR1, EIN2, EIN3, EIN5, EIN6, and EIN. Downstream branches identified by the HLS1, EIR1, and AUX1 genes involve interactions with other hormonal (auxin) signals in the process of differential cell elongation in the hypocotyl hook. Cloning and characterization of HLS1 (and three HLL genes) and ETO1 (and ETOL genes) in my laboratory has been supported under this award. HLS1 is required for differential elongation of cells in the hypocotyl and may act in the establishment of hormone gradients. Also during the previous period, we have identified and characterized a gene that genetically acts upstream of the ethylene receptors. ETO1 encodes negative regulators of ethylene biosynthesis.

A VESICLE TRAFFICKING PROTEIN αSNAP REGULATES PANETH CELL DIFFERENTIATION IN VIVO

Science.gov (United States)

Lechuga, Susana; Naydenov, Nayden G.; Feygin, Alex; Jimenez, Antonio J.; Ivanov, Andrei I.

2017-01-01

A soluble N-ethylmaleimide-sensitive factor-attachment protein alpha (αSNAP) is a multifunctional scaffolding protein that regulates intracellular vesicle trafficking and signaling. In cultured intestinal epithelial cells, αSNAP has been shown to be essential for cell survival, motility, and adhesion; however, its physiologic functions in the intestinal mucosa remain unknown. In the present study, we used a mouse with a spontaneous hydrocephalus with hop gait (hyh) mutation of αSNAP to examine the roles of this trafficking protein in regulating intestinal epithelial homeostasis in vivo. Homozygous hyh mice demonstrated decreased expression of αSNAP protein in the intestinal epithelium, but did not display gross abnormalities of epithelial architecture in the colon and ileum. Such αSNAP depletion attenuated differentiation of small intestinal epithelial enteroids ex vivo. Furthermore, αSNAP-deficient mutant animals displayed reduced formation of lysozyme granules in small intestinal crypts and decreased expression of lysozyme and defensins in the intestinal mucosa, which is indicative of defects in Paneth cell differentiation. By contrast, development of Goblet cells, enteroendocrine cells, and assembly of enterocyte apical junctions was not altered in hyh mutant mice. Our data revealed a novel role of αSNAP in the intestinal Paneth cell differentiation in vivo. PMID:28359759

Regulation of eukaryotic initiation factor 4AII by MyoD during murine myogenic cell differentiation.

Directory of Open Access Journals (Sweden)

Gabriela Galicia-Vázquez

Full Text Available Gene expression during muscle cell differentiation is tightly regulated at multiple levels, including translation initiation. The PI3K/mTOR signalling pathway exerts control over protein synthesis by regulating assembly of eukaryotic initiation factor (eIF 4F, a heterotrimeric complex that stimulates recruitment of ribosomes to mRNA templates. One of the subunits of eIF4F, eIF4A, supplies essential helicase function during this phase of translation. The presence of two cellular eIF4A isoforms, eIF4AI and eIF4AII, has long thought to impart equivalent functions to eIF4F. However, recent experiments have alluded to distinct activities between them. Herein, we characterize distinct regulatory mechanisms between the eIF4A isoforms during muscle cell differentiation. We find that eIF4AI levels decrease during differentiation whereas eIF4AII levels increase during myofiber formation in a MyoD-dependent manner. This study characterizes a previously undefined mechanism for eIF4AII regulation in differentiation and highlights functional differences between eIF4AI and eIF4AII. Finally, RNAi-mediated alterations in eIF4AI and eIF4AII levels indicate that the myogenic process can tolerate short term reductions in eIF4AI or eIF4AII levels, but not both.

Dementias show differential physiological responses to salient sounds.

Science.gov (United States)

Fletcher, Phillip D; Nicholas, Jennifer M; Shakespeare, Timothy J; Downey, Laura E; Golden, Hannah L; Agustus, Jennifer L; Clark, Camilla N; Mummery, Catherine J; Schott, Jonathan M; Crutch, Sebastian J; Warren, Jason D

2015-01-01

Abnormal responsiveness to salient sensory signals is often a prominent feature of dementia diseases, particularly the frontotemporal lobar degenerations, but has been little studied. Here we assessed processing of one important class of salient signals, looming sounds, in canonical dementia syndromes. We manipulated tones using intensity cues to create percepts of salient approaching ("looming") or less salient withdrawing sounds. Pupil dilatation responses and behavioral rating responses to these stimuli were compared in patients fulfilling consensus criteria for dementia syndromes (semantic dementia, n = 10; behavioral variant frontotemporal dementia, n = 16, progressive nonfluent aphasia, n = 12; amnestic Alzheimer's disease, n = 10) and a cohort of 26 healthy age-matched individuals. Approaching sounds were rated as more salient than withdrawing sounds by healthy older individuals but this behavioral response to salience did not differentiate healthy individuals from patients with dementia syndromes. Pupil responses to approaching sounds were greater than responses to withdrawing sounds in healthy older individuals and in patients with semantic dementia: this differential pupil response was reduced in patients with progressive nonfluent aphasia and Alzheimer's disease relative both to the healthy control and semantic dementia groups, and did not correlate with nonverbal auditory semantic function. Autonomic responses to auditory salience are differentially affected by dementias and may constitute a novel biomarker of these diseases.

Low-intensity pulsed ultrasound regulates proliferation and differentiation of osteoblasts through osteocytes

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Li, Lei, E-mail: geraldleelei@163.com [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu (China); Yang, Zheng [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu (China); Zhang, Hai [Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, WA (United States); Chen, Wenchuan [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu (China); Chen, Mengshi [Department of Biomechanics, Sichuan University, Chengdu (China); Zhu, Zhimin, E-mail: hxzhimin@163.com [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu (China)

2012-02-10

Highlights: Black-Right-Pointing-Pointer CM from LIPUS-stimulated osteocytes inhibits proliferation of osteoblasts. Black-Right-Pointing-Pointer CM from LIPUS-stimulated osteocytes enhances differentiation of osteoblasts. Black-Right-Pointing-Pointer LIPUS stimulates MLO-Y4 cells to secrete PGE{sub 2} and NO. -- Abstract: Low-intensity pulsed ultrasound (LIPUS) has been used as a safe and effective modality to enhance fracture healing. As the most abundant cells in bone, osteocytes orchestrate biological activities of effector cells via direct cell-to-cell contacts and by soluble factors. In this study, we have used the osteocytic MLO-Y4 cells to study the effects of conditioned medium from LIPUS-stimulated MLO-Y4 cells on proliferation and differentiation of osteoblastic MC3T3-E1 cells. Conditioned media from LIPUS-stimulated MLO-Y4 cells (LIPUS-Osteocyte-CM) were collected and added on MC3T3-E1 cell cultures. MC3T3-E1 cells cultured in LIPUS-Osteocyte-CM demonstrated a significant inhibition of proliferation and an increased alkaline phosphatase activity. The results of PGE{sub 2} and NO assay showed that LIPUS could enhance PGE{sub 2} and NO secretion from MLO-Y4 cells at all time points within 24 h after LIPUS stimulation. We conclude that LIPUS regulates proliferation and differentiation of osteoblasts through osteocytes in vitro. Increased secretion of PGE{sub 2} from osteocytes may play a role in this effect.

Epigenetic landscapes reveal transcription factors that regulate CD8+ T cell differentiation.

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Yu, Bingfei; Zhang, Kai; Milner, J Justin; Toma, Clara; Chen, Runqiang; Scott-Browne, James P; Pereira, Renata M; Crotty, Shane; Chang, John T; Pipkin, Matthew E; Wang, Wei; Goldrath, Ananda W

2017-05-01

Dynamic changes in the expression of transcription factors (TFs) can influence the specification of distinct CD8 + T cell fates, but the observation of equivalent expression of TFs among differentially fated precursor cells suggests additional underlying mechanisms. Here we profiled the genome-wide histone modifications, open chromatin and gene expression of naive, terminal-effector, memory-precursor and memory CD8 + T cell populations induced during the in vivo response to bacterial infection. Integration of these data suggested that the expression and binding of TFs contributed to the establishment of subset-specific enhancers during differentiation. We developed a new bioinformatics method using the PageRank algorithm to reveal key TFs that influence the generation of effector and memory populations. The TFs YY1 and Nr3c1, both constitutively expressed during CD8 + T cell differentiation, regulated the formation of terminal-effector cell fates and memory-precursor cell fates, respectively. Our data define the epigenetic landscape of differentiation intermediates and facilitate the identification of TFs with previously unappreciated roles in CD8 + T cell differentiation.

VMAT2 identified as a regulator of late-stage β-cell differentiation.

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Sakano, Daisuke; Shiraki, Nobuaki; Kikawa, Kazuhide; Yamazoe, Taiji; Kataoka, Masateru; Umeda, Kahoko; Araki, Kimi; Mao, Di; Matsumoto, Shirou; Nakagata, Naomi; Andersson, Olov; Stainier, Didier; Endo, Fumio; Kume, Kazuhiko; Uesugi, Motonari; Kume, Shoen

2014-02-01

Cell replacement therapy for diabetes mellitus requires cost-effective generation of high-quality, insulin-producing, pancreatic β cells from pluripotent stem cells. Development of this technique has been hampered by a lack of knowledge of the molecular mechanisms underlying β-cell differentiation. The present study identified reserpine and tetrabenazine (TBZ), both vesicular monoamine transporter 2 (VMAT2) inhibitors, as promoters of late-stage differentiation of Pdx1-positive pancreatic progenitor cells into Neurog3 (referred to henceforth as Ngn3)-positive endocrine precursors. VMAT2-controlled monoamines, such as dopamine, histamine and serotonin, negatively regulated β-cell differentiation. Reserpine or TBZ acted additively with dibutyryl adenosine 3',5'-cyclic AMP, a cell-permeable cAMP analog, to potentiate differentiation of embryonic stem (ES) cells into β cells that exhibited glucose-stimulated insulin secretion. When ES cell-derived β cells were transplanted into AKITA diabetic mice, the cells reversed hyperglycemia. Our protocol provides a basis for the understanding of β-cell differentiation and its application to a cost-effective production of functional β cells for cell therapy.

Bacterial competition reveals differential regulation of the pks genes by Bacillus subtilis.

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Vargas-Bautista, Carol; Rahlwes, Kathryn; Straight, Paul

2014-02-01

Bacillus subtilis is adaptable to many environments in part due to its ability to produce a broad range of bioactive compounds. One such compound, bacillaene, is a linear polyketide/nonribosomal peptide. The pks genes encode the enzymatic megacomplex that synthesizes bacillaene. The majority of pks genes appear to be organized as a giant operon (>74 kb from pksC-pksR). In previous work (P. D. Straight, M. A. Fischbach, C. T. Walsh, D. Z. Rudner, and R. Kolter, Proc. Natl. Acad. Sci. U. S. A. 104:305-310, 2007, doi:10.1073/pnas.0609073103), a deletion of the pks operon in B. subtilis was found to induce prodiginine production by Streptomyces coelicolor. Here, colonies of wild-type B. subtilis formed a spreading population that induced prodiginine production from Streptomyces lividans, suggesting differential regulation of pks genes and, as a result, bacillaene. While the parent colony showed widespread induction of pks expression among cells in the population, we found the spreading cells uniformly and transiently repressed the expression of the pks genes. To identify regulators that control pks genes, we first determined the pattern of pks gene expression in liquid culture. We next identified mutations in regulatory genes that disrupted the wild-type pattern of pks gene expression. We found that expression of the pks genes requires the master regulator of development, Spo0A, through its repression of AbrB and the stationary-phase regulator, CodY. Deletions of degU, comA, and scoC had moderate effects, disrupting the timing and level of pks gene expression. The observed patterns of expression suggest that complex regulation of bacillaene and other antibiotics optimizes competitive fitness for B. subtilis.

Pairwise comparisons of ten porcine tissues identify differential transcriptional regulation at the gene, isoform, promoter and transcription start site level

International Nuclear Information System (INIS)

Farajzadeh, Leila; Hornshøj, Henrik; Momeni, Jamal; Thomsen, Bo; Larsen, Knud; Hedegaard, Jakob; Bendixen, Christian; Madsen, Lone Bruhn

2013-01-01

Highlights: •Transcriptome sequencing yielded 223 mill porcine RNA-seq reads, and 59,000 transcribed locations. •Establishment of unique transcription profiles for ten porcine tissues including four brain tissues. •Comparison of transcription profiles at gene, isoform, promoter and transcription start site level. •Highlights a high level of regulation of neuro-related genes at both gene, isoform, and TSS level. •Our results emphasize the pig as a valuable animal model with respect to human biological issues. -- Abstract: The transcriptome is the absolute set of transcripts in a tissue or cell at the time of sampling. In this study RNA-Seq is employed to enable the differential analysis of the transcriptome profile for ten porcine tissues in order to evaluate differences between the tissues at the gene and isoform expression level, together with an analysis of variation in transcription start sites, promoter usage, and splicing. Totally, 223 million RNA fragments were sequenced leading to the identification of 59,930 transcribed gene locations and 290,936 transcript variants using Cufflinks with similarity to approximately 13,899 annotated human genes. Pairwise analysis of tissues for differential expression at the gene level showed that the smallest differences were between tissues originating from the porcine brain. Interestingly, the relative level of differential expression at the isoform level did generally not vary between tissue contrasts. Furthermore, analysis of differential promoter usage between tissues, revealed a proportionally higher variation between cerebellum (CBE) versus frontal cortex and cerebellum versus hypothalamus (HYP) than in the remaining comparisons. In addition, the comparison of differential transcription start sites showed that the number of these sites is generally increased in comparisons including hypothalamus in contrast to other pairwise assessments. A comprehensive analysis of one of the tissue contrasts, i

Single Low-Dose Radiation Induced Regulation of Keratinocyte Differentiation in Calcium-Induced HaCaT Cells

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Hahn, Hyung Jin; Youn, Hae Jeong; Cha, Hwa Jun; Kim, Karam; An, Sungkwan

2016-01-01

Background We are continually exposed to low-dose radiation (LDR) in the range 0.1 Gy from natural sources, medical devices, nuclear energy plants, and other industrial sources of ionizing radiation. There are three models for the biological mechanism of LDR: the linear no-threshold model, the hormetic model, and the threshold model. Objective We used keratinocytes as a model system to investigate the molecular genetic effects of LDR on epidermal cell differentiation. Methods To identify keratinocyte differentiation, we performed western blots using a specific antibody for involucrin, which is a precursor protein of the keratinocyte cornified envelope and a marker for keratinocyte terminal differentiation. We also performed quantitative polymerase chain reaction. We examined whether LDR induces changes in involucrin messenger RNA (mRNA) and protein levels in calcium-induced keratinocyte differentiation. Results Exposure of HaCaT cells to LDR (0.1 Gy) induced p21 expression. p21 is a key regulator that induces growth arrest and represses stemness, which accelerates keratinocyte differentiation. We correlated involucrin expression with keratinocyte differentiation, and examined the effects of LDR on involucrin levels and keratinocyte development. LDR significantly increased involucrin mRNA and protein levels during calcium-induced keratinocyte differentiation. Conclusion These studies provide new evidence for the biological role of LDR, and identify the potential to utilize LDR to regulate or induce keratinocyte differentiation. PMID:27489424

Gonad Transcriptome Analysis of the Pacific Oyster Crassostrea gigas Identifies Potential Genes Regulating the Sex Determination and Differentiation Process.

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Yue, Chenyang; Li, Qi; Yu, Hong

2018-04-01

The Pacific oyster Crassostrea gigas is a commercially important bivalve in aquaculture worldwide. C. gigas has a fascinating sexual reproduction system consisting of dioecism, sex change, and occasional hermaphroditism, while knowledge of the molecular mechanisms of sex determination and differentiation is still limited. In this study, the transcriptomes of male and female gonads at different gametogenesis stages were characterized by RNA-seq. Hierarchical clustering based on genes differentially expressed revealed that 1269 genes were expressed specifically in female gonads and 817 genes were expressed increasingly over the course of spermatogenesis. Besides, we identified two and one gene modules related to female and male gonad development, respectively, using weighted gene correlation network analysis (WGCNA). Interestingly, GO and KEGG enrichment analysis showed that neurotransmitter-related terms were significantly enriched in genes related to ovary development, suggesting that the neurotransmitters were likely to regulate female sex differentiation. In addition, two hub genes related to testis development, lncRNA LOC105321313 and Cg-Sh3kbp1, and one hub gene related to ovary development, Cg-Malrd1-like, were firstly investigated. This study points out the role of neurotransmitter and non-coding RNA regulation during gonad development and produces lists of novel relevant candidate genes for further studies. All of these provided valuable information to understand the molecular mechanisms of C. gigas sex determination and differentiation.

FOXO1-suppressed miR-424 regulates the proliferation and osteogenic differentiation of MSCs by targeting FGF2 under oxidative stress

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Li, Liangping; Qi, Qihua; Luo, Jiaquan; Huang, Sheng; Ling, Zemin; Gao, Manman; Zhou, Zhiyu; Stiehler, Maik; Zou, Xuenong

2017-02-01

Recently, microRNAs (miRNAs) have been identified as key regulators of the proliferation and differentiation of mesenchymal stem cells (MSCs). Our previous in vivo study and other in vitro studies using miRNA microarrays suggest that miR-424 is involved in the regulation of bone formation. However, the role and mechanism of miR-424 in bone formation still remain unknown. Here, we identified that the downregulation of miR-424 mediates bone formation under oxidative stress, and we explored its underlying mechanism. Our results showed that miR-424 was significantly downregulated in an anterior lumbar interbody fusion model of pigs and in a cell model of oxidative stress induced by H2O2. The overexpression of miR-424 inhibited proliferation and osteogenic differentiation shown by a decrease in alkaline phosphatase (ALP) activity, mineralization and osteogenic markers, including RUNX2 and ALP, whereas the knockdown of miR-424 led to the opposite results. Moreover, miR-424 exerts its effects by targeting FGF2. Furthermore, we found that FOXO1 suppressed miR-424 expression and bound to its promoter region. FOXO1 enhanced proliferation and osteogenic differentiation in part through the miR-424/FGF2 pathway. These results indicated that FOXO1-suppressed miR-424 regulates both the proliferation and osteogenic differentiation of MSCs via targeting FGF2, suggesting that miR-424 might be a potential novel therapeutic strategy for promoting bone formation.

Pupils' Self-Regulation in Physical Education: The Role of Motivational Climates and Differential Achievement Goals

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Ommundsen, Yngvar

2006-01-01

This study examined the relationship of motivational climate and differential achievement goals to meta-cognitive self-regulation, regulation of effort, help-seeking and self-handicapping in physical education (PE). The sample consisted of 273 pupils (boys n = 125; girls n = 148) attending 10th grade PE classes in Norway. Both motivational…

miR-146a modulates autoreactive Th17 cell differentiation and regulates organ-specific autoimmunity.

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Li, Bo; Wang, Xi; Choi, In Young; Wang, Yu-Chen; Liu, Siyuan; Pham, Alexander T; Moon, Heesung; Smith, Drake J; Rao, Dinesh S; Boldin, Mark P; Yang, Lili

2017-10-02

Autoreactive CD4 T cells that differentiate into pathogenic Th17 cells can trigger autoimmune diseases. Therefore, investigating the regulatory network that modulates Th17 differentiation may yield important therapeutic insights. miR-146a has emerged as a critical modulator of immune reactions, but its role in regulating autoreactive Th17 cells and organ-specific autoimmunity remains largely unknown. Here, we have reported that miR-146a-deficient mice developed more severe experimental autoimmune encephalomyelitis (EAE), an animal model of human multiple sclerosis (MS). We bred miR-146a-deficient mice with 2D2 T cell receptor-Tg mice to generate 2D2 CD4 T cells that are deficient in miR-146a and specific for myelin oligodendrocyte glycoprotein (MOG), an autoantigen in the EAE model. miR-146a-deficient 2D2 T cells induced more severe EAE and were more prone to differentiate into Th17 cells. Microarray analysis revealed enhancements in IL-6- and IL-21-induced Th17 differentiation pathways in these T cells. Further study showed that miR-146a inhibited the production of autocrine IL-6 and IL-21 in 2D2 T cells, which in turn reduced their Th17 differentiation. Thus, our study identifies miR-146a as an important molecular brake that blocks the autocrine IL-6- and IL-21-induced Th17 differentiation pathways in autoreactive CD4 T cells, highlighting its potential as a therapeutic target for treating autoimmune diseases.

miR-140-5p regulates hypoxia-mediated human pulmonary artery smooth muscle cell proliferation, apoptosis and differentiation by targeting Dnmt1 and promoting SOD2 expression

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Zhang, Yanwei; Xu, Jing, E-mail: xujingdoc@163.com

2016-04-22

miR-140-5p is down-regulated in patients with pulmonary arterial hypertension (PAH) and experimental models of PAH, and inhibits hypoxia-mediated pulmonary artery smooth muscle cell (PASMC) proliferation in vitro. Delivery of synthetic miR-140-5p prevents and treats established, experimental PAH. DNA methyltransferase 1 (Dnmt1) is up-regulated in PAH associated human PASMCs (HPASMCs), which promotes the development of PAH by hypermethylation of CpG islands within the promoter for superoxide dismutase 2 (SOD2) and down-regulating SOD2 expression. We searched for miR-140-5p targets using TargetScan, PicTar and MiRanda tools, and found that Dnmt1 is a potential target of miR-140-5p. Based on these findings, we speculated that miR-140-5p might target Dnmt1 and regulate SOD2 expression to regulate hypoxia-mediated HPASMC proliferation, apoptosis and differentiation. We detected the expression of miR-140-5p, Dnmt1 and SOD2 by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot assays, respectively, and found down-regulation of miR-140-5p and SOD2 and up-regulation of Dnmt1 exist in PAH tissues and hypoxia-mediated HPASMCs. Cell proliferation, apoptosis and differentiation detection showed that miR-140-5p inhibits proliferation and promotes apoptosis and differentiation of HPASMCs in hypoxia, while the effect of Dnmt1 on hypoxia-mediated HPASMCs is reversed. Luciferase assay confirmed that miR-140-5p targets Dnmt1 directly. An inverse correlation is also found between miR-140-5p and Dnmt1 in HPASMCs. In addition, we further investigated whether miR-140-5p and Dnmt1 regulate HPASMC proliferation, apoptosis and differentiation by regulating SOD2 expression, and the results confirmed our speculation. Taken together, these results indicated that miR-140-5p at least partly targets Dnmt1 and regulates SOD2 expression to inhibit proliferation and promote apoptosis and differentiation of HPASMCs in hypoxia. - Highlights: • miR-140-5p and SOD2 are down-regulated

Theories of estimation of differentiation for regulation of social-economic development of the city agglomeration

OpenAIRE

Anikina, Yu; Litovchenko, V.

2009-01-01

Theories of estimation of differentiation of social-economic development of territorial units in city agglomeration are discussed in the article. Approbation of the given methods helped find out successfulness of the regulation of municipal development of administrative-territorial units in Krasnoyarsk agglomeration, set the goals of regional policy on peculiarities of development of the phenomenon of differentiation.

Distinctive features and differential regulation of the DRTS genes of Arabidopsis thaliana.

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Maniga, Antonio; Ghisaura, Stefania; Perrotta, Lara; Marche, Maria Giovanna; Cella, Rino; Albani, Diego

2017-01-01

In plants and protists, dihydrofolate reductase (DHFR) and thymidylate synthase (TS) are part of a bifunctional enzyme (DRTS) that allows efficient recycling of the dihydrofolate resulting from TS activity. Arabidopsis thaliana possesses three DRTS genes, called AtDRTS1, AtDRTS2 and AtDRTS3, that are located downstream of three members of the sec14-like SFH gene family. In this study, a characterization of the AtDRTS genes identified alternatively spliced transcripts coding for AtDRTS isoforms which may account for monofunctional DHFR enzymes supporting pathways unrelated to DNA synthesis. Moreover, we discovered a complex differential regulation of the AtDRTS genes that confirms the expected involvement of the AtDRTS genes in cell proliferation and endoreduplication, but indicates also functions related to other cellular activities. AtDRTS1 is widely expressed in both meristematic and differentiated tissues, whereas AtDRTS2 expression is almost exclusively limited to the apical meristems and AtDRTS3 is preferentially expressed in the shoot apex, in stipules and in root cap cells. The differential regulation of the AtDRTS genes is associated to distinctive promoter architectures and the expression of AtDRTS1 in the apical meristems is strictly dependent on the presence of an intragenic region that includes the second intron of the gene. Upon activation of cell proliferation in germinating seeds, the activity of the AtDRTS1 and AtDRTS2 promoters in meristematic cells appears to be maximal at the G1/S phase of the cell cycle. In addition, the promoters of AtDRTS2 and AtDRTS3 are negatively regulated through E2F cis-acting elements and both genes, but not AtDRTS1, are downregulated in plants overexpressing the AtE2Fa factor. Our study provides new information concerning the function and the regulation of plant DRTS genes and opens the way to further investigations addressing the importance of folate synthesis with respect to specific cellular activities.

Rac1 Regulates the Proliferation, Adhesion, Migration, and Differentiation of MDPC-23 Cells.

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Ren, Jing; Liang, Guobin; Gong, Li; Guo, Bing; Jiang, Hongwei

2017-04-01

Stem cells are responsible for replacing damaged pulp tissue; therefore, promoting their survival and inducing their adhesion to dentin are vital. As a member of the Rho family of guanosine triphosphatases, Rac1 is an important regulator of osteoblast functions. However, little is known about its role in regenerative endodontic procedures. The current study examined the role of Rac1 in the proliferation, migration, and odontoblastic differentiation of MDPC-23 cells. MDPC-23 cells were transfected with small interfering RNA to knock down Rac1 expression, and then their proliferation, migration, adhesion, and odontoblastic differentiation were examined in vitro. MDPC-23 cells transfected with si-Rac1 exhibited the increased expression of several key odontogenic protein markers, including Dmp1, Dspp, Runx2, and alkaline phosphatase, as well as decreased proliferation and migration in vitro. The results suggest that Rac1 might regulate nuclear factor kappa B signaling in MDPC-23 cells. Rac1 may have vital roles in the proliferation, migration, adhesion, and odontoblastic differentiation of MDPC-23 cells. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Dementias show differential physiological responses to salient sounds

Directory of Open Access Journals (Sweden)

Phillip David Fletcher

2015-03-01

Full Text Available Abnormal responsiveness to salient sensory signals is often a prominent feature of dementia diseases, particularly the frontotemporal lobar degenerations, but has been little studied. Here we assessed processing of one important class of salient signals, looming sounds, in canonical dementia syndromes. We manipulated tones using intensity cues to create percepts of salient approaching (‘looming’ or less salient withdrawing sounds. Pupil dilatation responses and behavioural rating responses to these stimuli were compared in patients fulfilling consensus criteria for dementia syndromes (semantic dementia, n=10; behavioural variant frontotemporal dementia, n=16, progressive non-fluent aphasia, n=12; amnestic Alzheimer’s disease, n=10 and a cohort of 26 healthy age-matched individuals. Approaching sounds were rated as more salient than withdrawing sounds by healthy older individuals but this behavioural response to salience did not differentiate healthy individuals from patients with dementia syndromes. Pupil responses to approaching sounds were greater than responses to withdrawing sounds in healthy older individuals and in patients with semantic dementia: this differential pupil response was reduced in patients with progressive nonfluent aphasia and Alzheimer’s disease relative both to the healthy control and semantic dementia groups, and did not correlate with nonverbal auditory semantic function. Autonomic responses to auditory salience are differentially affected by dementias and may constitute a novel biomarker of these diseases.

Dementias show differential physiological responses to salient sounds

Science.gov (United States)

Fletcher, Phillip D.; Nicholas, Jennifer M.; Shakespeare, Timothy J.; Downey, Laura E.; Golden, Hannah L.; Agustus, Jennifer L.; Clark, Camilla N.; Mummery, Catherine J.; Schott, Jonathan M.; Crutch, Sebastian J.; Warren, Jason D.

2015-01-01

Abnormal responsiveness to salient sensory signals is often a prominent feature of dementia diseases, particularly the frontotemporal lobar degenerations, but has been little studied. Here we assessed processing of one important class of salient signals, looming sounds, in canonical dementia syndromes. We manipulated tones using intensity cues to create percepts of salient approaching (“looming”) or less salient withdrawing sounds. Pupil dilatation responses and behavioral rating responses to these stimuli were compared in patients fulfilling consensus criteria for dementia syndromes (semantic dementia, n = 10; behavioral variant frontotemporal dementia, n = 16, progressive nonfluent aphasia, n = 12; amnestic Alzheimer's disease, n = 10) and a cohort of 26 healthy age-matched individuals. Approaching sounds were rated as more salient than withdrawing sounds by healthy older individuals but this behavioral response to salience did not differentiate healthy individuals from patients with dementia syndromes. Pupil responses to approaching sounds were greater than responses to withdrawing sounds in healthy older individuals and in patients with semantic dementia: this differential pupil response was reduced in patients with progressive nonfluent aphasia and Alzheimer's disease relative both to the healthy control and semantic dementia groups, and did not correlate with nonverbal auditory semantic function. Autonomic responses to auditory salience are differentially affected by dementias and may constitute a novel biomarker of these diseases. PMID:25859194

Regulation of proximal tubular cell differentiation and proliferation in primary culture by matrix stiffness and ECM components.

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Chen, Wan-Chun; Lin, Hsi-Hui; Tang, Ming-Jer

2014-09-15

To explore whether matrix stiffness affects cell differentiation, proliferation, and transforming growth factor (TGF)-β1-induced epithelial-mesenchymal transition (EMT) in primary cultures of mouse proximal tubular epithelial cells (mPTECs), we used a soft matrix made from monomeric collagen type I-coated polyacrylamide gel or matrigel (MG). Both kinds of soft matrix benefited primary mPTECs to retain tubular-like morphology with differentiation and growth arrest and to evade TGF-β1-induced EMT. However, the potent effect of MG on mPTEC differentiation was suppressed by glutaraldehyde-induced cross-linking and subsequently stiffening MG or by an increasing ratio of collagen in the soft mixed gel. Culture media supplemented with MG also helped mPTECs to retain tubular-like morphology and a differentiated phenotype on stiff culture dishes as soft MG did. We further found that the protein level and activity of ERK were scaled with the matrix stiffness. U-0126, a MEK inhibitor, abolished the stiff matrix-induced dedifferentiation and proliferation. These data suggest that the ERK signaling pathway plays a vital role in matrix stiffness-regulated cell growth and differentiation. Taken together, both compliant property and specific MG signals from the matrix are required for the regulation of epithelial differentiation and proliferation. This study provides a basic understanding of how physical and chemical cues derived from the extracellular matrix regulate the physiological function of proximal tubules and the pathological development of renal fibrosis. Copyright © 2014 the American Physiological Society.

Coordinated Proliferation and Differentiation of Human-Induced Pluripotent Stem Cell-Derived Cardiac Progenitor Cells Depend on Bone Morphogenetic Protein Signaling Regulation by GREMLIN 2.

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Bylund, Jeffery B; Trinh, Linh T; Awgulewitsch, Cassandra P; Paik, David T; Jetter, Christopher; Jha, Rajneesh; Zhang, Jianhua; Nolan, Kristof; Xu, Chunhui; Thompson, Thomas B; Kamp, Timothy J; Hatzopoulos, Antonis K

2017-05-01

Heart development depends on coordinated proliferation and differentiation of cardiac progenitor cells (CPCs), but how the two processes are synchronized is not well understood. Here, we show that the secreted Bone Morphogenetic Protein (BMP) antagonist GREMLIN 2 (GREM2) is induced in CPCs shortly after cardiac mesoderm specification during differentiation of human pluripotent stem cells. GREM2 expression follows cardiac lineage differentiation independently of the differentiation method used, or the origin of the pluripotent stem cells, suggesting that GREM2 is linked to cardiogenesis. Addition of GREM2 protein strongly increases cardiomyocyte output compared to established procardiogenic differentiation methods. Our data show that inhibition of canonical BMP signaling by GREM2 is necessary to promote proliferation of CPCs. However, canonical BMP signaling inhibition alone is not sufficient to induce cardiac differentiation, which depends on subsequent JNK pathway activation specifically by GREM2. These findings may have broader implications in the design of approaches to orchestrate growth and differentiation of pluripotent stem cell-derived lineages that depend on precise regulation of BMP signaling.

Coordinated Proliferation and Differentiation of Human-Induced Pluripotent Stem Cell-Derived Cardiac Progenitor Cells Depend on Bone Morphogenetic Protein Signaling Regulation by GREMLIN 2

Science.gov (United States)

Bylund, Jeffery B.; Trinh, Linh T.; Awgulewitsch, Cassandra P.; Paik, David T.; Jetter, Christopher; Jha, Rajneesh; Zhang, Jianhua; Nolan, Kristof; Xu, Chunhui; Thompson, Thomas B.; Kamp, Timothy J.

2017-01-01

Heart development depends on coordinated proliferation and differentiation of cardiac progenitor cells (CPCs), but how the two processes are synchronized is not well understood. Here, we show that the secreted Bone Morphogenetic Protein (BMP) antagonist GREMLIN 2 (GREM2) is induced in CPCs shortly after cardiac mesoderm specification during differentiation of human pluripotent stem cells. GREM2 expression follows cardiac lineage differentiation independently of the differentiation method used, or the origin of the pluripotent stem cells, suggesting that GREM2 is linked to cardiogenesis. Addition of GREM2 protein strongly increases cardiomyocyte output compared to established procardiogenic differentiation methods. Our data show that inhibition of canonical BMP signaling by GREM2 is necessary to promote proliferation of CPCs. However, canonical BMP signaling inhibition alone is not sufficient to induce cardiac differentiation, which depends on subsequent JNK pathway activation specifically by GREM2. These findings may have broader implications in the design of approaches to orchestrate growth and differentiation of pluripotent stem cell-derived lineages that depend on precise regulation of BMP signaling. PMID:28125926

Molecular and Genetic Analysis of Hormone-Regulated Differential Cell Elongation in Arabidopsis

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Ecker, Joseph R.

2002-12-03

The authors have utilized the response of Arabidopsis seedlings to the plant hormone ethylene to identify new genes involved in the regulation of ethylene biosynthesis, perception, signal transduction and differential cell growth. In building a genetic framework for the action of these genes, they developed a molecular model that has facilitated the understanding of the molecular requirements of ethylene for cell elongation processes. The ethylene response pathway in Arabidopsis appears to be primarily linear and is defined by the genes: ETR1, ETR2, ERS1, ERS2, EIN4, CTR1, EIN2, EIN3, EIN5 EIN6, and EIN. Downstream branches identified by the HLS1, EIR1, and AUX1 genes involve interactions with other hormonal (auxin) signals in the process of differential cell elongation in the hypocotyl hook. Cloning and characterization of HLS1 and three HLS1-LIKE genes in the laboratory has been supported under this award. HLS1 is required for differential elongation of cells in the hypocotyl and may act in the establishment of hormone gradients. Also during the award period, they have identified and begun preliminary characterization of two genes that genetically act upstream of the ethylene receptors. ETO1 and RAN1 encode negative regulators of ethylene biosynthesis and signaling respectively. Progress on the analysis of these genes along with HOOKLESS1 is described.

Proximity-Based Differential Single-Cell Analysis of the Niche to Identify Stem/Progenitor Cell Regulators.

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Silberstein, Lev; Goncalves, Kevin A; Kharchenko, Peter V; Turcotte, Raphael; Kfoury, Youmna; Mercier, Francois; Baryawno, Ninib; Severe, Nicolas; Bachand, Jacqueline; Spencer, Joel A; Papazian, Ani; Lee, Dongjun; Chitteti, Brahmananda Reddy; Srour, Edward F; Hoggatt, Jonathan; Tate, Tiffany; Lo Celso, Cristina; Ono, Noriaki; Nutt, Stephen; Heino, Jyrki; Sipilä, Kalle; Shioda, Toshihiro; Osawa, Masatake; Lin, Charles P; Hu, Guo-Fu; Scadden, David T

2016-10-06

Physiological stem cell function is regulated by secreted factors produced by niche cells. In this study, we describe an unbiased approach based on the differential single-cell gene expression analysis of mesenchymal osteolineage cells close to, and further removed from, hematopoietic stem/progenitor cells (HSPCs) to identify candidate niche factors. Mesenchymal cells displayed distinct molecular profiles based on their relative location. We functionally examined, among the genes that were preferentially expressed in proximal cells, three secreted or cell-surface molecules not previously connected to HSPC biology-the secreted RNase angiogenin, the cytokine IL18, and the adhesion molecule Embigin-and discovered that all of these factors are HSPC quiescence regulators. Therefore, our proximity-based differential single-cell approach reveals molecular heterogeneity within niche cells and can be used to identify novel extrinsic stem/progenitor cell regulators. Similar approaches could also be applied to other stem cell/niche pairs to advance the understanding of microenvironmental regulation of stem cell function. Copyright © 2016 Elsevier Inc. All rights reserved.

Regulation of granulocyte colony-stimulating factor receptor-mediated granulocytic differentiation by C-mannosylation.

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Otani, Kei; Niwa, Yuki; Suzuki, Takehiro; Sato, Natsumi; Sasazawa, Yukiko; Dohmae, Naoshi; Simizu, Siro

2018-04-06

Granulocyte colony-stimulating factor (G-CSF) receptor (G-CSFR) is a type I cytokine receptor which is involved in hematopoietic cell maturation. G-CSFR has three putative C-mannosylation sites at W253, W318, and W446; however, it is not elucidated whether G-CSFR is C-mannosylated or not. In this study, we first demonstrated that G-CSFR was C-mannosylated at only W318. We also revealed that C-mannosylation of G-CSFR affects G-CSF-dependent downstream signaling through changing ligand binding capability but not cell surface localization. Moreover, C-mannosylation of G-CSFR was functional and regulated granulocytic differentiation in myeloid 32D cells. In conclusion, we found that G-CSFR is C-mannosylated at W318 and that this C-mannosylation has role(s) for myeloid cell differentiation through regulating downstream signaling. Copyright © 2018 Elsevier Inc. All rights reserved.

Bacterial Competition Reveals Differential Regulation of the pks Genes by Bacillus subtilis

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Vargas-Bautista, Carol; Rahlwes, Kathryn

2014-01-01

Bacillus subtilis is adaptable to many environments in part due to its ability to produce a broad range of bioactive compounds. One such compound, bacillaene, is a linear polyketide/nonribosomal peptide. The pks genes encode the enzymatic megacomplex that synthesizes bacillaene. The majority of pks genes appear to be organized as a giant operon (>74 kb from pksC-pksR). In previous work (P. D. Straight, M. A. Fischbach, C. T. Walsh, D. Z. Rudner, and R. Kolter, Proc. Natl. Acad. Sci. U. S. A. 104:305–310, 2007, doi:10.1073/pnas.0609073103), a deletion of the pks operon in B. subtilis was found to induce prodiginine production by Streptomyces coelicolor. Here, colonies of wild-type B. subtilis formed a spreading population that induced prodiginine production from Streptomyces lividans, suggesting differential regulation of pks genes and, as a result, bacillaene. While the parent colony showed widespread induction of pks expression among cells in the population, we found the spreading cells uniformly and transiently repressed the expression of the pks genes. To identify regulators that control pks genes, we first determined the pattern of pks gene expression in liquid culture. We next identified mutations in regulatory genes that disrupted the wild-type pattern of pks gene expression. We found that expression of the pks genes requires the master regulator of development, Spo0A, through its repression of AbrB and the stationary-phase regulator, CodY. Deletions of degU, comA, and scoC had moderate effects, disrupting the timing and level of pks gene expression. The observed patterns of expression suggest that complex regulation of bacillaene and other antibiotics optimizes competitive fitness for B. subtilis. PMID:24187085

Intracellular glutathione status regulates mouse bone marrow monocyte-derived macrophage differentiation and phagocytic activity

International Nuclear Information System (INIS)

Kim, Jin-Man; Kim, Hyunsoo; Kwon, Soon Bok; Lee, Soo Young; Chung, Sung-Chang; Jeong, Dae-Won; Min, Byung-Moo

2004-01-01

Although a redox shift can regulate the development of cells, including proliferation, differentiation, and survival, the role of the glutathione (GSH) redox status in macrophage differentiation remains unclear. In order to elucidate the role of a redox shift, macrophage-like cells were differentiated from the bone marrow-derived monocytes that were treated with a macrophage colony stimulating factor (M-CSF or CSF-1) for 3 days. The macrophagic cells were characterized by a time-dependent increase in three major symptoms: the number of phagocytic cells, the number of adherent cells, and the mRNA expression of c-fms, a M-CSF receptor that is one of the macrophage-specific markers and mediates development signals. Upon M-CSF-driven macrophage differentiation, the GSH/GSSG ratio was significantly lower on day 1 than that observed on day 0 but was constant on days 1-3. To assess the effect of the GSH-depleted and -repleted status on the differentiation and phagocytosis of the macrophages, GSH depletion by BSO, a specific inhibitor of the de novo GSH synthesis, inhibited the formation of the adherent macrophagic cells by the down-regulation of c-fms, but did not affect the phagocytic activity of the macrophages. To the contrary, GSH repletion by the addition of NAC, which is a GSH precursor, or reduced GSH in media had no effect on macrophage differentiation, and led to a decrease in the phagocytic activity. Furthermore, we observed that there is checkpoint that is capable of releasing from the inhibition of the formation of the adherent macrophagic cells according to GSH depletion by BSO. Summarizing, these results indicate that the intracellular GSH status plays an important role in the differentiation and phagocytosis of macrophages

Itga2b regulation at the onset of definitive hematopoiesis and commitment to differentiation.

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Stephanie Dumon

Full Text Available Product of the Itga2b gene, CD41 contributes to hematopoietic stem cell (HSC and megakaryocyte/platelet functions. CD41 expression marks the onset of definitive hematopoiesis in the embryo where it participates in regulating the numbers of multipotential progenitors. Key to platelet aggregation, CD41 expression also characterises their precursor, the megakaryocyte, and is specifically up regulated during megakaryopoiesis. Though phenotypically unique, megakaryocytes and HSC share numerous features, including key transcription factors, which could indicate common sub-regulatory networks. In these respects, Itga2b can serve as a paradigm to study features of both developmental-stage and HSC- versus megakaryocyte-specific regulations. By comparing different cellular contexts, we highlight a mechanism by which internal promoters participate in Itga2b regulation. A developmental process connects epigenetic regulation and promoter switching leading to CD41 expression in HSC. Interestingly, a similar process can be observed at the Mpl locus, which codes for another receptor that defines both HSC and megakaryocyte identities. Our study shows that Itga2b expression is controlled by lineage-specific networks and associates with H4K8ac in megakaryocyte or H3K27me3 in the multipotential hematopoietic cell line HPC7. Correlating with the decrease in H3K27me3 at the Itga2b Iocus, we find that following commitment to megakaryocyte differentiation, the H3K27 demethylase Jmjd3 up-regulation influences both Itga2b and Mpl expression.

1α,25(OH)2D3 differentially regulates miRNA expression in human bladder cancer cells.

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Ma, Yingyu; Hu, Qiang; Luo, Wei; Pratt, Rachel N; Glenn, Sean T; Liu, Song; Trump, Donald L; Johnson, Candace S

2015-04-01

Bladder cancer is the fourth most commonly diagnosed cancer in men and eighth leading cause of cancer-related death in the US. Epidemiological and experimental studies strongly suggest a role for 1α,25(OH)2D3 in cancer prevention and treatment. The antitumor activities of 1α,25(OH)2D3 are mediated by the induction of cell cycle arrest, apoptosis, differentiation and the inhibition of angiogenesis and metastasis. miRNAs play important regulatory roles in cancer development and progression. However, the role of 1α,25(OH)2D3 in the regulation of miRNA expression and the potential impact in bladder cancer has not been investigated. Therefore, we studied 1α,25(OH)2D3-regulated miRNA expression profiles in human bladder cancer cell line 253J and the highly tumorigenic and metastatic derivative line 253J-BV by miRNA qPCR panels. 253J and 253J-BV cells express endogenous vitamin D receptor (VDR), which can be further induced by 1α,25(OH)2D3. VDR target gene 24-hydroxylase was induced by 1α,25(OH)2D3 in both cell lines, indicating functional 1α,25(OH)2D3 signaling. The miRNA qPCR panel assay results showed that 253J and 253J-BV cells have distinct miRNA expression profiles. Further, 1α,25(OH)2D3 differentially regulated miRNA expression profiles in 253J and 253J-BV cells in a dynamic manner. Pathway analysis of the miRNA target genes revealed distinct patterns of contribution to the molecular functions and biological processes in the two cell lines. In conclusion, 1α,25(OH)2D3 differentially regulates the expression of miRNAs, which may contribute to distinct biological functions, in human bladder 253J and 253J-BV cells. This article is part of a Special Issue entitled '17th Vitamin D Workshop'. Copyright © 2014 Elsevier Ltd. All rights reserved.

Sox9-regulated miRNA-574-3p inhibits chondrogenic differentiation of mesenchymal stem cells.

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David Guérit

Full Text Available The aim of this study was to identify new microRNAs (miRNAs that are modulated during the differentiation of mesenchymal stem cells (MSCs toward chondrocytes. Using large scale miRNA arrays, we compared the expression of miRNAs in MSCs (day 0 and at early time points (day 0.5 and 3 after chondrogenesis induction. Transfection of premiRNA or antagomiRNA was performed on MSCs before chondrogenesis induction and expression of miRNAs and chondrocyte markers was evaluated at different time points during differentiation by RT-qPCR. Among miRNAs that were modulated during chondrogenesis, we identified miR-574-3p as an early up-regulated miRNA. We found that miR-574-3p up-regulation is mediated via direct binding of Sox9 to its promoter region and demonstrated by reporter assay that retinoid X receptor (RXRα is one gene specifically targeted by the miRNA. In vitro transfection of MSCs with premiR-574-3p resulted in the inhibition of chondrogenesis demonstrating its role during the commitment of MSCs towards chondrocytes. In vivo, however, both up- and down-regulation of miR-574-3p expression inhibited differentiation toward cartilage and bone in a model of heterotopic ossification. In conclusion, we demonstrated that Sox9-dependent up-regulation of miR-574-3p results in RXRα down-regulation. Manipulating miR-574-3p levels both in vitro and in vivo inhibited chondrogenesis suggesting that miR-574-3p might be required for chondrocyte lineage maintenance but also that of MSC multipotency.

Classical and alternative NF-κB signaling cooperate in regulating adipocyte differentiation and function

DEFF Research Database (Denmark)

Weidemann, A.; Lovas, A.; Rauch, A.

2016-01-01

Background and objective:Inflammation of adipose tissue (AT) is a central mediator of insulin resistance. However, the molecular mechanisms triggered by inflammatory cells are not fully understood. The aim of this study was to analyze the metabolic functions of lymphotoxin-β-receptor (LTβ...... to adipocytes. The molecular mechanism was elucidated by chromatin immunoprecipitation and combinatorial treatment with α-LTβR and tumor necrosis factor (TNF).Results:RelB FatKO mice showed improved insulin sensitivity despite increased adiposity and adipocyte hypertrophy. LTβR-induced activation of p52-Rel.......Conclusions:Our data describe an anti-adipogenic action of LTβR signaling and a novel synergism of alternative and classical NF-κB signaling in the regulation of adipocytes. In conclusion, this strong synergism between the two NF-κB pathways shows a method to inhibit adipocyte differentiation and to improve insulin...

The regulation of mitochondrial transcription factor A (Tfam) expression during skeletal muscle cell differentiation.

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Collu-Marchese, Melania; Shuen, Michael; Pauly, Marion; Saleem, Ayesha; Hood, David A

2015-05-19

The ATP demand required for muscle development is accommodated by elevations in mitochondrial biogenesis, through the co-ordinated activities of the nuclear and mitochondrial genomes. The most important transcriptional activator of the mitochondrial genome is mitochondrial transcription factor A (Tfam); however, the regulation of Tfam expression during muscle differentiation is not known. Thus, we measured Tfam mRNA levels, mRNA stability, protein expression and localization and Tfam transcription during the progression of muscle differentiation. Parallel 2-fold increases in Tfam protein and mRNA were observed, corresponding with 2-3-fold increases in mitochondrial content. Transcriptional activity of a 2051 bp promoter increased during this differentiation period and this was accompanied by a 3-fold greater Tfam mRNA stabilization. Interestingly, truncations of the promoter at 1706 bp, 978 bp and 393 bp promoter all exhibited 2-3-fold higher transcriptional activity than the 2051 bp construct, indicating the presence of negative regulatory elements within the distal 350 bp of the promoter. Activation of AMP kinase augmented Tfam transcription within the proximal promoter, suggesting the presence of binding sites for transcription factors that are responsive to cellular energy state. During differentiation, the accumulating Tfam protein was progressively distributed to the mitochondrial matrix where it augmented the expression of mtDNA and COX (cytochrome c oxidase) subunit I, an mtDNA gene product. Our data suggest that, during muscle differentiation, Tfam protein levels are regulated by the availability of Tfam mRNA, which is controlled by both transcription and mRNA stability. Changes in energy state and Tfam localization also affect Tfam expression and action in differentiating myotubes. © 2015 Authors.

GCN5 Regulates FGF Signaling and Activates Selective MYC Target Genes during Early Embryoid Body Differentiation

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Li Wang

2018-01-01

Full Text Available Precise control of gene expression during development is orchestrated by transcription factors and co-regulators including chromatin modifiers. How particular chromatin-modifying enzymes affect specific developmental processes is not well defined. Here, we report that GCN5, a histone acetyltransferase essential for embryonic development, is required for proper expression of multiple genes encoding components of the fibroblast growth factor (FGF signaling pathway in early embryoid bodies (EBs. Gcn5−/− EBs display deficient activation of ERK and p38, mislocalization of cytoskeletal components, and compromised capacity to differentiate toward mesodermal lineage. Genomic analyses identified seven genes as putative direct targets of GCN5 during early differentiation, four of which are cMYC targets. These findings established a link between GCN5 and the FGF signaling pathway and highlighted specific GCN5-MYC partnerships in gene regulation during early differentiation.

Regulation of Silk Genes by Hox and Homeodomain Proteins in the Terminal Differentiated Silk Gland of the Silkworm Bombyx mori

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Takiya, Shigeharu; Tsubota, Takuya; Kimoto, Mai

2016-01-01

The silk gland of the silkworm Bombyx mori is a long tubular organ that is divided into several subparts along its anteroposterior (AP) axis. As a trait of terminal differentiation of the silk gland, several silk protein genes are expressed with unique regional specificities. Most of the Hox and some of the homeobox genes are also expressed in the differentiated silk gland with regional specificities. The expression patterns of Hox genes in the silk gland roughly correspond to those in embryogenesis showing “colinearity”. The central Hox class protein Antennapedia (Antp) directly regulates the expression of several middle silk gland–specific silk genes, whereas the Lin-1/Isl-1/Mec3 (LIM)-homeodomain transcriptional factor Arrowhead (Awh) regulates the expression of posterior silk gland–specific genes for silk fiber proteins. We summarize our results and discuss the usefulness of the silk gland of Bombyx mori for analyzing the function of Hox genes. Further analyses of the regulatory mechanisms underlying the region-specific expression of silk genes will provide novel insights into the molecular bases for target-gene selection and regulation by Hox and homeodomain proteins. PMID:29615585

Regulation of Silk Genes by Hox and Homeodomain Proteins in the Terminal Differentiated Silk Gland of the Silkworm Bombyx mori

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Shigeharu Takiya

2016-05-01

Full Text Available The silk gland of the silkworm Bombyx mori is a long tubular organ that is divided into several subparts along its anteroposterior (AP axis. As a trait of terminal differentiation of the silk gland, several silk protein genes are expressed with unique regional specificities. Most of the Hox and some of the homeobox genes are also expressed in the differentiated silk gland with regional specificities. The expression patterns of Hox genes in the silk gland roughly correspond to those in embryogenesis showing “colinearity”. The central Hox class protein Antennapedia (Antp directly regulates the expression of several middle silk gland–specific silk genes, whereas the Lin-1/Isl-1/Mec3 (LIM-homeodomain transcriptional factor Arrowhead (Awh regulates the expression of posterior silk gland–specific genes for silk fiber proteins. We summarize our results and discuss the usefulness of the silk gland of Bombyx mori for analyzing the function of Hox genes. Further analyses of the regulatory mechanisms underlying the region-specific expression of silk genes will provide novel insights into the molecular bases for target-gene selection and regulation by Hox and homeodomain proteins.

A vesicle trafficking protein αSNAP regulates Paneth cell differentiation in vivo.

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Lechuga, Susana; Naydenov, Nayden G; Feygin, Alex; Jimenez, Antonio J; Ivanov, Andrei I

2017-05-13

A soluble N-ethylmaleimide-sensitive factor-attachment protein alpha (αSNAP) is a multifunctional scaffolding protein that regulates intracellular vesicle trafficking and signaling. In cultured intestinal epithelial cells, αSNAP has been shown to be essential for cell survival, motility, and adhesion; however, its physiologic functions in the intestinal mucosa remain unknown. In the present study, we used a mouse with a spontaneous hydrocephalus with hop gait (hyh) mutation of αSNAP to examine the roles of this trafficking protein in regulating intestinal epithelial homeostasis in vivo. Homozygous hyh mice demonstrated decreased expression of αSNAP protein in the intestinal epithelium, but did not display gross abnormalities of epithelial architecture in the colon and ileum. Such αSNAP depletion attenuated differentiation of small intestinal epithelial enteroids ex vivo. Furthermore, αSNAP-deficient mutant animals displayed reduced formation of lysozyme granules in small intestinal crypts and decreased expression of lysozyme and defensins in the intestinal mucosa, which is indicative of defects in Paneth cell differentiation. By contrast, development of Goblet cells, enteroendocrine cells, and assembly of enterocyte apical junctions was not altered in hyh mutant mice. Our data revealed a novel role of αSNAP in the intestinal Paneth cell differentiation in vivo. Copyright © 2017 Elsevier Inc. All rights reserved.

Keratin 5/14‑mediated cell differentiation and transformation are regulated by TAp63 and Notch‑1 in oral squamous cell carcinoma‑derived cells.

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Srivastava, Saumya S; Alam, Hunain; Patil, Sonam J; Shrinivasan, Rashmi; Raikundalia, Sweta; Chaudhari, Pratik Rajeev; Vaidya, Milind M

2018-05-01

Keratins 5/14 (K5/14) are intermediate filament proteins expressed in the basal layer of stratified epithelial cells and are known targets of p63. Previous research in our laboratory showed that upon K5/14 downregulation in oral squamous cell carcinoma (OSCC)‑derived cells, there was an increase in intracellular Notch‑1 levels and differentiation markers such as involucrin, keratin 1 and a decrease in tumorigenic potential in vivo. However, the molecules involved in the K14 regulated cell differentiation and transformation are not known to date. In order to understand the possible role of TAp63, we downregulated TAp63 in a K14‑knockdown background. We observed that there was a decrease in the expression of Notch‑1. Expression levels of differentiation markers such as involucrin, K1, loricrin and filaggrin were also decreased. Furthermore, TAp63 downregulation led to an increase in invasion, migration and in vivo tumorigenic potential of these cells. We observed a decrease in β‑catenin signaling in K14‑downregulated cells. Notably, when TAp63 was downregulated in K14‑knockdown cells, there was increase in non‑phospho β‑catenin levels. Hence, this study indicates that TAp63 plays an important role in K14‑downregulated cells possibly by regulating the Notch‑1 expression. K14 regulates the expression of TAp63 which in turn regulates expression of Notch‑1. The present study is a step forward in our quest to understand the functional significance of molecules that regulate the process of differentiation and tumorigenesis in stratified epithelial cells.

STUDY OF INTRA TESTICULAR REGULATIONS OF SPERMATOGENESIS DIFFERENTIATION BY EX-VIVO APPROACH

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A. Adaika

2010-12-01

Full Text Available The aim of this work is to study the regulation of intratesticular during spermatogenesis ex vivo. To highlight the progress of spermatogenesis ex vivo, we developed two cell culture systems of seminiferous tubules to study the role of local factors that control the proliferation and differentiation of male germ cells. Our studies are based on two main techniques: RT-PCR and RNA extraction to examine changes in the expression of some growth factors in the culture of seminiferous tubules as the SCF, c- Kit and TGFß. The results show, using RT-PCR, that expression of SCF, c-Kit and TGFb is probably not involved in the alterations of spermatogenesis ex vivo. Indeed, their expressions are not modified during three weeks of culture, and their expressions depend on the proportion of cells where they are expressed. Our results also show that clusterin is a marker of Sertoli cells in the culture of seminiferous tubules and its expression is not altered by the presence of germ cells.

HDAC4 regulates satellite cell proliferation and differentiation by targeting P21 and Sharp1 genes.

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Marroncelli, Nicoletta; Bianchi, Marzia; Bertin, Marco; Consalvi, Silvia; Saccone, Valentina; De Bardi, Marco; Puri, Pier Lorenzo; Palacios, Daniela; Adamo, Sergio; Moresi, Viviana

2018-02-22

Skeletal muscle exhibits a high regenerative capacity, mainly due to the ability of satellite cells to replicate and differentiate in response to appropriate stimuli. Epigenetic control is effective at different stages of this process. It has been shown that the chromatin-remodeling factor HDAC4 is able to regulate satellite cell proliferation and commitment. However, its molecular targets are still uncovered. To explain the signaling pathways regulated by HDAC4 in satellite cells, we generated tamoxifen-inducible mice with conditional inactivation of HDAC4 in Pax7 + cells (HDAC4 KO mice). We found that the proliferation and differentiation of HDAC4 KO satellite cells were compromised, although similar amounts of satellite cells were found in mice. Moreover, we found that the inhibition of HDAC4 in satellite cells was sufficient to block the differentiation process. By RNA-sequencing analysis we identified P21 and Sharp1 as HDAC4 target genes. Reducing the expression of these target genes in HDAC4 KO satellite cells, we also defined the molecular pathways regulated by HDAC4 in the epigenetic control of satellite cell expansion and fusion.

ADAMTS9-Regulated Pericellular Matrix Dynamics Governs Focal Adhesion-Dependent Smooth Muscle Differentiation

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Timothy J. Mead

2018-04-01

Full Text Available Summary: Focal adhesions anchor cells to extracellular matrix (ECM and direct assembly of a pre-stressed actin cytoskeleton. They act as a cellular sensor and regulator, linking ECM to the nucleus. Here, we identify proteolytic turnover of the anti-adhesive proteoglycan versican as a requirement for maintenance of smooth muscle cell (SMC focal adhesions. Using conditional deletion in mice, we show that ADAMTS9, a secreted metalloprotease, is required for myometrial activation during late gestation and for parturition. Through knockdown of ADAMTS9 in uterine SMC, and manipulation of pericellular versican via knockdown or proteolysis, we demonstrate that regulated pericellular matrix dynamics is essential for focal adhesion maintenance. By influencing focal adhesion formation, pericellular versican acts upstream of cytoskeletal assembly and SMC differentiation. Thus, pericellular versican proteolysis by ADAMTS9 balances pro- and anti-adhesive forces to maintain an SMC phenotype, providing a concrete example of the dynamic reciprocity of cells and their ECM. : Mead et al. identify a proteolytic mechanism that actively maintains a pericellular microenvironment conducive to uterine smooth muscle activation prior to parturition. They show that pericellular matrix proteolysis by the secreted metalloprotease ADAMTS9 is crucial for maintenance of focal adhesions in uterine smooth muscle cells, and its absence impairs parturition. Keywords: metalloprotease, extracellular matrix, smooth muscle, proteoglycan, myometrium, parturition, uterus, focal adhesion, proteolysis, interference reflection microscopy

REST represses a subset of the pancreatic endocrine differentiation program

DEFF Research Database (Denmark)

Martin, David; Kim, Yung-Hae; Sever, Dror

2015-01-01

in neurons and in endocrine cells, which is necessary for their normal function. During development, REST represses a subset of genes in the neuronal differentiation program and Rest is down-regulated as neurons differentiate. Here, we investigate the role of REST in the differentiation of pancreatic...... endocrine cells, which are molecularly close to neurons. We show that Rest is widely expressed in pancreas progenitors and that it is down-regulated in differentiated endocrine cells. Sustained expression of REST in Pdx1(+) progenitors impairs the differentiation of endocrine-committed Neurog3...

MicroRNAs regulate T-cell production of interleukin-9 and identify hypoxia-inducible factor-2α as an important regulator of T helper 9 and regulatory T-cell differentiation.

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Singh, Yogesh; Garden, Oliver A; Lang, Florian; Cobb, Bradley S

2016-09-01

MicroRNAs (miRNAs) regulate many aspects of helper T cell (Th) development and function. Here we found that they are required for the suppression of interleukin-9 (IL-9) expression in Th9 cells and other Th subsets. Two highly related miRNAs (miR-15b and miR-16) that we previously found to play an important role in regulatory T (Treg) cell differentiation were capable of suppressing IL-9 expression when they were over-expressed in Th9 cells. We used these miRNAs as tools to identify novel regulators of IL-9 expression and found that they could regulate the expression of Epas1, which encodes hypoxia-inducible factor (HIF)-2α. HIF proteins regulate metabolic pathway usage that is important in determining appropriate Th differentiation. The related protein, HIF-1α enhances Th17 differentiation and inhibits Treg cell differentiation. Here we found that HIF-2α was required for IL-9 expression in Th9 cells, but its expression was not sufficient in other Th subsets. Furthermore, HIF-2α suppressed Treg cell differentiation like HIF-1α, demonstrating both similar and distinct roles of the HIF proteins in Th differentiation and adding a further dimension to their function. Ironically, even though miR-15b and miR-16 suppressed HIF-2α expression in Treg cells, inhibiting their function in Treg cells did not lead to an increase in IL-9 expression. Therefore, the physiologically relevant miRNAs that regulate IL-9 expression in Treg cells and other subsets remain unknown. Nevertheless, the analysis of miR-15b and miR-16 function led to the discovery of the importance of HIF-2α so this work demonstrated the utility of studying miRNA function to identify novel regulatory pathways in helper T-cell development. © 2016 John Wiley & Sons Ltd.

Ly49Q, an ITIM-bearing NK receptor, positively regulates osteoclast differentiation

International Nuclear Information System (INIS)

Hayashi, Mikihito; Nakashima, Tomoki; Kodama, Tatsuhiko; Makrigiannis, Andrew P.; Toyama-Sorimachi, Noriko; Takayanagi, Hiroshi

2010-01-01

Osteoclasts, multinucleated cells that resorb bone, play a key role in bone remodeling. Although immunoreceptor tyrosine-based activation motif (ITAM)-mediated signaling is critical for osteoclast differentiation, the significance of immunoreceptor tyrosine-based inhibitory motif (ITIM) has not been well understood. Here we report the function of Ly49Q, an Ly49 family member possessing an ITIM motif, in osteoclastogenesis. Ly49Q is selectively induced by receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL) stimulation in bone marrow-derived monocyte/macrophage precursor cells (BMMs) among the Ly49 family of NK receptors. The knockdown of Ly49Q resulted in a significant reduction in the RANKL-induced formation of tartrate-resistance acid phosphatase (TRAP)-positive multinucleated cells, accompanied by a decreased expression of osteoclast-specific genes such as Nfatc1, Tm7sf4, Oscar, Ctsk, and Acp5. Osteoclastogenesis was also significantly impaired in Ly49Q-deficient cells in vitro. The inhibitory effect of Ly49Q-deficiency may be explained by the finding that Ly49Q competed for the association of Src-homology domain-2 phosphatase-1 (SHP-1) with paired immunoglobulin-like receptor-B (PIR-B), an ITIM-bearing receptor which negatively regulates osteoclast differentiation. Unexpectedly, Ly49Q deficiency did not lead to impaired osteoclast formation in vivo, suggesting the existence of a compensatory mechanism. This study provides an example in which an ITIM-bearing receptor functions as a positive regulator of osteoclast differentiation.

Differential Dopamine Regulation of Ca2+ Signaling and Its Timing Dependence in the Nucleus Accumbens

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Immani Swapna

2016-04-01

Full Text Available Dopamine action in the nucleus accumbens (NAc is thought to drive appetitive behavior and Pavlovian reward learning. However, it remains controversial how dopamine achieves these behavioral effects by regulating medium spiny projection neurons (MSNs of the NAc, especially on a behaviorally relevant timescale. Metabotropic glutamate receptor (mGluR-induced Ca2+ signaling dependent on the Ca2+- releasing messenger inositol 1,4,5-triphosphate (IP3 plays a critical role in controlling neuronal excitability and synaptic plasticity. Here, we show that transient dopamine application facilitates mGluR/IP3-induced Ca2+ signals within a time window of ∼2–10 s in a subpopulation of MSNs in the NAc core. Dopamine facilitation of IP3-induced Ca2+ signaling is mediated by D1 dopamine receptors. In dopamine-insensitive MSNs, activation of A2A adenosine receptors causes enhancement of IP3-evoked Ca2+ signals, which is reversed by D2 dopamine receptor activation. These results show that dopamine differentially regulates Ca2+ signaling on the order of seconds in two distinct MSN subpopulations.

Differential regulation of cystic fibrosis transmembrane conductance regulator and Na+,K+ -ATPase in gills of striped bass, Morone saxatilis: effect of salinity and hormones

DEFF Research Database (Denmark)

Madsen, Steffen; Jensen, Lars Nørholm; Tipsmark, Christian Kølbaek

2007-01-01

-regulated kinase (ERK) 1/2 was stimulated by EGF but not affected by IGF-I. This study is the first to report a branchial EGF response and to demonstrate a functional ERK 1/2 pathway in the teleost gill. In conclusion, CFTR and Na(+),K(+) -ATPase are differentially regulated by salinity and hormones in gills...

Estrogen-Induced Maldevelopment of the Penis Involves Down-Regulation of Myosin Heavy Chain 11 (MYH11) Expression, a Biomarker for Smooth Muscle Cell Differentiation1

Science.gov (United States)

Okumu, L.A.; Bruinton, Sequoia; Braden, Tim D.; Simon, Liz; Goyal, Hari O.

2012-01-01

ABSTRACT Cavernous smooth muscle cells are essential components in penile erection. In this study, we investigated effects of estrogen exposure on biomarkers for smooth muscle cell differentiation in the penis. Neonatal rats received diethylstilbestrol (DES), with or without the estrogen receptor (ESR) antagonist ICI 182,780 (ICI) or the androgen receptor (AR) agonist dihydrotestosterone (DHT), from Postnatal Days 1 to 6. Tissues were collected at 7, 10, or 21 days of age. The smooth muscle cell biomarker MYH11 was studied in depth because microarray data showed it was significantly down-regulated, along with other biomarkers, in DES treatment. Quantitative real time-PCR and Western blot analyses showed 50%–80% reduction (P ≤ 0.05) in Myh11 expression in DES-treated rats compared to that in controls; and ICI and DHT coadministration mitigated the decrease. Temporally, from 7 to 21 days of age, Myh11 expression was onefold increased (P ≥ 0.05) in DES-treated rats versus threefold increased (P ≤ 0.001) in controls, implying the long-lasting inhibitory effect of DES on smooth muscle cell differentiation. Immunohistochemical localization of smooth muscle alpha actin, another biomarker for smooth muscle cell differentiation, showed fewer cavernous smooth muscle cells in DES-treated animals than in controls. Additionally, DES treatment significantly up-regulated Esr1 mRNA expression and suppressed the neonatal testosterone surge by 90%, which was mitigated by ICI coadministration but not by DHT coadministration. Collectively, results provided evidence that DES treatment in neonatal rats inhibited cavernous smooth muscle cell differentiation, as shown by down-regulation of MYH11 expression at the mRNA and protein levels and by reduced immunohistochemical staining of smooth muscle alpha actin. Both the ESR and the AR pathways probably mediate this effect. PMID:22976277

Serum cholinesterases are differentially regulated in normal and dystrophin-deficient mutant mice

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Andrea R. Durrant

2012-06-01

Full Text Available The cholinesterases, acetylcholinesterase and butyrylcholinesterase (pseudocholinesterase, are abundant in the nervous system and in other tissues. The role of acetylcholinesterase in terminating transmitter action in the peripheral and central nervous system is well understood. However, both knowledge of the function(s of the cholinesterases in serum, and of their metabolic and endocrine regulation under normal and pathological conditions, is limited. This study investigates acetylcholinesterase and butyrylcholinesterase in sera of dystrophin-deficient mdx mutant mice, an animal model for the human Duchenne muscular dystrophy and in control healthy mice. The data show systematic and differential variations in the concentrations of both enzymes in the sera, and specific changes dictated by alteration of hormonal balance in both healthy and dystrophic mice. While acetylcholinesterase in mdx-sera is elevated, butyrylcholinesterase is markedly diminished, resulting in an overall cholinesterase decrease compared to sera of healthy controls. The androgen testosterone (T is a negative modulator of butyrylcholinesterase, but not of acetylcholinesterase, in male mouse sera. T-removal elevated both butyrylcholinesterase activity and the butyrylcholinesterase/acetylcholinesterase ratio in mdx male sera to values resembling those in healthy control male mice. Mechanisms of regulation of the circulating cholinesterases and their impairment in the dystrophic mice are suggested, and clinical implications for diagnosis and treatment are considered.

RNase L controls terminal adipocyte differentiation, lipids storage and insulin sensitivity via CHOP10 mRNA regulation

DEFF Research Database (Denmark)

Fabre, Odile Martine Julie; Salehzada, T; Lambert, K

2012-01-01

Adipose tissue structure is altered during obesity, leading to deregulation of whole-body metabolism. Its function depends on its structure, in particular adipocytes number and differentiation stage. To better understand the mechanisms regulating adipogenesis, we have investigated the role...... is associated with CHOP10 mRNA and regulates its stability. CHOP10 expression is conserved in RNase L(-/-)-MEFs, maintaining preadipocyte state while impairing their terminal differentiation. RNase L(-/-)-MEFs have decreased lipids storage capacity, insulin sensitivity and glucose uptake. Expression of ectopic...... RNase L in RNase L(-/-)-MEFs triggers CHOP10 mRNA instability, allowing increased lipids storage, insulin response and glucose uptake. Similarly, downregulation of CHOP10 mRNA with CHOP10 siRNA in RNase L(-/-)-MEFs improves their differentiation in adipocyte. In vivo, aged RNase L(-)/(-) mice present...

The ROCK isoforms differentially regulate the morphological characteristics of carcinoma cells.

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Jerrell, Rachel J; Leih, Mitchell J; Parekh, Aron

2017-06-26

Rho-associated kinase (ROCK) activity drives cell migration via actomyosin contractility. During invasion, individual cancer cells can transition between 2 modes of migration, mesenchymal and amoeboid. Changes in ROCK activity can cause a switch between these migration phenotypes which are defined by distinct morphologies. However, recent studies have shown that the ROCK isoforms are not functionally redundant as previously thought. Therefore, it is unclear whether the ROCK isoforms play different roles in regulating migration phenotypes. Here, we found that ROCK1 and ROCK2 differentially regulate carcinoma cell morphology resulting in intermediate phenotypes that share some mesenchymal and amoeboid characteristics. These findings suggest that the ROCK isoforms play unique roles in the phenotypic plasticity of mesenchymal carcinoma cells which may have therapeutic implications.

Differential co-expression and regulation analyses reveal different mechanisms underlying major depressive disorder and subsyndromal symptomatic depression.

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Xu, Fan; Yang, Jing; Chen, Jin; Wu, Qingyuan; Gong, Wei; Zhang, Jianguo; Shao, Weihua; Mu, Jun; Yang, Deyu; Yang, Yongtao; Li, Zhiwei; Xie, Peng

2015-04-03

Recent depression research has revealed a growing awareness of how to best classify depression into depressive subtypes. Appropriately subtyping depression can lead to identification of subtypes that are more responsive to current pharmacological treatment and aid in separating out depressed patients in which current antidepressants are not particularly effective. Differential co-expression analysis (DCEA) and differential regulation analysis (DRA) were applied to compare the transcriptomic profiles of peripheral blood lymphocytes from patients with two depressive subtypes: major depressive disorder (MDD) and subsyndromal symptomatic depression (SSD). Six differentially regulated genes (DRGs) (FOSL1, SRF, JUN, TFAP4, SOX9, and HLF) and 16 transcription factor-to-target differentially co-expressed gene links or pairs (TF2target DCLs) appear to be the key differential factors in MDD; in contrast, one DRG (PATZ1) and eight TF2target DCLs appear to be the key differential factors in SSD. There was no overlap between the MDD target genes and SSD target genes. Venlafaxine (Efexor™, Effexor™) appears to have a significant effect on the gene expression profile of MDD patients but no significant effect on the gene expression profile of SSD patients. DCEA and DRA revealed no apparent similarities between the differential regulatory processes underlying MDD and SSD. This bioinformatic analysis may provide novel insights that can support future antidepressant R&D efforts.

Identification of a Dynamic Core Transcriptional Network in t(8;21 AML that Regulates Differentiation Block and Self-Renewal

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Anetta Ptasinska

2014-09-01

Full Text Available Oncogenic transcription factors such as RUNX1/ETO, which is generated by the chromosomal translocation t(8;21, subvert normal blood cell development by impairing differentiation and driving malignant self-renewal. Here, we use digital footprinting and chromatin immunoprecipitation sequencing (ChIP-seq to identify the core RUNX1/ETO-responsive transcriptional network of t(8;21 cells. We show that the transcriptional program underlying leukemic propagation is regulated by a dynamic equilibrium between RUNX1/ETO and RUNX1 complexes, which bind to identical DNA sites in a mutually exclusive fashion. Perturbation of this equilibrium in t(8;21 cells by RUNX1/ETO depletion leads to a global redistribution of transcription factor complexes within preexisting open chromatin, resulting in the formation of a transcriptional network that drives myeloid differentiation. Our work demonstrates on a genome-wide level that the extent of impaired myeloid differentiation in t(8;21 is controlled by the dynamic balance between RUNX1/ETO and RUNX1 activities through the repression of transcription factors that drive differentiation.

Delayed Mesoderm and Erythroid Differentiation of Murine Embryonic Stem Cells in the Absence of the Transcriptional Regulator FUBP1

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Josephine Wesely

2017-01-01

Full Text Available The transcriptional regulator far upstream binding protein 1 (FUBP1 is essential for fetal and adult hematopoietic stem cell (HSC self-renewal, and the constitutive absence of FUBP1 activity during early development leads to embryonic lethality in homozygous mutant mice. To investigate the role of FUBP1 in murine embryonic stem cells (ESCs and in particular during differentiation into hematopoietic lineages, we generated Fubp1 knockout (KO ESC clones using CRISPR/Cas9 technology. Although FUBP1 is expressed in undifferentiated ESCs and during spontaneous differentiation following aggregation into embryoid bodies (EBs, absence of FUBP1 did not affect ESC maintenance. Interestingly, we observed a delayed differentiation of FUBP1-deficient ESCs into the mesoderm germ layer, as indicated by impaired expression of several mesoderm markers including Brachyury at an early time point of ESC differentiation upon aggregation to EBs. Coculture experiments with OP9 cells in the presence of erythropoietin revealed a diminished differentiation capacity of Fubp1 KO ESCs into the erythroid lineage. Our data showed that FUBP1 is important for the onset of mesoderm differentiation and maturation of hematopoietic progenitor cells into the erythroid lineage, a finding that is supported by the phenotype of FUBP1-deficient mice.

Local Inflammatory Cues Regulate Differentiation and Persistence of CD8+ Tissue-Resident Memory T Cells

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Tessa Bergsbaken

2017-04-01

Full Text Available Many pathogens initiate infection at mucosal surfaces, and tissue-resident memory T (Trm cells play an important role in protective immunity, yet the tissue-specific signals that regulate Trm differentiation are poorly defined. During Yersinia infection, CD8+ T cell recruitment to areas of inflammation within the intestine is required for differentiation of the CD103−CD69+ Trm subset. Intestinal proinflammatory microenvironments have elevated interferon (IFN-β and interleukin-12 (IL-12, which regulated Trm markers, including CD103. Type I interferon-receptor- or IL-12-receptor-deficient T cells functioned similarly to wild-type (WT cells during infection; however, the inability of T cells to respond to inflammation resulted in defective differentiation of CD103−CD69+ Trm cells and reduced Trm persistence. Intestinal macrophages were the main producers of IFN-β and IL-12 during infection, and deletion of CCR2+ IL-12-producing cells reduced the size of the CD103− Trm population. These data indicate that intestinal inflammation drives phenotypic diversity and abundance of Trm cells for optimal tissue-specific immunity.

Roles of Retinoids and Retinoic Acid Receptors in the Regulation of Hematopoietic Stem Cell Self-Renewal and Differentiation

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Louise E. Purton

2007-01-01

Full Text Available Multipotent hematopoietic stem cells (HSCs sustain blood cell production throughout an individual's lifespan through complex processes ultimately leading to fates of self-renewal, differentiation or cell death decisions. A fine balance between these decisions in vivo allows for the size of the HSC pool to be maintained. While many key factors involved in regulating HSC/progenitor cell differentiation and cell death are known, the critical regulators of HSC self-renewal are largely unknown. In recent years, however, a number of studies describing methods of increasing or decreasing the numbers of HSCs in a given population have emerged. Of major interest here are the emerging roles of retinoids in the regulation of HSCs.

Legumain Regulates Differentiation Fate of Human Bone Marrow Stromal Cells and Is Altered in Postmenopausal Osteoporosis

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Abbas Jafari

2017-02-01

Full Text Available Secreted factors are a key component of stem cell niche and their dysregulation compromises stem cell function. Legumain is a secreted cysteine protease involved in diverse biological processes. Here, we demonstrate that legumain regulates lineage commitment of human bone marrow stromal cells and that its expression level and cellular localization are altered in postmenopausal osteoporotic patients. As shown by genetic and pharmacological manipulation, legumain inhibited osteoblast (OB differentiation and in vivo bone formation through degradation of the bone matrix protein fibronectin. In addition, genetic ablation or pharmacological inhibition of legumain activity led to precocious OB differentiation and increased vertebral mineralization in zebrafish. Finally, we show that localized increased expression of legumain in bone marrow adipocytes was inversely correlated with adjacent trabecular bone mass in a cohort of patients with postmenopausal osteoporosis. Our data suggest that altered proteolytic activity of legumain in the bone microenvironment contributes to decreased bone mass in postmenopausal osteoporosis.

Arginine Methylation Regulates MEIS2 Nuclear Localization to Promote Neuronal Differentiation of Adult SVZ Progenitors

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Jasmine Kolb

2018-04-01

Full Text Available Summary: Adult neurogenesis is regulated by stem cell niche-derived extrinsic factors and cell-intrinsic regulators, yet the mechanisms by which niche signals impinge on the activity of intrinsic neurogenic transcription factors remain poorly defined. Here, we report that MEIS2, an essential regulator of adult SVZ neurogenesis, is subject to posttranslational regulation in the SVZ olfactory bulb neurogenic system. Nuclear accumulation of MEIS2 in adult SVZ-derived progenitor cells follows downregulation of EGFR signaling and is modulated by methylation of MEIS2 on a conserved arginine, which lies in close proximity to nested binding sites for the nuclear export receptor CRM1 and the MEIS dimerization partner PBX1. Methylation impairs interaction with CRM1 without affecting PBX1 dimerization and thereby allows MEIS2 nuclear accumulation, a prerequisite for neuronal differentiation. Our results describe a form of posttranscriptional modulation of adult SVZ neurogenesis whereby an extrinsic signal fine-tunes neurogenesis through posttranslational modification of a transcriptional regulator of cell fate. : A hallmark of adult neurogenesis is its strong dependence on physiological stimuli and environmental signals. Schulte and colleagues show that the nuclear localization and activity of a transcriptional regulator of adult neurogenesis is controlled by posttranslational modification. Their results link intrinsic control over neuron production to external signals and help to explain how adult neurogenesis can occur “on demand.” Keywords: subventricular zone, stem cell niche, posttranslational modification, controlled nuclear import, TALE-homdomain protein, MEIS2, PBX1, CRM1, neurogenesis, stem cell niche

Erk1 positively regulates osteoclast differentiation and bone resorptive activity.

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Yongzheng He

Full Text Available The extracellular signal-regulated kinases (ERK1 and 2 are widely-expressed and they modulate proliferation, survival, differentiation, and protein synthesis in multiple cell lineages. Altered ERK1/2 signaling is found in several genetic diseases with skeletal phenotypes, including Noonan syndrome, Neurofibromatosis type 1, and Cardio-facio-cutaneous syndrome, suggesting that MEK-ERK signals regulate human skeletal development. Here, we examine the consequence of Erk1 and Erk2 disruption in multiple functions of osteoclasts, specialized macrophage/monocyte lineage-derived cells that resorb bone. We demonstrate that Erk1 positively regulates osteoclast development and bone resorptive activity, as genetic disruption of Erk1 reduced osteoclast progenitor cell numbers, compromised pit formation, and diminished M-CSF-mediated adhesion and migration. Moreover, WT mice reconstituted long-term with Erk1(-/- bone marrow mononuclear cells (BMMNCs demonstrated increased bone mineral density as compared to recipients transplanted with WT and Erk2(-/- BMMNCs, implicating marrow autonomous, Erk1-dependent osteoclast function. These data demonstrate Erk1 plays an important role in osteoclast functions while providing rationale for the development of Erk1-specific inhibitors for experimental investigation and/or therapeutic modulation of aberrant osteoclast function.

2-Bromopalmitate modulates neuronal differentiation through the regulation of histone acetylation

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Xueran Chen

2014-03-01

Full Text Available In order to evaluate the functional significance of palmitoylation during multi-potent neural stem/progenitor cell proliferation and differentiation, retinoic acid-induced P19 cells were used in this study as a model system. Cell behaviour was monitored in the presence of the protein palmitoylation inhibitor 2-bromopalmitate (2BP. Here, we observed a significant reduction in neuronal differentiation in the 2BP-treated cell model. We further explored the underlying mechanisms and found that 2BP resulted in the decreased acetylation of histones H3 and H4 and interfered with cell cycle withdrawal and neural stem/progenitor cells' renewal. Our results established a direct link between palmitoylation and the regulation of neural cell fate specification and revealed the epigenetic regulatory mechanisms that are involved in the effects of palmitoylation during neural development.

Neuronal differentiation is associated with a redox-regulated increase of copper flow to the secretory pathway

OpenAIRE

Hatori, Yuta; Yan, Ye; Schmidt, Katharina; Furukawa, Eri; Hasan, Nesrin M.; Yang, Nan; Liu, Chin-Nung; Sockanathan, Shanthini; Lutsenko, Svetlana

2016-01-01

Brain development requires a fine-tuned copper homoeostasis. Copper deficiency or excess results in severe neuro-pathologies. We demonstrate that upon neuronal differentiation, cellular demand for copper increases, especially within the secretory pathway. Copper flow to this compartment is facilitated through transcriptional and metabolic regulation. Quantitative real-time imaging revealed a gradual change in the oxidation state of cytosolic glutathione upon neuronal differentiation. Transiti...

Distinct roles of the receptor tyrosine kinases c-ErbB and c-Kit in regulating the balance between erythroid cell proliferation and differentiation

NARCIS (Netherlands)

Wessely, O.; Mellitzer, G.; von Lindern, M.; Levitzki, A.; Gazit, A.; Ischenko, I.; Hayman, M. J.; Beug, H.

1997-01-01

In the bone marrow, multipotent and committed hematopoietic progenitors have to closely regulate their balance between sustained proliferation without differentiation (self renewal) and entering a terminal differentiation pathway. A useful model to analyze this regulation at the molecular level is

Differential regulation of GluA1 expression by ketamine and memantine.

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Zhang, Ke; Yamaki, Vitor Nagai; Wei, Zhisheng; Zheng, Yu; Cai, Xiang

2017-01-01

Evidence from preclinical and clinical studies shows that ketamine, a noncompetitive NMDA receptor antagonist, exerts rapid and sustained antidepressant responses. However, ketamine's psychotomimetic side effects and abuse liability limit the clinical use of the compound. Interestingly, memantine, another NMDA receptor channel blocker, processes no defined antidepressant property but is much safer and clinical tolerated. Understanding why ketamine but not memantine exhibits rapid antidepressant responses is important to elucidate the cellular signaling underlying the fast antidepressant actions of ketamine and to design a new safer generation of fast-acting antidepressants. Here we show that ketamine but memantine caused a rapid and sustained antidepressant-like responses in forced swim test (FST). Both drugs enhanced GluA1 S845 phosphorylation and potentiated Schaffer collateral-CA1 synaptic transmission. However, ketamine but not memantine elevated the expression of GluA1. Incubating acutely prepared hippocampal slices with ketamine but not memantine enhanced mTOR phosphorylation in a time course parallel to the time course of GluA1 elevation. Our results suggest that distinct properties in regulation of mTOR phosphorylation and synaptic protein expression may underlie the differential effectiveness of ketamine and memantine in their antidepressant responses. Copyright © 2016 Elsevier B.V. All rights reserved.

PI3K/AKT and ERK regulate retinoic acid-induced neuroblastoma cellular differentiation

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Qiao, Jingbo [Department of Pediatric Surgery, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Paul, Pritha; Lee, Sora [Department of Pediatric Surgery, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Qiao, Lan; Josifi, Erlena; Tiao, Joshua R. [Department of Pediatric Surgery, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Chung, Dai H., E-mail: dai.chung@vanderbilt.edu [Department of Pediatric Surgery, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN 37232 (United States)

2012-08-03

Highlights: Black-Right-Pointing-Pointer Retinoic acid (RA) induces neuroblastoma cells differentiation, which is accompanied by G0/G1 cell cycle arrest. Black-Right-Pointing-Pointer RA resulted in neuroblastoma cell survival and inhibition of DNA fragmentation; this is regulated by PI3K pathway. Black-Right-Pointing-Pointer RA activates PI3K and ERK1/2 pathway; PI3K pathway mediates RA-induced neuroblastoma cell differentiation. Black-Right-Pointing-Pointer Upregulation of p21 is necessary for RA-induced neuroblastoma cell differentiation. -- Abstract: Neuroblastoma, the most common extra-cranial solid tumor in infants and children, is characterized by a high rate of spontaneous remissions in infancy. Retinoic acid (RA) has been known to induce neuroblastoma differentiation; however, the molecular mechanisms and signaling pathways that are responsible for RA-mediated neuroblastoma cell differentiation remain unclear. Here, we sought to determine the cell signaling processes involved in RA-induced cellular differentiation. Upon RA administration, human neuroblastoma cell lines, SK-N-SH and BE(2)-C, demonstrated neurite extensions, which is an indicator of neuronal cell differentiation. Moreover, cell cycle arrest occurred in G1/G0 phase. The protein levels of cyclin-dependent kinase inhibitors, p21 and p27{sup Kip}, which inhibit cell proliferation by blocking cell cycle progression at G1/S phase, increased after RA treatment. Interestingly, RA promoted cell survival during the differentiation process, hence suggesting a potential mechanism for neuroblastoma resistance to RA therapy. Importantly, we found that the PI3K/AKT pathway is required for RA-induced neuroblastoma cell differentiation. Our results elucidated the molecular mechanism of RA-induced neuroblastoma cellular differentiation, which may be important for developing novel therapeutic strategy against poorly differentiated neuroblastoma.

RSPO1/β-catenin signaling pathway regulates oogonia differentiation and entry into meiosis in the mouse fetal ovary

NARCIS (Netherlands)

Chassot, Anne-Amandine; Gregoire, Elodie P.; Lavery, Rowena; Taketo, Makoto M.; de Rooij, Dirk G.; Adams, Ian R.; Chaboissier, Marie-Christine

2011-01-01

Differentiation of germ cells into male gonocytes or female oocytes is a central event in sexual reproduction. Proliferation and differentiation of fetal germ cells depend on the sex of the embryo. In male mouse embryos, germ cell proliferation is regulated by the RNA helicase Mouse Vasa homolog

RSPO1/beta-Catenin Signaling Pathway Regulates Oogonia Differentiation and Entry into Meiosis in the Mouse Fetal Ovary

NARCIS (Netherlands)

Chassot, A.A.; Gregoire, E.P.; Lavery, R.; Taketo, M.M.; de Rooij, D.G.; Adams, I.R.; Chaboissier, M.C.

2011-01-01

Differentiation of germ cells into male gonocytes or female oocytes is a central event in sexual reproduction. Proliferation and differentiation of fetal germ cells depend on the sex of the embryo. In male mouse embryos, germ cell proliferation is regulated by the RNA helicase Mouse Vasa homolog

Regulator of calcineurin 1 differentially regulates TLR-dependent MyD88 and TRIF signaling pathways.

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Zheng Pang

Full Text Available Toll-like receptors (TLRs recognize the conserved molecular patterns in microorganisms and trigger myeloid differentiation primary response 88 (MyD88 and/or TIR-domain-containing adapter-inducing interferon-β (TRIF pathways that are critical for host defense against microbial infection. However, the molecular mechanisms that govern TLR signaling remain incompletely understood. Regulator of calcineurin-1 (RCAN1, a small evolutionarily conserved protein that inhibits calcineurin phosphatase activity, suppresses inflammation during Pseudomonas aeruginosa infection. Here, we define the roles for RCAN1 in P. aeruginosa lipopolysaccharide (LPS-activated TLR4 signaling. We compared the effects of P. aeruginosa LPS challenge on bone marrow-derived macrophages from both wild-type and RCAN1-deficient mice and found that RCAN1 deficiency increased the MyD88-NF-κB-mediated cytokine production (IL-6, TNF and MIP-2, whereas TRIF-interferon-stimulated response elements (ISRE-mediated cytokine production (IFNβ, RANTES and IP-10 was suppressed. RCAN1 deficiency caused increased IκBα phosphorylation and NF-κB activity in the MyD88-dependent pathway, but impaired ISRE activation and reduced IRF7 expression in the TRIF-dependent pathway. Complementary studies of a mouse model of P. aeruginosa LPS-induced acute pneumonia confirmed that RCAN1-deficient mice displayed greatly enhanced NF-κB activity and MyD88-NF-κB-mediated cytokine production, which correlated with enhanced pulmonary infiltration of neutrophils. By contrast, RCAN1 deficiency had little effect on the TRIF pathway in vivo. These findings demonstrate a novel regulatory role of RCAN1 in TLR signaling, which differentially regulates MyD88 and TRIF pathways.

RNF20 and USP44 regulate stem cell differentiation by modulating H2B monoubiquitylation

Science.gov (United States)

Fuchs, Gilad; Shema, Efrat; Vesterman, Rita; Kotler, Eran; Wolchinsky, Zohar; Wilder, Sylvia; Golomb, Lior; Pribluda, Ariel; Zhang, Feng; Haj-Yahya, Mahmood; Feldmesser, Ester; Brik, Ashraf; Yu, Xiaochun; Hanna, Jacob; Aberdam, Daniel; Domany, Eytan; Oren, Moshe

2012-01-01

Summary Embryonic stem cells (ESC) maintain high genomic plasticity, essential for their capacity to enter diverse differentiation pathways. Post-transcriptional modifications of chromatin histones play a pivotal role in maintaining this plasticity. We now report that one such modification, monoubiquitylation of histone H2B on lysine 120 (H2Bub1), catalyzed by the E3 ligase RNF20, increases during ESC differentiation and is required for efficient execution of this process. This increase is particularly important for the transcriptional induction of relatively long genes during ESC differentiation. Furthermore, we identify the deubiquitinase USP44 as a negative regulator of H2B ubiquitylation, whose downregulation during ESC differentiation contributes to the increase in H2Bub1. Our findings suggest that optimal ESC differentiation requires dynamic changes in H2B ubiquitylation patterns, which must occur in a timely and well-coordinated manner. PMID:22681888

HIF-1α as a Regulator of BMP2-Induced Chondrogenic Differentiation, Osteogenic Differentiation, and Endochondral Ossification in Stem Cells

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Nian Zhou

2015-04-01

Full Text Available Background/Aims: Joint cartilage defects are difficult to treat due to the limited self-repair capacities of cartilage. Cartilage tissue engineering based on stem cells and gene enhancement is a potential alternative for cartilage repair. Bone morphogenetic protein 2 (BMP2 has been shown to induce chondrogenic differentiation in mesenchymal stem cells (MSCs; however, maintaining the phenotypes of MSCs during cartilage repair since differentiation occurs along the endochondral ossification pathway. In this study, hypoxia inducible factor, or (HIF-1α, was determined to be a regulator of BMP2-induced chondrogenic differentiation, osteogenic differentiation, and endochondral bone formation. Methods: BMP2 was used to induce chondrogenic and osteogenic differentiation in stem cells and fetal limb development. After HIF-1α was added to the inducing system, any changes in the differentiation markers were assessed. Results: HIF-1α was found to potentiate BMP2-induced Sox9 and the expression of chondrogenesis by downstream markers, and inhibit Runx2 and the expression of osteogenesis by downstream markers in vitro. In subcutaneous stem cell implantation studies, HIF-1α was shown to potentiate BMP2-induced cartilage formation and inhibit endochondral ossification during ectopic bone/cartilage formation. In the fetal limb culture, HIF-1α and BMP2 synergistically promoted the expansion of the proliferating chondrocyte zone and inhibited chondrocyte hypertrophy and endochondral ossification. Conclusion: The results of this study indicated that, when combined with BMP2, HIF-1α induced MSC differentiation could become a new method of maintaining cartilage phenotypes during cartilage tissue engineering.

Sex-lethal enables germline stem cell differentiation by down-regulating Nanos protein levels during Drosophila oogenesis.

Science.gov (United States)

Chau, Johnnie; Kulnane, Laura Shapiro; Salz, Helen K

2012-06-12

Drosophila ovarian germ cells require Sex-lethal (Sxl) to exit from the stem cell state and to enter the differentiation pathway. Sxl encodes a female-specific RNA binding protein and in somatic cells serves as the developmental switch gene for somatic sex determination and X-chromosome dosage compensation. None of the known Sxl target genes are required for germline differentiation, leaving open the question of how Sxl promotes the transition from stem cell to committed daughter cell. We address the mechanism by which Sxl regulates this transition through the identification of nanos as one of its target genes. Previous studies have shown that Nanos protein is necessary for GSC self-renewal and is rapidly down-regulated in the daughter cells fated to differentiate in the adult ovary. We find that this dynamic expression pattern is limited to female germ cells and is under Sxl control. In the absence of Sxl, or in male germ cells, Nanos protein is continuously expressed. Furthermore, this female-specific expression pattern is dependent on the presence of canonical Sxl binding sites located in the nanos 3' untranslated region. These results, combined with the observation that nanos RNA associates with the Sxl protein in ovarian extracts and loss and gain of function studies, suggest that Sxl enables the switch from germline stem cell to committed daughter cell by posttranscriptional down-regulation of nanos expression. These findings connect sexual identity to the stem cell self-renewal/differentiation decision and highlight the importance of posttranscriptional gene regulatory networks in controlling stem cell behavior.

Identification of genes differentially regulated in rat alveolar bone wound healing by subtractive hybridization.

Science.gov (United States)

Ohira, T; Myokai, F; Shiomi, N; Yamashiro, K; Yamamoto, T; Murayama, Y; Arai, H; Nishimura, F; Takashiba, S

2004-07-01

Periodontal healing requires the participation of regulatory molecules, cells, and scaffold or matrix. Here, we hypothesized that a certain set of genes is expressed in alveolar bone wound healing. Reciprocal subtraction gave 400 clones from the injured alveolar bone of Wistar rats. Identification of 34 genes and analysis of their expression in injured tissue revealed several clusters of unique gene regulation patterns, including the up-regulation at 1 wk of cytochrome c oxidase regulating electron transfer and energy metabolism, presumably occurring at the site of inflammation; up-regulation at 2.5 wks of pro-alpha-2 type I collagen involving the formation of a connective tissue structure; and up-regulation at 1 and 2 wks and down-regulation at 2.5 and 4 wks of ubiquitin carboxyl-terminal hydrolase l3 involving cell cycle, DNA repair, and stress response. The differential expression of genes may be associated with the processes of inflammation, wound contraction, and formation of a connective tissue structure.

Regulation of differentiation flux by Notch signalling influences the number of dopaminergic neurons in the adult brain

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Niurka Trujillo-Paredes

2016-03-01

Full Text Available Notch signalling is a well-established pathway that regulates neurogenesis. However, little is known about the role of Notch signalling in specific neuronal differentiation. Using Dll1 null mice, we found that Notch signalling has no function in the specification of mesencephalic dopaminergic neural precursor cells (NPCs, but plays an important role in regulating their expansion and differentiation into neurons. Premature neuronal differentiation was observed in mesencephalons of Dll1-deficient mice or after treatment with a Notch signalling inhibitor. Coupling between neurogenesis and dopaminergic differentiation was indicated from the coincident emergence of neuronal and dopaminergic markers. Early in differentiation, decreasing Notch signalling caused a reduction in NPCs and an increase in dopaminergic neurons in association with dynamic changes in the proportion of sequentially-linked dopaminergic NPCs (Msx1/2+, Ngn2+, Nurr1+. These effects in differentiation caused a significant reduction in the number of dopaminergic neurons produced. Accordingly, Dll1 haploinsufficient adult mice, in comparison with their wild-type littermates, have a consistent reduction in neuronal density that was particularly evident in the substantia nigra pars compacta. Our results are in agreement with a mathematical model based on a Dll1-mediated regulatory feedback loop between early progenitors and their dividing precursors that controls the emergence and number of dopaminergic neurons.

Monocyte to macrophage differentiation-associated (MMD) positively regulates ERK and Akt activation and TNF-α and NO production in macrophages.

Science.gov (United States)

Liu, Qiang; Zheng, Jin; Yin, Dan-Dan; Xiang, Jie; He, Fei; Wang, Yao-Chun; Liang, Liang; Qin, Hong-Yan; Liu, Li; Liang, Ying-Min; Han, Hua

2012-05-01

Macrophage activation is modulated by both environmental cues and endogenous programs. In the present study, we investigated the role of a PAQR family protein, monocyte to macrophage differentiation-associated (MMD), in macrophage activation and unveiled its underlying molecular mechanism. Our results showed that while MMD expression could be detected in all tissues examined, its expression level is significantly up-regulated upon monocyte differentiation. Within cells, EGFP-MMD fusion protein could be co-localized to endoplasmic reticulum, mitochondria, Golgi apparatus, but not lysosomes and cytoplasm. MMD expression is up-regulated in macrophages after LPS stimulation, and this might be modulated by RBP-J, the critical transcription factor of Notch signaling. Overexpression of MMD in macrophages increased the production of TNF-α and NO upon LPS stimulation. We found that MMD overexpression enhanced ERK1/2 and Akt phosphorylation in macrophages after LPS stimulation. Blocking Erk or Akt by pharmacological agent reduced TNF-α or NO production in MMD-overexpressing macrophages, respectively. These results suggested that MMD modulates TNF-α and NO production in macrophages, and this process might involves Erk or Akt.

Knock-in strategy at 3'-end of Crx gene by CRISPR/Cas9 system shows the gene expression profiles during human photoreceptor differentiation.

Science.gov (United States)

Homma, Kohei; Usui, Sumiko; Kaneda, Makoto

2017-03-01

Fluorescent reporter gene knock-in induced pluripotent stem cell (iPSC) lines have been used to evaluate the efficiency of differentiation into specific cell lineages. Here, we report a knock-in strategy for the generation of human iPSC reporter lines in which a 2A peptide sequence and a red fluorescent protein (E2-Crimson) gene were inserted at the termination codon of the cone-rod homeobox (Crx) gene, a photoreceptor-specific transcriptional factor gene. The knock-in iPSC lines were differentiated into fluorescence-expressing cells in 3D retinal differentiation culture, and the fluorescent cells also expressed Crx specifically in the nucleus. We found that the fluorescence intensity was positively correlated with the expression levels of Crx mRNA and that fluorescent cells expressed rod photoreceptor-specific genes in the later stage of differentiation. Finally, we treated the fluorescent cells with DAPT, a Notch inhibitor, and found that DAPT-enhanced retinal differentiation was associated with up-regulation of Crx, Otx2 and NeuroD1, and down-regulation of Hes5 and Ngn2. These suggest that this knock-in strategy at the 3'-end of the target gene, combined with the 2A peptide linked to fluorescent proteins, offers a useful tool for labeling specific cell lineages or monitoring expression of any marker genes without affecting the function of the target gene. © 2017 Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.

[PRODUCT OF THE BMI1--A KEY COMPONENT OF POLYCOMB--POSITIVELY REGULATES ADIPOCYTE DIFFERENTIATION OF MOUSE MESENCHYMAL STEM CELLS].

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Petrov, N S; Vereschagina, N A; Sushilova, E N; Kropotov, A V; Miheeva, N F; Popov, B V

2016-01-01

Bmil is a key component of Polycomb (PcG), which in mammals controls the basic functions of mammalian somatic stem cells (SSC) such as self-renewal and differentiation. Bmi1 supports SSC via transcriptional suppression of genes associated with cell cycle and differentiation. The most studied target genes of Bmi1 are the genes of Ink4 locus, CdkI p16(Ink4a) and p1(Arf), suppression of which due to activating mutations of the BMI1 results in formation of cancer stem cells (CSC) and carcinomas in various tissues. In contrast, inactivation of BMI1 results in cell cycle arrest and cell senescence. Although clinical phenomena of hypo- and hyperactivation of BMI1 are well known, its targets and mechanisms of regulation of tissue specific SSC are still obscure. The goal of this study was to evaluate the regulatory role of BMI1 in adipocyte differentiation (AD) of mouse mesenchymal stem cells (MSC). Induction of AD in mouse MSC of the C3H10T1/2 cell line was associated with an increase in the expression levels of BMI1, the genes of pRb family (RB, p130) and demethylase UTX, but not methyltransferase EZH2, whose products regulate the methylation levels of H3K27. It was observed earlier that H3K27me3 may play the role of the epigenetic switch by promoting AD of human MSC via activating expression of the PPARγ2, the master gene of AD (Hemming et al., 2014). Here we show that inactivation of BMI1 using specific siRNA slows and decreases the levels of AD, but does not abolish it. This is associated with a complete inhibition of the expression of adipogenic marker genes--PPARγ2, ADIPOQ and a decrease in the expression of RB, p130, but not UTX. The results obtained give evidence that the epigenetic mechanism regulating AD differentiation in mouse and human MSC is different.

Spontaneous Vesicle Fusion Is Differentially Regulated at Cholinergic and GABAergic Synapses

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Haowen Liu

2018-02-01

Full Text Available The locomotion of C. elegans is balanced by excitatory and inhibitory neurotransmitter release at neuromuscular junctions. However, the molecular mechanisms that maintain the balance of synaptic transmission remain enigmatic. Here, we investigated the function of voltage-gated Ca2+ channels in triggering spontaneous release at cholinergic and GABAergic synapses. Recordings of the miniature excitatory/inhibitory postsynaptic currents (mEPSCs and mIPSCs, respectively showed that UNC-2/CaV2 and EGL-19/CaV1 channels are the two major triggers for spontaneous release. Notably, however, Ca2+-independent spontaneous release was observed at GABAergic but not cholinergic synapses. Functional screening led to the identification of hypomorphic unc-64/Syntaxin-1A and snb-1/VAMP2 mutants in which mEPSCs are severely impaired, whereas mIPSCs remain unaltered, indicating differential regulation of these currents at cholinergic and GABAergic synapses. Moreover, Ca2+-independent spontaneous GABA release was nearly abolished in the hypomorphic unc-64 and snb-1 mutants, suggesting distinct mechanisms for Ca2+-dependent and Ca2+-independent spontaneous release.

Indian hedgehog (Ihh) both promotes and restricts thymocyte differentiation.

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Outram, Susan V; Hager-Theodorides, Ariadne L; Shah, Divya K; Rowbotham, Nicola J; Drakopoulou, Ekati; Ross, Susan E; Lanske, Beate; Dessens, Johannes T; Crompton, Tessa

2009-03-05

We show that Indian Hedgehog (Ihh) regulates T-cell development and homeostasis in both fetal and adult thymus, controlling thymocyte number. Fetal Ihh(-/-) thymi had reduced differentiation to double-positive (DP) cell and reduced cell numbers compared with wild-type littermates. Surprisingly, fetal Ihh(+/-) thymi had increased thymocyte numbers and proportion of DP cells relative to wild type, indicating that Ihh also negatively regulates thymocyte development. In vitro treatment of thymus explants with exogenous recombinant Hedgehog protein promoted thymocyte development in Ihh(-/-) thymi but inhibited thymocyte development in Ihh(+/-), confirming both positive and negative regulatory functions of Ihh. Analysis of Rag(-/-)Ihh(+/-) thymi showed that Ihh promotes T-cell development before pre-T-cell receptor (pre-TCR) signaling, but negatively regulates T-cell development only after pre-TCR signaling has taken place. We show that Ihh is most highly expressed by the DP population and that Ihh produced by DP cells feeds back to negatively regulate the differentiation and proliferation of their double-negative progenitors. Thus, differentiation from double-negative to DP cell, and hence the size of the DP population, is dependent on the concentration of Ihh in the thymus. Analysis of Ihh conditional knockout and heterozygote adult mice showed that Ihh also influences thymocyte number in the adult.

Hidradenocarcinoma showing prominent mucinous and squamous differentiation and associated pagetoid cells.

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Honda, Yumi; Tanigawa, Hiroki; Harada, Miho; Fukushima, Satoshi; Masuguchi, Shinichi; Ishihara, Tsuyoshi; Ihn, Hironobu; Iyama, Ken-ichi

2013-05-01

Herein, we report a 63-year-old man presenting with hidradenocarcinoma showing prominent mucinous and squamous differentiation on his back. The tumor was dermal-based, solid and cystic. Tumor cells with squamous differentiation and with keratin pearl formation were identified predominantly in the superficial dermis, and mucinous cells were identified principally in the cystic lesion in the deep dermis. Interestingly, the additional feature of pagetoid cells was identified in the overlying epidermis. Both the mucinous cells in hidradenocarcinoma and pagetoid cells had intracytoplasmic mucin; however, they had different histopathologic findings and immunophenotypes. Mucinous cells in hidradenocarcinoma had small nuclei and abundant intracytoplasmic mucin presenting goblet cells with low rate of positive immunostaining for p53 and Ki67. In contrast, pagetoid cells had larger nuclei with less intracytoplasmic mucin. Both p53- and Ki67-positive cells were increased in pagetoid cells. Additionally, mucinous cells in hidradenocarcinoma were MUC1(+)/MUC2(-)/MUC5AC(+)/MUC6(+), but pagetoid cells were MUC1(+; focal)/MUC2(-)/MUC5AC(-)/MUC6(+; focal). The derivation of pagetoid cells is unclear; however, the localized small region of pagetoid cells over the hidradenocarcinoma in the present case may suggest a common histogenesis of these two malignant neoplasms. Copyright © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

NADPH oxidases differentially regulate ROS metabolism and nutrient uptake under cadmium toxicity.

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Gupta, D K; Pena, L B; Romero-Puertas, M C; Hernández, A; Inouhe, M; Sandalio, L M

2017-04-01

The role of NADPH oxidases under cadmium (Cd) toxicity was studied using Arabidopsis thaliana mutants AtrbohC, AtrbohD and AtrbohF, which were grown under hydroponic conditions with 25 and 100 μM Cd for 1 and 5 days. Cadmium reduced the growth of leaves in WT, AtrbohC and D, but not in AtrbohF. A time-dependent increase in H 2 O 2 and lipid peroxidation was observed in all genotypes, with AtrbohC showing the smallest increase. An opposite behaviour was observed with NO accumulation. Cadmium increased catalase activity in WT plants and decreased it in Atrboh mutants, while glutathione reductase and glycolate oxidase activities increased in Atrboh mutants, and superoxide dismutases were down-regulated in AtrbohC. The GSH/GSSG and ASA/DHA couples were also affected by the treatment, principally in AtrbohC and AtrbohF, respectively. Cadmium translocation to the leaves was severely reduced in Atrboh mutants after 1 day of treatment and even after 5 days in AtrbohF. Similar results were observed for S, P, Ca, Zn and Fe accumulation, while an opposite trend was observed for K accumulation, except in AtrbohF. Thus, under Cd stress, RBOHs differentially regulate ROS metabolism, redox homeostasis and nutrient balance and could be of potential interest in biotechnology for the phytoremediation of polluted soils. © 2016 John Wiley & Sons Ltd.

Interferon-γ regulates the proliferation and differentiation of mesenchymal stem cells via activation of indoleamine 2,3 dioxygenase (IDO.

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Juliana Croitoru-Lamoury

Full Text Available The kynurenine pathway (KP of tryptophan metabolism is linked to antimicrobial activity and modulation of immune responses but its role in stem cell biology is unknown. We show that human and mouse mesenchymal and neural stem cells (MSCs and NSCs express the complete KP, including indoleamine 2,3 dioxygenase 1 (IDO and IDO2, that it is highly regulated by type I (IFN-β and II interferons (IFN-γ, and that its transcriptional modulation depends on the type of interferon, cell type and species. IFN-γ inhibited proliferation and altered human and mouse MSC neural, adipocytic and osteocytic differentiation via the activation of IDO. A functional KP present in MSCs, NSCs and perhaps other stem cell types offers novel therapeutic opportunities for optimisation of stem cell proliferation and differentiation.

CDH1 regulates E2F1 degradation in response to differentiation signals in keratinocytes.

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Singh, Randeep K; Dagnino, Lina

2017-01-17

The E2F1 transcription factor plays key roles in skin homeostasis. In the epidermis, E2F1 expression is essential for normal proliferation of undifferentiated keratinocytes, regeneration after injury and DNA repair following UV radiation-induced photodamage. Abnormal E2F1 expression promotes nonmelanoma skin carcinoma. In addition, E2F1 must be downregulated for proper keratinocyte differentiation, but the relevant mechanisms involved remain poorly understood. We show that differentiation signals induce a series of post-translational modifications in E2F1 that are jointly required for its downregulation. Analysis of the structural determinants that govern these processes revealed a central role for S403 and T433. In particular, substitution of these two amino acid residues with non-phosphorylatable alanine (E2F1 ST/A) interferes with E2F1 nuclear export, K11- and K48-linked polyubiquitylation and degradation in differentiated keratinocytes. In contrast, replacement of S403 and T433 with phosphomimetic aspartic acid to generate a pseudophosphorylated E2F1 mutant protein (E2F1 ST/D) generates a protein that is regulated in a manner indistinguishable from that of wild type E2F1. Cdh1 is an activating cofactor that interacts with the anaphase-promoting complex/cyclosome (APC/C) ubiquitin E3 ligase, promoting proteasomal degradation of various substrates. We found that Cdh1 associates with E2F1 in keratinocytes. Inhibition or RNAi-mediated silencing of Cdh1 prevents E2F1 degradation in response to differentiation signals. Our results reveal novel regulatory mechanisms that jointly modulate post-translational modifications and downregulation of E2F1, which are necessary for proper epidermal keratinocyte differentiation.

The transcription factor Jdp2 controls bone homeostasis and antibacterial immunity by regulating osteoclast and neutrophil differentiation.

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Maruyama, Kenta; Fukasaka, Masahiro; Vandenbon, Alexis; Saitoh, Tatsuya; Kawasaki, Takumi; Kondo, Takeshi; Yokoyama, Kazunari K; Kidoya, Hiroyasu; Takakura, Nobuyuki; Standley, Daron; Takeuchi, Osamu; Akira, Shizuo

2012-12-14

Jdp2 is an AP-1 family transcription factor that regulates the epigenetic status of histones. Previous in vitro studies revealed that Jdp2 is involved in osteoclastogenesis. However, the roles of Jdp2 in vivo and its pleiotropic functions are largely unknown. Here we generated Jdp2(-/-) mice and discovered its crucial roles not only in bone metabolism but also in differentiation of neutrophils. Jdp2(-/-) mice exhibited osteopetrosis resulting from impaired osteoclastogenesis. Jdp2(-/-) neutrophils were morphologically normal but had impaired surface expression of Ly6G, bactericidal function, and apoptosis. We also found that ATF3 was an inhibitor of neutrophil differentiation and that Jdp2 directly suppresses its expression via inhibition of histone acetylation. Strikingly, Jdp2(-/-) mice were highly susceptible to Staphylococcus aureus and Candida albicans infection. Thus, Jdp2 plays pivotal roles in in vivo bone homeostasis and host defense by regulating osteoclast and neutrophil differentiation. Copyright © 2012 Elsevier Inc. All rights reserved.

Bone morphogenic protein-2 regulates the myogenic differentiation of PMVECs in CBDL rat serum-induced pulmonary microvascular remodeling

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Liu, Chang; Chen, Lin; Zeng, Jing; Cui, Jian; Ning, Jiao-nin [Department of Anesthesia, Southwest Hospital, The Third Military Medical University, Chongqing 400038 (China); Wang, Guan-song [Institute of Respiratory Disease, Xinqiao Hospital, The Third Military Medical University, Chongqing 400037 (China); Belguise, Karine; Wang, Xiaobo [Université P. Sabatier Toulouse III and CNRS, LBCMCP, 31062 Toulouse Cedex 9 (France); Qian, Gui-sheng [Institute of Respiratory Disease, Xinqiao Hospital, The Third Military Medical University, Chongqing 400037 (China); Lu, Kai-zhi [Department of Anesthesia, Southwest Hospital, The Third Military Medical University, Chongqing 400038 (China); Yi, Bin, E-mail: yibin1974@163.com [Department of Anesthesia, Southwest Hospital, The Third Military Medical University, Chongqing 400038 (China)

2015-08-01

Hepatopulmonary syndrome (HPS) is characterized by an arterial oxygenation defect induced by intrapulmonary vasodilation (IPVD) that increases morbidity and mortality. In our previous study, it was determined that both the proliferation and the myogenic differentiation of pulmonary microvascular endothelial cells (PMVECs) play a key role in the development of IPVD. However, the molecular mechanism underlying the relationship between IPVD and the myogenic differentiation of PMVECs remains unknown. Additionally, it has been shown that bone morphogenic protein-2 (BMP2), via the control of protein expression, may regulate cell differentiation including cardiomyocyte differentiation, neuronal differentiation and odontoblastic differentiation. In this study, we observed that common bile duct ligation (CBDL)-rat serum induced the upregulation of the expression of several myogenic proteins (SM-α-actin, calponin, SM-MHC) and enhanced the expression levels of BMP2 mRNA and protein in PMVECs. We also observed that both the expression levels of Smad1/5 and the activation of phosphorylated Smad1/5 were significantly elevated in PMVECs following exposure to CBDL-rat serum, which was accompanied by the down-regulation of Smurf1. The blockage of the BMP2/Smad signaling pathway with Noggin inhibited the myogenic differentiation of PMVECs, a process that was associated with relatively low expression levels of both SM-α-actin and calponin in the setting of CBDL-rat serum exposure, although SM-MHC expression was not affected. These findings suggested that the BMP2/Smad signaling pathway is involved in the myogenic differentiation of the PMVECs. In conclusion, our data highlight the pivotal role of BMP2 in the CBDL-rat serum-induced myogenic differentiation of PMVECs via the activation of both Smad1 and Smad5 and the down-regulation of Smurf1, which may represent a potential therapy for HPS-induced pulmonary vascular remodeling. - Highlights: • CBDL-rat serum promotes the myogenic

LIF inhibits osteoblast differentiation at least in part by regulation of HAS2 and its product hyaluronan.

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Falconi, Dominic; Aubin, Jane E

2007-08-01

LIF arrests osteogenesis in fetal rat calvaria cells in a differentiation stage-specific manner. Differential display identified HAS2 as a LIF-induced gene and its product, HA, modulated osteoblast differentiation similarly to LIF. Our data suggest that LIF arrests osteoblast differentiation by altering HA content of the extracellular matrix. Leukemia inhibitory factor (LIF) elicits both anabolic and catabolic effects on bone. We previously showed in the fetal rat calvaria (RC) cell system that LIF inhibits osteoblast differentiation at the late osteoprogenitor/early osteoblast stage. To uncover potential molecular mediators of this inhibitory activity, we used a positive-negative genome-wide differential display screen to identify LIF-induced changes in the developing osteoblast transcriptome. Although LIF signaling is active throughout the RC cell proliferation-differentiation sequence, only a relatively small number of genes, in several different functional clusters, are modulated by LIF specifically during the LIF-sensitive inhibitory time window. Based on their known and predicted functions, most of the LIF-regulated genes identified are plausible candidates to be involved in the LIF-induced arrest of osteoprogenitor differentiation. To test this hypothesis, we further analyzed the function of one of the genes identified, hyaluronan synthase 2 (HAS2), in the LIF-induced inhibition. Synthesis of hyaluronan (HA), the product of HAS enzymatic activity, was stimulated by LIF and mimicked the HAS2 expression profile, with highest expression in early/proliferative and late/maturing cultures and lowest levels in intermediate/late osteoprogenitor-early osteoblast cultures. Exogenously added high molecular weight HA, the product of HAS2, dose-dependently inhibited osteoblast differentiation, with pulse-treatment effective in the same differentiation stage-specific inhibitory window as seen with LIF. In addition, however, pulse treatment with HA in early cultures

Regulation of intracellular free calcium concentration during heterocyst differentiation by HetR and NtcA in Anabaena sp. PCC 7120.

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Shi, Yunming; Zhao, Weixing; Zhang, Wei; Ye, Zi; Zhao, Jindong

2006-07-25

Calcium ions are important to some prokaryotic cellular processes, such as heterocyst differentiation of cyanobacteria. Intracellular free Ca(2+)concentration, [Ca(2+)](i), increases several fold in heterocysts and is regulated by CcbP, a Ca(2+)-binding protein found in heterocyst-forming cyanobacteria. We demonstrate here that CcbP is degraded by HetR, a serine-type protease that controls heterocyst differentiation. The degradation depends on Ca(2+) and appears to be specific because HetR did not digest other tested proteins. CcbP was found to bind two Ca(2+) per molecule with K(D) values of 200 nM and 12.8 microM. Degradation of CcbP releases bound Ca(2+) that contributes significantly to the increase of [Ca(2+)](i) during the process of heterocyst differentiation in Anabaena sp. strain PCC 7120. We suggest that degradation of CcbP is a mechanism of positive autoregulation of HetR. The down-regulation of ccbP in differentiating cells and mature heterocysts, which also is critical to the regulation of [Ca(2+)](i), depends on NtcA. Coexpression of ntcA and a ccbP promoter-controlled gfp in Escherichia coli diminished production of GFP, and the decrease is enhanced by alpha-ketoglutarate. It was also found that NtcA could bind a fragment of the ccbP promoter containing an NtcA-binding sequence in a alpha-ketoglutarate-dependent fashion. Therefore, [Ca(2+)](i) is regulated by a collaboration of HetR and NtcA in heterocyst differentiation in Anabaena sp. strain PCC 7120.

Identification of key factors regulating self-renewal and differentiation in EML hematopoietic precursor cells by RNA-sequencing analysis.

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Zong, Shan; Deng, Shuyun; Chen, Kenian; Wu, Jia Qian

2014-11-11

Hematopoietic stem cells (HSCs) are used clinically for transplantation treatment to rebuild a patient's hematopoietic system in many diseases such as leukemia and lymphoma. Elucidating the mechanisms controlling HSCs self-renewal and differentiation is important for application of HSCs for research and clinical uses. However, it is not possible to obtain large quantity of HSCs due to their inability to proliferate in vitro. To overcome this hurdle, we used a mouse bone marrow derived cell line, the EML (Erythroid, Myeloid, and Lymphocytic) cell line, as a model system for this study. RNA-sequencing (RNA-Seq) has been increasingly used to replace microarray for gene expression studies. We report here a detailed method of using RNA-Seq technology to investigate the potential key factors in regulation of EML cell self-renewal and differentiation. The protocol provided in this paper is divided into three parts. The first part explains how to culture EML cells and separate Lin-CD34+ and Lin-CD34- cells. The second part of the protocol offers detailed procedures for total RNA preparation and the subsequent library construction for high-throughput sequencing. The last part describes the method for RNA-Seq data analysis and explains how to use the data to identify differentially expressed transcription factors between Lin-CD34+ and Lin-CD34- cells. The most significantly differentially expressed transcription factors were identified to be the potential key regulators controlling EML cell self-renewal and differentiation. In the discussion section of this paper, we highlight the key steps for successful performance of this experiment. In summary, this paper offers a method of using RNA-Seq technology to identify potential regulators of self-renewal and differentiation in EML cells. The key factors identified are subjected to downstream functional analysis in vitro and in vivo.

Transiently truncated and differentially regulated expression of midkine during mouse embryogenesis

International Nuclear Information System (INIS)

Chen Qin; Yuan Yuanyang; Lin Shuibin; Chang Youde; Zhuo Xinming; Wei Wei; Tao Ping; Ruan Lingjuan; Li Qifu; Li Zhixing

2005-01-01

Midkine (MK) is a retinoic acid response cytokine, mostly expressed in embryonic tissues. Aberrant expression of MK was found in numerous cancers. In human, a truncated MK was expressed specifically in tumor/cancer tissues. Here we report the discovery of a novel truncated form of MK transiently expressed during normal mouse embryonic development. In addition, MK is concentrated at the interface between developing epithelium and mesenchyme as well as highly proliferating cells. Its expression, which is closely coordinated with angiogenesis and vasculogenesis, is spatiotemporally regulated with peaks in extensive organogenesis period and undifferentiated cells tailing off in maturing cells, implying its role in nascent blood vessel (endothelial) signaling of tissue differentiation and stem cell renewal/differentiation.. Cloning and sequencing analysis revealed that the embryonic truncated MK, in which the conserved domain is in-frame deleted, presumably producing a novel secreted small peptide, is different from the truncated form in human cancer tissues, whose deletion results in a frame-shift mutation. Our data suggest that MK may play a role in epithelium-mesenchyme interactions, blood vessel signaling, and the decision of proliferation vs differentiation. Detection of the transiently expressed truncated MK reveals its novel function in development and sheds light on its role in carcinogenesis

Differential Regulation of Elastic Fiber Formation by Fibulin-4 and -5*

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Choudhury, Rawshan; McGovern, Amanda; Ridley, Caroline; Cain, Stuart A.; Baldwin, Andrew; Wang, Ming-Chuan; Guo, Chun; Mironov, Aleksandr; Drymoussi, Zoe; Trump, Dorothy; Shuttleworth, Adrian; Baldock, Clair; Kielty, Cay M.

2009-01-01

Fibulin-4 and -5 are extracellular glycoproteins with essential non-compensatory roles in elastic fiber assembly. We have determined how they interact with tropoelastin, lysyl oxidase, and fibrillin-1, thereby revealing how they differentially regulate assembly. Strong binding between fibulin-4 and lysyl oxidase enhanced the interaction of fibulin-4 with tropoelastin, forming ternary complexes that may direct elastin cross-linking. In contrast, fibulin-5 did not bind lysyl oxidase strongly but bound tropoelastin in terminal and central regions and could concurrently bind fibulin-4. Both fibulins differentially bound N-terminal fibrillin-1, which strongly inhibited their binding to lysyl oxidase and tropoelastin. Knockdown experiments revealed that fibulin-5 controlled elastin deposition on microfibrils, although fibulin-4 can also bind fibrillin-1. These experiments provide a molecular account of the distinct roles of fibulin-4 and -5 in elastic fiber assembly and how they act in concert to chaperone cross-linked elastin onto microfibrils. PMID:19570982

SAM pointed domain ETS factor (SPDEF) regulates terminal differentiation and maturation of intestinal goblet cells

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Noah, Taeko K.; Kazanjian, Avedis [Gastroenterology, Hepatology and Nutrition, Cincinnati Children' s Hospital Medical Center and University of Cincinnati College of Medicine, Cincinnati, OH (United States); Whitsett, Jeffrey [Developmental Biology, Cincinnati Children' s Hospital Medical Center and University of Cincinnati College of Medicine, Cincinnati, OH (United States); Neonatology and Pulmonary Biology, Cincinnati Children' s Hospital Medical Center and University of Cincinnati College of Medicine, Cincinnati, OH (United States); Shroyer, Noah F., E-mail: noah.shroyer@cchmc.org [Gastroenterology, Hepatology and Nutrition, Cincinnati Children' s Hospital Medical Center and University of Cincinnati College of Medicine, Cincinnati, OH (United States); Developmental Biology, Cincinnati Children' s Hospital Medical Center and University of Cincinnati College of Medicine, Cincinnati, OH (United States)

2010-02-01

Background and Aims: SPDEF (also termed PDEF or PSE) is an ETS family transcription factor that regulates gene expression in the prostate and goblet cell hyperplasia in the lung. Spdef has been reported to be expressed in the intestine. In this paper, we identify an important role for Spdef in regulating intestinal epithelial cell homeostasis and differentiation. Methods: SPDEF expression was inhibited in colon cancer cells to determine its ability to control goblet cell gene activation. The effects of transgenic expression of Spdef on intestinal differentiation and homeostasis were determined. Results: In LS174T colon cancer cells treated with Notch/{gamma}-secretase inhibitor to activate goblet cell gene expression, shRNAs that inhibited SPDEF also repressed expression of goblet cell genes AGR2, MUC2, RETLNB, and SPINK4. Transgenic expression of Spdef caused the expansion of intestinal goblet cells and corresponding reduction in Paneth, enteroendocrine, and absorptive enterocytes. Spdef inhibited proliferation of intestinal crypt cells without induction of apoptosis. Prolonged expression of the Spdef transgene caused a progressive reduction in the number of crypts that expressed Spdef, consistent with its inhibitory effects on cell proliferation. Conclusions: Spdef was sufficient to inhibit proliferation of intestinal progenitors and induce differentiation into goblet cells; SPDEF was required for activation of goblet cell associated genes in vitro. These data support a model in which Spdef promotes terminal differentiation into goblet cells of a common goblet/Paneth progenitor.

Osteogenic differentiation of mesenchymal stem cells is regulated by osteocyte and osteoblast cells in a simplified bone niche

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LM McNamara

2012-01-01

Full Text Available Mesenchymal stem cells (MSCs within their native environment of the stem cell niche in bone receive biochemical stimuli from surrounding cells. These stimuli likely influence how MSCs differentiate to become bone precursors. The ability of MSCs to undergo osteogenic differentiation is well established in vitro;however, the role of the natural cues from bone’s regulatory cells, osteocytes and osteoblasts in regulating the osteogenic differentiation of MSCs in vivo are unclear. In this study we delineate the role of biochemical signalling from osteocytes and osteoblasts, using conditioned media and co-culture experiments, to understand how they direct osteogenic differentiation of MSCs. Furthermore, the synergistic relationship between osteocytes and osteoblasts is examined by transwell co-culturing of MSCs with both simultaneously. Osteogenic differentiation of MSCs was quantified by monitoring alkaline phosphatase (ALP activity, calcium deposition and cell number. Intracellular ALP was found to peak earlier and there was greater calcium deposition when MSCs were co-cultured with osteocytes rather than osteoblasts, suggesting that osteocytes are more influential than osteoblasts in stimulating osteogenesis in MSCs. Osteoblasts initially stimulated an increase in the number of MSCs, but ultimately regulated MSC differentiation down the same pathway. Our novel co-culture system confirmed a synergistic relationship between osteocytes and osteoblasts in producing biochemical signals to stimulate the osteogenic differentiation of MSCs. This study provides important insights into the mechanisms at work within the native stem cell niche to stimulate osteogenic differentiation and outlines a possible role for the use of co-culture or conditioned media methodologies for tissue engineering applications.

Down-regulation of E protein activity augments an ILC2 differentiation program in the thymus

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Innate lymphoid cells (ILCs) are important regulators in various immune responses. Current paradigm states that all newly-made ILCs originate from common lymphoid progenitors (CLP) in the bone marrow. Id2, an inhibitor of E protein transcription factors, is indispensable for ILC differentiation. Une...

Four and a half domain 2 (FHL2) scaffolding protein is a marker of connective tissues of developing digits and regulates fibrogenic differentiation of limb mesodermal progenitors.

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Lorda-Diez, C I; Montero, J A; Sanchez-Fernandez, C; Garcia-Porrero, J A; Chimal-Monroy, J; Hurle, J M

2018-04-01

Four and a half LIM domain 2 (FHL2) is a multifunctional scaffolding protein of well-known function regulating cell signalling cascades and gene transcription in cancer tissues. However, its function in embryonic systems is poorly characterized. Here, we show that Fhl2 is involved in the differentiation of connective tissues of developing limb autopod. We show that Fhl2 exhibits spatially restricted and temporally dynamic expression around the tendons of developing digits, interphalangeal joint capsules, and fibrous peridigital tissue. Immunolabelling analysis of the skeletal progenitors identified a predominant, but not exclusive, cytoplasmic distribution of FHL2 being associated with focal adhesions and actin cytoskeleton. In the course of chondrogenic differentiation of cultures of limb skeletal progenitors, the expression of Fhl2 is down-regulated. Furthermore, cultures of skeletal progenitors overexpressing Fhl2 take on a predominant fibrogenic appearance. Both gain-of-function and loss-of-function experiments in the micromass culture assays revealed a positive transcriptional influence of Fhl2 in the expression of fibrogenic markers including Scleraxis, Tenomodulin, Tenascin C, βig-h3, and Tgif1. We further show that the expression of Fhl2 is positively regulated by profibrogenic signals including Tgfβ2, all-trans-retinoic acid, and canonical Wnt signalling molecules and negatively regulated by prochondrogenic factors of the bone morphogenetic protein family. Expression of Fhl2 is also regulated negatively in immobilized limbs, but this influence appears to be mediated by other connective tissue markers, such as Tgfβs and Scleraxis. Copyright © 2018 John Wiley & Sons, Ltd.

Differential regulation of EGFR-MAPK signaling by deoxycholic acid (DCA) and ursodeoxycholic acid (UDCA) in colon cancer.

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Centuori, Sara M; Martinez, Jesse D

2014-10-01

A high-fat diet coincides with increased levels of bile acids. This increase in bile acids, particularly deoxycholic acid (DCA), has been strongly associated with the development of colon cancer. Conversely, ursodeoxycholic acid (UDCA) may have chemopreventive properties. Although structurally similar, DCA and UDCA present different biological and pathological effects in colon cancer progression. The differential regulation of cancer by these two bile acids is not yet fully understood. However, one possible explanation for their diverging effects is their ability to differentially regulate signaling pathways involved in the multistep progression of colon cancer, such as the epidermal growth factor receptor (EGFR)-mitogen-activated protein kinase (MAPK) pathway. This review will examine the biological effects of DCA and UDCA on colon cancer development, as well as the diverging effects of these bile acids on the oncogenic signaling pathways that play a role in colon cancer development, with a particular emphasis on bile acid regulation of the EGFR-MAPK pathway.

Ethanol negatively regulates hepatic differentiation of hESC by inhibition of the MAPK/ERK signaling pathway in vitro.

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Wei Gao

Full Text Available Alcohol insult triggers complex events in the liver, promoting fibrogenic/inflammatory signals and in more advanced cases, aberrant matrix deposition. It is well accepted that the regenerative capacity of the adult liver is impaired during alcohol injury. The liver progenitor/stem cells have been shown to play an important role in liver regeneration -in response to various chronic injuries; however, the effects of alcohol on stem cell differentiation in the liver are not well understood.We employed hepatic progenitor cells derived from hESCs to study the impact of ethanol on hepatocyte differentiation by exposure of these progenitor cells to ethanol during hepatocyte differentiation.We found that ethanol negatively regulated hepatic differentiation of hESC-derived hepatic progenitor cells in a dose-dependent manner. There was also a moderate cell cycle arrest at G1/S checkpoint in the ethanol treated cells, which is associated with a reduced level of cyclin D1 in these cells. Ethanol treatment specifically inhibited the activation of the ERK but not JNK nor the p38 MAP signaling pathway. At the same time, the WNT signaling pathway was also reduced in the cells exposed to ethanol. Upon evaluating the effects of the inhibitors of these two signaling pathways, we determined that the Erk inhibitor replicated the effects of ethanol on the hepatocyte differentiation and attenuated the WNT/β-catenin signaling, however, inhibitors of WNT only partially replicated the effects of ethanol on the hepatocyte differentiation.Our results demonstrated that ethanol negatively regulated hepatic differentiation of hESC-derived hepatic progenitors through inhibiting the MAPK/ERK signaling pathway, and subsequently attenuating the WNT signaling pathway. Thus, our finding provides a novel insight into the mechanism by which alcohol regulates cell fate selection of hESC-derived hepatic progenitor cells, and the identified pathways may provide therapeutic targets

Leptin differentially regulates chondrogenesis in mouse vertebral and tibial growth plates.

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Yu, Bo; Jiang, Kaibiao; Chen, Bin; Wang, Hantao; Li, Xinfeng; Liu, Zude

2017-05-31

Leptin plays an important role in mediating chondrogenesis of limb growth plate. Previous studies suggest that bone structures and development of spine and limb are different. The expression of Ob-Rb, the gene that encodes leptin receptors, is vertebral and appendicular region-specific, suggesting the regulation of leptin on VGP and TGP chondrogenesis may be very different. The aim of the present study was to investigate the differential regulation of leptin on the chondrogenesis of vertebral growth plate (VGP) and tibial growth plate (TGP). We compared the VGP and TGP from wild type (C57BL/6) and leptin-deficient (ob/ob) mice. We then generated primary cultures of TGP and VGP chondrocytes. By treating the primary cells with different concentrations of leptin in vitro, we analyzed proliferation and apoptosis of the primary chondrocytes from TGP and VGP. We further measured expression of chondrogenic-related genes in these cells that had been incubated with different doses of leptin. Leptin-deficient mice of 8-week-old had shorter tibial and longer vertebral lengths than the wide type mice. Disturbed columnar structure was observed for TGP but not for VGP. In primary chondrocyte cultures, leptin inhibited VGP chondrocyte proliferation but promoted their apoptosis. Collagen IIA and aggrecan mRNA, and the protein levels of proliferation- and chondrogenesis-related markers, including PCNA, Sox9, and Smad4, were downregulated by leptin in a dose-dependent manner. In contrast, leptin stimulated the proliferation and chondrogenic differentiation of TGP chondrocytes at physiological levels (i.e., 10 and 50 ng/mL) but not at high levels (i.e., 100 and 1000 ng/mL). Leptin exerts a stimulatory effect on the proliferation and chondrogenic differentiation of the long bone growth plate but an inhibitory effect on the spine growth plate. The ongoing study will shed light on the regulatory mechanisms of leptin in bone development and metabolism.

The gga-let-7 family post-transcriptionally regulates TGFBR1 and LIN28B during the differentiation process in early chick development.

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Lee, Sang In; Jeon, Mi-Hyang; Kim, Jeom Sun; Jeon, Ik-Soo; Byun, Sung June

2015-12-01

Early chick embryogenesis is governed by a complex mechanism involving transcriptional and post-transcriptional regulation, although how post-transcriptional processes influence the balance between pluripotency and differentiation during early chick development have not been previously investigated. Here, we characterized the microRNA (miRNA) signature associated with differentiation in the chick embryo, and found that as expression of the gga-let-7 family increases through early development, expression of their direct targets, TGFBR1 and LIN28B, decreases; indeed, gga-let-7a-5p and gga-let-7b miRNAs directly bind to TGFBR1 and LIN28B transcripts. Our data further indicate that TGFBR1 and LIN28B maintain pluripotency by regulating POUV, NANOG, and CRIPTO. Therefore, gga-let-7 miRNAs act as post-transcriptional regulators of differentiation in blastodermal cells by repressing the expression of the TGFBR1 and LIN28B, which intrinsically controls blastodermal cell differentiation in early chick development. © 2015 Wiley Periodicals, Inc.

The Regulation of Chemerin and CMKLR1 Genes Expression by TNF-α, Adiponectin, and Chemerin Analog in Bovine Differentiated Adipocytes

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Y. Suzuki

2012-09-01

Full Text Available Adipokines, adipocyte-derived protein, have important roles in various kinds of physiology including energy homeostasis. Chemerin, one of adipocyte-derived adipokines, is highly expressed in differentiated adipocytes and is known to induce macrophage chemotaxis and glucose intolerance. The objective of the present study was to investigate the changes of chemerin and the chemokine-like-receptor 1 (CMKLR1 gene expression levels during differentiation of the bovine adipocyte and in differentiated adipocytes treated with tumor necrosis factor-α (TNF-α, adiponectin, leptin, and chemerin (peptide analog. The expression levels of the chemerin gene increased at d 6 and 12 of the differentiation period accompanied by increased cytoplasm lipid droplets. From d 6 onward, peroxisome proliferator-activated receptor-γ2 (PPAR-γ2 gene expression levels were significantly higher than that of d 0 and 3. In contrast, CMKLR1 expression levels decreased at the end of the differentiation period. In fully differentiated adipocytes (i.e. at d 12, the treatment of TNF-α and adiponectin upregulated both chemerin and CMKLR1 gene expression levels, although leptin did not show such effects. Moreover, chemerin analog treatment was shown to upregulate chemerin gene expression levels regardless of doses. These results suggest that the expression of chemerin in bovine adipocyte might be regulated by chemerin itself and other adipokines, which indicates its possible role in modulating the adipokine secretions in adipose tissues.

ERK2 protein regulates the proliferation of human mesenchymal stem cells without affecting their mobilization and differentiation potential

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Carcamo-Orive, Ivan; Tejados, Naiara; Delgado, Jesus; Gaztelumendi, Ainhoa; Otaegui, David; Lang, Valerie; Trigueros, Cesar

2008-01-01

Human Mesenchymal Stem Cells (hMSC), derived mainly from adult bone marrow, are valuable models for the study of processes involved in stem cell self-renewal and differentiation. As the Extracellular signal-Regulated Kinase (ERK) signalling pathway is a major contributor to cellular growth, differentiation and survival, we have studied the functions of this kinase in hMSC activity. Ablation of ERK2 gene expression (but not ERK1) by RNA interference significantly reduced proliferation of hMSC. This reduction was due to a defect in Cyclin D1 expression and subsequent arrest in the G0/G1 phase of the cell cycle. hMSC growth is enhanced through culture medium supplementation with growth factors (GFs) such as Platelet-Derived Growth Factor (PDGF), basic Fibroblast Growth Factor (bFGF) or Epidermal Growth Factor (EGF). However, these supplements could not rescue the defect observed after ERK2 knockdown, suggesting a common signalling pathway used by these GFs for proliferation. In contrast, ERK1/2 may be dissociated from chemotactic signalling induced by the same GFs. Additionally, hMSCs were capable of differentiating into adipocytes even in the absence of either ERK1 or ERK2 proteins. Our data show that hMSCs do not require cell division to enter the adipogenic differentiation process, indicating that clonal amplification of these cells is not a critical step. However, cell-cell contact seems to be an essential requirement to be able to differentiate into mature adipocytes

Quantitative Phosphoproteomic Study Reveals that Protein Kinase A Regulates Neural Stem Cell Differentiation Through Phosphorylation of Catenin Beta-1 and Glycogen Synthase Kinase 3β.

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Wang, Shuxin; Li, Zheyi; Shen, Hongyan; Zhang, Zhong; Yin, Yuxin; Wang, Qingsong; Zhao, Xuyang; Ji, Jianguo

2016-08-01

Protein phosphorylation is central to the understanding of multiple cellular signaling pathways responsible for regulating the self-renewal and differentiation of neural stem cells (NSCs). Here we performed a large-scale phosphoproteomic analysis of rat fetal NSCs using strong cation exchange chromatography prefractionation and citric acid-assisted two-step enrichment with TiO2 strategy followed by nanoLC-MS/MS analysis. Totally we identified 32,546 phosphosites on 5,091 phosphoproteins, among which 23,945 were class I phosphosites, and quantified 16,000 sites during NSC differentiation. More than 65% of class I phosphosites were novel when compared with PhosphoSitePlus database. Quantification results showed that the early and late stage of NSC differentiation differ greatly. We mapped 69 changed phosphosites on 20 proteins involved in Wnt signaling pathway, including S552 on catenin beta-1 (Ctnnb1) and S9 on glycogen synthase kinase 3β (Gsk3β). Western blotting and real-time PCR results proved that Wnt signaling pathway plays critical roles in NSC fate determination. Furthermore, inhibition and activation of PKA dramatically affected the phosphorylation state of Ctnnb1 and Gsk3β, which regulates the differentiation of NSCs. Our data provides a valuable resource for studying the self-renewal and differentiation of NSCs. Stem Cells 2016;34:2090-2101. © 2016 AlphaMed Press.

c-Myb Regulates the T-Bet-Dependent Differentiation Program in B Cells to Coordinate Antibody Responses

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Dana Piovesan

2017-04-01

Full Text Available Summary: Humoral immune responses are tailored to the invading pathogen through regulation of key transcription factors and their networks. This is critical to establishing effective antibody-mediated responses, yet it is unknown how B cells integrate pathogen-induced signals to drive or suppress transcriptional programs specialized for each class of pathogen. Here, we detail the key role of the transcription factor c-Myb in regulating the T-bet-mediated anti-viral program. Deletion of c-Myb in mature B cells significantly increased serum IgG2c and CXCR3 expression by upregulating T-bet, normally suppressed during Th2-cell-mediated responses. Enhanced expression of T-bet resulted in aberrant plasma cell differentiation within the germinal center, mediated by CXCR3 expression. These findings identify a dual role for c-Myb in limiting inappropriate effector responses while coordinating plasma cell differentiation with germinal center egress. Identifying such intrinsic regulators of specialized antibody responses can assist in vaccine design and therapeutic intervention in B-cell-mediated immune disorders. : Piovesan et al. examine how B cells establish transcriptional programs that result in tailored responses to invading pathogens. The authors find that the transcription factor c-Myb represses the T-bet-mediated anti-viral program in B cells. c-Myb limits inappropriate effector responses while coordinating plasma cell differentiation with germinal center egress. Keywords: B cells, c-Myb, T-bet, immunoglobulin, CXCR3, plasma cell, germinal center

Activation of the Extracellular Signal-Regulated Kinase Signaling Is Critical for Human Umbilical Cord Mesenchymal Stem Cell Osteogenic Differentiation

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Chen-Shuang Li

2016-01-01

Full Text Available Human umbilical cord mesenchymal stem cells (hUCMSCs are recognized as candidate progenitor cells for bone regeneration. However, the mechanism of hUCMSC osteogenesis remains unclear. In this study, we revealed that mitogen-activated protein kinases (MAPKs signaling is involved in hUCMSC osteogenic differentiation in vitro. Particularly, the activation of c-Jun N-terminal kinases (JNK and p38 signaling pathways maintained a consistent level in hUCMSCs through the entire 21-day osteogenic differentiation period. At the same time, the activation of extracellular signal-regulated kinases (ERK signaling significantly increased from day 5, peaked at day 9, and declined thereafter. Moreover, gene profiling of osteogenic markers, alkaline phosphatase (ALP activity measurement, and alizarin red staining demonstrated that the application of U0126, a specific inhibitor for ERK activation, completely prohibited hUCMSC osteogenic differentiation. However, when U0126 was removed from the culture at day 9, ERK activation and osteogenic differentiation of hUCMSCs were partially recovered. Together, these findings demonstrate that the activation of ERK signaling is essential for hUCMSC osteogenic differentiation, which points out the significance of ERK signaling pathway to regulate the osteogenic differentiation of hUCMSCs as an alternative cell source for bone tissue engineering.

IL-13 regulates human nasal epithelial cell differentiation via H3K4me3 modification

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Yu L

2018-01-01

Full Text Available Lei Yu,1 Na Li,1 Jisheng Zhang,2 Yan Jiang1 1Department of Otorhinolaryngology, 2Key Laboratory of Otolaryngology-Head and Neck Surgery, Affiliated Hospital of Qingdao University, Qingdao, China Introduction: Epigenetic regulation has been shown to play an important role in the development of inflammatory diseases, including chronic rhinosinusitis and nasal polyps. The latter are characterized by epithelial mis-differentiation and infiltration of inflammatory cytokines. H3K4me3 has been shown to be involved in regulating lineage commitment. However, the underlying mechanisms, especially in human nasal epithelial cells (HNEpC, remain underexplored. The objective of this study was to investigate the role of H3K4me3 in HNEpC differentiation treated with the Th2 cytokine IL-13. Patients and methods: The expression levels of mRNA and proteins were investigated using reverse transcription-polymerase chain reaction (RT-PCR assays and Western blot in nasal polyp tissues and human nasal epithelial cells respectively. We measured these levels of H3K4me3, MLL1 and targeted genes compared with control subjects.Results: We demonstrate that expression of H3K4me3 and its methyltransferase MLL1 was significantly upregulated in IL-13-treated HNEpC. This elevation was also observed in nasal polyps. Expression of cilia-related transcription factors FOXJ1 and DNAI2 decreased, while goblet cell-derived genes CLCA1 and MUC5a increased upon IL-13 treatment. Mechanistically, knockdown of MLL1 restored expression of these four genes induced by IL-13. Conclusion: These findings suggest that H3K4me3 is a critical regulator in control of nasal epithelial cell differentiation. MLL1 may be a potential therapeutic target for nasal inflammatory diseases. Keywords: IL-13, H3K4me3 modification, nasal epithelial cell, differentiation 

NHE10, a novel osteoclast-specific member of the Na+/H+ exchanger family, regulates osteoclast differentiation and survival

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Lee, Seoung Hoon; Kim, Taesoo; Park, Eui-Soon; Yang, Sujeong; Jeong, Daewon; Choi, Yongwon; Rho, Jaerang

2008-01-01

Bone homeostasis is tightly regulated by the balanced actions of osteoblasts (OBs) and osteoclasts (OCs). We previously analyzed the gene expression profile of OC differentiation using a cDNA microarray, and identified a novel osteoclastogenic gene candidate, clone OCL-1-E7 [J. Rho, C.R. Altmann, N.D. Socci, L. Merkov, N. Kim, H. So, O. Lee, M. Takami, A.H. Brivanlou, Y. Choi, Gene expression profiling of osteoclast differentiation by combined suppression subtractive hybridization (SSH) and cDNA microarray analysis, DNA Cell Biol. 21 (2002) 541-549]. In this study, we have isolated full-length cDNAs corresponding to this clone from mice and humans to determine the functional roles of this gene in osteoclastogenesis. The full-length cDNA of OCL-1-E7 encodes 12 membrane-spanning domains that are typical of isoforms of the Na + /H + exchangers (NHEs), indicating that this clone is a novel member of the NHE family (hereafter referred to as NHE10). Here, we show that NHE10 is highly expressed in OCs in response to receptor activator of nuclear factor-κB ligand signaling and is required for OC differentiation and survival

Peroxisome Proliferator-Activated Receptor Gamma Negatively Regulates the Differentiation of Bone Marrow-Derived Mesenchymal Stem Cells Toward Myofibroblasts in Liver Fibrogenesis

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Shuangshuang Jia

2015-11-01

Full Text Available Background/Aims: Bone marrow-derived mesenchymal stem cells (BMSCs have been confirmed to have capacity to differentiate toward hepatic myofibroblasts, which contribute to fibrogenesis in chronic liver diseases. Peroxisome proliferator-activated receptor gamma (PPARγ, a ligand-activated transcription factor, has gained a great deal of recent attention as it is involved in fibrosis and cell differentiation. However, whether it regulates the differentiation of BMSCs toward myofibroblasts remains to be defined. Methods: Carbon tetrachloride or bile duct ligation was used to induce mouse liver fibrosis. Expressions of PPARγ, α-smooth muscle actin, collagen α1 (I and collagen α1 (III were detected by real-time RT-PCR and Western blot or immunofluorescence assay. Results: PPARγ expression was decreased in mouse fibrotic liver. In addition, PPARγ was declined during the differentiation of BMSCs toward myofibroblasts induced by transforming growth factor β1. Activation of PPARγ stimulated by natural or synthetic ligands suppressed the differentiation of BMSCs. Additionally, knock down of PPARγ by siRNA contributed to BMSC differentiation toward myofibroblasts. Furthermore, PPARγ activation by natural ligand significantly inhibited the differentiation of BMSCs toward myofibroblasts in liver fibrogenesis and alleviated liver fibrosis. Conclusions: PPARγ negatively regulates the differentiation of BMSCs toward myofibroblasts, which highlights a further mechanism implicated in the BMSC differentiation.

MLL5, a trithorax homolog, indirectly regulates H3K4 methylation, represses cyclin A2 expression, and promotes myogenic differentiation

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Sebastian, Soji; Sreenivas, Prethish; Sambasivan, Ramkumar; Cheedipudi, Sirisha; Kandalla, Prashanth; Pavlath, Grace K.; Dhawan, Jyotsna

2009-01-01

Most cells in adult tissues are nondividing. In skeletal muscle, differentiated myofibers have exited the cell cycle permanently, whereas satellite stem cells withdraw transiently, returning to active proliferation to repair damaged myofibers. We have examined the epigenetic mechanisms operating in conditional quiescence by analyzing the function of a predicted chromatin regulator mixed lineage leukemia 5 (MLL5) in a culture model of reversible arrest. MLL5 is induced in quiescent myoblasts and regulates both the cell cycle and differentiation via a hierarchy of chromatin and transcriptional regulators. Knocking down MLL5 delays entry of quiescent myoblasts into S phase, but hastens S-phase completion. Cyclin A2 (CycA) mRNA is no longer restricted to S phase, but is induced throughout G0/G1, with activation of the cell cycle regulated element (CCRE) in the CycA promoter. Overexpressed MLL5 physically associates with the CCRE and impairs its activity. MLL5 also regulates CycA indirectly: Cux, an activator of CycA promoter and S phase is induced in RNAi cells, and Brm/Brg1, CCRE-binding repressors that promote differentiation are repressed. In knockdown cells, H3K4 methylation at the CCRE is reduced, reflecting quantitative global changes in methylation. MLL5 appears to lack intrinsic histone methyl transferase activity, but regulates expression of histone-modifying enzymes LSD1 and SET7/9, suggesting an indirect mechanism. Finally, expression of muscle regulators Pax7, Myf5, and myogenin is impaired in MLL5 knockdown cells, which are profoundly differentiation defective. Collectively, our results suggest that MLL5 plays an integral role in novel chromatin regulatory mechanisms that suppress inappropriate expression of S-phase-promoting genes and maintain expression of determination genes in quiescent cells. PMID:19264965

The JAK-STAT transcriptional regulator, STAT-5, activates the ATM DNA damage pathway to induce HPV 31 genome amplification upon epithelial differentiation.

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Shiyuan Hong

Full Text Available High-risk human papillomavirus (HPV must evade innate immune surveillance to establish persistent infections and to amplify viral genomes upon differentiation. Members of the JAK-STAT family are important regulators of the innate immune response and HPV proteins downregulate expression of STAT-1 to allow for stable maintenance of viral episomes. STAT-5 is another member of this pathway that modulates the inflammatory response and plays an important role in controlling cell cycle progression in response to cytokines and growth factors. Our studies show that HPV E7 activates STAT-5 phosphorylation without altering total protein levels. Inhibition of STAT-5 phosphorylation by the drug pimozide abolishes viral genome amplification and late gene expression in differentiating keratinocytes. In contrast, treatment of undifferentiated cells that stably maintain episomes has no effect on viral replication. Knockdown studies show that the STAT-5β isoform is mainly responsible for this activity and that this is mediated through the ATM DNA damage response. A downstream target of STAT-5, the peroxisome proliferator-activated receptor γ (PPARγ contributes to the effects on members of the ATM pathway. Overall, these findings identify an important new regulatory mechanism by which the innate immune regulator, STAT-5, promotes HPV viral replication through activation of the ATM DNA damage response.

Chondrocytic Atf4 regulates osteoblast differentiation and function via Ihh.

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Wang, Weiguang; Lian, Na; Ma, Yun; Li, Lingzhen; Gallant, Richard C; Elefteriou, Florent; Yang, Xiangli

2012-02-01

Atf4 is a leucine zipper-containing transcription factor that activates osteocalcin (Ocn) in osteoblasts and indian hedgehog (Ihh) in chondrocytes. The relative contribution of Atf4 in chondrocytes and osteoblasts to the regulation of skeletal development and bone formation is poorly understood. Investigations of the Atf4(-/-);Col2a1-Atf4 mouse model, in which Atf4 is selectively overexpressed in chondrocytes in an Atf4-null background, demonstrate that chondrocyte-derived Atf4 regulates osteogenesis during development and bone remodeling postnatally. Atf4 overexpression in chondrocytes of the Atf4(-/-);Col2a1-Atf4 double mutants corrects the reduction in stature and limb in Atf4(-/-) embryos and rectifies the decrease in Ihh expression, Hh signaling, proliferation and accelerated hypertrophy that characterize the Atf4(-/-) developing growth plate cartilages. Unexpectedly, this genetic manipulation also restores the expression of osteoblastic marker genes, namely Ocn and bone sialoprotein, in Atf4(-/-) developing bones. In Atf4(-/-);Col2a1-Atf4 adult mice, all the defective bone parameters found in Atf4(-/-) mice, including bone volume, trabecular number and thickness, and bone formation rate, are rescued. In addition, the conditioned media of ex vivo cultures from wild-type or Atf4(-/-);Col2a1-Atf4, but not Atf4(-/-) cartilage, corrects the differentiation defects of Atf4(-/-) bone marrow stromal cells and Ihh-blocking antibody eliminates this effect. Together, these data indicate that Atf4 in chondrocytes is required for normal Ihh expression and for its paracrine effect on osteoblast differentiation. Therefore, the cell-autonomous role of Atf4 in chondrocytes dominates the role of Atf4 in osteoblasts during development for the control of early osteogenesis and skeletal growth.

Proliferation and osteo/odontogenic differentiation of stem cells from apical papilla regulated by Zinc fingers and homeoboxes 2: An in vitro study.

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Wan, Fang; Gao, Lifen; Lu, Yating; Ma, Hongxin; Wang, Hongxing; Liang, Xiaohong; Wang, Yan; Ma, Chunhong

2016-01-15

In the process of tooth root development, stem cells from the apical papilla (SCAPs) can differentiate into odontoblasts and form root dentin, however, molecules regulating SCAPs differentiation have not been elucidated. Zinc fingers and homeoboxes 2 (ZHX2) is a novel transcriptional inhibitor. It is reported to modulate the development of nerve cells, liver cells, B cells, red blood cells, and so on. However, the role of ZHX2 in tooth root development remains unclear. In this study, we explored the potential role of ZHX2 in the process of SCAPs differentiation. The results showed that overexpression of ZHX2 upregulated the expression of osteo/odontogenic related genes and ALP activity, inhibited the proliferation of SCAPs. Consistently, ZHX2 knockdown reduced SCAPs mineralization and promoted SCAPs proliferation. These results indicated that ZHX2 plays a critical role in the proliferation and osteo/odontogenic differentiation of SCAPs. Copyright © 2015 Elsevier Inc. All rights reserved.

The Induction Effect of Am80 and TSA on ESC Differentiation via Regulation of Stra8 in Chicken.

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Zhang, Yani; Zuo, Qisheng; Liu, Zhiyong; Li, Dong; Tang, Beibei; Xiao, Tian-Rong; Lian, Chao; Wang, Yingjie; Jin, Kai; Wang, Yilin; Zhang, Wenhui; Li, Bichun

2015-01-01

Stra8 encodes stimulated by retinoic acid gene 8, a protein that is important for initiation of meiosis in mammals and birds. This study was aimed at identifying the active control area of chicken STRA8 gene core promoter, to screen optimum inducers of the STRA8 gene, thus to enhance the differentiation of embryonic stem cells (ESCs) into spermatogonial stem cells. Fragments of chicken STRA8 gene promoter were cloned into fluorescent reporter plasmids and transfected into DF-1 cells. Then Dual-Luciferase® Reporter Assay System was used to identify the activity of the STRA8 gene under different inducers. Our studies showed that the promoter fragment -1055 bp to +54 bp of Suqin chicken Stra8 revealed the strongest activity. The dual-luciferase® reporter showed that Tamibarotene (Am80) and TrichostatinA (TSA) could significantly enhance STRA8 transcription. The in vitro inductive culture of chicken ESCs demonstrated that spermatogonial stem cells (SSC)-like cells appeared and Integrinβ1 protein was expressed on day 10, indicating that Am80 and TSA can promote ESCs differentiation into SSCs via regulation of Stra8.

PPARγ and MyoD are differentially regulated by myostatin in adipose-derived stem cells and muscle satellite cells

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Zhang, Feng; Deng, Bing; Wen, Jianghui; Chen, Kun; Liu, Wu; Ye, Shengqiang; Huang, Haijun; Jiang, Siwen; Xiong, Yuanzhu

2015-01-01

Myostatin (MSTN) is a secreted protein belonging to the transforming growth factor-β (TGF-β) family that is primarily expressed in skeletal muscle and also functions in adipocyte maturation. Studies have shown that MSTN can inhibit adipogenesis in muscle satellite cells (MSCs) but not in adipose-derived stem cells (ADSCs). However, the mechanism by which MSTN differently regulates adipogenesis in these two cell types remains unknown. Peroxisome proliferator-activated receptor-γ (PPARγ) and myogenic differentiation factor (MyoD) are two key transcription factors in fat and muscle cell development that influence adipogenesis. To investigate whether MSTN differentially regulates PPARγ and MyoD, we analyzed PPARγ and MyoD expression by assessing mRNA, protein and methylation levels in ADSCs and MSCs after treatment with 100 ng/mL MSTN for 0, 24, and 48 h. PPARγ mRNA levels were downregulated after 24 h and upregulated after 48 h of treatment in ADSCs, whereas in MSCs, PPARγ levels were downregulated at both time points. MyoD expression was significantly increased in ADSCs and decreased in MSCs. PPARγ and MyoD protein levels were upregulated in ADSCs and downregulated in MSCs. The CpG methylation levels of the PPARγ and MyoD promoters were decreased in ADSCs and increased in MSCs. Therefore, this study demonstrated that the different regulatory adipogenic roles of MSTN in ADSCs and MSCs act by differentially regulating PPARγ and MyoD expression. - Highlights: • PPARγ and MyoD mRNA and protein levels are upregulated by myostatin in ADSCs. • PPARγ and MyoD mRNA and protein levels are downregulated by myostatin in MSCs. • PPARγ exhibited different methylation levels in myostatin-treated ADSCs and MSCs. • MyoD exhibited different methylation levels in myostatin-treated ADSCs and MSCs. • PPARγ and MyoD are differentially regulated by myostatin in ADSCs and MSCs

PPARγ and MyoD are differentially regulated by myostatin in adipose-derived stem cells and muscle satellite cells

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Zhang, Feng [Key Laboratory of Swine Genetics and Breeding of the Agricultural Ministry and Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of the Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430070 (China); Deng, Bing [Wuhan Institute of Animal Science and Veterinary Medicine, Wuhan Academy of Agricultural Science and Technology, Wuhan, Hubei, 430208 (China); Wen, Jianghui [Wu Han University of Technology, Wuhan 430074 (China); Chen, Kun [Key Laboratory of Swine Genetics and Breeding of the Agricultural Ministry and Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of the Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430070 (China); Liu, Wu; Ye, Shengqiang; Huang, Haijun [Wuhan Institute of Animal Science and Veterinary Medicine, Wuhan Academy of Agricultural Science and Technology, Wuhan, Hubei, 430208 (China); Jiang, Siwen, E-mail: jiangsiwen@mail.hzau.edu.cn [Key Laboratory of Swine Genetics and Breeding of the Agricultural Ministry and Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of the Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430070 (China); Xiong, Yuanzhu, E-mail: xiongyzhu@163.com [Key Laboratory of Swine Genetics and Breeding of the Agricultural Ministry and Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of the Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430070 (China)

2015-03-06

Myostatin (MSTN) is a secreted protein belonging to the transforming growth factor-β (TGF-β) family that is primarily expressed in skeletal muscle and also functions in adipocyte maturation. Studies have shown that MSTN can inhibit adipogenesis in muscle satellite cells (MSCs) but not in adipose-derived stem cells (ADSCs). However, the mechanism by which MSTN differently regulates adipogenesis in these two cell types remains unknown. Peroxisome proliferator-activated receptor-γ (PPARγ) and myogenic differentiation factor (MyoD) are two key transcription factors in fat and muscle cell development that influence adipogenesis. To investigate whether MSTN differentially regulates PPARγ and MyoD, we analyzed PPARγ and MyoD expression by assessing mRNA, protein and methylation levels in ADSCs and MSCs after treatment with 100 ng/mL MSTN for 0, 24, and 48 h. PPARγ mRNA levels were downregulated after 24 h and upregulated after 48 h of treatment in ADSCs, whereas in MSCs, PPARγ levels were downregulated at both time points. MyoD expression was significantly increased in ADSCs and decreased in MSCs. PPARγ and MyoD protein levels were upregulated in ADSCs and downregulated in MSCs. The CpG methylation levels of the PPARγ and MyoD promoters were decreased in ADSCs and increased in MSCs. Therefore, this study demonstrated that the different regulatory adipogenic roles of MSTN in ADSCs and MSCs act by differentially regulating PPARγ and MyoD expression. - Highlights: • PPARγ and MyoD mRNA and protein levels are upregulated by myostatin in ADSCs. • PPARγ and MyoD mRNA and protein levels are downregulated by myostatin in MSCs. • PPARγ exhibited different methylation levels in myostatin-treated ADSCs and MSCs. • MyoD exhibited different methylation levels in myostatin-treated ADSCs and MSCs. • PPARγ and MyoD are differentially regulated by myostatin in ADSCs and MSCs.

The Onecut Transcription Factors Regulate Differentiation and Distribution of Dorsal Interneurons during Spinal Cord Development

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Karolina U. Kabayiza

2017-05-01

Full Text Available During embryonic development, the dorsal spinal cord generates numerous interneuron populations eventually involved in motor circuits or in sensory networks that integrate and transmit sensory inputs from the periphery. The molecular mechanisms that regulate the specification of these multiple dorsal neuronal populations have been extensively characterized. In contrast, the factors that contribute to their diversification into smaller specialized subsets and those that control the specific distribution of each population in the developing spinal cord remain unknown. Here, we demonstrate that the Onecut transcription factors, namely Hepatocyte Nuclear Factor-6 (HNF-6 (or OC-1, OC-2 and OC-3, regulate the diversification and the distribution of spinal dorsal interneuron (dINs. Onecut proteins are dynamically and differentially distributed in spinal dINs during differentiation and migration. Analyzes of mutant embryos devoid of Onecut factors in the developing spinal cord evidenced a requirement in Onecut proteins for proper production of a specific subset of dI5 interneurons. In addition, the distribution of dI3, dI5 and dI6 interneuron populations was altered. Hence, Onecut transcription factors control genetic programs that contribute to the regulation of spinal dIN diversification and distribution during embryonic development.

Methylation of miR-145a-5p promoter mediates adipocytes differentiation

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Du, Jingjing; Cheng, Xiao; Shen, Linyuan; Tan, Zhendong; Luo, Jia; Wu, Xiaoqian; Liu, Chendong [College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130 (China); Yang, Qiong [Department of Animal Husbandry and Veterinary Medicine, Chengdu Agricultural College, Chengdu 611100, Sichuan (China); Jiang, Yanzhi [College of Life and Science, Sichuan Agricultural University, Chengdu 611130 (China); Tang, Guoqing; Li, Xuewei [College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130 (China); Zhang, Shunhua, E-mail: zhangsh1919@163.com [College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130 (China); Zhu, Li, E-mail: zhuli7508@163.com [College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130 (China)

2016-06-17

MicroRNAs (miRNAs, miR) play important roles in adipocyte development. Recent studies showed that the expression of several miRNAs is closely related with promoter methylation. However, it is not known whether miRNA mediates adipocytes differentiation by means of DNA methylation. Here, we showed that miR-145a-5p was poorly expressed in adipose tissue from mice fed a high fat diet (HFD). Overexpression or inhibition of miR-145a-5p was unfavorable or beneficial, respectively, for adipogenesis, and these effects were achieved by regulating adipocyte-specific genes involved in lipogenic transcription, fatty acid synthesis, and fatty acid transportation. Particularly, we first suggested that miR-145a-5p mimics or inhibitors promoted or repressed adipocytes proliferation by regulating p53 and p21, which act as cell cycle regulating factors. Surprisingly, the miR-145a-5p-repressed adipocyte differentiation was enhanced or rescued when cells treated with 5-Aza-dC were transfected with miR-145a-5p mimics or inhibitors, respectively. These data indicated that, as a new mean to positively regulate adipocyte proliferation, the process of miR-145a-5p-inhibited adipogenesis may be regulated by DNA methylation. -- Highlights: •MiR-145a-5p promotes adipocytes proliferation. •MiR-145a-5p is negatively correlated with obesity. •MiR-145a-5p mediates adipocytes differentiation via regulating pathway related adipocytes differentiation. MiR-145a-5p mediating adipocytes differentiation was regulated by DNA methylation.

Transcriptional up-regulation of restin by all-trans retinoic acid through STAT1 in cancer cell differentiation process

International Nuclear Information System (INIS)

Fu Haiyan; Yang Guodong; Lu Fan; Wang Ruihua; Yao Libo; Lu Zifan

2006-01-01

RESTIN, a member of the melanoma-associated antigen superfamily, is a nuclear protein induced by atRA (all-trans retinoic acid) in HL60 cells. HeLa cells stably transfected with restin results in G1 cell cycle arrest. How this gene is regulated by atRA in the cell differentiation process is still unclear. In this study, we observed that up-regulation of restin was present during the atRA-induced HL60 cell differentiation process, suggesting the functional relevance between RESTIN and atRA-induced cellular effects. In order to further define the transcriptional regulation of restin by atRA, we analyzed the promoter region of restin. About 2.1 kb 5' flanking sequence of this gene was cloned into vector pGL3 and its core promoter region was identified through systemic deletions. Interestingly, restin promoter containing several potential consensus-binding sites of STAT-1α was activated by atRA in ER + MCF-7 cells but not in ER - MDA-MB-231 cells, over-expression of STAT-1α in latter rescued the activation effect of restin promoter in response to atRA and IFNγ. Our evidence supported that STAT-1α plays an important role in the atRA-induced transcriptional up-regulation of restin, which was associated with the atRA-induced HL60 cell differentiation and potentially mediated the downstream effects of atRA signal pathway via STAT-1α in some cancer cells

Biglycan deficiency increases osteoclast differentiation and activity due to defective osteoblasts

DEFF Research Database (Denmark)

Bi, Yanming; Nielsen, Karina L; Kilts, Tina M

2006-01-01

to be independent of the differential production of soluble RANKL and OPG and, instead, due to a decrease in osteoblast maturation accompanied by increase in osteoblastic proliferation. In addition to the imbalance between differentiation and proliferation, there was a differential decrease in secretory leukocyte......Bone mass is maintained by a fine balance between bone formation by osteoblasts and bone resorption by osteoclasts. Although osteoblasts and osteoclasts have different developmental origins, it is generally believed that the differentiation, function, and survival of osteoclasts are regulated...... by osteogenic cells. We have previously shown that the extracellular matrix protein, biglycan (Bgn), plays an important role in the differentiation of osteoblast precursors. In this paper, we showed that Bgn is involved in regulating osteoclast differentiation through its effect on osteoblasts...

Differentially expressed miRNAs after GnRH treatment and their potential roles in FSH regulation in porcine anterior pituitary cell.

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Rui-Song Ye

Full Text Available Hypothalamic gonadotropin-releasing hormone (GnRH is a major regulator of follicle-stimulating hormone (FSH secretion in gonadotrope cell in the anterior pituitary gland. microRNAs (miRNAs are small RNA molecules that control gene expression by imperfect binding to the 3'-untranslated region (3'-UTR of mRNA at the post-transcriptional level. It has been proven that miRNAs play an important role in hormone response and/or regulation. However, little is known about miRNAs in the regulation of FSH secretion. In this study, primary anterior pituitary cells were treated with 100 nM GnRH. The supernatant of pituitary cell was collected for FSH determination by enzyme-linked immunosorbent assay (ELISA at 3 hours and 6 hours post GnRH treatment respectively. Results revealed that GnRH significantly promoted FSH secretion at 3 h and 6 h post-treatment by 1.40-fold and 1.80-fold, respectively. FSHβ mRNA at 6 h post GnRH treatment significantly increased by 1.60-fold. At 6 hours, cells were collected for miRNA expression profile analysis using MiRCURY LNA Array and quantitative PCR (qPCR. Consequently, 21 up-regulated and 10 down-regulated miRNAs were identified, and qPCR verification of 10 randomly selected miRNAs showed a strong correlation with microarray results. Chromosome location analysis indicated that 8 miRNAs were mapped to chromosome 12 and 4 miRNAs to chromosome X. Target and pathway analysis showed that some miRNAs may be associated with GnRH regulation pathways. In addition, In-depth analysis indicated that 10 up-regulated and 3 down-regulated miRNAs probably target FSHβ mRNA 3'-UTR directly, including miR-361-3p, a highly conserved X-linked miRNA. Most importantly, functional experimental results showed that miR-361-3p was involved in FSH secretion regulation, and up-regulated miR-361-3p expression inhibited FSH secretion, while down-regulated miR-361-3p expression promoted FSH secretion in pig pituitary cell model. These differentially

A supramolecular look at microenvironmental regulation of limbal epithelial stem cells and the differentiation of their progeny

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Marcela Aldrovani

Full Text Available ABSTRACT Various approaches have been taken to improve our knowledge of the microenvironmental regulation of limbal epithelial stem cells. Researchers have extensively investigated the roles of growth factors, survival factors, cytokines, enzymes, and permeable molecules secreted by the limbal cells. However, recent evidence suggests that stem cell fate (i.e., self-renewal or differentiation can also be influenced by biophysical and mechanical cues related to the supramolecular organization and the liquid crystalline (mesophase nature of the stromal extracellular matrix. These cues can be sensed by stem cells and transduced into intracellular biochemical and functional responses, a process known as mechanotransduction. The objective of this review is to offer perspectives on the supramolecular microenvironmental regulation of limbal epithelial stem cells and the differentiation of their progeny.

SHP1 Regulates Bone Mass by Directing Mesenchymal Stem Cell Differentiation

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Menghui Jiang

2016-07-01

Full Text Available Osteoblasts and adipocytes are derived from a common precursor, mesenchymal stem cells (MSCs. Alterations in the normal fate of differentiating MSCs are involved in the development of obesity and osteoporosis. Here, we report that viable motheaten (mev mice, which are deficient in the SH2-domain-containing phosphatase-1 (SHP1, develop osteoporosis spontaneously. Consistently, MSCs from mev/mev mice exhibit significantly reduced osteogenic potential and greatly increased adipogenic potential. When MSCs were transplanted into nude mice, SHP1-deficient MSCs resulted in diminished bone formation compared with wild-type MSCs. SHP1 was found to bind to GSK3β and suppress its kinase activity by dephosphorylating pY216, thus resulting in β-catenin stabilization. Mice, in which SHP1 was deleted in MSCs using SHP1fl/flDermo1-cre, displayed significantly decreased bone mass and increased adipose tissue. Taken together, these results suggest a possible role for SHP1 in controlling tissue homeostasis through modulation of MSC differentiation via Wnt signaling regulation.

Sumoylation of Sir2 differentially regulates transcriptional silencing in yeast.

Science.gov (United States)

Hannan, Abdul; Abraham, Neethu Maria; Goyal, Siddharth; Jamir, Imlitoshi; Priyakumar, U Deva; Mishra, Krishnaveni

2015-12-02

Silent information regulator 2 (Sir2), the founding member of the conserved sirtuin family of NAD(+)-dependent histone deacetylase, regulates several physiological processes including genome stability, gene silencing, metabolism and life span in yeast. Within the nucleus, Sir2 is associated with telomere clusters in the nuclear periphery and rDNA in the nucleolus and regulates gene silencing at these genomic sites. How distribution of Sir2 between telomere and rDNA is regulated is not known. Here we show that Sir2 is sumoylated and this modification modulates the intra-nuclear distribution of Sir2. We identify Siz2 as the key SUMO ligase and show that multiple lysines in Sir2 are subject to this sumoylation activity. Mutating K215 alone counteracts the inhibitory effect of Siz2 on telomeric silencing. SUMO modification of Sir2 impairs interaction with Sir4 but not Net1 and, furthermore, SUMO modified Sir2 shows predominant nucleolar localization. Our findings demonstrate that sumoylation of Sir2 modulates distribution between telomeres and rDNA and this is likely to have implications for Sir2 function in other loci as well. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

The splicing regulator PTBP1 controls the activity of the transcription factor Pbx1 during neuronal differentiation.

Science.gov (United States)

Linares, Anthony J; Lin, Chia-Ho; Damianov, Andrey; Adams, Katrina L; Novitch, Bennett G; Black, Douglas L

2015-12-24

The RNA-binding proteins PTBP1 and PTBP2 control programs of alternative splicing during neuronal development. PTBP2 was found to maintain embryonic splicing patterns of many synaptic and cytoskeletal proteins during differentiation of neuronal progenitor cells (NPCs) into early neurons. However, the role of the earlier PTBP1 program in embryonic stem cells (ESCs) and NPCs was not clear. We show that PTBP1 controls a program of neuronal gene expression that includes the transcription factor Pbx1. We identify exons specifically regulated by PTBP1 and not PTBP2 as mouse ESCs differentiate into NPCs. We find that PTBP1 represses Pbx1 exon 7 and the expression of the neuronal Pbx1a isoform in ESCs. Using CRISPR-Cas9 to delete regulatory elements for exon 7, we induce Pbx1a expression in ESCs, finding that this activates transcription of neuronal genes. Thus, PTBP1 controls the activity of Pbx1 to suppress its neuronal transcriptional program prior to induction of NPC development.

Let7a involves in neural stem cell differentiation relating with TLX level

Energy Technology Data Exchange (ETDEWEB)

Song, Juhyun [Department of Anatomy, Yonsei University College of Medicine, Seoul (Korea, Republic of); Cho, Kyoung Joo; Oh, Yumi [Department of Anatomy, Yonsei University College of Medicine, Seoul (Korea, Republic of); BK21 Plus Project for Medical Sciences, and Brain Research Institute, Yonsei University College of Medicine, Seoul (Korea, Republic of); Lee, Jong Eun, E-mail: jelee@yuhs.ac [Department of Anatomy, Yonsei University College of Medicine, Seoul (Korea, Republic of); BK21 Plus Project for Medical Sciences, and Brain Research Institute, Yonsei University College of Medicine, Seoul (Korea, Republic of)

2015-07-10

Neural stem cells (NSCs) have the potential for differentiation into neurons known as a groundbreaking therapeutic solution for central nervous system (CNS) diseases. To resolve the therapeutic efficiency of NSCs, recent researchers have focused on the study on microRNA's role in CNS. Some micro RNAs have been reported significant functions in NSC self-renewal and differentiation through the post-transcriptional regulation of neurogenesis genes. MicroRNA-Let7a (Let7a) has known as the regulator of diverse cellular mechanisms including cell differentiation and proliferation. In present study, we investigated whether Let7a regulates NSC differentiation by targeting the nuclear receptor TLX, which is an essential regulator of NSC self-renewal, proliferation and differentiation. We performed the following experiments: western blot analysis, TaqMan assay, RT-PCR, and immunocytochemistry to confirm the alteration of NSCs. Our data showed that let7a play important roles in controlling NSC fate determination. Thus, manipulating Let-7A and TLX could be a novel strategy to enhance the efficiency of NSC's neuronal differentiation for CNS disorders. - Highlights: • Let7a influences on NSC differentiation and proliferation. • Let7a involves in mainly NSC differentiation rather than proliferation. • Let7a positively regulates the TLX expression.

Let7a involves in neural stem cell differentiation relating with TLX level

International Nuclear Information System (INIS)

Song, Juhyun; Cho, Kyoung Joo; Oh, Yumi; Lee, Jong Eun

2015-01-01

Neural stem cells (NSCs) have the potential for differentiation into neurons known as a groundbreaking therapeutic solution for central nervous system (CNS) diseases. To resolve the therapeutic efficiency of NSCs, recent researchers have focused on the study on microRNA's role in CNS. Some micro RNAs have been reported significant functions in NSC self-renewal and differentiation through the post-transcriptional regulation of neurogenesis genes. MicroRNA-Let7a (Let7a) has known as the regulator of diverse cellular mechanisms including cell differentiation and proliferation. In present study, we investigated whether Let7a regulates NSC differentiation by targeting the nuclear receptor TLX, which is an essential regulator of NSC self-renewal, proliferation and differentiation. We performed the following experiments: western blot analysis, TaqMan assay, RT-PCR, and immunocytochemistry to confirm the alteration of NSCs. Our data showed that let7a play important roles in controlling NSC fate determination. Thus, manipulating Let-7A and TLX could be a novel strategy to enhance the efficiency of NSC's neuronal differentiation for CNS disorders. - Highlights: • Let7a influences on NSC differentiation and proliferation. • Let7a involves in mainly NSC differentiation rather than proliferation. • Let7a positively regulates the TLX expression

KDM1A/LSD1 regulates the differentiation and maintenance of spermatogonia in mice.

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Dexter A Myrick

Full Text Available The proper regulation of spermatogenesis is crucial to ensure the continued production of sperm and fertility. Here, we investigated the function of the H3K4me2 demethylase KDM1A/LSD1 during spermatogenesis in developing and adult mice. Conditional deletion of Kdm1a in the testis just prior to birth leads to fewer spermatogonia and germ cell loss before 3 weeks of age. These results demonstrate that KDM1A is required for spermatogonial differentiation, as well as germ cell survival, in the developing testis. In addition, inducible deletion of Kdm1a in the adult testis results in the abnormal accumulation of meiotic spermatocytes, as well as apoptosis and progressive germ cell loss. These results demonstrate that KDM1A is also required during adult spermatogenesis. Furthermore, without KDM1A, the stem cell factor OCT4 is ectopically maintained in differentiating germ cells. This requirement for KDM1A is similar to what has been observed in other stem cell populations, suggesting a common function. Taken together, we propose that KDM1A is a key regulator of spermatogenesis and germ cell maintenance in the mouse.

Growth/differentiation factor 15 promotes EGFR signalling, and regulates proliferation and migration in the hippocampus of neonatal and young adult mice.

Science.gov (United States)

Carrillo-García, Carmen; Prochnow, Sebastian; Simeonova, Ina K; Strelau, Jens; Hölzl-Wenig, Gabriele; Mandl, Claudia; Unsicker, Klaus; von Bohlen Und Halbach, Oliver; Ciccolini, Francesca

2014-02-01

The activation of epidermal growth factor receptor (EGFR) affects multiple aspects of neural precursor behaviour, including proliferation and migration. Telencephalic precursors acquire EGF responsiveness and upregulate EGFR expression at late stages of development. The events regulating this process and its significance are still unclear. We here show that in the developing and postnatal hippocampus (HP), growth/differentiation factor (GDF) 15 and EGFR are co-expressed in primitive precursors as well as in more differentiated cells. We also provide evidence that GDF15 promotes responsiveness to EGF and EGFR expression in hippocampal precursors through a mechanism that requires active CXC chemokine receptor (CXCR) 4. Besides EGFR expression, GDF15 ablation also leads to decreased proliferation and migration. In particular, lack of GDF15 impairs both processes in the cornu ammonis (CA) 1 and only proliferation in the dentate gyrus (DG). Importantly, migration and proliferation in the mutant HP were altered only perinatally, when EGFR expression was also affected. These data suggest that GDF15 regulates migration and proliferation by promoting EGFR signalling in the perinatal HP and represent a first description of a functional role for GDF15 in the developing telencephalon.

Differential regulation of c-di-GMP metabolic enzymes by environmental signals modulates biofilm formation in Yersinia pestis

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Gai-Xian eRen

2016-06-01

Full Text Available Cyclic diguanylate (c-di-GMP is essential for Yersinia pestis biofilm formation, which is important for flea-borne blockage-dependent plague transmission. Two diguanylate cyclases (DGCs, HmsT and HmsD and one phosphodiesterase (PDE, HmsP are responsible for the synthesis and degradation of c-di-GMP in Y. pestis. Here, we systematically analyzed the effect of various environmental signals on regulation of the biofilm phenotype, the c-di-GMP levels, and expression of HmsT, HmsD and HmsP in Y. pestis. Biofilm formation was higher in the presence of nonlethal high concentration of CaCl2, MgCl2, CuSO4, sucrose, sodium dodecyl sulfonate, or dithiothreitol, and was lower in the presence of FeCl2 or NaCl. In addition, we found that HmsD plays a major role in biofilm formation in acidic or redox environments. These environmental signals differentially regulated expression of HmsT, HmsP and HmsD, resulting in changes in the intracellular levels of c-di-GMP in Y. pestis. Our results suggest that bacteria can sense various environmental signals, and differentially regulates their DGCs and PDEs to coordinately regulate and adapt metabolism of c-di-GMP and biofilm formation to changing environments.

Entry Regulations, Product Differentiation and Determinants of Market Structure

OpenAIRE

Maican, Florin; Orth, ´Matilda

2013-01-01

We use a dynamic oligopoly model of entry and exit to evaluate how entry regulations affect profitability and market structure in retail. The model incorporates demand and store-level heterogeneity. Based on unique data for all retail food stores in Sweden, we find that the average entry costs for small and large stores are 10 and 18 percent lower, respectively, in markets with liberal compared with restrictive regulations. Counterfactual simulations show that lower entry costs in restrictive...

Selective phosphorylation during early macrophage differentiation

KAUST Repository

Zhang, Huoming

2015-08-26

The differentiation of macrophages from monocytes is a tightly controlled and complex biological process. Although numerous studies have been conducted using biochemical approaches or global gene/gene profiling, the mechanisms of the early stages of differentiation remain unclear. Here we used SILAC-based quantitative proteomics approach to perform temporal phosphoproteome profiling of early macrophage differentiation. We identified a large set of phosphoproteins and grouped them as PMA-regulated and non-regulated phosphoproteins in the early stages of differentiation. Further analysis of the PMA-regulated phosphoproteins revealed that transcriptional suppression, cytoskeletal reorganization and cell adhesion were among the most significantly activated pathways. Some key involved regulators of these pathways are mTOR, MYB, STAT1 and CTNNB. Moreover, we were able to classify the roles and activities of several transcriptional factors during different differentiation stages and found that E2F is likely to be an important regulator during the relatively late stages of differentiation. This study provides the first comprehensive picture of the dynamic phosphoproteome during myeloid cells differentiation, and identifies potential molecular targets in leukemic cells.

Differential arousal regulation by prokineticin 2 signaling in the nocturnal mouse and the diurnal monkey.

Science.gov (United States)

Zhou, Qun-Yong; Burton, Katherine J; Neal, Matthew L; Qiao, Yu; Kanthasamy, Anumantha G; Sun, Yanjun; Xu, Xiangmin; Ma, Yuanye; Li, Xiaohan

2016-08-18

The temporal organization of activity/rest or sleep/wake rhythms for mammals is regulated by the interaction of light/dark cycle and circadian clocks. The neural and molecular mechanisms that confine the active phase to either day or night period for the diurnal and the nocturnal mammals are unclear. Here we report that prokineticin 2, previously shown as a circadian clock output molecule, is expressed in the intrinsically photosensitive retinal ganglion cells, and the expression of prokineticin 2 in the intrinsically photosensitive retinal ganglion cells is oscillatory in a clock-dependent manner. We further show that the prokineticin 2 signaling is required for the activity and arousal suppression by light in the mouse. Between the nocturnal mouse and the diurnal monkey, a signaling receptor for prokineticin 2 is differentially expressed in the retinorecipient suprachiasmatic nucleus and the superior colliculus, brain projection targets of the intrinsically photosensitive retinal ganglion cells. Blockade with a selective antagonist reveals the respectively inhibitory and stimulatory effect of prokineticin 2 signaling on the arousal levels for the nocturnal mouse and the diurnal monkey. Thus, the mammalian diurnality or nocturnality is likely determined by the differential signaling of prokineticin 2 from the intrinsically photosensitive retinal ganglion cells onto their retinorecipient brain targets.

Adhesive and mechanical regulation of mesenchymal stem cell differentiation in human bone marrow and periosteum-derived progenitor cells

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Jeroen Eyckmans

2012-08-01

It has previously been demonstrated that cell shape can influence commitment of human bone marrow-derived mesenchymal stem cells (hBMCs to adipogenic, osteogenic, chondrogenic, and other lineages. Human periosteum-derived cells (hPDCs exhibit multipotency similar to hBMCs, but hPDCs may offer enhanced potential for osteogenesis and chondrogenesis given their apparent endogenous role in bone and cartilage repair in vivo. Here, we examined whether hPDC differentiation is regulated by adhesive and mechanical cues comparable to that reported for hBMC differentiation. When cultured in the appropriate induction media, hPDCs at high cell seeding density demonstrated enhanced levels of adipogenic or chondrogenic markers as compared with hPDCs at low cell seeding density. Cell seeding density correlated inversely with projected area of cell spreading, and directly limiting cell spreading with micropatterned substrates promoted adipogenesis or chondrogenesis while substrates promoting cell spreading supported osteogenesis. Interestingly, cell seeding density influenced differentiation through both changes in cell shape and non-shape-mediated effects: density-dependent adipogenesis and chondrogenesis were regulated primarily by cell shape whereas non-shape effects strongly influenced osteogenic potential. Inhibition of cytoskeletal contractility by adding the Rho kinase inhibitor Y27632 further enhanced adipogenic differentiation and discouraged osteogenic differentiation of hPDCs. Together, our results suggest that multipotent lineage decisions of hPDCs are impacted by cell adhesive and mechanical cues, though to different extents than hBMCs. Thus, future studies of hPDCs and other primary stem cell populations with clinical potential should consider varying biophysical metrics for more thorough optimization of stem cell differentiation.

Genome-wide functional analysis of plasmodium protein phosphatases reveals key regulators of parasite development and differentiation

KAUST Repository

Guttery, David  S.; Poulin, Benoit; Ramaprasad, Abhinay; Wall, Richard  J.; Ferguson, David  J.P.; Brady, Declan; Patzewitz, Eva-Maria; Whipple, Sarah; Straschil, Ursula; Wright, Megan  H.; Mohamed, Alyaa  M.A.H.; Radhakrishnan, Anand; Arold, Stefan T.; Tate, Edward  W.; Holder, Anthony  A.; Wickstead, Bill; Pain, Arnab; Tewari, Rita

2014-01-01

Reversible protein phosphorylation regulated by kinases and phosphatases controls many cellular processes. Although essential functions for the malaria parasite kinome have been reported, the roles of most protein phosphatases (PPs) during Plasmodium development are unknown. We report a functional analysis of the Plasmodium berghei protein phosphatome, which exhibits high conservation with the P. falciparum phosphatome and comprises 30 predicted PPs with differential and distinct expression patterns during various stages of the life cycle. Gene disruption analysis of P. berghei PPs reveals that half of the genes are likely essential for asexual blood stage development, whereas six are required for sexual development/sporogony in mosquitoes. Phenotypic screening coupled with transcriptome sequencing unveiled morphological changes and altered gene expression in deletion mutants of two N-myristoylated PPs. These findings provide systematic functional analyses of PPs in Plasmodium, identify how phosphatases regulate parasite development and differentiation, and can inform the identification of drug targets for malaria. © 2014 The Authors.

Genome-wide functional analysis of plasmodium protein phosphatases reveals key regulators of parasite development and differentiation

KAUST Repository

Guttery, David S.

2014-07-09

Reversible protein phosphorylation regulated by kinases and phosphatases controls many cellular processes. Although essential functions for the malaria parasite kinome have been reported, the roles of most protein phosphatases (PPs) during Plasmodium development are unknown. We report a functional analysis of the Plasmodium berghei protein phosphatome, which exhibits high conservation with the P. falciparum phosphatome and comprises 30 predicted PPs with differential and distinct expression patterns during various stages of the life cycle. Gene disruption analysis of P. berghei PPs reveals that half of the genes are likely essential for asexual blood stage development, whereas six are required for sexual development/sporogony in mosquitoes. Phenotypic screening coupled with transcriptome sequencing unveiled morphological changes and altered gene expression in deletion mutants of two N-myristoylated PPs. These findings provide systematic functional analyses of PPs in Plasmodium, identify how phosphatases regulate parasite development and differentiation, and can inform the identification of drug targets for malaria. © 2014 The Authors.

Analysis of mammary specific gene locus regulation in differentiated cells derived by somatic cell fusion

International Nuclear Information System (INIS)

Robinson, Claire; Kolb, Andreas F.

2009-01-01

The transcriptional regulation of a gene is best analysed in the context of its normal chromatin surroundings. However, most somatic cells, in contrast to embryonic stem cells, are refractory to accurate modification by homologous recombination. We show here that it is possible to introduce precise genomic modifications in ES cells and to analyse the phenotypic consequences in differentiated cells by using a combination of gene targeting, site-specific recombination and somatic cell fusion. To provide a proof of principle, we have analysed the regulation of the casein gene locus in mammary gland cells derived from modified murine ES cells by somatic cell fusion. A β-galactosidase reporter gene was inserted in place of the β-casein gene and the modified ES cells, which do not express the reporter gene, were fused with the mouse mammary gland cell line HC11. The resulting cell clones expressed the β-galactosidase gene to a similar extent and with similar hormone responsiveness as the endogenous gene. However, a reporter gene under the control of a minimal β-casein promoter (encompassing the two consensus STAT5 binding sites which mediate the hormone response of the casein genes) was unable to replicate expression levels or hormone responsiveness of the endogenous gene when inserted into the same site of the casein locus. As expected, these results implicate sequences other than the STAT5 sites in the regulation of the β-casein gene

CSK negatively regulates nerve growth factor induced neural differentiation and augments AKT kinase activity

International Nuclear Information System (INIS)

Dey, Nandini; Howell, Brian W.; De, Pradip K.; Durden, Donald L.

2005-01-01

Src family kinases are involved in transducing growth factor signals for cellular differentiation and proliferation in a variety of cell types. The activity of all Src family kinases (SFKs) is controlled by phosphorylation at their C-terminal 527-tyrosine residue by C-terminal SRC kinase, CSK. There is a paucity of information regarding the role of CSK and/or specific Src family kinases in neuronal differentiation. Pretreatment of PC12 cells with the Src family kinase inhibitor, PP1, blocked NGF-induced activation of SFKs and obliterated neurite outgrowth. To confirm a role for CSK and specific isoforms of SFKs in neuronal differentiation, we overexpressed active and catalytically dead CSK in the rat pheochromocytoma cell line, PC12. CSK overexpression caused a profound inhibition of NGF-induced activation of FYN, YES, RAS, and ERK and inhibited neurite outgrowth, NGF-stimulated integrin-directed migration and blocked the NGF-induced conversion of GDP-RAC to its GTP-bound active state. CSK overexpression markedly augmented the activation state of AKT following NGF stimulation. In contrast, kinase-dead CSK augmented the activation of FYN, RAS, and ERK and increased neurite outgrowth. These data suggest a distinct requirement for CSK in the regulation of NGF/TrkA activation of RAS, RAC, ERK, and AKT via the differential control of SFKs in the orchestration of neuronal differentiation

Platyphylloside Isolated From Betula platyphylla Inhibit Adipocyte Differentiation and Induce Lipolysis Via Regulating Adipokines Including PPARγ in 3T3-L1 Cells

Science.gov (United States)

Lee, Mina; Sung, Sang Hyun

2016-01-01

Background: Obesity causes or aggravates many health problems, both independently and in association with several pathological disorders, including Type II diabetes, hypertension, atherosclerosis, and cancer. Therefore, we screened small compounds isolated from natural products for the development of anti-obesity drugs. Objective: The purpose of this study was to investigate the anti-adipogenic activities of platyphylloside, diarylheptanoid isolated from Betula platyphylla, which was selected based on the screening using 3T3-L1 cells. Materials and Methods: To evaluate the inhibition of adipocyte differentiation and lipolysis, lipid contents of BPP on were measured using Oil Red O staining in 3T3-L1 cells. The mRNA and protein expression levels of various adipokines were measured by Quantitative real-time PCR and Western blotting analysis, respectively. Results: Platyphylloside showed significant inhibitory activity on adipocyte differentiation in 3T3-L1 cells and suppressed adipocyte differentiation even in the presence of troglitazone, a PPARγ agonist. Platyphylloside might suppress adipocyte differentiation through PPARγ, C/EBPα, and SREBP1-induced adipogenesis, which is synergistically associated with downstream adipocyte-specific gene promoters such as aP2, FAS, SCD-1, LPL, and Adiponectin. In addition, platyphylloside affected lipolysis by down-regulating perilipin and HSL and up-regulating TNFα. Conclusion: Taken together, the results reveal that platyphylloside has anti-adipogenic activity and highlight its potential in the prevention and treatment of obesity. SUMMARY The extract of B. platyphylla bark and its isolate, BPP, had anti-adipogenic activity in 3T3-L1 cells via suppression of adipocyte differentiation from preadipocytes.Treatment with BPP significantly down-regulated the expression of PPARγ, C/EBP, C/EBPβ, C/EBPδ, SREBP1c, SCD-1, FAS, aP2 and LPL.BPP induced a lipolytic response in mature adipocytes via up-regulation krof TNFá and down-regulation

Members of the barley NAC transcription factor gene family show differential co-regulation with senescence-associated genes during senescence of flag leaves

DEFF Research Database (Denmark)

Christiansen, Michael W; Gregersen, Per L.

2014-01-01

-expressed with members of the NAC gene family. In conclusion, a list of up to 15 NAC genes from barley that are strong candidates for being regulatory factors of importance for senescence and biotic stress-related traits affecting the productivity of cereal crop plants has been generated. Furthermore, a list of 71...... in the NAC transcription factor family during senescence of barley flag leaves was studied. Several members of the NAC transcription factor gene family were up-regulated during senescence in a microarray experiment, together with a large range of senescence-associated genes, reflecting the coordinated...... activation of degradation processes in senescing barley leaf tissues. This picture was confirmed in a detailed quantitative reverse transcription–PCR (qRT–PCR) experiment, which also showed distinct gene expression patterns for different members of the NAC gene family, suggesting a group of ~15 out of the 47...

Dopamine receptors D3 and D5 regulate CD4(+)T-cell activation and differentiation by modulating ERK activation and cAMP production.

Science.gov (United States)

Franz, Dafne; Contreras, Francisco; González, Hugo; Prado, Carolina; Elgueta, Daniela; Figueroa, Claudio; Pacheco, Rodrigo

2015-07-15

Dopamine receptors have been described in T-cells, however their signalling pathways coupled remain unknown. Since cAMP and ERKs play key roles regulating T-cell physiology, we aim to determine whether cAMP and ERK1/2-phosphorylation are modulated by dopamine receptor 3 (D3R) and D5R, and how this modulation affects CD4(+) T-cell activation and differentiation. Our pharmacologic and genetic evidence shows that D3R-stimulation reduced cAMP levels and ERK2-phosphorylation, consequently increasing CD4(+) T-cell activation and Th1-differentiation, respectively. Moreover, D5R expression reinforced TCR-triggered ERK1/2-phosphorylation and T-cell activation. In conclusion, these findings demonstrate how D3R and D5R modulate key signalling pathways affecting CD4(+) T-cell activation and Th1-differentiation. Copyright © 2015 Elsevier B.V. All rights reserved.

Proliferation and osteo/odontogenic differentiation of stem cells from apical papilla regulated by Zinc fingers and homeoboxes 2: An in vitro study

International Nuclear Information System (INIS)

Wan, Fang; Gao, Lifen; Lu, Yating; Ma, Hongxin; Wang, Hongxing; Liang, Xiaohong; Wang, Yan; Ma, Chunhong

2016-01-01

In the process of tooth root development, stem cells from the apical papilla (SCAPs) can differentiate into odontoblasts and form root dentin, however, molecules regulating SCAPs differentiation have not been elucidated. Zinc fingers and homeoboxes 2 (ZHX2) is a novel transcriptional inhibitor. It is reported to modulate the development of nerve cells, liver cells, B cells, red blood cells, and so on. However, the role of ZHX2 in tooth root development remains unclear. In this study, we explored the potential role of ZHX2 in the process of SCAPs differentiation. The results showed that overexpression of ZHX2 upregulated the expression of osteo/odontogenic related genes and ALP activity, inhibited the proliferation of SCAPs. Consistently, ZHX2 knockdown reduced SCAPs mineralization and promoted SCAPs proliferation. These results indicated that ZHX2 plays a critical role in the proliferation and osteo/odontogenic differentiation of SCAPs. - Highlights: • Zinc fingers and homeoboxes 2 (ZHX2) is a novel transcriptional inhibitor. • we found another new biological function of ZHX2 for the first time. • ZHX2 inhibit SCAPs proliferation. • ZHX2 promote the osteo/odontogenic differentiation of SCAPs.

Proliferation and osteo/odontogenic differentiation of stem cells from apical papilla regulated by Zinc fingers and homeoboxes 2: An in vitro study

Energy Technology Data Exchange (ETDEWEB)

Wan, Fang [Department of Immunology, Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Provincial Key Laboratory of Infection & Immunology, Shandong University School of Medicine, 44 Wenhua Xi Road, Jinan, Shandong 250012 (China); VIP Center, Shandong Provincial Key Laboratory of Oral Biomedicine, School and Hospital of Stomatology, Shandong University, 44 Wenhua Xi Road, Jinan, Shandong 250012 (China); Gao, Lifen [Department of Immunology, Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Provincial Key Laboratory of Infection & Immunology, Shandong University School of Medicine, 44 Wenhua Xi Road, Jinan, Shandong 250012 (China); Lu, Yating [VIP Center, Shandong Provincial Key Laboratory of Oral Biomedicine, School and Hospital of Stomatology, Shandong University, 44 Wenhua Xi Road, Jinan, Shandong 250012 (China); Ma, Hongxin; Wang, Hongxing; Liang, Xiaohong [Department of Immunology, Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Provincial Key Laboratory of Infection & Immunology, Shandong University School of Medicine, 44 Wenhua Xi Road, Jinan, Shandong 250012 (China); Wang, Yan, E-mail: wangyan1965@sdu.edu.cn [VIP Center, Shandong Provincial Key Laboratory of Oral Biomedicine, School and Hospital of Stomatology, Shandong University, 44 Wenhua Xi Road, Jinan, Shandong 250012 (China); Ma, Chunhong, E-mail: machunhong@sdu.edu.cn [Department of Immunology, Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Provincial Key Laboratory of Infection & Immunology, Shandong University School of Medicine, 44 Wenhua Xi Road, Jinan, Shandong 250012 (China)

2016-01-15

In the process of tooth root development, stem cells from the apical papilla (SCAPs) can differentiate into odontoblasts and form root dentin, however, molecules regulating SCAPs differentiation have not been elucidated. Zinc fingers and homeoboxes 2 (ZHX2) is a novel transcriptional inhibitor. It is reported to modulate the development of nerve cells, liver cells, B cells, red blood cells, and so on. However, the role of ZHX2 in tooth root development remains unclear. In this study, we explored the potential role of ZHX2 in the process of SCAPs differentiation. The results showed that overexpression of ZHX2 upregulated the expression of osteo/odontogenic related genes and ALP activity, inhibited the proliferation of SCAPs. Consistently, ZHX2 knockdown reduced SCAPs mineralization and promoted SCAPs proliferation. These results indicated that ZHX2 plays a critical role in the proliferation and osteo/odontogenic differentiation of SCAPs. - Highlights: • Zinc fingers and homeoboxes 2 (ZHX2) is a novel transcriptional inhibitor. • we found another new biological function of ZHX2 for the first time. • ZHX2 inhibit SCAPs proliferation. • ZHX2 promote the osteo/odontogenic differentiation of SCAPs.

Sex Reversal and Comparative Data Undermine the W Chromosome and Support Z-linked DMRT1 as the Regulator of Gonadal Sex Differentiation in Birds.

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Hirst, Claire E; Major, Andrew T; Ayers, Katie L; Brown, Rosie J; Mariette, Mylene; Sackton, Timothy B; Smith, Craig A

2017-09-01

The exact genetic mechanism regulating avian gonadal sex differentiation has not been completely resolved. The most likely scenario involves a dosage mechanism, whereby the Z-linked DMRT1 gene triggers testis development. However, the possibility still exists that the female-specific W chromosome may harbor an ovarian determining factor. In this study, we provide evidence that the universal gene regulating gonadal sex differentiation in birds is Z-linked DMRT1 and not a W-linked (ovarian) factor. Three candidate W-linked ovarian determinants are HINTW, female-expressed transcript 1 (FET1), and female-associated factor (FAF). To test the association of these genes with ovarian differentiation in the chicken, we examined their expression following experimentally induced female-to-male sex reversal using the aromatase inhibitor fadrozole (FAD). Administration of FAD on day 3 of embryogenesis induced a significant loss of aromatase enzyme activity in female gonads and masculinization. However, expression levels of HINTW, FAF, and FET1 were unaltered after experimental masculinization. Furthermore, comparative analysis showed that FAF and FET1 expression could not be detected in zebra finch gonads. Additionally, an antibody raised against the predicted HINTW protein failed to detect it endogenously. These data do not support a universal role for these genes or for the W sex chromosome in ovarian development in birds. We found that DMRT1 (but not the recently identified Z-linked HEMGN gene) is male upregulated in embryonic zebra finch and emu gonads, as in the chicken. As chicken, zebra finch, and emu exemplify the major evolutionary clades of birds, we propose that Z-linked DMRT1, and not the W sex chromosome, regulates gonadal sex differentiation in birds. Copyright © 2017 Endocrine Society.

Retinoic Acid Signaling in Thymic Epithelial Cells Regulates Thymopoiesis

DEFF Research Database (Denmark)

Wendland, Kerstin; Niss, Kristoffer; Kotarsky, Knut

2018-01-01

Despite the essential role of thymic epithelial cells (TEC) in T cell development, the signals regulating TEC differentiation and homeostasis remain incompletely understood. In this study, we show a key in vivo role for the vitamin A metabolite, retinoic acid (RA), in TEC homeostasis. In the abse......Despite the essential role of thymic epithelial cells (TEC) in T cell development, the signals regulating TEC differentiation and homeostasis remain incompletely understood. In this study, we show a key in vivo role for the vitamin A metabolite, retinoic acid (RA), in TEC homeostasis...

The NO signaling pathway differentially regulates KCC3a and KCC3b mRNA expression.

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Di Fulvio, Mauricio; Lauf, Peter K; Adragna, Norma C

2003-11-01

Nitric oxide (NO) donors and protein kinase G (PKG) acutely up-regulate K-Cl cotransporter-1 and -3 (KCC1 and KCC3) mRNA expression in vascular smooth muscle cells (VSMCs). Here, we report the presence, relative abundance, and regulation by sodium nitroprusside (SNP) of the novel KCC3a and KCC3b mRNAs, in primary cultures of rat VSMCs. KCC3a and KCC3b mRNAs were expressed in an approximate 3:1 ratio, as determined by semiquantitative RT-PCR analysis. SNP as well as YC-1 and 8-Br-cGMP, a NO-independent stimulator of soluble guanylyl cyclase (sGC) and PKG, respectively, increased KCC3a and KCC3b mRNA expression by 2.5-fold and 8.1-fold in a time-dependent manner, following a differential kinetics. Stimulation of the NO/sGC/PKG signaling pathway with either SNP, YC-1, or 8-Br-cGMP decreased the KCC3a/KCC3b ratio from 3.0+/-0.4 to 0.9+/-0.1. This is the first report on a differential regulation by the NO/sGC/PKG signaling pathway of a cotransporter and of KCC3a and KCC3b mRNA expression.

An automated high throughput screening-compatible assay to identify regulators of stem cell neural differentiation.

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Casalino, Laura; Magnani, Dario; De Falco, Sandro; Filosa, Stefania; Minchiotti, Gabriella; Patriarca, Eduardo J; De Cesare, Dario

2012-03-01

The use of Embryonic Stem Cells (ESCs) holds considerable promise both for drug discovery programs and the treatment of degenerative disorders in regenerative medicine approaches. Nevertheless, the successful use of ESCs is still limited by the lack of efficient control of ESC self-renewal and differentiation capabilities. In this context, the possibility to modulate ESC biological properties and to obtain homogenous populations of correctly specified cells will help developing physiologically relevant screens, designed for the identification of stem cell modulators. Here, we developed a high throughput screening-suitable ESC neural differentiation assay by exploiting the Cell(maker) robotic platform and demonstrated that neural progenies can be generated from ESCs in complete automation, with high standards of accuracy and reliability. Moreover, we performed a pilot screening providing proof of concept that this assay allows the identification of regulators of ESC neural differentiation in full automation.

PR-957, a selective inhibitor of immunoproteasome subunit low-MW polypeptide 7, attenuates experimental autoimmune neuritis by suppressing Th17-cell differentiation and regulating cytokine production.

Science.gov (United States)

Liu, Haijie; Wan, Chunxiao; Ding, Yanan; Han, Ranran; He, Yating; Xiao, Jinting; Hao, Junwei

2017-04-01

Experimental autoimmune neuritis (EAN) is a CD4 + T-cell-mediated autoimmune inflammatory demyelinating disease of the peripheral nervous system. It has been replicated in an animal model of human inflammatory demyelinating polyradiculoneuropathy, Guillain-Barré syndrome. In this study, we evaluated the therapeutic efficacy of a selective inhibitor of the immunoproteasome subunit, low-MW polypeptide 7 (PR-957) in rats with EAN. Our results showed that PR-957 significantly delayed onset day, reduced severity and shortened duration of EAN, and alleviated demyelination and inflammatory infiltration in sciatic nerves. In addition to significantly regulating expression of the cytokine profile, PR-957 treatment down-regulated the proportion of proinflammatory T-helper (T h )17 cells in sciatic nerves and spleens of rats with EAN. Data presented show the role of PR-957 in the signal transducer and activator of transcription 3 (STAT3) pathway. PR-957 not only decreased expression of IL-6 and IL-23 but also led to down-regulation of STAT3 phosphorylation in CD4 + T cells. Regulation of the STAT3 pathway led to a reduction in retinoid-related orphan nuclear receptor γ t and IL-17 production. Furthermore, reduction of STAT3 phosphorylation may have directly suppressed T h 17-cell differentiation. Therefore, our study demonstrates that PR-957 could potently alleviate inflammation in rats with EAN and that it may be a likely candidate for treating Guillain-Barré syndrome.-Liu, H., Wan, C., Ding, Y., Han, R., He, Y., Xiao, J., Hao, J. PR-957, a selective inhibitor of immunoproteasome subunit low-MW polypeptide 7, attenuates experimental autoimmune neuritis by suppressing T h 17-cell differentiation and regulating cytokine production. © FASEB.

Wnt and Hedgehog Signaling Regulate the Differentiation of F9 Cells into Extraembryonic Endoderm

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Gurjoth S. J. Deol

2017-10-01

Full Text Available Mouse F9 cells differentiate into primitive extraembryonic endoderm (PrE when treated with retinoic acid (RA, and this is accompanied by an up-regulation of Gata6. The role of the GATA6 network in PrE differentiation is known, and we have shown it directly activates Wnt6. Canonical Wnt/β-catenin signaling is required by F9 cells to differentiate to PrE, and this, like most developmental processes, requires input from one or more additional pathways. We found both RA and Gata6 overexpression, can induce the expression of Indian Hedgehog (Ihh and a subset of its target genes through Gli activation during PrE induction. Chemical activation of the Hh pathway using a Smoothened agonist (SAG also increased Gli reporter activity, and as expected, when Hh signaling was blocked with a Smoothened antagonist, cyclopamine, this RA-induced reporter activity was reduced. Interestingly, SAG alone failed to induce markers of PrE differentiation, and had no effect on Wnt/β-catenin-dependent TCF-LEF reporter activity. The expected increase in Wnt/β-catenin-dependent TCF-LEF reporter activity and PrE markers induced by RA was, however, blocked by cyclopamine. Finally, inhibiting GSK3 activity with BIO increased both TCF-LEF and Gli reporter activities. Together, we demonstrate the involvement of Hh signaling in the RA-induced differentiation of F9 cells into PrE, and while the activation of the Hh pathway itself is not sufficient, it as well as active Wnt/β-catenin are necessary for F9 cell differentiation.

Mechanically stimulated bone cells secrete paracrine factors that regulate osteoprogenitor recruitment, proliferation, and differentiation

International Nuclear Information System (INIS)

Brady, Robert T.; O'Brien, Fergal J.; Hoey, David A.

2015-01-01

Bone formation requires the recruitment, proliferation and osteogenic differentiation of mesenchymal progenitors. A potent stimulus driving this process is mechanical loading, yet the signalling mechanisms underpinning this are incompletely understood. The objective of this study was to investigate the role of the mechanically-stimulated osteocyte and osteoblast secretome in coordinating progenitor contributions to bone formation. Initially osteocytes (MLO-Y4) and osteoblasts (MC3T3) were mechanically stimulated for 24hrs and secreted factors within the conditioned media were collected and used to evaluate mesenchymal stem cell (MSC) and osteoblast recruitment, proliferation and osteogenesis. Paracrine factors secreted by mechanically stimulated osteocytes significantly enhanced MSC migration, proliferation and osteogenesis and furthermore significantly increased osteoblast migration and proliferation when compared to factors secreted by statically cultured osteocytes. Secondly, paracrine factors secreted by mechanically stimulated osteoblasts significantly enhanced MSC migration but surprisingly, in contrast to the osteocyte secretome, inhibited MSC proliferation when compared to factors secreted by statically cultured osteoblasts. A similar trend was observed in osteoblasts. This study provides new information on mechanically driven signalling mechanisms in bone and highlights a contrasting secretome between cells at different stages in the bone lineage, furthering our understanding of loading-induced bone formation and indirect biophysical regulation of osteoprogenitors. - Highlights: • Physically stimulated osteocytes secrete factors that regulate osteoprogenitors. • These factors enhance recruitment, proliferation and osteogenic differentiation. • Physically stimulated osteoblasts secrete factors that also regulate progenitors. • These factors enhance recruitment but inhibit proliferation of osteoprogenitors. • This study highlights a contrasting

Mechanically stimulated bone cells secrete paracrine factors that regulate osteoprogenitor recruitment, proliferation, and differentiation

Energy Technology Data Exchange (ETDEWEB)

Brady, Robert T. [Tissue Engineering Research Group, Dept. of Anatomy, Royal College of Surgeons in Ireland (Ireland); Trinity Centre for Bioengineering, School of Engineering, Trinity College Dublin (Ireland); Advanced Materials and BioEngineering Research Centre (AMBER), Trinity College Dublin & Royal College of Surgeons in Ireland (Ireland); Dept. of Mechanical, Aeronautical and Biomedical Engineering, University of Limerick (Ireland); O' Brien, Fergal J. [Tissue Engineering Research Group, Dept. of Anatomy, Royal College of Surgeons in Ireland (Ireland); Trinity Centre for Bioengineering, School of Engineering, Trinity College Dublin (Ireland); Advanced Materials and BioEngineering Research Centre (AMBER), Trinity College Dublin & Royal College of Surgeons in Ireland (Ireland); Hoey, David A., E-mail: david.hoey@ul.ie [Trinity Centre for Bioengineering, School of Engineering, Trinity College Dublin (Ireland); Dept. of Mechanical, Aeronautical and Biomedical Engineering, University of Limerick (Ireland); The Centre for Applied Biomedical Engineering Research, University of Limerick (Ireland); Materials & Surface Science Institute, University of Limerick (Ireland)

2015-03-27

Bone formation requires the recruitment, proliferation and osteogenic differentiation of mesenchymal progenitors. A potent stimulus driving this process is mechanical loading, yet the signalling mechanisms underpinning this are incompletely understood. The objective of this study was to investigate the role of the mechanically-stimulated osteocyte and osteoblast secretome in coordinating progenitor contributions to bone formation. Initially osteocytes (MLO-Y4) and osteoblasts (MC3T3) were mechanically stimulated for 24hrs and secreted factors within the conditioned media were collected and used to evaluate mesenchymal stem cell (MSC) and osteoblast recruitment, proliferation and osteogenesis. Paracrine factors secreted by mechanically stimulated osteocytes significantly enhanced MSC migration, proliferation and osteogenesis and furthermore significantly increased osteoblast migration and proliferation when compared to factors secreted by statically cultured osteocytes. Secondly, paracrine factors secreted by mechanically stimulated osteoblasts significantly enhanced MSC migration but surprisingly, in contrast to the osteocyte secretome, inhibited MSC proliferation when compared to factors secreted by statically cultured osteoblasts. A similar trend was observed in osteoblasts. This study provides new information on mechanically driven signalling mechanisms in bone and highlights a contrasting secretome between cells at different stages in the bone lineage, furthering our understanding of loading-induced bone formation and indirect biophysical regulation of osteoprogenitors. - Highlights: • Physically stimulated osteocytes secrete factors that regulate osteoprogenitors. • These factors enhance recruitment, proliferation and osteogenic differentiation. • Physically stimulated osteoblasts secrete factors that also regulate progenitors. • These factors enhance recruitment but inhibit proliferation of osteoprogenitors. • This study highlights a contrasting

Arginine Methylation Regulates MEIS2 Nuclear Localization to Promote Neuronal Differentiation of Adult SVZ Progenitors.

Science.gov (United States)

Kolb, Jasmine; Anders-Maurer, Marie; Müller, Tanja; Hau, Ann-Christin; Grebbin, Britta Moyo; Kallenborn-Gerhardt, Wiebke; Behrends, Christian; Schulte, Dorothea

2018-04-10

Adult neurogenesis is regulated by stem cell niche-derived extrinsic factors and cell-intrinsic regulators, yet the mechanisms by which niche signals impinge on the activity of intrinsic neurogenic transcription factors remain poorly defined. Here, we report that MEIS2, an essential regulator of adult SVZ neurogenesis, is subject to posttranslational regulation in the SVZ olfactory bulb neurogenic system. Nuclear accumulation of MEIS2 in adult SVZ-derived progenitor cells follows downregulation of EGFR signaling and is modulated by methylation of MEIS2 on a conserved arginine, which lies in close proximity to nested binding sites for the nuclear export receptor CRM1 and the MEIS dimerization partner PBX1. Methylation impairs interaction with CRM1 without affecting PBX1 dimerization and thereby allows MEIS2 nuclear accumulation, a prerequisite for neuronal differentiation. Our results describe a form of posttranscriptional modulation of adult SVZ neurogenesis whereby an extrinsic signal fine-tunes neurogenesis through posttranslational modification of a transcriptional regulator of cell fate. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Heterokaryon analysis of muscle differentiation: regulation of the postmitotic state.

Science.gov (United States)

Clegg, C H; Hauschka, S D

1987-08-01

MM14 mouse myoblasts withdraw irreversibly from the cell cycle and become postmitotic within a few hours of being deprived of fibroblast growth factor (Clegg, C. H., T. A. Linkhart, B. B. Olwin, and S. D. Hauschka, 1987, J. Cell Biol., 105:949-956). To examine the mechanisms that may regulate this developmental state of skeletal muscle, we tested the mitogen responsiveness of various cell types after their polyethylene glycol-mediated fusion with post-mitotic myocytes. Heterokaryons containing myocytes and quiescent nonmyogenic cells such as 3T3, L cell, and a differentiation-defective myoblast line (DD-1) responded to mitogen-rich medium by initiating DNA synthesis. Myonuclei replicated DNA and reexpressed thymidine kinase. In contrast, (myocyte x G1 myoblast) heterokaryons failed to replicate DNA in mitogen-rich medium and became postmitotic. This included cells with a nuclear ratio of three myoblasts to one myocyte. Proliferation dominance in (myocyte x 3T3 cell) and (myocyte x DD-1) heterokaryons was conditionally regulated by the timing of mitogen treatment; such cells became postmitotic when mitogen exposure was delayed for as little as 6 h after cell fusion. In addition, (myocyte x DD-1) heterokaryons expressed a muscle-specific trait and lost epidermal growth factor receptors when they became postmitotic. These results demonstrate that DNA synthesis is not irreversibly blocked in skeletal muscle; myonuclei readily express proliferation-related functions when provided with a mitogenic signal. Rather, myocyte-specific repression of DNA synthesis in heterokaryons argues that the postmitotic state of skeletal muscle is regulated by diffusible factors that inhibit processes of cellular mitogenesis.

Inhibition of Rho kinase regulates specification of early differentiation events in P19 embryonal carcinoma stem cells.

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Roman J Krawetz

Full Text Available The Rho kinase pathway plays a key role in many early cell/tissue determination events that take place in embryogenesis. Rho and its downstream effector Rho kinase (ROCK play pivotal roles in cell migration, apoptosis (membrane blebbing, cell proliferation/cell cycle, cell-cell adhesion and gene regulation. We and others have previously demonstrated that inhibition of ROCK blocks endoderm differentiation in embryonal carcinoma stem cells, however, the effect of ROCK inhibition on mesoderm and ectoderm specification has not been fully examined. In this study, the role of ROCK within the specification and differentiation of all three germ layers was examined.P19 cells were treated with the specific ROCK inhibitor Y-27623, and increase in differentiation efficiency into neuro-ectodermal and mesodermal lineages was observed. However, as expected a dramatic decrease in early endodermal markers was observed when ROCK was inhibited. Interestingly, within these ROCK-inhibited RA treated cultures, increased levels of mesodermal or ectodermal markers were not observed, instead it was found that the pluripotent markers SSEA-1 and Oct-4 remained up-regulated similar to that seen in undifferentiated cultures. Using standard and widely accepted methods for reproducible P19 differentiation into all three germ layers, an enhancement of mesoderm and ectoderm differentiation with a concurrent loss of endoderm lineage specification was observed with Y-27632 treatment. Evidence would suggest that this effect is in part mediated through TGF-β and SMAD signaling as ROCK-inhibited cells displayed aberrant SMAD activation and did not return to a 'ground' state after the inhibition had been removed.Given this data and the fact that only a partial rescue of normal differentiation capacity occurred when ROCK inhibition was alleviated, the effect of ROCK inhibition on the differentiation capacity of pluripotent cell populations should be further examined to elucidate the

Gene function in early mouse embryonic stem cell differentiation

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Campbell Pearl A

2007-03-01

Full Text Available Abstract Background Little is known about the genes that drive embryonic stem cell differentiation. However, such knowledge is necessary if we are to exploit the therapeutic potential of stem cells. To uncover the genetic determinants of mouse embryonic stem cell (mESC differentiation, we have generated and analyzed 11-point time-series of DNA microarray data for three biologically equivalent but genetically distinct mESC lines (R1, J1, and V6.5 undergoing undirected differentiation into embryoid bodies (EBs over a period of two weeks. Results We identified the initial 12 hour period as reflecting the early stages of mESC differentiation and studied probe sets showing consistent changes of gene expression in that period. Gene function analysis indicated significant up-regulation of genes related to regulation of transcription and mRNA splicing, and down-regulation of genes related to intracellular signaling. Phylogenetic analysis indicated that the genes showing the largest expression changes were more likely to have originated in metazoans. The probe sets with the most consistent gene changes in the three cell lines represented 24 down-regulated and 12 up-regulated genes, all with closely related human homologues. Whereas some of these genes are known to be involved in embryonic developmental processes (e.g. Klf4, Otx2, Smn1, Socs3, Tagln, Tdgf1, our analysis points to others (such as transcription factor Phf21a, extracellular matrix related Lama1 and Cyr61, or endoplasmic reticulum related Sc4mol and Scd2 that have not been previously related to mESC function. The majority of identified functions were related to transcriptional regulation, intracellular signaling, and cytoskeleton. Genes involved in other cellular functions important in ESC differentiation such as chromatin remodeling and transmembrane receptors were not observed in this set. Conclusion Our analysis profiles for the first time gene expression at a very early stage of m

Differential regulation of HIF-1α and HIF-2α in neuroblastoma: Estrogen-related receptor alpha (ERRα) regulates HIF2A transcription and correlates to poor outcome

International Nuclear Information System (INIS)

Hamidian, Arash; Stedingk, Kristoffer von; Munksgaard Thorén, Matilda; Mohlin, Sofie; Påhlman, Sven

2015-01-01

Hypoxia-inducible factors (HIFs) are differentially regulated in tumor cells. While the current paradigm supports post-translational regulation of the HIF-α subunits, we recently showed that hypoxic HIF-2α is also transcriptionally regulated via insulin-like growth factor (IGF)-II in the childhood tumor neuroblastoma. Here, we demonstrate that transcriptional regulation of HIF-2α seems to be restricted to neural cell-derived tumors, while HIF-1α is canonically regulated at the post-translational level uniformly across different tumor forms. Enhanced expression of HIF2A mRNA at hypoxia is due to de novo transcription rather than increased mRNA stability, and chemical stabilization of the HIF-α proteins at oxygen-rich conditions unexpectedly leads to increased HIF2A transcription. The enhanced HIF2A levels do not seem to be dependent on active HIF-1. Using a transcriptome array approach, we identified members of the Peroxisome proliferator-activated receptor gamma coactivator (PGC)/Estrogen-related receptor (ERR) complex families as potential regulators of HIF2A. Knockdown or inhibition of one of the members, ERRα, leads to decreased expression of HIF2A, and high expression of the ERRα gene ESRRA correlates with poor overall and progression-free survival in a clinical neuroblastoma material consisting of 88 tumors. Thus, targeting of ERRα and pathways regulating transcriptional HIF-2α are promising therapeutic avenues in neuroblastoma. - Highlights: • Transcriptional control of HIF-2α is restricted to neural cell-derived tumors. • Enhanced transcription of HIF2A is not due to increased mRNA stability. • Chemical stabilization of the HIF-α subunits leads to increased HIF2A transcription. • ERRα regulates HIF2A mRNA expression in neuroblastoma. • High expression of ESRRA correlates to poor outcome in neuroblastoma

Differential regulation of HIF-1α and HIF-2α in neuroblastoma: Estrogen-related receptor alpha (ERRα) regulates HIF2A transcription and correlates to poor outcome

Energy Technology Data Exchange (ETDEWEB)

Hamidian, Arash; Stedingk, Kristoffer von; Munksgaard Thorén, Matilda; Mohlin, Sofie; Påhlman, Sven, E-mail: sven.pahlman@med.lu.se

2015-06-05

Hypoxia-inducible factors (HIFs) are differentially regulated in tumor cells. While the current paradigm supports post-translational regulation of the HIF-α subunits, we recently showed that hypoxic HIF-2α is also transcriptionally regulated via insulin-like growth factor (IGF)-II in the childhood tumor neuroblastoma. Here, we demonstrate that transcriptional regulation of HIF-2α seems to be restricted to neural cell-derived tumors, while HIF-1α is canonically regulated at the post-translational level uniformly across different tumor forms. Enhanced expression of HIF2A mRNA at hypoxia is due to de novo transcription rather than increased mRNA stability, and chemical stabilization of the HIF-α proteins at oxygen-rich conditions unexpectedly leads to increased HIF2A transcription. The enhanced HIF2A levels do not seem to be dependent on active HIF-1. Using a transcriptome array approach, we identified members of the Peroxisome proliferator-activated receptor gamma coactivator (PGC)/Estrogen-related receptor (ERR) complex families as potential regulators of HIF2A. Knockdown or inhibition of one of the members, ERRα, leads to decreased expression of HIF2A, and high expression of the ERRα gene ESRRA correlates with poor overall and progression-free survival in a clinical neuroblastoma material consisting of 88 tumors. Thus, targeting of ERRα and pathways regulating transcriptional HIF-2α are promising therapeutic avenues in neuroblastoma. - Highlights: • Transcriptional control of HIF-2α is restricted to neural cell-derived tumors. • Enhanced transcription of HIF2A is not due to increased mRNA stability. • Chemical stabilization of the HIF-α subunits leads to increased HIF2A transcription. • ERRα regulates HIF2A mRNA expression in neuroblastoma. • High expression of ESRRA correlates to poor outcome in neuroblastoma.

Sex Differences in Drosophila Somatic Gene Expression: Variation and Regulation by doublesex

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Michelle N. Arbeitman

2016-07-01

Full Text Available Sex differences in gene expression have been widely studied in Drosophila melanogaster. Sex differences vary across strains, but many molecular studies focus on only a single strain, or on genes that show sexually dimorphic expression in many strains. How extensive variability is and whether this variability occurs among genes regulated by sex determination hierarchy terminal transcription factors is unknown. To address these questions, we examine differences in sexually dimorphic gene expression between two strains in Drosophila adult head tissues. We also examine gene expression in doublesex (dsx mutant strains to determine which sex-differentially expressed genes are regulated by DSX, and the mode by which DSX regulates expression. We find substantial variation in sex-differential expression. The sets of genes with sexually dimorphic expression in each strain show little overlap. The prevalence of different DSX regulatory modes also varies between the two strains. Neither the patterns of DSX DNA occupancy, nor mode of DSX regulation explain why some genes show consistent sex-differential expression across strains. We find that the genes identified as regulated by DSX in this study are enriched with known sites of DSX DNA occupancy. Finally, we find that sex-differentially expressed genes and genes regulated by DSX are highly enriched on the fourth chromosome. These results provide insights into a more complete pool of potential DSX targets, as well as revealing the molecular flexibility of DSX regulation.

Erythroid Differentiation Regulator 1 as a Novel Biomarker for Hair Loss Disorders.

Science.gov (United States)

Woo, Yu Ri; Hwang, Sewon; Jeong, Seo Won; Cho, Dae Ho; Park, Hyun Jeong

2017-02-03

Erythroid differentiation regulator 1 (Erdr1) is known to be involved in the inflammatory process via regulating the immune system in many cutaneous disorders, such as psoriasis and rosacea. However, the role of Erdr1 in various hair loss disorders remains unclear. The aim of this study was to investigate the putative role of Erdr1 in alopecias. Skin samples from 21 patients with hair loss disorders and five control subjects were retrieved, in order to assess their expression levels of Erdr1. Results revealed that expression of Erdr1 was significantly downregulated in the epidermis and hair follicles of patients with hair loss disorders, when compared to that in the control group. In particular, the expression of Erdr1 was significantly decreased in patients with alopecia areata. We propose that Erdr1 downregulation might be involved in the pathogenesis of hair loss, and could be considered as a novel biomarker for hair loss disorders.

Epidermis-type lipoxygenase 3 regulates adipocyte differentiation and peroxisome proliferator-activated receptor gamma activity

DEFF Research Database (Denmark)

Hallenborg, Philip; Jørgensen, Claus; Petersen, Rasmus K

2010-01-01

preadipocytes. Here, we show that forced expression of eLOX3 or addition of eLOX3 products stimulated adipogenesis under conditions that normally require an exogenous PPAR gamma ligand for differentiation. Hepoxilins, a group of oxidized arachidonic acid derivatives produced by eLOX3, bound to and activated...... PPAR gamma. Production of hepoxilins was increased transiently during the initial stages of adipogenesis. Furthermore, small interfering RNA-mediated or retroviral short hairpin RNA-mediated knockdown of eLOX3 expression abolished differentiation of 3T3-L1 preadipocytes. Finally, we demonstrate...... differentiation has remained enigmatic. Previously, we showed that lipoxygenase (LOX) activity is involved in activation of PPAR gamma during the early stages of adipocyte differentiation. Of the seven known murine LOXs, only the unconventional LOX epidermis-type lipoxygenase 3 (eLOX3) is expressed in 3T3-L1...

The excretory-secretory products of Echinococcus granulosus protoscoleces directly regulate the differentiation of B10, B17 and Th17 cells.

Science.gov (United States)

Pan, Wei; Hao, Wen-Ting; Shen, Yu-Juan; Li, Xiang-Yang; Wang, Yan-Juan; Sun, Fen-Fen; Yin, Jian-Hai; Zhang, Jing; Tang, Ren-Xian; Cao, Jian-Ping; Zheng, Kui-Yang

2017-07-21

Excretory-secretory products (ESPs) released by helminths are well-known to regulate T cell responses in the host. However, their direct influence in the differentiation of naïve T cells, and especially B cells, remains largely unknown. This study investigated the effects of Echinococcus granulosus protoscoleces ESPs (EgPSC-ESPs) on the differentiation of IL-10-producing B cells (B10), IL-17A-producing B cells (B17) and Th17 cells. BALB/c mice injected with EgPSC were used to evaluate the in vivo profiles of B10, B17 and Th17 cells. In vitro purified CD19 + B and naïve CD4 + T cells were cultured in the presence of native, heat-inactivated or periodate-treated EgPSC-ESPs, and the differentiation of these cell subsets were compared. In contrast to the control group, infected mice showed higher frequencies of B10, B17 and Th17 cells, and higher levels of IL-10 and IL-17A in the sera. Interestingly, B17 cells were first identified to express CD19 + CD1d high . In vitro, B cells cultured with native ESPs exhibited a higher percentage of B10 cells but lower percentage of B17 and Th17 cells compared to the PBS group. Moreover, the relative expression of IL-10 and IL-17A mRNA were consistent with the altered frequencies. However, ESPs subjected to heat-inactivation or periodate treatment exhibited an inverse effect on the induction of these cell subsets. Our findings indicate that ESPs released by EgPSC can directly regulate the differentiation of B10, B17 and Th17 cells, which appear to be heat-labile and carbohydrate-dependent.

GSK3 is a regulator of RAR-mediated differentiation

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Gupta, K; Gulen, F; Sun, L; Aguilera, R; Chakrabarti, A; Kiselar, J; Agarwal, MK; Wald, DN

2015-01-01

Acute myeloid leukemia (AML) is the most common form of leukemia in adults. Unfortunately, the standard therapeutic agents used for this disease have high toxicities and poor efficacy. The one exception to these poor outcomes is the use of the retinoid, all-trans retinoic acid (ATRA), for a rare subtype of AML (APL). The use of the differentiation agent, ATRA, in combination with low-dose chemotherapy leads to the long-term survival and presumed cure of 75–85% of patients. Unfortunately ATRA has not been clinically useful for other subtypes of AML. Though many non-APL leukemic cells respond to ATRA, they require significantly higher concentrations of ATRA for effective differentiation. Here we show that the combination of ATRA with glycogen synthase kinase 3 (GSK3) inhibition significantly enhances ATRA-mediated AML differentiation and growth inhibition. These studies have revealed that ATRA's receptor, the retinoic acid receptor (RAR), is a novel target of GSK3 phosphorylation and that GSK3 can impact the expression and transcriptional activity of the RAR. Overall, our studies suggest the clinical potential of ATRA and GSK3 inhibition for AML and provide a mechanistic framework to explain the promising activity of this combination regimen. PMID:22222598

Gene trapping in differentiating cell lines: regulation of the lysosomal protease cathepsin B in skeletal myoblast growth and fusion.

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Gogos, J A; Thompson, R; Lowry, W; Sloane, B F; Weintraub, H; Horwitz, M

1996-08-01

To identify genes regulated during skeletal muscle differentiation, we have infected mouse C2C12 myoblasts with retroviral gene trap vectors, containing a promoterless marker gene with a 5' splice acceptor signal. Integration of the vector adjacent to an actively transcribed gene places the marker under the transcriptional control of the endogenous gene, while the adjacent vector sequences facilitate cloning. The vector insertionally mutates the trapped locus and may also form fusion proteins with the endogenous gene product. We have screened several hundred clones, each containing a trapping vector integrated into a different endogenous gene. In agreement with previous estimates based on hybridization kinetics, we find that a large proportion of all genes expressed in myoblasts are regulated during differentiation. Many of these genes undergo unique temporal patterns of activation or repression during cell growth and myotube formation, and some show specific patterns of subcellular localization. The first gene we have identified with this strategy is the lysosomal cysteine protease cathepsin B. Expression from the trapped allele is upregulated during early myoblast fusion and downregulated in myotubes. A direct role for cathepsin B in myoblast growth and fusion is suggested by the observation that the trapped cells deficient in cathepsin B activity have an unusual morphology and reduced survival in low-serum media and undergo differentiation with impaired cellular fusion. The phenotype is reproduced by antisense cathepsin B expression in parental C2C12 myoblasts. The cellular phenotype is similar to that observed in cultured myoblasts from patients with I cell disease, in which there is diminished accumulation of lysosomal enzymes. This suggests that a specific deficiency of cathepsin B could contribute to the myopathic component of this illness.

Differential regulation of the foraging gene associated with task behaviors in harvester ants

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Kleeman Lindsay

2011-08-01

Full Text Available Abstract Background The division of labor in social insect colonies involves transitions by workers from one task to another and is critical to the organization and ecological success of colonies. The differential regulation of genetic pathways is likely to be a key mechanism involved in plasticity of social insect task behavior. One of the few pathways implicated in social organization involves the cGMP-activated protein kinase gene, foraging, a gene associated with foraging behavior in social insect species. The association of the foraging gene with behavior is conserved across diverse species, but the observed expression patterns and proposed functions of this gene vary across taxa. We compared the protein sequence of foraging across social insects and explored whether the differential regulation of this gene is associated with task behaviors in the harvester ant, Pogonomyrmex occidentalis. Results Phylogenetic analysis of the coding region of the foraging gene reveals considerable conservation in protein sequence across insects, particularly among hymenopteran species. The absence of amino acid variation in key active and binding sites suggests that differences in behaviors associated with this gene among species may be the result of changes in gene expression rather than gene divergence. Using real time qPCR analyses with a harvester ant ortholog to foraging (Pofor, we found that the brains of harvester ant foragers have a daily fluctuation in expression of foraging with mRNA levels peaking at midday. In contrast, young workers inside the nest have low levels of Pofor mRNA with no evidence of daily fluctuations in expression. As a result, the association of foraging expression with task behavior within a species changes depending on the time of day the individuals are sampled. Conclusions The amino acid protein sequence of foraging is highly conserved across social insects. Differences in foraging behaviors associated with this gene among

TCR Signal Strength Regulates Akt Substrate Specificity To Induce Alternate Murine Th and T Regulatory Cell Differentiation Programs.

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Hawse, William F; Boggess, William C; Morel, Penelope A

2017-07-15

The Akt/mTOR pathway is a key driver of murine CD4 + T cell differentiation, and induction of regulatory T (Treg) cells results from low TCR signal strength and low Akt/mTOR signaling. However, strong TCR signals induce high Akt activity that promotes Th cell induction. Yet, it is unclear how Akt controls alternate T cell fate decisions. We find that the strength of the TCR signal results in differential Akt enzymatic activity. Surprisingly, the Akt substrate networks associated with T cell fate decisions are qualitatively different. Proteomic profiling of Akt signaling networks during Treg versus Th induction demonstrates that Akt differentially regulates RNA processing and splicing factors to drive T cell differentiation. Interestingly, heterogeneous nuclear ribonucleoprotein (hnRNP) L or hnRNP A1 are Akt substrates during Treg induction and have known roles in regulating the stability and splicing of key mRNAs that code for proteins in the canonical TCR signaling pathway, including CD3ζ and CD45. Functionally, inhibition of Akt enzymatic activity results in the dysregulation of splicing during T cell differentiation, and knockdown of hnRNP L or hnRNP A1 results in the lower induction of Treg cells. Together, this work suggests that a switch in substrate specificity coupled to the phosphorylation status of Akt may lead to alternative cell fates and demonstrates that proteins involved with alternative splicing are important factors in T cell fate decisions. Copyright © 2017 by The American Association of Immunologists, Inc.

Human neuroblastoma SH-SY5Y cells show increased resistance to hyperthermic stress after differentiation, associated with elevated levels of Hsp72.

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Cheng, Lesley; Smith, Danielle J; Anderson, Robin L; Nagley, Phillip

2011-01-01

Terminally differentiated neurones in the central nervous system need to be protected from stress. We ask here whether differentiation of progenitor cells to neurones is accompanied by up-regulation of Hsp72, with acquisition of enhanced thermotolerance. Human neuroblastoma SH-SY5Y cells were propagated in an undifferentiated form and subsequently differentiated into neurone-like cells. Thermotolerance tests were carried out by exposure of cells to various temperatures, monitoring nuclear morphology as index of cell death. Abundance of Hsp72 was measured in cell lysates by western immunoblotting. The differentiation of SH-SY5Y cells was accompanied by increased expression of Hsp72. Further, in both cell states, exposure to mild hyperthermic stress (43°C for 30 min) increased Hsp72 expression. After differentiation, SH-SY5Y cells were more resistant to hyperthermic stress compared to their undifferentiated state, correlating with levels of Hsp72. Stable exogenous expression of Hsp72 in SH-SY5Y cells (transfected line 5YHSP72.1, containing mildly elevated levels of Hsp72), led to enhanced resistance to hyperthermic stress. Hsp72 was found to be inducible in undifferentiated 5YHSP72.1 cells; such heat-treated cells displayed enhanced thermotolerance. Treatment of cells with KNK437, a suppressor of Hsp72 induction, resulted in acute thermosensitisation of all cell types tested here. Hsp72 has a major role in the enhanced hyperthermic resistance acquired during neuronal differentiation of SH-SY5Y cells. These findings model the requirement in intact organisms for highly differentiated neurones to be specially protected against thermal stress.

PTEN drives Th17 cell differentiation by preventing IL-2 production.

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Kim, Hyeong Su; Jang, Sung Woong; Lee, Wonyong; Kim, Kiwan; Sohn, Hyogon; Hwang, Soo Seok; Lee, Gap Ryol

2017-11-06

T helper 17 (Th17) cells are a CD4 + T cell subset that produces IL-17A to mediate inflammation and autoimmunity. IL-2 inhibits Th17 cell differentiation. However, the mechanism by which IL-2 is suppressed during Th17 cell differentiation remains unclear. Here, we show that phosphatase and tensin homologue (PTEN) is a key factor that regulates Th17 cell differentiation by suppressing IL-2 production. Th17-specific Pten deletion ( Pten fl/fl Il17a cre ) impairs Th17 cell differentiation in vitro and ameliorated symptoms of experimental autoimmune encephalomyelitis (EAE), a model of Th17-mediated autoimmune disease. Mechanistically, Pten deficiency up-regulates IL-2 and phosphorylation of STAT5, but reduces STAT3 phosphorylation, thereby inhibiting Th17 cell differentiation. PTEN inhibitors block Th17 cell differentiation in vitro and in the EAE model. Thus, PTEN plays a key role in Th17 cell differentiation by blocking IL-2 expression. © 2017 Kim et al.

Let7a involves in neural stem cell differentiation relating with TLX level.

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Song, Juhyun; Cho, Kyoung Joo; Oh, Yumi; Lee, Jong Eun

2015-07-10

Neural stem cells (NSCs) have the potential for differentiation into neurons known as a groundbreaking therapeutic solution for central nervous system (CNS) diseases. To resolve the therapeutic efficiency of NSCs, recent researchers have focused on the study on microRNA's role in CNS. Some micro RNAs have been reported significant functions in NSC self-renewal and differentiation through the post-transcriptional regulation of neurogenesis genes. MicroRNA-Let7a (Let7a) has known as the regulator of diverse cellular mechanisms including cell differentiation and proliferation. In present study, we investigated whether Let7a regulates NSC differentiation by targeting the nuclear receptor TLX, which is an essential regulator of NSC self-renewal, proliferation and differentiation. We performed the following experiments: western blot analysis, TaqMan assay, RT-PCR, and immunocytochemistry to confirm the alteration of NSCs. Our data showed that let7a play important roles in controlling NSC fate determination. Thus, manipulating Let-7A and TLX could be a novel strategy to enhance the efficiency of NSC's neuronal differentiation for CNS disorders. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Repression of TSC1/TSC2 mediated by MeCP2 regulates human embryo lung fibroblast cell differentiation and proliferation.

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Wang, Yuanyuan; Chen, Chen; Deng, Ziyu; Bian, Erbao; Huang, Cheng; Lei, Ting; Lv, Xiongwen; Liu, Liping; Li, Jun

2017-03-01

Pulmonary fibrosis (PF) is a severe inflammatory disease with limited effective treatments. It is known that the transdifferentiation of human embryo lung fibroblast (HELF) cells from pulmonary fibroblasts into myofibroblasts, contributes to the progression of pulmonary fibrogenesis. The tuberous sclerosis proteins TSC1 and TSC2 are two key signaling factors which can suppress cell growth and proliferation. However, the roles of TSC1 and TSC2 in lung fibroblast are unclear. Here, we developed a PF model with bleomycin (BLM) in mice and conducted several simulation experiments in HELF cells. Our study shows that the expression of TSC1 and TSC2 in fibrotic mice lung was reduced and stimulation of HELF cells with TGF-β1 resulted in a down-regulation of TSC1 and TSC2. In addition, overexpression of TSC1 or TSC2 decreased cell proliferation and differentiation. Furthermore, we found that reduced expression of TSC1 and TSC2 caused by TGF-β1 is associated with the promoter methylation status of TSC1 and TSC2. MeCP2, controls an epigenetic pathway that promotes myofibroblast transdifferentiation and fibrosis. We found that expression of TSC1 and TSC2 can be repressed by MeCP2, which regulates HELF cell differentiation and proliferation as myofibroblasts and lead to PF ultimately. Copyright © 2016. Published by Elsevier B.V.

Insight into podocyte differentiation from the study of human genetic disease: nail-patella syndrome and transcriptional regulation in podocytes.

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Morello, Roy; Lee, Brendan

2002-05-01

In recent years, our understanding of the molecular basis of kidney development has benefited from the study of rare genetic diseases affecting renal function. This has especially been the case with the differentiation of the highly specialized podocyte in the pathogenesis of human disorders and mouse phenotypes affecting the renal filtration barrier. This filtration barrier represents the end product of a complex series of signaling events that produce a tripartite structure consisting of interdigitating podocyte foot processes with intervening slit diaphragms, the glomerular basement membrane, and the fenestrated endothelial cell. Dysregulation of unique cytoskeletal and extracellular matrix proteins in genetic forms of nephrotic syndrome has shown how specific structural proteins contribute to podocyte function and differentiation. However, much less is known about the transcriptional determinants that both specify and maintain this differentiated cell. Our studies of a skeletal malformation syndrome, nail-patella syndrome, have shown how the LIM homeodomain transcription factor, Lmx1b, contributes to transcriptional regulation of glomerular basement membrane collagen expression by podocytes. Moreover, they raise intriguing questions about more global transcriptional regulation of podocyte morphogenesis.

NRF2 Signaling Negatively Regulates Phorbol-12-Myristate-13-Acetate (PMA-Induced Differentiation of Human Monocytic U937 Cells into Pro-Inflammatory Macrophages.

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Min-Gu Song

Full Text Available Blood monocytes are recruited to injured tissue sites and differentiate into macrophages, which protect against pathogens and repair damaged tissues. Reactive oxygen species (ROS are known to be an important contributor to monocytes' differentiation and macrophages' function. NF-E2-related factor 2 (NRF2, a transcription factor regulating cellular redox homeostasis, is known to be a critical modulator of inflammatory responses. We herein investigated the role of NRF2 in macrophage differentiation using the human monocytic U937 cell line and phorbol-12-myristate-13-acetate (PMA. In U937 cells with NRF2 silencing, PMA-stimulated cell adherence was significantly facilitated when compared to control U937 cells. Both transcript and protein levels for pro-inflammatory cytokines, including interleukine-1β (IL-1β, IL-6, and tumor necrosis factor-α (TNFα were highly elevated in PMA-stimulated NRF2-silenced U937 compared to the control. In addition, PMA-inducible secretion of monocyte chemotactic protein 1 (MCP-1 was significantly high in NRF2-silenced U937. As an underlying mechanism, we showed that NRF2-knockdown U937 retained high levels of cellular ROS and endoplasmic reticulum (ER stress markers expression; and subsequently, PMA-stimulated levels of Ca2+ and PKCα were greater in NRF2-knockdown U937 cells, which caused enhanced nuclear accumulation of nuclear factor-ҡB (NFҡB p50 and extracellular signal-regulated kinase (ERK-1/2 phosphorylation. Whereas the treatment of NRF2-silenced U937 cells with pharmacological inhibitors of NFҡB or ERK1/2 largely blocked PMA-induced IL-1β and IL-6 expression, indicating that these pathways are associated with cell differentiation. Taken together, our results suggest that the NRF2 system functions to suppress PMA-stimulated U937 cell differentiation into pro-inflammatory macrophages and provide evidence that the ROS-PKCα-ERK-NFҡB axis is involved in PMA-facilitated differentiation of NRF2-silenced U937

Hyperglycemia Promotes Schwann Cell De-differentiation and De-myelination via Sorbitol Accumulation and Igf1 Protein Down-regulation*

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Hao, Wu; Tashiro, Syoichi; Hasegawa, Tomoka; Sato, Yuiko; Kobayashi, Tami; Tando, Toshimi; Katsuyama, Eri; Fujie, Atsuhiro; Watanabe, Ryuichi; Morita, Mayu; Miyamoto, Kana; Morioka, Hideo; Nakamura, Masaya; Matsumoto, Morio; Amizuka, Norio; Toyama, Yoshiaki; Miyamoto, Takeshi

2015-01-01

Diabetes mellitus (DM) is frequently accompanied by complications, such as peripheral nerve neuropathy. Schwann cells play a pivotal role in regulating peripheral nerve function and conduction velocity; however, changes in Schwann cell differentiation status in DM are not fully understood. Here, we report that Schwann cells de-differentiate into immature cells under hyperglycemic conditions as a result of sorbitol accumulation and decreased Igf1 expression in those cells. We found that de-differentiated Schwann cells could be re-differentiated in vitro into mature cells by treatment with an aldose reductase inhibitor, to reduce sorbitol levels, or with vitamin D3, to elevate Igf1 expression. In vivo DM models exhibited significantly reduced nerve function and conduction, Schwann cell de-differentiation, peripheral nerve de-myelination, and all conditions were significantly rescued by aldose reductase inhibitor or vitamin D3 administration. These findings reveal mechanisms underlying pathological changes in Schwann cells seen in DM and suggest ways to treat neurological conditions associated with this condition. PMID:25998127

33 CFR 165.1319 - Safety Zone Regulations, Seafair Blue Angels Air Show Performance, Seattle, WA.

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2010-07-01

... Blue Angels Air Show Performance, Seattle, WA. 165.1319 Section 165.1319 Navigation and Navigable... Thirteenth Coast Guard District § 165.1319 Safety Zone Regulations, Seafair Blue Angels Air Show Performance... Peninsula; thence northerly along the shore of Mercer Island to the point of origin. [Datum: NAD 1983] (c...

Network-based differential gene expression analysis suggests cell cycle related genes regulated by E2F1 underlie the molecular difference between smoker and non-smoker lung adenocarcinoma

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2013-01-01

Background Differential gene expression (DGE) analysis is commonly used to reveal the deregulated molecular mechanisms of complex diseases. However, traditional DGE analysis (e.g., the t test or the rank sum test) tests each gene independently without considering interactions between them. Top-ranked differentially regulated genes prioritized by the analysis may not directly relate to the coherent molecular changes underlying complex diseases. Joint analyses of co-expression and DGE have been applied to reveal the deregulated molecular modules underlying complex diseases. Most of these methods consist of separate steps: first to identify gene-gene relationships under the studied phenotype then to integrate them with gene expression changes for prioritizing signature genes, or vice versa. It is warrant a method that can simultaneously consider gene-gene co-expression strength and corresponding expression level changes so that both types of information can be leveraged optimally. Results In this paper, we develop a gene module based method for differential gene expression analysis, named network-based differential gene expression (nDGE) analysis, a one-step integrative process for prioritizing deregulated genes and grouping them into gene modules. We demonstrate that nDGE outperforms existing methods in prioritizing deregulated genes and discovering deregulated gene modules using simulated data sets. When tested on a series of smoker and non-smoker lung adenocarcinoma data sets, we show that top differentially regulated genes identified by the rank sum test in different sets are not consistent while top ranked genes defined by nDGE in different data sets significantly overlap. nDGE results suggest that a differentially regulated gene module, which is enriched for cell cycle related genes and E2F1 targeted genes, plays a role in the molecular differences between smoker and non-smoker lung adenocarcinoma. Conclusions In this paper, we develop nDGE to prioritize

Matrix Metalloproteinases Are Differentially Regulated and Responsive to Compression Therapy in a Red Duroc Model of Hypertrophic Scar.

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Travis, Taryn E; Ghassemi, Pejhman; Prindeze, Nicholas J; Moffatt, Lauren T; Carney, Bonnie C; Alkhalil, Abdulnaser; Ramella-Roman, Jessica C; Shupp, Jeffrey W

2018-01-01

Objective: Proteins of the matrix metalloproteinases family play a vital role in extracellular matrix maintenance and basic physiological processes in tissue homeostasis. The function and activities of matrix metalloproteinases in response to compression therapies have yet to be defined. Here, a swine model of hypertrophic scar was used to profile the transcription of all known 26 matrix metalloproteinases in scars treated with a precise compression dose. Methods: Full-thickness excisional wounds were created. Wounds underwent healing and scar formation. A subset of scars underwent 2 weeks of compression therapy. Biopsy specimens were preserved, and microarrays, reverse transcription-polymerase chain reaction, Western blotting, and immunohistochemistry were performed to characterize the transcription and expression of various matrix metalloproteinase family members. Results: Microarray results showed that 13 of the known 26 matrix metalloproteinases were differentially transcribed in wounds relative to the preinjury skin. The predominant upregulation of these matrix metalloproteinases during early wound-healing stages declined gradually in later stages of wound healing. The use of compression therapy reduced this decline in 10 of the 13 differentially regulated matrix metalloproteinases. Further investigation of MMP7 using reverse transcription-polymerase chain reaction confirmed the effect of compression on transcript levels. Assessment of MMP7 at the protein level using Western blotting and immunohistochemistry was concordant. Conclusions: In a swine model of hypertrophic scar, the application of compression to hypertrophic scar attenuated a trend of decreasing levels of matrix metalloproteinases during the process of hypertrophic wound healing, including MMP7, whose enzyme regulation was confirmed at the protein level.

Keratinocyte proliferation, differentiation, and apoptosis-Differential mechanisms of regulation by curcumin, EGCG and apigenin

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Balasubramanian, Sivaprakasam; Eckert, Richard L.

2007-01-01

We have proposed that it is important to examine the impact of chemopreventive agents on the function of normal human epidermal keratinocytes since these cells comprise the barrier that protects the body from a range of environmental insults. In this context, it is widely appreciated that cancer may be retarded by consumption or topical application of naturally occurring food-derived chemopreventive agents. Our studies show that (-)-epigallocatechin-3-gallate (EGCG), a green tea-derived polyphenol, acts to enhance the differentiation of normal human keratinocytes as evidenced by its ability to increase involucrin (hINV), transglutaminase type 1 (TG1) and caspase-14 gene expression. EGCG also stimulates keratinocyte morphological differentiation. These actions of EGCG are mediated via activation of a nPKC, Ras, MEKK1, MEK3, p38δ-ERK1/2 signaling cascade which leads to increased activator protein 1 (AP1) and CAATT enhancer binding protein (C/EBP) transcription factor expression, increased binding of these factors to DNA, and increased gene transcription. In contrast, apigenin, a dietary flavonoid derived from plants and vegetables, and curcumin, an agent derived from turmeric, inhibit differentiation by suppressing MAPK signal transduction and reducing API transcription factor level. Curcumin also acts to enhance apoptosis, although EGCG and apigenin do not stimulate apoptosis. In addition, all of these agents inhibit keratinocyte proliferation. These findings indicate that each of these diet-derived chemopreventive agents has a profound impact on normal human keratinocyte function and that they operate via distinct and sometimes opposing mechanisms. However, all are expected to act as chemopreventive agents

Molecular and biophysical mechanisms regulating hypertrophic differentiation in chondrocytes and mesenchymal stem cells

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D Studer

2012-07-01

Full Text Available Chondrocyte hypertrophy is one of the key physiological processes involved in the longitudinal growth of long bones, yet the regulation of hypertrophy is also becoming increasingly relevant for clinical application of mesenchymal stem cells (MSCs and screening for drugs to treat hypertrophic osteoarthritis. The extraordinary cell volume increase during hypertrophy is accompanied by an up-regulation of collagen X, matrix metalloproteinases (MMPs, and vascular endothelial growth factor (VEGF, all which are targets of the runt-related transcription factor 2 (Runx2. Many pathways, including parathyroid hormone-related protein (PTHrP/Indian Hedgehog, Wingless/Int (Wnt/β-catenin, and transforming growth factor beta (TGF-β/Sma and Mad Related Family (Smad pathways, can regulate hypertrophy, but factors as diverse as hypoxia, co-culture, epigenetics and biomaterial composition can also potently affect Runx2 expression. Control of hypertrophic differentiation can be exploited both for cartilage repair, where a stable phenotype is desired, but also in bone regeneration, where hypertrophic cartilage could act as a template for endochondral bone formation. We hope this review will motivate the design of novel engineered microenvironments for skeletal regeneration applications.

Pseudomonas aeruginosa AlgR Phosphorylation Status Differentially Regulates Pyocyanin and Pyoverdine Production

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Alexander S. Little

2018-01-01

Full Text Available Pseudomonas aeruginosa employs numerous, complex regulatory elements to control expression of its many virulence systems. The P. aeruginosa AlgZR two-component regulatory system controls the expression of several crucial virulence phenotypes. We recently determined, through transcriptomic profiling of a PAO1 ΔalgR mutant strain compared to wild-type PAO1, that algZR and hemCD are cotranscribed and show differential iron-dependent gene expression. Previous expression profiling was performed in strains without algR and revealed that AlgR acts as either an activator or repressor, depending on the gene. Thus, examination of P. aeruginosa gene expression from cells locked into different AlgR phosphorylation states reveals greater physiological relevance. Therefore, gene expression from strains carrying algR alleles encoding a phosphomimetic (AlgR D54E or a phosphoablative (AlgR D54N form were compared by microarray to PAO1. Transcriptome analyses of these strains revealed 25 differentially expressed genes associated with iron siderophore biosynthesis or heme acquisition or production. The PAO1 algR D54N mutant produced lower levels of pyoverdine but increased expression of the small RNAs prrf1 and prrf2 compared to PAO1. In contrast, the algR D54N mutant produced more pyocyanin than wild-type PAO1. On the other hand, the PAO1 algR D54E mutant produced higher levels of pyoverdine, likely due to increased expression of an iron-regulated gene encoding the sigma factor pvdS, but it had decreased pyocyanin production. AlgR specifically bound to the prrf2 and pvdS promoters in vitro. AlgR-dependent pyoverdine production was additionally influenced by carbon source rather than the extracellular iron concentration per se. AlgR phosphorylation effects were also examined in a Drosophila melanogaster feeding, murine acute pneumonia, and punch wound infection models. Abrogation of AlgR phosphorylation attenuated P. aeruginosa virulence in these infection

Slit/Robo1 signaling regulates neural tube development by balancing neuroepithelial cell proliferation and differentiation

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Wang, Guang; Li, Yan; Wang, Xiao-yu [Key Laboratory for Regenerative Medicine of The Ministry of Education, Department of Histology and Embryology, School of Medicine, Jinan University, Guangzhou 510632 (China); Han, Zhe [Institute of Vascular Biological Sciences, Guangdong Pharmaceutical University, Guangzhou 510224 (China); Chuai, Manli [College of Life Sciences Biocentre, University of Dundee, Dundee DD1 5EH (United Kingdom); Wang, Li-jing [Institute of Vascular Biological Sciences, Guangdong Pharmaceutical University, Guangzhou 510224 (China); Ho Lee, Kenneth Ka [Stem Cell and Regeneration Thematic Research Programme, School of Biomedical Sciences, Chinese University of Hong Kong, Shatin (Hong Kong); Geng, Jian-guo, E-mail: jgeng@umich.edu [Institute of Vascular Biological Sciences, Guangdong Pharmaceutical University, Guangzhou 510224 (China); Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI 48109 (United States); Yang, Xuesong, E-mail: yang_xuesong@126.com [Key Laboratory for Regenerative Medicine of The Ministry of Education, Department of Histology and Embryology, School of Medicine, Jinan University, Guangzhou 510632 (China)

2013-05-01

development by tightly coordinating cell proliferation and differentiation during neurulation. - Highlights: ► The role of Slit/Robo1 signaling was investigated with chick and mouse models. ► Disturbance of Slit/Robo1 signaling resulted in neural tube defects. ► Slit/Robo1 signaling regulated the proliferation of neural tube cells. ► Slit/Robo1 signaling modulated the differentiation of neural tube cells. ► Slit/Robo1 signaling balanced the proliferation and differentiation of neural tube.

Financial Incentives Differentially Regulate Neural Processing of Positive and Negative Emotions during Value-Based Decision-Making

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Anne M. Farrell

2018-02-01

Full Text Available Emotional and economic incentives often conflict in decision environments. To make economically desirable decisions then, deliberative neural processes must be engaged to regulate automatic emotional reactions. In this functional magnetic resonance imaging (fMRI study, we evaluated how fixed wage (FW incentives and performance-based (PB financial incentives, in which pay is proportional to outcome, differentially regulate positive and negative emotional reactions to hypothetical colleagues that conflicted with the economics of available alternatives. Neural activity from FW to PB incentive contexts decreased for positive emotional stimuli but increased for negative stimuli in middle temporal, insula, and medial prefrontal regions. In addition, PB incentives further induced greater responses to negative than positive emotional decisions in the frontal and anterior cingulate regions involved in emotion regulation. Greater response to positive than negative emotional features in these regions also correlated with lower frequencies of economically desirable choices. Our findings suggest that whereas positive emotion regulation involves a reduction of responses in valence representation regions, negative emotion regulation additionally engages brain regions for deliberative processing and signaling of incongruous events.

Financial Incentives Differentially Regulate Neural Processing of Positive and Negative Emotions during Value-Based Decision-Making.

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Farrell, Anne M; Goh, Joshua O S; White, Brian J

2018-01-01

Emotional and economic incentives often conflict in decision environments. To make economically desirable decisions then, deliberative neural processes must be engaged to regulate automatic emotional reactions. In this functional magnetic resonance imaging (fMRI) study, we evaluated how fixed wage (FW) incentives and performance-based (PB) financial incentives, in which pay is proportional to outcome, differentially regulate positive and negative emotional reactions to hypothetical colleagues that conflicted with the economics of available alternatives. Neural activity from FW to PB incentive contexts decreased for positive emotional stimuli but increased for negative stimuli in middle temporal, insula, and medial prefrontal regions. In addition, PB incentives further induced greater responses to negative than positive emotional decisions in the frontal and anterior cingulate regions involved in emotion regulation. Greater response to positive than negative emotional features in these regions also correlated with lower frequencies of economically desirable choices. Our findings suggest that whereas positive emotion regulation involves a reduction of responses in valence representation regions, negative emotion regulation additionally engages brain regions for deliberative processing and signaling of incongruous events.

Ibandronate promotes osteogenic differentiation of periodontal ligament stem cells by regulating the expression of microRNAs

Energy Technology Data Exchange (ETDEWEB)

Zhou, Qiang [Department of General Dentistry and Emergency, College of Stomatology, Fourth Military Medical University, Xi' an, Shaanxi 710032 (China); Zhao, Zhi-Ning [Clinical Laboratory, 451 Hospital of Chinese PLA, Xi' an 710054 (China); Cheng, Jing-Tao [Department of Special Dentistry, College of Stomatology, Fourth Military Medical University, Xi' an, Shaanxi 710032 (China); Zhang, Bin [Department of Orthodontics, College of Stomatology, Fourth Military Medical University, Xi' an, Shaanxi 710032 (China); Xu, Jie [Department of Periodontology, College of Stomatology, Fourth Military Medical University, Xi' an, Shaanxi 710032 (China); Huang, Fei; Zhao, Rui-Ni [Department of General Dentistry and Emergency, College of Stomatology, Fourth Military Medical University, Xi' an, Shaanxi 710032 (China); Chen, Yong-Jin, E-mail: cyj1229@fmmu.edu.cn [Department of General Dentistry and Emergency, College of Stomatology, Fourth Military Medical University, Xi' an, Shaanxi 710032 (China)

2011-01-07

Research highlights: {yields} Ibandronate significantly promote the proliferation of PDLSC cells. {yields} Ibandronate enhanced the expression of ALP, COL-1, OPG, OCN, Runx2. {yields} The expression of a class of miRNAs, e.g., miR-18a, miR-133a, miR-141 and miR-19a, was significantly modified in PDLSC cells cultured with ibandronate. {yields} Ibandronate regulates the expression of diverse bone formation-related genes via miRNAs in PDLSCs. {yields} Ibandronate can suppress the activity of osteoclast while promoting the proliferation of osteoblast by regulating the expression of microRNAs. -- Abstract: Bisphosphonates (BPs) have a profound effect on bone resorption and are widely used to treat osteoclast-mediated bone diseases. They suppress bone resorption by inhibiting the activity of mature osteoclasts and/or the formation of new osteoclasts. Osteoblasts may be an alternative target for BPs. Periodontal ligament stem cells (PDLSCs) exhibit osteoblast-like features and are capable of differentiating into osteoblasts or cementoblasts. This study aimed to determine the effects of ibandronate, a nitrogen-containing BP, on the proliferation and the differentiation of PDLSCs and to identify the microRNAs (miRNAs) that mediate these effects. The PDLSCs were treated with ibandronate, and cell proliferation was measured using the MTT (3-dimethylthiazol-2,5-diphenyltetrazolium bromide) assay. The expression of genes and miRNAs involved in osteoblastic differentiation was assayed using quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR). Ibandronate promoted the proliferation of PDLSCs and enhanced the expression of alkaline phosphatase (ALP), type I collagen (COL-1), osteoprotegerin (OPG), osteocalcin (OCN), and Runx2. The expression of miRNAs, including miR-18a, miR-133a, miR-141 and miR-19a, was significantly altered in the PDLSCs cultured with ibandronate. In PDLSCs, ibandronate regulates the expression of diverse bone formation

Ibandronate promotes osteogenic differentiation of periodontal ligament stem cells by regulating the expression of microRNAs

International Nuclear Information System (INIS)

Zhou, Qiang; Zhao, Zhi-Ning; Cheng, Jing-Tao; Zhang, Bin; Xu, Jie; Huang, Fei; Zhao, Rui-Ni; Chen, Yong-Jin

2011-01-01

Research highlights: → Ibandronate significantly promote the proliferation of PDLSC cells. → Ibandronate enhanced the expression of ALP, COL-1, OPG, OCN, Runx2. → The expression of a class of miRNAs, e.g., miR-18a, miR-133a, miR-141 and miR-19a, was significantly modified in PDLSC cells cultured with ibandronate. → Ibandronate regulates the expression of diverse bone formation-related genes via miRNAs in PDLSCs. → Ibandronate can suppress the activity of osteoclast while promoting the proliferation of osteoblast by regulating the expression of microRNAs. -- Abstract: Bisphosphonates (BPs) have a profound effect on bone resorption and are widely used to treat osteoclast-mediated bone diseases. They suppress bone resorption by inhibiting the activity of mature osteoclasts and/or the formation of new osteoclasts. Osteoblasts may be an alternative target for BPs. Periodontal ligament stem cells (PDLSCs) exhibit osteoblast-like features and are capable of differentiating into osteoblasts or cementoblasts. This study aimed to determine the effects of ibandronate, a nitrogen-containing BP, on the proliferation and the differentiation of PDLSCs and to identify the microRNAs (miRNAs) that mediate these effects. The PDLSCs were treated with ibandronate, and cell proliferation was measured using the MTT (3-dimethylthiazol-2,5-diphenyltetrazolium bromide) assay. The expression of genes and miRNAs involved in osteoblastic differentiation was assayed using quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR). Ibandronate promoted the proliferation of PDLSCs and enhanced the expression of alkaline phosphatase (ALP), type I collagen (COL-1), osteoprotegerin (OPG), osteocalcin (OCN), and Runx2. The expression of miRNAs, including miR-18a, miR-133a, miR-141 and miR-19a, was significantly altered in the PDLSCs cultured with ibandronate. In PDLSCs, ibandronate regulates the expression of diverse bone formation-related genes via miRNAs. The exact

Decorin gene expression and its regulation in human keratinocytes

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Velez-DelValle, Cristina; Marsch-Moreno, Meytha; Castro-Munozledo, Federico [Department of Cell Biology, Centro de Investigacion y de Estudios Avanzados del IPN, Apdo. Postal 14-740, Mexico D.F. 07000 (Mexico); Kuri-Harcuch, Walid, E-mail: walidkuri@gmail.com [Department of Cell Biology, Centro de Investigacion y de Estudios Avanzados del IPN, Apdo. Postal 14-740, Mexico D.F. 07000 (Mexico)

2011-07-22

Highlights: {yields} We showed that cultured human diploid epidermal keratinocytes express and synthesize decorin. {yields} Decorin is found intracytoplasmic in suprabasal cells of cultures and in human epidermis. {yields} Decorin mRNA expression in cHEK is regulated by pro-inflammatory and proliferative cytokines. {yields} Decorin immunostaining of psoriatic lesions showed a lower intensity and altered intracytoplasmic arrangements. -- Abstract: In various cell types, including cancer cells, decorin is involved in regulation of cell attachment, migration and proliferation. In skin, decorin is seen in dermis, but not in keratinocytes. We show that decorin gene (DCN) is expressed in the cultured keratinocytes, and the protein is found in the cytoplasm of differentiating keratinocytes and in suprabasal layers of human epidermis. RT-PCR experiments showed that DCN expression is regulated by pro-inflammatory and proliferative cytokines. Our data suggest that decorin should play a significant role in keratinocyte terminal differentiation, cutaneous homeostasis and dermatological diseases.

The Signaling Pathways Involved in Chondrocyte Differentiation and Hypertrophic Differentiation

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Jianmei Li

2016-01-01

Full Text Available Chondrocytes communicate with each other mainly via diffusible signals rather than direct cell-to-cell contact. The chondrogenic differentiation of mesenchymal stem cells (MSCs is well regulated by the interactions of varieties of growth factors, cytokines, and signaling molecules. A number of critical signaling molecules have been identified to regulate the differentiation of chondrocyte from mesenchymal progenitor cells to their terminal maturation of hypertrophic chondrocytes, including bone morphogenetic proteins (BMPs, SRY-related high-mobility group-box gene 9 (Sox9, parathyroid hormone-related peptide (PTHrP, Indian hedgehog (Ihh, fibroblast growth factor receptor 3 (FGFR3, and β-catenin. Except for these molecules, other factors such as adenosine, O2 tension, and reactive oxygen species (ROS also have a vital role in cartilage formation and chondrocyte maturation. Here, we outlined the complex transcriptional network and the function of key factors in this network that determine and regulate the genetic program of chondrogenesis and chondrocyte differentiation.

Functions of Heterogeneous Nuclear Ribonucleoproteins in Stem Cell Potency and Differentiation

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Qishan Chen

2013-01-01

Full Text Available Stem cells possess huge importance in developmental biology, disease modelling, cell replacement therapy, and tissue engineering in regenerative medicine because they have the remarkable potential for self-renewal and to differentiate into almost all the cell types in the human body. Elucidation of molecular mechanisms regulating stem cell potency and differentiation is essential and critical for extensive application. Heterogeneous nuclear ribonucleoproteins (hnRNPs are modular proteins consisting of RNA-binding motifs and auxiliary domains characterized by extensive and divergent functions in nucleic acid metabolism. Multiple roles of hnRNPs in transcriptional and posttranscriptional regulation enable them to be effective gene expression regulators. More recent findings show that hnRNP proteins are crucial factors implicated in maintenance of stem cell self-renewal and pluripotency and cell differentiation. The hnRNPs interact with certain sequences in target gene promoter regions to initiate transcription. In addition, they recognize 3′UTR or 5′UTR of specific gene mRNA forming mRNP complex to regulate mRNA stability and translation. Both of these regulatory pathways lead to modulation of gene expression that is associated with stem cell proliferation, cell cycle control, pluripotency, and committed differentiation.

CHD1 regulates cell fate determination by activation of differentiation-induced genes

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Baumgart, Simon J; Najafova, Zeynab; Hossan, Tareq

2017-01-01

The coordinated temporal and spatial activation of gene expression is essential for proper stem cell differentiation. The Chromodomain Helicase DNA-binding protein 1 (CHD1) is a chromatin remodeler closely associated with transcription and nucleosome turnover downstream of the transcriptional start...... site (TSS). In this study, we show that CHD1 is required for the induction of osteoblast-specific gene expression, extracellular-matrix mineralization and ectopic bone formation in vivo. Genome-wide occupancy analyses revealed increased CHD1 occupancy around the TSS of differentiation-activated genes....... Furthermore, we observed that CHD1-dependent genes are mainly induced during osteoblast differentiation and are characterized by higher levels of CHD1 occupancy around the TSS. Interestingly, CHD1 depletion resulted in increased pausing of RNA Polymerase II (RNAPII) and decreased H2A.Z occupancy close...

Regulation of epithelial differentiation in rat intestine by intraluminal delivery of an adenoviral vector or silencing RNA coding for Schlafen 3.

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Pavlo L Kovalenko

Full Text Available Although we stimulate enterocytic proliferation to ameliorate short gut syndrome or mucosal atrophy, less effort has been directed at enterocytic differentiation. Schlafen 3 (Slfn3 is a poorly understood protein induced during IEC-6 enterocytic differentiation. We hypothesized that exogenous manipulation of Slfn3 would regulate enterocytic differentiation in vivo. Adenoviral vector coding for Slfn3 cDNA (Ad-GFP-Slfn3 or silencing RNA for Slfn3 (siSlfn3 was introduced intraluminally into rat intestine. We assessed Slfn3, villin, sucrase-isomaltase (SI, Dpp4, and Glut2 by qRT-PCR, Western blot, and immunohistochemistry. We also studied Slfn3 and these differentiation markers in atrophic defunctionalized jejunal mucosa and the crypt-villus axis of normal jejunum. Ad-GFP-Slfn3 but not Ad-GFP increased Slfn3, villin and Dpp4 expression in human Caco-2 intestinal epithelial cells. Injecting Ad-GFP-Slfn3 into rat jejunum in vivo increased mucosal Slfn3 mRNA three days later vs. intraluminal Ad-GFP. This Slfn3 overexpression was associated with increases in all four differentiation markers. Injecting siSlfn3 into rat jejunum in vivo substantially reduced Slfn3 and all four intestinal mucosal differentiation markers three days later, as well as Dpp4 specific activity. Endogenous Slfn3 was reduced in atrophic mucosa from a blind-end Roux-en-Y anastomosis in parallel with differentiation marker expression together with AKT and p38 signaling. Slfn3 was more highly expressed in the villi than the crypts, paralleling Glut2, SI and Dpp4. Slfn3 is a key intracellular regulator of rat enterocytic differentiation. Understanding how Slfn3 works may identify targets to promote enterocytic differentiation and maintain mucosal function in vivo, facilitating enteral nutrition and improving survival in patients with mucosal atrophy or short gut syndrome.

IGF-1/IGF-1R/hsa-let-7c axis regulates the committed differentiation of stem cells from apical papilla

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Ma, Shu; Liu, Genxia; Jin, Lin; Pang, Xiyao; Wang, Yanqiu; Wang, Zilu; Yu, Yan; Yu, Jinhua

2016-01-01

Insulin-like growth factor-1 (IGF-1) and its receptor IGF-1R play a paramount role in tooth/bone formation while hsa-let-7c actively participates in the osteogenic differentiation of mesenchymal stem cells. However, the interaction between IGF-1/IGF-1R and hsa-let-7c on the committed differentiation of stem cells from apical papilla (SCAPs) remains unclear. In this study, human SCAPs were isolated and treated with IGF-1 and hsa-let-7c over/low-expression viruses. The odonto/osteogenic differentiation of these stem cells and the involvement of mitogen-activated protein kinase (MAPK) pathway were subsequently investigated. Alizarin red staining showed that hsa-let-7c low-expression can significantly promote the mineralization of IGF-1 treated SCAPs, while hsa-let-7c over-expression can decrease the calcium deposition of IGF-1 treated SCAPs. Western blot assay and real-time reverse transcription polymerase chain reaction further demonstrated that the expression of odonto/osteogenic markers (ALP, RUNX2/RUNX2, OSX/OSX, OCN/OCN, COL-I/COL-I, DSPP/DSP, and DMP-1/DMP-1) in IGF-1 treated SCAPs were significantly upregulated in Let-7c-low group. On the contrary, hsa-let-7c over-expression could downregulate the expression of these odonto/osteogenic markers. Moreover, western blot assay showed that the JNK and p38 MAPK signaling pathways were activated in Let-7c-low SCAPs but inhibited in Let-7c-over SCAPs. Together, the IGF-1/IGF-1R/hsa-let-7c axis can control the odonto/osteogenic differentiation of IGF-1-treated SCAPs via the regulation of JNK and p38 MAPK signaling pathways. PMID:27833148

VEGF-C and TGF-β reciprocally regulate mesenchymal stem cell commitment to differentiation into lymphatic endothelial or osteoblastic phenotypes.

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Igarashi, Yasuyuki; Chosa, Naoyuki; Sawada, Shunsuke; Kondo, Hisatomo; Yaegashi, Takashi; Ishisaki, Akira

2016-04-01

The direction of mesenchymal stem cell (MSC) differentiation is regulated by stimulation with various growth factors and cytokines. We recently established MSC lines, [transforming growth factor-β (TGF-β)-responsive SG‑2 cells, bone morphogenetic protein (BMP)-responsive SG‑3 cells, and TGF-β/BMP-non-responsive SG‑5 cells], derived from the bone marrow of green fluorescent protein-transgenic mice. In this study, to compare gene expression profiles in these MSC lines, we used DNA microarray analysis to characterize the specific gene expression profiles observed in the TGF-β-responsive SG‑2 cells. Among the genes that were highly expressed in the SG‑2 cells, we focused on vascular endothelial growth factor (VEGF) receptor 3 (VEGFR3), the gene product of FMS-like tyrosine kinase 4 (Flt4). We found that VEGF-C, a specific ligand of VEGFR3, significantly induced the cell proliferative activity, migratory ability (as shown by Transwell migration assay), as well as the phosphorylation of extracellular signal-regulated kinase (ERK)1/2 in the SG‑2 cells. Additionally, VEGF-C significantly increased the expression of prospero homeobox 1 (Prox1) and lymphatic vessel endothelial hyaluronan receptor 1 (Lyve1), which are lymphatic endothelial cell markers, and decreased the expression of osteogenic differentiation marker genes in these cells. By contrast, TGF-β significantly increased the expression of early-phase osteogenic differentiation marker genes in the SG‑2 cells and markedly decreased the expression of lymphatic endothelial cell markers. The findings of our study strongly suggest the following: i) that VEGF-C promotes the proliferative activity and migratory ability of MSCs; and ii) VEGF-C and TGF-β reciprocally regulate MSC commitment to differentiation into lymphatic endothelial or osteoblastic phenotypes, respectively. Our findings provide new insight into the molecular mechanisms underlying the regenerative ability of MSCs.

Integrated Transcriptomic and Epigenomic Analysis of Primary Human Lung Epithelial Cell Differentiation

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Marconett, Crystal N.; Zhou, Beiyun; Rieger, Megan E.; Selamat, Suhaida A.; Dubourd, Mickael; Fang, Xiaohui; Lynch, Sean K.; Stueve, Theresa Ryan; Siegmund, Kimberly D.; Berman, Benjamin P.

2013-01-01

Elucidation of the epigenetic basis for cell-type specific gene regulation is key to gaining a full understanding of how the distinct phenotypes of differentiated cells are achieved and maintained. Here we examined how epigenetic changes are integrated with transcriptional activation to determine cell phenotype during differentiation. We performed epigenomic profiling in conjunction with transcriptomic profiling using in vitro differentiation of human primary alveolar epithelial cells (AEC). This model recapitulates an in vivo process in which AEC transition from one differentiated cell type to another during regeneration following lung injury. Interrogation of histone marks over time revealed enrichment of specific transcription factor binding motifs within regions of changing chromatin structure. Cross-referencing of these motifs with pathways showing transcriptional changes revealed known regulatory pathways of distal alveolar differentiation, such as the WNT and transforming growth factor beta (TGFB) pathways, and putative novel regulators of adult AEC differentiation including hepatocyte nuclear factor 4 alpha (HNF4A), and the retinoid X receptor (RXR) signaling pathways. Inhibition of the RXR pathway confirmed its functional relevance for alveolar differentiation. Our incorporation of epigenetic data allowed specific identification of transcription factors that are potential direct upstream regulators of the differentiation process, demonstrating the power of this approach. Integration of epigenomic data with transcriptomic profiling has broad application for the identification of regulatory pathways in other models of differentiation. PMID:23818859

Differential regulation of BACE1 expression by oxidative and nitrosative signals

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Xu Huaxi

2011-03-01

Full Text Available Abstract Background It is well established that both cerebral hypoperfusion/stroke and type 2 diabetes are risk factors for Alzheimer's disease (AD. Recently, the molecular link between ischemia/hypoxia and amyloid precursor protein (APP processing has begun to be established. However, the role of the key common denominator, namely nitric oxide (NO, in AD is largely unknown. In this study, we investigated redox regulation of BACE1, the rate-limiting enzyme responsible for the β-cleavage of APP to Aβ peptides. Results Herein, we studied events such as S-nitrosylation, a covalent modification of cysteine residues by NO, and H2O2-mediated oxidation. We found that NO and H2O2 differentially modulate BACE1 expression and enzymatic activity: NO at low concentrations (2O2 (1-10 μM induces BACE1 expression via transcriptional activation, resulting in increased enzymatic activity. The differential effects of NO and H2O2 on BACE1 expression and activity are also reflected in their opposing effects on Aβ generation in cultured neurons in a dose-dependent manner. Furthermore, we found that BACE1 is highly S-nitrosylated in normal aging brains while S-nitrosylation is markedly reduced in AD brains. Conclusion This study demonstrates for the first time that BACE1 is highly modified by NO via multiple mechanisms: low and high levels of NO suppress BACE1 via transcriptional and post translational regulation, in contrast with the upregulation of BACE1 by H2O2-mediated oxidation. These novel NO-mediated regulatory mechanisms likely protect BACE1 from being further oxidized by excessive oxidative stress, as from H2O2 and peroxynitrite which are known to upregulate BACE1 and activate the enzyme, resulting in excessive cleavage of APP and Aβ generation; they likely represent the crucial house-keeping mechanism for BACE1 expression/activation under physiological conditions.

Neuronal differentiation is associated with a redox-regulated increase of copper flow to the secretory pathway.

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Hatori, Yuta; Yan, Ye; Schmidt, Katharina; Furukawa, Eri; Hasan, Nesrin M; Yang, Nan; Liu, Chin-Nung; Sockanathan, Shanthini; Lutsenko, Svetlana

2016-02-16

Brain development requires a fine-tuned copper homoeostasis. Copper deficiency or excess results in severe neuro-pathologies. We demonstrate that upon neuronal differentiation, cellular demand for copper increases, especially within the secretory pathway. Copper flow to this compartment is facilitated through transcriptional and metabolic regulation. Quantitative real-time imaging revealed a gradual change in the oxidation state of cytosolic glutathione upon neuronal differentiation. Transition from a broad range of redox states to a uniformly reducing cytosol facilitates reduction of the copper chaperone Atox1, liberating its metal-binding site. Concomitantly, expression of Atox1 and its partner, a copper transporter ATP7A, is upregulated. These events produce a higher flux of copper through the secretory pathway that balances copper in the cytosol and increases supply of the cofactor to copper-dependent enzymes, expression of which is elevated in differentiated neurons. Direct link between glutathione oxidation and copper compartmentalization allows for rapid metabolic adjustments essential for normal neuronal function.

Effects of let-7b and TLX on the proliferation and differentiation of retinal progenitor cells in vitro.

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Ni, Ni; Zhang, Dandan; Xie, Qing; Chen, Junzhao; Wang, Zi; Deng, Yuan; Wen, Xuyang; Zhu, Mengyu; Ji, Jing; Fan, Xianqun; Luo, Min; Gu, Ping

2014-10-20

MicroRNAs manifest significant functions in brain neural stem cell (NSC) self-renewal and differentiation through the post-transcriptional regulation of neurogenesis genes. Let-7b is expressed in the mammalian brain and regulates NSC proliferation and differentiation by targeting the nuclear receptor TLX, which is an essential regulator of NSC self-renewal. Whether let-7b and TLX act as important regulators in retinal progenitor cell (RPC) proliferation and differentiation remains unknown. Here, our data show that let-7b and TLX play important roles in controlling RPC fate determination in vitro. Let-7b suppresses TLX expression to negatively regulate RPC proliferation and accelerate the neuronal and glial differentiation of RPCs. The overexpression of let-7b downregulates TLX levels in RPCs, leading to reduced RPC proliferation and increased neuronal and glial differentiation, whereas antisense knockdown of let-7b produces robust TLX expression,enhanced RPC proliferation and decreased differentiation. Moreover, the inhibition of endogenous TLX by small interfering RNA suppresses RPC proliferation and promotes RPC differentiation. Furthermore, overexpression of TLX rescues let-7b-induced proliferation deficiency and weakens the RPC differentiation enhancement caused by let-7b alone. These results suggest that let-7b, by forming a negative feedback loop with TLX, provides a novel model to regulate the proliferation and differentiation of retinal progenitors in vitro.

miR-96 regulates the progression of differentiation in mammalian cochlear inner and outer hair cells.

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Kuhn, Stephanie; Johnson, Stuart L; Furness, David N; Chen, Jing; Ingham, Neil; Hilton, Jennifer M; Steffes, Georg; Lewis, Morag A; Zampini, Valeria; Hackney, Carole M; Masetto, Sergio; Holley, Matthew C; Steel, Karen P; Marcotti, Walter

2011-02-08

MicroRNAs (miRNAs) are small noncoding RNAs able to regulate a broad range of protein-coding genes involved in many biological processes. miR-96 is a sensory organ-specific miRNA expressed in the mammalian cochlea during development. Mutations in miR-96 cause nonsyndromic progressive hearing loss in humans and mice. The mouse mutant diminuendo has a single base change in the seed region of the Mir96 gene leading to widespread changes in the expression of many genes. We have used this mutant to explore the role of miR-96 in the maturation of the auditory organ. We found that the physiological development of mutant sensory hair cells is arrested at around the day of birth, before their biophysical differentiation into inner and outer hair cells. Moreover, maturation of the hair cell stereocilia bundle and remodelling of auditory nerve connections within the cochlea fail to occur in miR-96 mutants. We conclude that miR-96 regulates the progression of the physiological and morphological differentiation of cochlear hair cells and, as such, coordinates one of the most distinctive functional refinements of the mammalian auditory system.

Retinoic acid-loaded polymeric nanoparticles enhance vascular regulation of neural stem cell survival and differentiation after ischaemia

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Ferreira, R.; Fonseca, M. C.; Santos, T.; Sargento-Freitas, J.; Tjeng, R.; Paiva, F.; Castelo-Branco, M.; Ferreira, L. S.; Bernardino, L.

2016-04-01

Stroke is one of the leading causes of death and disability worldwide. However, current therapies only reach a small percentage of patients and may cause serious side effects. We propose the therapeutic use of retinoic acid-loaded nanoparticles (RA-NP) to safely and efficiently repair the ischaemic brain by creating a favourable pro-angiogenic environment that enhances neurogenesis and neuronal restitution. Our data showed that RA-NP enhanced endothelial cell proliferation and tubule network formation and protected against ischaemia-induced death. To evaluate the effect of RA-NP on vascular regulation of neural stem cell (NSC) survival and differentiation, endothelial cell-conditioned media (EC-CM) were collected. EC-CM from healthy RA-NP-treated cells reduced NSC death and promoted proliferation while EC-CM from ischaemic RA-NP-treated cells decreased cell death, increased proliferation and neuronal differentiation. In parallel, human endothelial progenitor cells (hEPC), which are part of the endogenous repair response to vascular injury, were collected from ischaemic stroke patients. hEPC treated with RA-NP had significantly higher proliferation, which further highlights the therapeutic potential of this formulation. To conclude, RA-NP protected endothelial cells from ischaemic death and stimulated the release of pro-survival, proliferation-stimulating factors and differentiation cues for NSC. RA-NP were shown to be up to 83-fold more efficient than free RA and to enhance hEPC proliferation. These data serve as a stepping stone to use RA-NP as vasculotrophic and neurogenic agents for vascular disorders and neurodegenerative diseases with compromised vasculature.

Systematic analysis of DEMETER-like DNA glycosylase genes shows lineage-specific Smi-miR7972 involved in SmDML1 regulation in Salvia miltiorrhiza.

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Li, Jiang; Li, Caili; Lu, Shanfa

2018-05-08

DEMETER-like DNA glycosylases (DMLs) initiate the base excision repair-dependent DNA demethylation to regulate a wide range of biological processes in plants. Six putative SmDML genes, termed SmDML1-SmDML6, were identified from the genome of S. miltiorrhiza, an emerging model plant for Traditional Chinese Medicine (TCM) studies. Integrated analysis of gene structures, sequence features, conserved domains and motifs, phylogenetic analysis and differential expression showed the conservation and divergence of SmDMLs. SmDML1, SmDML2 and SmDML4 were significantly down-regulated by the treatment of 5Aza-dC, a general DNA methylation inhibitor, suggesting involvement of SmDMLs in genome DNA methylation change. SmDML1 was predicted and experimentally validated to be target of Smi-miR7972. Computational analysis of forty whole genome sequences and almost all of RNA-seq data from Lamiids revealed that MIR7972s were only distributed in some plants of the three orders, including Lamiales, Solanales and Boraginales, and the number of MIR7972 genes varied among species. It suggests that MIR7972 genes underwent expansion and loss during the evolution of some Lamiids species. Phylogenetic analysis of MIR7972s showed closer evolutionary relationships between MIR7972s in Boraginales and Solanales in comparison with Lamiales. These results provide a valuable resource for elucidating DNA demethylation mechanism in S. miltiorrhiza.

Estrogen inhibits RANKL-stimulated osteoclastic differentiation of human monocytes through estrogen and RANKL-regulated interaction of estrogen receptor-α with BCAR1 and Traf6

International Nuclear Information System (INIS)

Robinson, Lisa J.; Yaroslavskiy, Beatrice B.; Griswold, Reed D.; Zadorozny, Eva V.; Guo, Lida; Tourkova, Irina L.; Blair, Harry C.

2009-01-01

The effects of estrogen on osteoclast survival and differentiation were studied using CD14-selected mononuclear osteoclast precursors from peripheral blood. Estradiol at ∼ 1 nM reduced RANKL-dependent osteoclast differentiation by 40-50%. Osteoclast differentiation was suppressed 14 days after addition of RANKL even when estradiol was withdrawn after 18 h. In CD14+ cells apoptosis was rare and was not augmented by RANKL or by 17-β-estradiol. Estrogen receptor-α (ERα) expression was strongly down-regulated by RANKL, whether or not estradiol was present. Mature human osteoclasts thus cannot respond to estrogen via ERα. However, ERα was present in CD14+ osteoclast progenitors, and a scaffolding protein, BCAR1, which binds ERα in the presence of estrogen, was abundant. Immunoprecipitation showed rapid (∼ 5 min) estrogen-dependent formation of ERα-BCAR1 complexes, which were increased by RANKL co-treatment. The RANKL-signaling intermediate Traf6, which regulates NF-κB activity, precipitated with this complex. Reduction of NF-κB nuclear localization occurred within 30 min of RANKL stimulation, and estradiol inhibited the phosphorylation of IκB in response to RANKL. Inhibition by estradiol was abolished by siRNA knockdown of BCAR1. We conclude that estrogen directly, but only partially, curtails human osteoclast formation. This effect requires BCAR1 and involves a non-genomic interaction with ERα.

Estrogen inhibits RANKL-stimulated osteoclastic differentiation of human monocytes through estrogen and RANKL-regulated interaction of estrogen receptor-{alpha} with BCAR1 and Traf6

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Robinson, Lisa J., E-mail: robinsonlj@msx.upmc.edu [Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Yaroslavskiy, Beatrice B.; Griswold, Reed D.; Zadorozny, Eva V.; Guo, Lida; Tourkova, Irina L. [Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Blair, Harry C. [Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Veteran' s Affairs Medical Center, Pittsburgh, PA 15243 (United States)

2009-04-15

The effects of estrogen on osteoclast survival and differentiation were studied using CD14-selected mononuclear osteoclast precursors from peripheral blood. Estradiol at {approx} 1 nM reduced RANKL-dependent osteoclast differentiation by 40-50%. Osteoclast differentiation was suppressed 14 days after addition of RANKL even when estradiol was withdrawn after 18 h. In CD14+ cells apoptosis was rare and was not augmented by RANKL or by 17-{beta}-estradiol. Estrogen receptor-{alpha} (ER{alpha}) expression was strongly down-regulated by RANKL, whether or not estradiol was present. Mature human osteoclasts thus cannot respond to estrogen via ER{alpha}. However, ER{alpha} was present in CD14+ osteoclast progenitors, and a scaffolding protein, BCAR1, which binds ER{alpha} in the presence of estrogen, was abundant. Immunoprecipitation showed rapid ({approx} 5 min) estrogen-dependent formation of ER{alpha}-BCAR1 complexes, which were increased by RANKL co-treatment. The RANKL-signaling intermediate Traf6, which regulates NF-{kappa}B activity, precipitated with this complex. Reduction of NF-{kappa}B nuclear localization occurred within 30 min of RANKL stimulation, and estradiol inhibited the phosphorylation of I{kappa}B in response to RANKL. Inhibition by estradiol was abolished by siRNA knockdown of BCAR1. We conclude that estrogen directly, but only partially, curtails human osteoclast formation. This effect requires BCAR1 and involves a non-genomic interaction with ER{alpha}.

Hyperglycemia Promotes Schwann Cell De-differentiation and De-myelination via Sorbitol Accumulation and Igf1 Protein Down-regulation.

Science.gov (United States)

Hao, Wu; Tashiro, Syoichi; Hasegawa, Tomoka; Sato, Yuiko; Kobayashi, Tami; Tando, Toshimi; Katsuyama, Eri; Fujie, Atsuhiro; Watanabe, Ryuichi; Morita, Mayu; Miyamoto, Kana; Morioka, Hideo; Nakamura, Masaya; Matsumoto, Morio; Amizuka, Norio; Toyama, Yoshiaki; Miyamoto, Takeshi

2015-07-10

Diabetes mellitus (DM) is frequently accompanied by complications, such as peripheral nerve neuropathy. Schwann cells play a pivotal role in regulating peripheral nerve function and conduction velocity; however, changes in Schwann cell differentiation status in DM are not fully understood. Here, we report that Schwann cells de-differentiate into immature cells under hyperglycemic conditions as a result of sorbitol accumulation and decreased Igf1 expression in those cells. We found that de-differentiated Schwann cells could be re-differentiated in vitro into mature cells by treatment with an aldose reductase inhibitor, to reduce sorbitol levels, or with vitamin D3, to elevate Igf1 expression. In vivo DM models exhibited significantly reduced nerve function and conduction, Schwann cell de-differentiation, peripheral nerve de-myelination, and all conditions were significantly rescued by aldose reductase inhibitor or vitamin D3 administration. These findings reveal mechanisms underlying pathological changes in Schwann cells seen in DM and suggest ways to treat neurological conditions associated with this condition. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

MicroRNA-4739 regulates osteogenic and adipocytic differentiation of immortalized human bone marrow stromal cells via targeting LRP3

Directory of Open Access Journals (Sweden)

Mona Elsafadi

2017-04-01

Full Text Available Understanding the regulatory networks underlying lineage differentiation and fate determination of human bone marrow stromal cells (hBMSC is a prerequisite for their therapeutic use. The goal of the current study was to unravel the novel role of the low-density lipoprotein receptor-related protein 3 (LRP3 in regulating the osteogenic and adipogenic differentiation of immortalized hBMSCs. Gene expression profiling revealed significantly higher LRP3 levels in the highly osteogenic hBMSC clone imCL1 than in the less osteogenic clone imCL2, as well as a significant upregulation of LRP3 during the osteogenic induction of the imCL1 clone. Data from functional and gene expression assays demonstrated the role of LRP3 as a molecular switch promoting hBMSC lineage differentiation into osteoblasts and inhibiting differentiation into adipocytes. Interestingly, microRNA (miRNA expression profiling identified miR-4739 as the most under-represented miRNA (−36.11 fold in imCL1 compared to imCL2. The TargetScan prediction algorithm, combined with functional and biochemical assays, identified LRP3 mRNA as a novel target of miR-4739, with a single potential binding site for miR-4739 located in the LRP3 3′ UTR. Regulation of LRP3 expression by miR-4739 was subsequently confirmed by qRT-PCR, western blotting, and luciferase assays. Over-expression of miR-4739 mimicked the effects of LRP3 knockdown on promoting adipogenic and suppressing osteogenic differentiation of hBMSCs. Hence, we report for the first time a novel biological role for the LRP3/hsa-miR-4739 axis in balancing osteogenic and adipocytic differentiation of hBMSCs. Our data support the potential utilization of miRNA-based therapies in regenerative medicine.

Modeling endocrine regulation of the menstrual cycle using delay differential equations.

Science.gov (United States)

Harris, Leona A; Selgrade, James F

2014-11-01

This article reviews an effective mathematical procedure for modeling hormonal regulation of the menstrual cycle of adult women. The procedure captures the effects of hormones secreted by several glands over multiple time scales. The specific model described here consists of 13 nonlinear, delay, differential equations with 44 parameters and correctly predicts blood levels of ovarian and pituitary hormones found in the biological literature for normally cycling women. In addition to this normal cycle, the model exhibits another stable cycle which may describe a biologically feasible "abnormal" condition such as polycystic ovarian syndrome. Model simulations illustrate how one cycle can be perturbed to the other cycle. Perturbations due to the exogenous administration of each ovarian hormone are examined. This model may be used to test the effects of hormone therapies on abnormally cycling women as well as the effects of exogenous compounds on normally cycling women. Sensitive parameters are identified and bifurcations in model behavior with respect to parameter changes are discussed. Modeling various aspects of menstrual cycle regulation should be helpful in predicting successful hormone therapies, in studying the phenomenon of cycle synchronization and in understanding many factors affecting the aging of the female reproductive endocrine system. Copyright © 2014 Elsevier Inc. All rights reserved.

Study of differential gene expression in human hepatocyte exposed to 50 cGy γ ray

International Nuclear Information System (INIS)

Wen Jianhua; Li Jianguo; Tian Huancheng; Li Yanling; Wang Xiaoli; Zuo Yanhui

2008-01-01

The study analyzed the differential transcriptional profile of the normal human hepatic cell and the human hepatic cell radiated with 50 cGy γ ray by gene chip technique. The results showed that there were 614 differentially expressed genes among 14 112 human genes analyzed, in which 521 genes were up-regulated and 93 genes down-regulated. These genes are associated with mitochondrial regulation, homo sapiens hepatitis A virus cellular receptor, tumor necrosis factor, cell cycle regulation, kinase and zinc finger protein etc. RT-PCR results indicated that up-regulated expression of gene HAVcr-1, HAVcr-2, MFTC, MOAP1 and down-regulated expression of gene TRIP12, DCN were consistent with gene chip data. (authors)

Study on differential transcriptional profile in human hepatocyte exposed to different doses γ ray

International Nuclear Information System (INIS)

Li Jianguo; Wen Jianhua; Duan Zhikai; Tian Yu; Wang Fang; Zuo Yahui

2009-01-01

The study analyzed the differential transcriptional profile of normal human hepatic cell and human hepatic cell radiated with three different doses (0.5 Gy, 2 Gy, 4 Gy γ ray) by gene chip technique. The results showed that the whole differentially expressed genes of three different doses have 284 in 14112 human genes analyzed, in which 261 genes were up-regulated and 23 genes were down-regulated. These genes are mainly associated with interferon receptor, mitochondrial regulation, homo sapiens hepatitis A virus cellular receptor, cell cycle regulation, kinase and zinc finger protein etc. RT-PCR results indicated that up-regulated expression of gene HAVcr-1, HAVcr-2, MFTC, MOAP1 and down-regulated expression of gene TRIP12, DCN are consistent with gene chip data. (authors)

Macrophage activation and differentiation signals regulate schlafen-4 gene expression: evidence for Schlafen-4 as a modulator of myelopoiesis.

Directory of Open Access Journals (Sweden)

Wendy J van Zuylen

Full Text Available BACKGROUND: The ten mouse and six human members of the Schlafen (Slfn gene family all contain an AAA domain. Little is known of their function, but previous studies suggest roles in immune cell development. In this report, we assessed Slfn regulation and function in macrophages, which are key cellular regulators of innate immunity. METHODOLOGY/PRINCIPAL FINDINGS: Multiple members of the Slfn family were up-regulated in mouse bone marrow-derived macrophages (BMM by the Toll-like Receptor (TLR4 agonist lipopolysaccharide (LPS, the TLR3 agonist Poly(I∶C, and in disease-affected joints in the collagen-induced model of rheumatoid arthritis. Of these, the most inducible was Slfn4. TLR agonists that signal exclusively through the MyD88 adaptor protein had more modest effects on Slfn4 mRNA levels, thus implicating MyD88-independent signalling and autocrine interferon (IFN-β in inducible expression. This was supported by the substantial reduction in basal and LPS-induced Slfn4 mRNA expression in IFNAR-1⁻/⁻ BMM. LPS causes growth arrest in macrophages, and other Slfn family genes have been implicated in growth control. Slfn4 mRNA levels were repressed during macrophage colony-stimulating factor (CSF-1-mediated differentiation of bone marrow progenitors into BMM. To determine the role of Slfn4 in vivo, we over-expressed the gene specifically in macrophages in mice using a csf1r promoter-driven binary expression system. Transgenic over-expression of Slfn4 in myeloid cells did not alter macrophage colony formation or proliferation in vitro. Monocyte numbers, as well as inflammatory macrophages recruited to the peritoneal cavity, were reduced in transgenic mice that specifically over-expressed Slfn4, while macrophage numbers and hematopoietic activity were increased in the livers and spleens. CONCLUSIONS: Slfn4 mRNA levels were up-regulated during macrophage activation but down-regulated during differentiation. Constitutive Slfn4 expression in the