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Ornelas IM, Silva TM, Pereira MR, França GR, Ventura ALM. Cell cycle regulation by ADP and IGF-1 in cultured late developing glia progenitors of the avian retina. Purinergic Signal 2023:10.1007/s11302-023-09982-7. [PMID: 38151691 DOI: 10.1007/s11302-023-09982-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 11/30/2023] [Indexed: 12/29/2023] Open
Abstract
In the avian retina, ADP induces the proliferation of late developing glia progenitors. Here, we show that in serum-containing retinal cell cultures, ADP-induced increase in [3H]-thymidine incorporation can be prevented by the IGF-1 receptor antagonists AG1024 and I-OMe-Tyrphostin AG 538, suggesting the participation of IGF-1 in ADP-mediated progenitor proliferation. In contrast, no increase in [3H]-thymidine incorporation is observed in retinal cultures treated only with IGF-1. Under serum starvation, while no increase in cell proliferation is detected in cultures treated only with ADP or IGF-1, a significant increase in [3H]-thymidine incorporation and number of PCNA expressing cells is observed in cultures treated concomitantly with ADP plus IGF-1, suggesting that both molecules are required to induce proliferation of retinal progenitors. In serum-starved cultures, although an increase in cell viability is detected by MTT assays in IGF-1-treated cultures, no significant increase in viability of [3H]-thymidine labeled progenitors is observed, suggesting that IGF-1 may contribute to survival of postmitotic cells in culture. While only ADP increases intracellular calcium, only IGF-1 induces the phosphorylation of Akt in the retinal cultures. IGF-1 through the PI3K/Akt pathway induces a significant increase in the transcription and expression of CDK1 with a decrease in phospho-histone H3 expression that is concomitant with an increase in the expression of cyclins D1 and E and CDK2. These findings suggest that IGF-1 stimulates CDK-1 mRNA and protein expression that enable progenitors to progress through the cell cycle. However, signaling of ADP in the presence IGF-I seems to be required for DNA synthesis.
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Affiliation(s)
- Isis Moraes Ornelas
- Department of Physiological Sciences, Federal University of Espírito Santo, Vitória, Espírito Santo, 29047-105, Brazil
| | - Thayane Martins Silva
- Department of Neurobiology, Neuroscience Program, Federal Fluminense University, Rua Prof. M.W. de Freitas Reis, bloco M, sala 409, São Domingos, Niterói, Rio de Janeiro, CEP 24210-201, Brazil
| | - Mariana Rodrigues Pereira
- Department of Neurobiology, Neuroscience Program, Federal Fluminense University, Rua Prof. M.W. de Freitas Reis, bloco M, sala 409, São Domingos, Niterói, Rio de Janeiro, CEP 24210-201, Brazil
| | - Guilherme Rapozeiro França
- Department of Physiological Sciences, Federal University of the State of Rio de Janeiro, Rua Frei Caneca 94, Centro, Rio de Janeiro, RJ, CEP 20211-040, Brazil
| | - Ana Lucia Marques Ventura
- Department of Neurobiology, Neuroscience Program, Federal Fluminense University, Rua Prof. M.W. de Freitas Reis, bloco M, sala 409, São Domingos, Niterói, Rio de Janeiro, CEP 24210-201, Brazil.
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2
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Correale J, Ysrraelit MC. Multiple Sclerosis and Aging: The Dynamics of Demyelination and Remyelination. ASN Neuro 2022; 14:17590914221118502. [PMID: 35938615 PMCID: PMC9364177 DOI: 10.1177/17590914221118502] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system
(CNS) leading to demyelination and neurodegeneration. Life expectancy and age of onset in
MS patients have been rising over the last decades, and previous studies have shown that
age affects disease progression. Therefore, age appears as one of the most important
factors in accumulating disability in MS patients. Indeed, the degeneration of
oligodendrocytes (OGDs) and OGD precursors (OPCs) increases with age, in association with
increased inflammatory activity of astrocytes and microglia. Similarly, age-related
neuronal changes such as mitochondrial alterations, an increase in oxidative stress, and
disrupted paranodal junctions can impact myelin integrity. Conversely, once myelination is
complete, the long-term integrity of axons depends on OGD supply of energy. These
alterations determine pathological myelin changes consisting of myelin outfolding,
splitting, and accumulation of multilamellar fragments. Overall, these data demonstrate
that old mature OGDs lose their ability to produce and maintain healthy myelin over time,
to induce de novo myelination, and to remodel pre-existing myelinated
axons that contribute to neural plasticity in the CNS. Furthermore, as observed in other
tissues, aging induces a general decline in regenerative processes and, not surprisingly,
progressively hinders remyelination in MS. In this context, this review will provide an
overview of the current knowledge of age-related changes occurring in cells of the
oligodendroglial lineage and how they impact myelin synthesis, axonal degeneration, and
remyelination efficiency.
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Affiliation(s)
- Jorge Correale
- Departamento de Neurología, 58782Fleni, Buenos Aires, Argentina
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3
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Binamé F, Pham-Van LD, Bagnard D. Manipulating oligodendrocyte intrinsic regeneration mechanism to promote remyelination. Cell Mol Life Sci 2021; 78:5257-5273. [PMID: 34019104 PMCID: PMC11073109 DOI: 10.1007/s00018-021-03852-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/14/2021] [Accepted: 05/08/2021] [Indexed: 02/06/2023]
Abstract
In demyelinated lesions, astrocytes, activated microglia and infiltrating macrophages secrete several factors regulating oligodendrocyte precursor cells' behaviour. What appears to be the initiation of an intrinsic mechanism of myelin repair is only leading to partial recovery and inefficient remyelination, a process worsening over the course of the disease. This failure is largely due to the concomitant accumulation of inhibitory cues in and around the lesion sites opposing to growth promoting factors. Here starts a complex game of interactions between the signalling pathways controlling oligodendrocytes migration or differentiation. Receptors of positive or negative cues are modulating Ras, PI3K or RhoGTPases pathways acting on oligodendrocyte cytoskeleton remodelling. From the description of this intricate signalling network, this review addresses the extent to which the modulation of the global response to inhibitory cues may pave the route towards novel therapeutic approaches for myelin repair.
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Affiliation(s)
- Fabien Binamé
- INSERM U1119, Biopathology of Myelin, Neuroprotection and Therapeutic Strategy (BMNST Lab), Labex Medalis, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Pôle API, Ecole Supérieure de Biotechnologie, 300 Boulevard Sébastien Brant, 67412, Illkirch, France
| | - Lucas D Pham-Van
- INSERM U1119, Biopathology of Myelin, Neuroprotection and Therapeutic Strategy (BMNST Lab), Labex Medalis, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Pôle API, Ecole Supérieure de Biotechnologie, 300 Boulevard Sébastien Brant, 67412, Illkirch, France
| | - Dominique Bagnard
- INSERM U1119, Biopathology of Myelin, Neuroprotection and Therapeutic Strategy (BMNST Lab), Labex Medalis, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Pôle API, Ecole Supérieure de Biotechnologie, 300 Boulevard Sébastien Brant, 67412, Illkirch, France.
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4
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Insulin-like growth factor-I rescue of primary keratinocytes from pre- and post-ultraviolet B radiation effects. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2020; 209:111951. [DOI: 10.1016/j.jphotobiol.2020.111951] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 06/26/2020] [Accepted: 06/30/2020] [Indexed: 01/13/2023]
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5
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Janowska J, Gargas J, Ziemka-Nalecz M, Zalewska T, Sypecka J. Oligodendrocyte Response to Pathophysiological Conditions Triggered by Episode of Perinatal Hypoxia-Ischemia: Role of IGF-1 Secretion by Glial Cells. Mol Neurobiol 2020; 57:4250-4268. [PMID: 32691304 PMCID: PMC7467917 DOI: 10.1007/s12035-020-02015-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 07/08/2020] [Indexed: 12/11/2022]
Abstract
Differentiation of oligodendrocyte progenitors towards myelinating cells is influenced by a plethora of exogenous instructive signals. Insulin-like growth factor 1 (IGF-1) is one of the major factors regulating cell survival, proliferation, and maturation. Recently, there is an ever growing recognition concerning the role of autocrine/paracrine IGF-1 signaling in brain development and metabolism. Since oligodendrocyte functioning is altered after the neonatal hypoxic-ischemic (HI) insult, a question arises if the injury exerts any influence on the IGF-1 secreted by neural cells and how possibly the change in IGF-1 concentration affects oligodendrocyte growth. To quantify the secretory activity of neonatal glial cells, the step-wise approach by sequentially using the in vivo, ex vivo, and in vitro models of perinatal asphyxia was applied. A comparison of the results of in vivo and ex vivo studies allowed evaluating the role of autocrine/paracrine IGF-1 signaling. Accordingly, astroglia were indicated to be the main local source of IGF-1 in the developing brain, and the factor secretion was shown to be significantly upregulated during the first 24 h after the hypoxic-ischemic insult. And conversely, the IGF-1 amounts released by oligodendrocytes and microglia significantly decreased. A morphometric examination of oligodendrocyte differentiation by means of the Sholl analysis showed that the treatment with low IGF-1 doses markedly improved the branching of oligodendroglial cell processes and, in this way, promoted their differentiation. The changes in the IGF-1 amounts in the nervous tissue after HI might contribute to the resulting white matter disorders, observed in newborn children who experienced perinatal asphyxia. Pharmacological modulation of IGF-1 secretion by neural cells could be reasonable solution in studies aimed at searching for therapies alleviating the consequences of perinatal asphyxia.
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Affiliation(s)
- Justyna Janowska
- NeuroRepair Department, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5, A. Pawinskiego Str., 02-106, Warsaw, Poland
| | - Justyna Gargas
- NeuroRepair Department, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5, A. Pawinskiego Str., 02-106, Warsaw, Poland
| | - Malgorzata Ziemka-Nalecz
- NeuroRepair Department, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5, A. Pawinskiego Str., 02-106, Warsaw, Poland
| | - Teresa Zalewska
- NeuroRepair Department, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5, A. Pawinskiego Str., 02-106, Warsaw, Poland
| | - Joanna Sypecka
- NeuroRepair Department, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5, A. Pawinskiego Str., 02-106, Warsaw, Poland.
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Kim HN, Langley MR, Simon WL, Yoon H, Kleppe L, Lanza IR, LeBrasseur NK, Matveyenko A, Scarisbrick IA. A Western diet impairs CNS energy homeostasis and recovery after spinal cord injury: Link to astrocyte metabolism. Neurobiol Dis 2020; 141:104934. [PMID: 32376475 PMCID: PMC7982964 DOI: 10.1016/j.nbd.2020.104934] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 03/28/2020] [Accepted: 04/29/2020] [Indexed: 12/12/2022] Open
Abstract
A diet high in fat and sucrose (HFHS), the so-called Western diet promotes metabolic syndrome, a significant co-morbidity for individuals with spinal cord injury (SCI). Here we demonstrate that the spinal cord of mice consuming HFHS expresses reduced insulin-like growth factor 1 (IGF-1) and its receptor and shows impaired tricarboxylic acid cycle function, reductions in PLP and increases in astrogliosis, all prior to SCI. After SCI, Western diet impaired sensorimotor and bladder recovery, increased microgliosis, exacerbated oligodendrocyte loss and reduced axon sprouting. Direct and indirect neural injury mechanisms are suggested since HFHS culture conditions drove parallel injury responses directly and indirectly after culture with conditioned media from HFHS-treated astrocytes. In each case, injury mechanisms included reductions in IGF-1R, SIRT1 and PGC-1α and were prevented by metformin. Results highlight the potential for a Western diet to evoke signs of neural insulin resistance and injury and metformin as a strategy to improve mechanisms of neural neuroprotection and repair.
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Affiliation(s)
- Ha Neui Kim
- Department of Physical Medicine and Rehabilitation, Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN 55905, United States of America; Rehabilitation Medicine Research Center, Department of Physiology and Biomedical Engineering, Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN 55905, United States of America
| | - Monica R Langley
- Department of Physical Medicine and Rehabilitation, Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN 55905, United States of America; Rehabilitation Medicine Research Center, Department of Physiology and Biomedical Engineering, Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN 55905, United States of America
| | - Whitney L Simon
- Department of Physical Medicine and Rehabilitation, Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN 55905, United States of America
| | - Hyesook Yoon
- Department of Physical Medicine and Rehabilitation, Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN 55905, United States of America; Rehabilitation Medicine Research Center, Department of Physiology and Biomedical Engineering, Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN 55905, United States of America
| | - Laurel Kleppe
- Department of Physical Medicine and Rehabilitation, Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN 55905, United States of America
| | - Ian R Lanza
- Rehabilitation Medicine Research Center, Department of Physiology and Biomedical Engineering, Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN 55905, United States of America
| | - Nathan K LeBrasseur
- Department of Physical Medicine and Rehabilitation, Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN 55905, United States of America; Rehabilitation Medicine Research Center, Department of Physiology and Biomedical Engineering, Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN 55905, United States of America
| | - Aleksey Matveyenko
- Rehabilitation Medicine Research Center, Department of Physiology and Biomedical Engineering, Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN 55905, United States of America
| | - Isobel A Scarisbrick
- Department of Physical Medicine and Rehabilitation, Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN 55905, United States of America; Rehabilitation Medicine Research Center, Department of Physiology and Biomedical Engineering, Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN 55905, United States of America; Neurosciuence Program, Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN 55905, United States of America.
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7
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Hao Y, Wu M, Wang J. Fibroblast growth factor-2 ameliorates tumor necrosis factor-alpha-induced osteogenic damage of human bone mesenchymal stem cells by improving oxidative phosphorylation. Mol Cell Probes 2020; 52:101538. [PMID: 32084581 DOI: 10.1016/j.mcp.2020.101538] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 01/30/2020] [Accepted: 02/17/2020] [Indexed: 12/13/2022]
Abstract
Tumor necrosis factor-alpha (TNF-α) has been shown to have an inhibitory effect on the osteogenic differentiation of mesenchymal stem cells. The metabolic switch from glycolysis to oxidative phosphorylation (OXPHOS) is vital for energy supply during osteogenic differentiation. However, the metabolic switch is inhibited under inflammatory stimulation. FGF2 has shown that it can improve osteogenic differentiation and promote autoimmune inflammation. In this study, we investigated whether FGF2 can ameliorate TNF-a-inhibited osteogenic damage by improving OXPHOS. Effects of TNF-α or FGF2 on the proliferation and osteogenic differentiation of hBMSCs were evaluated by MTT assay, qRT-PCR, and ALP activity tests. The function of FGF2 on the TNF-a-inhibited metabolic switch was determined by Mito Stress test. The results showed that TNF-α was able to inhibit the osteogenic differentiation and OXPHOS of hBMSCs. FGF2 has no obvious function in improving the osteogenic-related genes, but it can ameliorate the impaired osteogenesis and OCR value caused by TNF-α. These findings suggest that FGF2 can prevent the impaired osteogenic differentiation and metabolic switch of hBMSCs under inflammatory stimulation, which might enhance the regeneration capacity of hBMSCs.
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Affiliation(s)
- Yishan Hao
- Department of Oral Implantology, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China; Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - Minting Wu
- Department of Oral Implantology, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China; Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - Jinming Wang
- Department of Oral Implantology, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China; Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, China.
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8
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Fingolimod inhibits proliferation and epithelial-mesenchymal transition in sacral chordoma by inactivating IL-6/STAT3 signalling. Biosci Rep 2020; 40:222049. [PMID: 32027356 PMCID: PMC7029154 DOI: 10.1042/bsr20200221] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 02/05/2020] [Accepted: 02/05/2020] [Indexed: 12/18/2022] Open
Abstract
Purpose: To explore the sensitivity of the immunosuppressive agent fingolimod (FTY720) in chordoma and determine whether it can serve as an appropriate alternate treatment for unresectable tumours in patients after incomplete surgery. Methods: Cell viability assays, colony formation assays and EdU assays were performed to evaluate the sensitivity of chordoma cell lines to FTY720. Transwell invasion assays, wound healing assays, flow cytometry, cell cycle analysis, immunofluorescence analysis, Western blotting analysis and enzyme-linked immunosorbent assays (ELISAs) were performed to evaluate cell invasion, epithelial–mesenchymal transition (EMT) and activation of related pathways after treatment with FTY720. The effect of FTY720 was also evaluated in vivo in a xenograft model. Results: We found that FTY720 inhibited the proliferation, invasion and metastasis of sacral chordoma cells (P < 0.01). FTY720 also inhibited the proliferation of tumour cells in a xenograft model using sacral chordoma cell lines (P < 0.01). The mechanism was related to the EMT and apoptosis of chordoma cells and inactivation of IL-6/STAT3 signalling in vitro and in vivo. Conclusions: Our findings indicate that FTY720 may be an effective therapeutic agent against chordoma. These findings suggest that FTY720 is a novel agent that can treat locally advanced and metastatic chordoma.
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9
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Blocking the Thrombin Receptor Promotes Repair of Demyelinated Lesions in the Adult Brain. J Neurosci 2020; 40:1483-1500. [PMID: 31911460 DOI: 10.1523/jneurosci.2029-19.2019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 12/15/2019] [Accepted: 12/17/2019] [Indexed: 01/14/2023] Open
Abstract
Myelin loss limits neurological recovery and myelin regeneration and is critical for restoration of function. We recently discovered that global knock-out of the thrombin receptor, also known as Protease Activated Receptor 1 (PAR1), accelerates myelin development. Here we demonstrate that knocking out PAR1 also promotes myelin regeneration. Outcomes in two unique models of myelin injury and repair, that is lysolecithin or cuprizone-mediated demyelination, showed that PAR1 knock-out in male mice improves replenishment of myelinating cells and remyelinated nerve fibers and slows early axon damage. Improvements in myelin regeneration in PAR1 knock-out mice occurred in tandem with a skewing of reactive astrocyte signatures toward a prorepair phenotype. In cell culture, the promyelinating effects of PAR1 loss of function are consistent with possible direct effects on the myelinating potential of oligodendrocyte progenitor cells (OPCs), in addition to OPC-indirect effects involving enhanced astrocyte expression of promyelinating factors, such as BDNF. These findings highlight previously unrecognized roles of PAR1 in myelin regeneration, including integrated actions across the oligodendrocyte and astroglial compartments that are at least partially mechanistically linked to the powerful BDNF-TrkB neurotrophic signaling system. Altogether, findings suggest PAR1 may be a therapeutically tractable target for demyelinating disorders of the CNS.SIGNIFICANCE STATEMENT Replacement of oligodendroglia and myelin regeneration holds tremendous potential to improve function across neurological conditions. Here we demonstrate Protease Activated Receptor 1 (PAR1) is an important regulator of the capacity for myelin regeneration across two experimental murine models of myelin injury. PAR1 is a G-protein-coupled receptor densely expressed in the CNS, however there is limited information regarding its physiological roles in health and disease. Using a combination of PAR1 knock-out mice, oligodendrocyte monocultures and oligodendrocyte-astrocyte cocultures, we demonstrate blocking PAR1 improves myelin production by a mechanism related to effects across glial compartments and linked in part to regulatory actions toward growth factors such as BDNF. These findings set the stage for development of new clinically relevant myelin regeneration strategies.
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10
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Ornelas IM, Khandker L, Wahl SE, Hashimoto H, Macklin WB, Wood TL. The mechanistic target of rapamycin pathway downregulates bone morphogenetic protein signaling to promote oligodendrocyte differentiation. Glia 2020; 68:1274-1290. [PMID: 31904150 DOI: 10.1002/glia.23776] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 11/26/2019] [Accepted: 11/29/2019] [Indexed: 12/13/2022]
Abstract
Oligodendrocyte precursor cells (OPCs) differentiate and mature into oligodendrocytes, which produce myelin in the central nervous system. Prior studies have shown that the mechanistic target of rapamycin (mTOR) is necessary for proper myelination of the mouse spinal cord and that bone morphogenetic protein (BMP) signaling inhibits oligodendrocyte differentiation, in part by promoting expression of inhibitor of DNA binding 2 (Id2). Here we provide evidence that mTOR functions specifically in the transition from early stage OPC to immature oligodendrocyte by downregulating BMP signaling during postnatal spinal cord development. When mTOR is deleted from the oligodendrocyte lineage, expression of the FK506 binding protein 1A (FKBP12), a suppressor of BMP receptor activity, is reduced, downstream Smad activity is increased and Id2 expression is elevated. Additionally, mTOR inhibition with rapamycin in differentiating OPCs alters the transcriptional complex present at the Id2 promoter. Deletion of mTOR in oligodendroglia in vivo resulted in fewer late stage OPCs and fewer newly formed oligodendrocytes in the spinal cord with no effect on OPC proliferation or cell cycle exit. Finally, we demonstrate that inhibiting BMP signaling rescues the rapamycin-induced deficit in myelin protein expression. We conclude that mTOR promotes early oligodendrocyte differentiation by suppressing BMP signaling in OPCs.
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Affiliation(s)
- Isis M Ornelas
- Department of Pharmacology, Physiology & Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Luipa Khandker
- Department of Pharmacology, Physiology & Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Stacey E Wahl
- Department of Pharmacology, Physiology & Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Hirokazu Hashimoto
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado
| | - Wendy B Macklin
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado
| | - Teresa L Wood
- Department of Pharmacology, Physiology & Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey
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11
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Yang H, Liu C, Fan H, Chen B, Huang D, Zhang L, Zhang Q, An J, Zhao J, Wang Y, Hao D. Sonic Hedgehog Effectively Improves Oct4-Mediated Reprogramming of Astrocytes into Neural Stem Cells. Mol Ther 2019; 27:1467-1482. [PMID: 31153826 DOI: 10.1016/j.ymthe.2019.05.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 05/01/2019] [Accepted: 05/04/2019] [Indexed: 01/19/2023] Open
Abstract
Irreversible neuron loss following spinal cord injury (SCI) usually results in persistent neurological dysfunction. The generation of autologous neural stem cells (NSCs) holds great potential for neural replenishment therapies and drug screening in SCI. Our recent studies demonstrated that mature astrocytes from the spinal cord can directly revert back to a pluripotent state under appropriate signals. However, in previous attempts, the reprogramming of astrocytes into induced NSCs (iNSCs) was unstable, inefficient, and frequently accompanied by generation of intermediate precursors. It remained unknown how to further increase the efficiency of astrocyte reprogramming into iNSCs. Here, we show that mature astrocytes could be directly converted into iNSCs by a single transcription factor, Oct4, and that the iNSCs displayed typical neurosphere morphology, authentic NSC gene expression, self-renewal capacity, and multipotency. Strikingly, Oct4-driven reprogramming of astrocytes into iNSCs was potentiated with continuous sonic hedgehog (Shh) stimulation, as demonstrated by a sped-up reprogramming and increased conversion efficiency. Moreover, the iNSC-derived neurons possessed functionality as neurons. Importantly, crosstalk between Sox2/Shh-targeted downstream signals and phosphatidylinositol 3-kinase/cyclin-dependent kinase 2/Smad ubiquitin regulatory factor 2 (PI3K/Cdk2/Smurf2) signaling is likely involved in the mechanisms underlying this cellular event. The highly efficient reprogramming of astrocytes to generate iNSCs will provide an alternative therapeutic approach for SCI using autologous cells.
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Affiliation(s)
- Hao Yang
- Translational Medicine Center, Hong Hui Hospital, Xi'an Jiaotong University, Shaanxi 710054, China.
| | - Cuicui Liu
- Translational Medicine Center, Hong Hui Hospital, Xi'an Jiaotong University, Shaanxi 710054, China
| | - Hong Fan
- Translational Medicine Center, Hong Hui Hospital, Xi'an Jiaotong University, Shaanxi 710054, China
| | - Bo Chen
- Translational Medicine Center, Hong Hui Hospital, Xi'an Jiaotong University, Shaanxi 710054, China
| | - Dageng Huang
- Department of Spine Surgery, Hong Hui Hospital, Xi'an Jiaotong University, Shaanxi 710054, China
| | - Lingling Zhang
- Translational Medicine Center, Hong Hui Hospital, Xi'an Jiaotong University, Shaanxi 710054, China
| | - Qian Zhang
- Translational Medicine Center, Hong Hui Hospital, Xi'an Jiaotong University, Shaanxi 710054, China
| | - Jing An
- Translational Medicine Center, Hong Hui Hospital, Xi'an Jiaotong University, Shaanxi 710054, China
| | - Jingjing Zhao
- Translational Medicine Center, Hong Hui Hospital, Xi'an Jiaotong University, Shaanxi 710054, China
| | - Yi Wang
- Translational Medicine Center, Hong Hui Hospital, Xi'an Jiaotong University, Shaanxi 710054, China
| | - Dingjun Hao
- Translational Medicine Center, Hong Hui Hospital, Xi'an Jiaotong University, Shaanxi 710054, China; Department of Spine Surgery, Hong Hui Hospital, Xi'an Jiaotong University, Shaanxi 710054, China.
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12
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Nadadhur AG, Alsaqati M, Gasparotto L, Cornelissen-Steijger P, van Hugte E, Dooves S, Harwood AJ, Heine VM. Neuron-Glia Interactions Increase Neuronal Phenotypes in Tuberous Sclerosis Complex Patient iPSC-Derived Models. Stem Cell Reports 2018; 12:42-56. [PMID: 30581017 PMCID: PMC6335594 DOI: 10.1016/j.stemcr.2018.11.019] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 11/21/2018] [Accepted: 11/22/2018] [Indexed: 12/20/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is a rare neurodevelopmental disorder resulting from autosomal dominant mutations in the TSC1 or TSC2 genes, leading to a hyperactivated mammalian target of rapamycin (mTOR) pathway, and gray and white matter defects in the brain. To study the involvement of neuron-glia interactions in TSC phenotypes, we generated TSC patient induced pluripotent stem cell (iPSC)-derived cortical neuronal and oligodendrocyte (OL) cultures. TSC neuron mono-cultures showed increased network activity, as measured by calcium transients and action potential firing, and increased dendritic branching. However, in co-cultures with OLs, neuronal defects became more apparent, showing cellular hypertrophy and increased axonal density. In addition, TSC neuron-OL co-cultures showed increased OL cell proliferation and decreased OL maturation. Pharmacological intervention with the mTOR regulator rapamycin suppressed these defects. Our patient iPSC-based model, therefore, shows a complex cellular TSC phenotype arising from the interaction of neuronal and glial cells and provides a platform for TSC disease modeling and drug development. TSC neuron mono-cultures show an increase in network activity and dendritic branching TSC co-cultures show hypertrophy and an increase in axonal length and OL proliferation mTOR regulators normalize TSC neuronal and glial phenotypes
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Affiliation(s)
- Aishwarya G Nadadhur
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam 1081 HV, the Netherlands
| | - Mouhamed Alsaqati
- Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff CF24 4HQ, UK
| | - Lisa Gasparotto
- Pediatric Neurology, Emma Children's Hospital, Amsterdam UMC, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam 1081 HV, the Netherlands
| | - Paulien Cornelissen-Steijger
- Pediatric Neurology, Emma Children's Hospital, Amsterdam UMC, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam 1081 HV, the Netherlands
| | - Eline van Hugte
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam 1081 HV, the Netherlands
| | - Stephanie Dooves
- Pediatric Neurology, Emma Children's Hospital, Amsterdam UMC, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam 1081 HV, the Netherlands
| | - Adrian J Harwood
- Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff CF24 4HQ, UK
| | - Vivi M Heine
- Pediatric Neurology, Emma Children's Hospital, Amsterdam UMC, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam 1081 HV, the Netherlands; Department of Complex Trait Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam 1081 HV, the Netherlands.
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13
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Cheng X, Xie B, Qi J, Zhao X, Zhang Z, Qiu M, Yang J. Rat astrocytes are more supportive for mouse OPC self-renewal than mouse astrocytes in culture. Dev Neurobiol 2016; 77:907-916. [PMID: 28033654 DOI: 10.1002/dneu.22476] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 11/27/2016] [Accepted: 12/09/2016] [Indexed: 11/08/2022]
Abstract
Mouse primary oligodendrocyte precursor cells (OPCs) are increasingly used to study the molecular mechanisms underlying the phenotype changes in oligodendrocyte differentiation and axonal myelination observed in transgenic or mutant mouse models. However, mouse OPCs are much more difficult to be isolated by the simple dissociation culture of brain tissues than their rat counterparts. To date, the mechanisms underlying the species difference in OPC preparation remain obscure. In this study, we showed that astrocytes from rats have a stronger effect than those from mouse in promoting OPC proliferation and survival in vitro. Mouse astrocytes displayed significantly weaker viability in culture and reduced potential in maintaining OPC self-renewal, as confirmed by culturing OPCs with conditioned media from rat or mouse astrocytes. These results explained the reason for why stratified cultures of OPCs and astrocytes are difficult to be achieved in mouse CNS tissues. Based on these findings, we adopted inactivated rat astrocytes as feeder cells to support the self-renewal of mouse cortical OPCs and preparation of high-purity mouse OPCs. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 907-916, 2017.
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Affiliation(s)
- Xuejun Cheng
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environment Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China
| | - Binghua Xie
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environment Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China
| | - Jiajun Qi
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environment Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China
| | - Xiaofeng Zhao
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environment Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China
| | - Zunyi Zhang
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environment Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China
| | - Mengsheng Qiu
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environment Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China.,Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, Kentucky, 40292
| | - Junlin Yang
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environment Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China
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14
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Chew LJ, DeBoy CA. Pharmacological approaches to intervention in hypomyelinating and demyelinating white matter pathology. Neuropharmacology 2016; 110:605-625. [PMID: 26116759 PMCID: PMC4690794 DOI: 10.1016/j.neuropharm.2015.06.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 06/10/2015] [Accepted: 06/17/2015] [Indexed: 12/17/2022]
Abstract
White matter disease afflicts both developing and mature central nervous systems. Both cell intrinsic and extrinsic dysregulation result in profound changes in cell survival, axonal metabolism and functional performance. Experimental models of developmental white matter (WM) injury and demyelination have not only delineated mechanisms of signaling and inflammation, but have also paved the way for the discovery of pharmacological approaches to intervention. These reagents have been shown to enhance protection of the mature oligodendrocyte cell, accelerate progenitor cell recruitment and/or differentiation, or attenuate pathological stimuli arising from the inflammatory response to injury. Here we highlight reports of studies in the CNS in which compounds, namely peptides, hormones, and small molecule agonists/antagonists, have been used in experimental animal models of demyelination and neonatal brain injury that affect aspects of excitotoxicity, oligodendrocyte development and survival, and progenitor cell function, and which have been demonstrated to attenuate damage and improve WM protection in experimental models of injury. The molecular targets of these agents include growth factor and neurotransmitter receptors, morphogens and their signaling components, nuclear receptors, as well as the processes of iron transport and actin binding. By surveying the current evidence in non-immune targets of both the immature and mature WM, we aim to better understand pharmacological approaches modulating endogenous oligodendroglia that show potential for success in the contexts of developmental and adult WM pathology. This article is part of the Special Issue entitled 'Oligodendrocytes in Health and Disease'.
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Affiliation(s)
- Li-Jin Chew
- Center for Neuroscience Research, Children's Research Institute, Children's National Medical Center, Washington, DC, USA.
| | - Cynthia A DeBoy
- Biology Department, Trinity Washington University, Washington, DC, USA
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15
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Wang T, He Y, Zhu Y, Chen M, Weng M, Yang C, Zhang Y, Ning N, Zhao R, Yang W, Jin Y, Li J, Redpath RJRE, Zhang L, Jin X, Zhong Z, Zhang F, Wei Y, Shen G, Wang D, Liu Y, Wang G, Li X. Comparison of the expression and function of Lin28A and Lin28B in colon cancer. Oncotarget 2016; 7:79605-79616. [PMID: 27793004 PMCID: PMC5346739 DOI: 10.18632/oncotarget.12869] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 10/14/2016] [Indexed: 12/25/2022] Open
Abstract
Lin28A and Lin28B are highly conserved RNA binding proteins with similar structure and functions. Recent studies demonstrated that both of them act as oncogenes and promote cancer progression. However, few researches compared the expression and functions of both oncogenes in human malignant tumors at same time. Additionally, although the expression and role of Lin28B in colon cancer is frequently reported, the expression and functions of Lin28A in colon cancer are largely unknown. In this study, we have systematically evaluated the expressional pattern, mutation status and correlation of both Lin28A and Lin28B in colon cancer tissues for the first time, and compared the roles of Lin28A and Lin28B in the proliferation, migration, invasion and apoptosis of colon cancer cells in vitro. We have showed that they are co-expressed and have functional similarities, however, the molecular mechanisms underlying their similar functions may not be identical. This study contributes to clarify the similarities and differences of Lin28A and Lin28B in colon cancer progression.
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Affiliation(s)
- Tianzhen Wang
- 1 Department of Pathology, Harbin Medical University, Harbin, China
| | - Yan He
- 1 Department of Pathology, Harbin Medical University, Harbin, China
| | - Yuanyuan Zhu
- 2 Department of Gastrointestinal Medical Oncology, the Affiliated Tumor Hospital of Harbin Medical University, Harbin, China
| | - Mingwei Chen
- 3 Department of Anatomy, Harbin Medical University, Harbin, China
| | - Mingjiao Weng
- 1 Department of Pathology, Harbin Medical University, Harbin, China
| | - Chao Yang
- 1 Department of Pathology, Harbin Medical University, Harbin, China
| | - Yan Zhang
- 4 Department of Nutrition and Food Hygiene, Public Health College, Harbin Medical University, Harbin, China
| | - Ning Ning
- 5 Department of Gastrointestinal Surgery, International Hospital of Pecking University, Beijing, China
| | - Ran Zhao
- 1 Department of Pathology, Harbin Medical University, Harbin, China
| | - Weiwei Yang
- 1 Department of Pathology, Harbin Medical University, Harbin, China
| | - Yinji Jin
- 1 Department of Pathology, Harbin Medical University, Harbin, China
| | - Jing Li
- 1 Department of Pathology, Harbin Medical University, Harbin, China
| | | | - Lei Zhang
- 1 Department of Pathology, Harbin Medical University, Harbin, China
| | - Xiaoming Jin
- 1 Department of Pathology, Harbin Medical University, Harbin, China
| | - Zhaohua Zhong
- 6 Department of Microbiology, Harbin Medical University, Harbin, China
| | - Fengmin Zhang
- 6 Department of Microbiology, Harbin Medical University, Harbin, China
| | - Yunwei Wei
- 7 Department of General Surgery, the First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Guomin Shen
- 8 Department of Medical Genetics, Medical College, Henan University of Science and Technology, Luoyang, China
| | - Dong Wang
- 9 College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, China
| | - Ying Liu
- 4 Department of Nutrition and Food Hygiene, Public Health College, Harbin Medical University, Harbin, China
| | - Guangyu Wang
- 2 Department of Gastrointestinal Medical Oncology, the Affiliated Tumor Hospital of Harbin Medical University, Harbin, China
| | - Xiaobo Li
- 1 Department of Pathology, Harbin Medical University, Harbin, China,10 The Northern Medicine Translational Center, Heilongjiang Province Academy of Medical Science, Harbin, China
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16
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Huang Y, Dreyfus CF. The role of growth factors as a therapeutic approach to demyelinating disease. Exp Neurol 2016; 283:531-40. [PMID: 27016070 PMCID: PMC5010931 DOI: 10.1016/j.expneurol.2016.02.023] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 02/19/2016] [Accepted: 02/24/2016] [Indexed: 01/19/2023]
Abstract
A variety of growth factors are being explored as therapeutic agents relevant to the axonal and oligodendroglial deficits that occur as a result of demyelinating lesions such as are evident in Multiple Sclerosis (MS). This review focuses on five such proteins that are present in the lesion site and impact oligodendrocyte regeneration. It then presents approaches that are being exploited to manipulate the lesion environment affiliated with multiple neurodegenerative diseases and suggests that the utility of these approaches can extend to demyelination. Challenges are to further understand the roles of specific growth factors on a cellular and tissue level. Emerging technologies can then be employed to optimize the use of growth factors to ameliorate the deficits associated with demyelinating degenerative diseases.
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Affiliation(s)
- Yangyang Huang
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, 683 Hoes Lane West, Piscataway, NJ 08854, USA.
| | - Cheryl F Dreyfus
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, 683 Hoes Lane West, Piscataway, NJ 08854, USA.
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17
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Regulation of PERK-eIF2α signalling by tuberous sclerosis complex-1 controls homoeostasis and survival of myelinating oligodendrocytes. Nat Commun 2016; 7:12185. [PMID: 27416896 PMCID: PMC4947172 DOI: 10.1038/ncomms12185] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 06/08/2016] [Indexed: 12/20/2022] Open
Abstract
Tuberous sclerosis complex-1 or 2 (TSC1/2) mutations cause white matter abnormalities, including myelin deficits in the CNS; however, underlying mechanisms are not fully understood. TSC1/2 negatively regulate the function of mTOR, which is required for oligodendrocyte differentiation. Here we report that, unexpectedly, constitutive activation of mTOR signalling by Tsc1 deletion in the oligodendrocyte lineage results in severe myelination defects and oligodendrocyte cell death in mice, despite an initial increase of oligodendrocyte precursors during early development. Expression profiling analysis reveals that Tsc1 ablation induces prominent endoplasmic reticulum (ER) stress responses by activating a PERK–eIF2α signalling axis and Fas–JNK apoptotic pathways. Enhancement of the phospho-eIF2α adaptation pathway by inhibition of Gadd34-PP1 phosphatase with guanabenz protects oligodendrocytes and partially rescues myelination defects in Tsc1 mutants. Thus, TSC1-mTOR signalling acts as an important checkpoint for maintaining oligodendrocyte homoeostasis, pointing to a previously uncharacterized ER stress mechanism that contributes to hypomyelination in tuberous sclerosis. The molecular mechanisms regulating myelination are only partially understood. Here authors show that Tsc1 ablation in oligodendrocyte lineage activates ER stress and apoptotic programs in mice, and that enhancing PERK-eIF2α signalling partially rescues the myelination defects in Tsc1 mutants.
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18
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Begolly S, Shrager PG, Olschowka JA, Williams JP, O'Banion MK. Fractionation Spares Mice From Radiation-Induced Reductions in Weight Gain But Does Not Prevent Late Oligodendrocyte Lineage Side Effects. Int J Radiat Oncol Biol Phys 2016; 96:449-457. [PMID: 27478169 DOI: 10.1016/j.ijrobp.2016.05.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 04/28/2016] [Accepted: 05/04/2016] [Indexed: 01/05/2023]
Abstract
PURPOSE To determine the late effects of fractionated versus single-dose cranial radiation on murine white matter. METHODS AND MATERIALS Mice were exposed to 0 Gy, 6 × 6 Gy, or 1 × 20 Gy cranial irradiation at 10 to 12 weeks of age. Endpoints were assessed through 18 months from exposure using immunohistochemistry, electron microscopy, and electrophysiology. RESULTS Weight gain was temporarily reduced after irradiation; greater loss was seen after single versus fractionated doses. Oligodendrocyte progenitor cells were reduced early and late after both single and fractionated irradiation. Both protocols also increased myelin g-ratio, reduced the number of nodes of Ranvier, and promoted a shift in the proportion of small, unmyelinated versus large, myelinated axon fibers. CONCLUSIONS Fractionation does not adequately spare normal white matter from late radiation side effects.
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Affiliation(s)
- Sage Begolly
- Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York
| | - Peter G Shrager
- Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York; Department of Pharmacology and Physiology, University of Rochester School of Medicine and Dentistry, Rochester, New York
| | - John A Olschowka
- Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York
| | - Jacqueline P Williams
- Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York; Department of Radiation Oncology, University of Rochester School of Medicine and Dentistry, Rochester, New York
| | - M Kerry O'Banion
- Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York; Department of Neurology, University of Rochester School of Medicine and Dentistry, Rochester, New York.
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19
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Seidel HS, Kimble J. Cell-cycle quiescence maintains Caenorhabditis elegans germline stem cells independent of GLP-1/Notch. eLife 2015; 4. [PMID: 26551561 PMCID: PMC4718729 DOI: 10.7554/elife.10832] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 11/07/2015] [Indexed: 12/13/2022] Open
Abstract
Many types of adult stem cells exist in a state of cell-cycle quiescence, yet it has remained unclear whether quiescence plays a role in maintaining the stem cell fate. Here we establish the adult germline of Caenorhabditis elegans as a model for facultative stem cell quiescence. We find that mitotically dividing germ cells--including germline stem cells--become quiescent in the absence of food. This quiescence is characterized by a slowing of S phase, a block to M-phase entry, and the ability to re-enter M phase rapidly in response to re-feeding. Further, we demonstrate that cell-cycle quiescence alters the genetic requirements for stem cell maintenance: The signaling pathway required for stem cell maintenance under fed conditions--GLP-1/Notch signaling--becomes dispensable under conditions of quiescence. Thus, cell-cycle quiescence can itself maintain stem cells, independent of the signaling pathway otherwise essential for such maintenance.
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Affiliation(s)
- Hannah S Seidel
- Department of Biochemistry, University of Wisconsin-Madison, Madison, United States.,The Ellison Medical Foundation Fellow of the Life Sciences Research Foundation, The Lawrence Ellison Foundation, Mount Airy, United States
| | - Judith Kimble
- Department of Biochemistry, University of Wisconsin-Madison, Madison, United States.,Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, United States
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20
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Oligodendrocyte precursor cell-intrinsic effect of Rheb1 controls differentiation and mediates mTORC1-dependent myelination in brain. J Neurosci 2015; 34:15764-78. [PMID: 25411504 DOI: 10.1523/jneurosci.2267-14.2014] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Rheb1 is an immediate early gene that functions to activate mammalian target of rapamycin (mTor) selectively in complex 1 (mTORC1). We have demonstrated previously that Rheb1 is essential for myelination in the CNS using a Nestin-Cre driver line that deletes Rheb1 in all neural cell lineages, and recent studies using oligodendrocyte-specific CNP-Cre have suggested a preferential role for mTORC1 is myelination in the spinal cord. Here, we examine the role of Rheb1/mTORC1 in mouse oligodendrocyte lineage using separate Cre drivers for oligodendrocyte progenitor cells (OPCs) including Olig1-Cre and Olig2-Cre as well as differentiated and mature oligodendrocytes including CNP-Cre and Tmem10-Cre. Deletion of Rheb1 in OPCs impairs their differentiation to mature oligodendrocytes. This is accompanied by reduced OPC cell-cycle exit suggesting a requirement for Rheb1 in OPC differentiation. The effect of Rheb1 on OPC differentiation is mediated by mTor since Olig1-Cre deletion of mTor phenocopies Olig1-Cre Rheb1 deletion. Deletion of Rheb1 in mature oligodendrocytes, in contrast, does not disrupt developmental myelination or myelin maintenance. Loss of Rheb1 in OPCs or neural progenitors does not affect astrocyte formation in gray and white matter, as indicated by the pan-astrocyte marker Aldh1L1. We conclude that OPC-intrinsic mTORC1 activity mediated by Rheb1 is critical for differentiation of OPCs to mature oligodendrocytes, but that mature oligodendrocytes do not require Rheb1 to make myelin or maintain it in the adult brain. These studies reveal mechanisms that may be relevant for both developmental myelination and impaired remyelination in myelin disease.
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21
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Loddo M, Andryszkiewicz J, Rodriguez-Acebes S, Stoeber K, Jones A, Dafou D, Apostolidou S, Wollenschlaeger A, Widschwendter M, Sainsbury R, Tudzarova S, Williams GH. Pregnancy-associated plasma protein A regulates mitosis and is epigenetically silenced in breast cancer. J Pathol 2014; 233:344-56. [PMID: 24931331 DOI: 10.1002/path.4393] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 06/06/2014] [Accepted: 06/10/2014] [Indexed: 01/23/2023]
Abstract
Aberrant mitosis is a common feature of cancer, yet little is known about the altered genes causing mitotic defects. We screened human tumours for cells with morphological signatures of highly specific mitotic defects previously assigned to candidate genes in a genome-wide RNA interference screen carried out in HeLa cells (www.mitocheck.org). We discovered a striking enrichment of early mitotic configurations indicative of prophase/prometaphase delay in breast cancer. Promoter methylation analysis of MitoCheck candidate genes assigned to the corresponding 'mitotic delay' class linked this defect to epigenetic silencing of the gene encoding pregnancy-associated plasma protein-A (PAPPA), a secreted protease. PAPPA silencing was highly prevalent in precursor lesions and invasive breast cancer. Experimental manipulation of PAPPA protein levels in human mammary epithelial cells and in breast cancer cell lines demonstrates that progression through early mitosis is dependent on PAPPA function, and that breast cancer cells become more invasive after down-regulation of this protease. PAPPA regulates mitotic progression through modulating the IGF-1 signalling pathway resulting in activation of the forkhead transcription factor FoxM1, which drives a transcriptional cluster of essential mitotic genes. Our results show that PAPPA has a critical function in normal cell division and is targeted early in breast cancer development.
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Affiliation(s)
- Marco Loddo
- UCL Cancer Institute, University College London, UK
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22
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Craven CJ. A model to explain specific cellular communications and cellular harmony:- a hypothesis of coupled cells and interactive coupling molecules. Theor Biol Med Model 2014; 11:40. [PMID: 25218581 PMCID: PMC4237941 DOI: 10.1186/1742-4682-11-40] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 09/02/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The various cell types and their relative numbers in multicellular organisms are controlled by growth factors and related extracellular molecules which affect genetic expression pathways. However, these substances may have both/either inhibitory and/or stimulatory effects on cell division and cell differentiation depending on the cellular environment. It is not known how cells respond to these substances in such an ambiguous way. Many cellular effects have been investigated and reported using cell culture from cancer cell lines in an effort to define normal cellular behaviour using these abnormal cells.A model is offered to explain the harmony of cellular life in multicellular organisms involving interacting extracellular substances. METHODS A basic model was proposed based on asymmetric cell division and evidence to support the hypothetical model was accumulated from the literature. In particular, relevant evidence was selected for the Insulin-Like Growth Factor system from the published data, especially from certain cell lines, to support the model. The evidence has been selective in an attempt to provide a picture of normal cellular responses, derived from the cell lines. RESULTS The formation of a pair of coupled cells by asymmetric cell division is an integral part of the model as is the interaction of couplet molecules derived from these cells. Each couplet cell will have a receptor to measure the amount of the couplet molecule produced by the other cell; each cell will be receptor-positive or receptor-negative for the respective receptors. The couplet molecules will form a binary complex whose level is also measured by the cell. The hypothesis is heavily supported by selective collection of circumstantial evidence and by some direct evidence. The basic model can be expanded to other cellular interactions. CONCLUSIONS These couplet cells and interacting couplet molecules can be viewed as a mechanism that provides a controlled and balanced division-of-labour between the two progeny cells, and, in turn, their progeny. The presence or absence of a particular receptor for a couplet molecule will define a cell type and the presence or absence of many such receptors will define the cell types of the progeny within cell lineages.
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Affiliation(s)
- Cyril J Craven
- Queensland University of Technology (QUT), Brisbane, Australia.
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23
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Gallo V, Deneen B. Glial development: the crossroads of regeneration and repair in the CNS. Neuron 2014; 83:283-308. [PMID: 25033178 DOI: 10.1016/j.neuron.2014.06.010] [Citation(s) in RCA: 150] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/11/2014] [Indexed: 02/07/2023]
Abstract
Given the complexities of the mammalian CNS, its regeneration is viewed as the holy grail of regenerative medicine. Extraordinary efforts have been made to understand developmental neurogenesis, with the hopes of clinically applying this knowledge. CNS regeneration also involves glia, which comprises at least 50% of the cellular constituency of the brain and is involved in all forms of injury and disease response, recovery, and regeneration. Recent developmental studies have given us unprecedented insight into the processes that regulate the generation of CNS glia. Because restorative processes often parallel those found in development, we will peer through the lens of developmental gliogenesis to gain a clearer understanding of the processes that underlie glial regeneration under pathological conditions. Specifically, this review will focus on key signaling pathways that regulate astrocyte and oligodendrocyte development and describe how these mechanisms are reutilized in these populations during regeneration and repair after CNS injury.
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Affiliation(s)
- Vittorio Gallo
- Center for Neuroscience Research, Children's National Medical Center, Washington, DC 20010, USA.
| | - Benjamin Deneen
- Department of Neuroscience and Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, TX 77030, USA.
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Annenkov A. Receptor tyrosine kinase (RTK) signalling in the control of neural stem and progenitor cell (NSPC) development. Mol Neurobiol 2013; 49:440-71. [PMID: 23982746 DOI: 10.1007/s12035-013-8532-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Accepted: 08/09/2013] [Indexed: 01/04/2023]
Abstract
Important developmental responses are elicited in neural stem and progenitor cells (NSPC) by activation of the receptor tyrosine kinases (RTK), including the fibroblast growth factor receptors, epidermal growth factor receptor, platelet-derived growth factor receptors and insulin-like growth factor receptor (IGF1R). Signalling through these RTK is necessary and sufficient for driving a number of developmental processes in the central nervous system. Within each of the four RTK families discussed here, receptors are activated by sets of ligands that do not cross-activate receptors of the other three families, and therefore, their activation can be independently regulated by ligand availability. These RTK pathways converge on a conserved core of signalling molecules, but differences between the receptors in utilisation of signalling molecules and molecular adaptors for intracellular signal propagation become increasingly apparent. Intracellular inhibitors of RTK signalling are widely involved in the regulation of developmental signalling in NSPC and often determine developmental outcomes of RTK activation. In addition, cellular responses of NSPC to the activation of a given RTK may be significantly modulated by signal strength. Cellular propensity to respond also plays a role in developmental outcomes of RTK signalling. In combination, these mechanisms regulate the balance between NSPC maintenance and differentiation during development and in adulthood. Attribution of particular developmental responses of NSPC to specific pathways of RTK signalling becomes increasingly elucidated. Co-activation of several RTK in developing NSPC is common, and analysis of co-operation between their signalling pathways may advance knowledge of RTK role in NSPC development.
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Affiliation(s)
- Alexander Annenkov
- Bone and Joint Research Unit, William Harvey Research Institute, Bart's and The London School of Medicine, Queen Mary University of London, Charterhouse Square, London, EC1M 6BQ, UK,
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25
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Shim KW, Xi G, Farnell BM, Kim DS, Tsurubuchi T, Tomita T, Mayanil CS. Epigenetic modification after inhibition of IGF-1R signaling in human central nervous system atypical teratoid rhabdoid tumor (AT/RT). Childs Nerv Syst 2013; 29:1245-51. [PMID: 23624780 DOI: 10.1007/s00381-013-2087-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Accepted: 03/18/2013] [Indexed: 01/11/2023]
Abstract
OBJECTIVE This study investigated epigenetic modifications in human central nervous system atypical teratoid rhabdoid tumors (AT/RTs), in response to inhibition of insulin-like growth factor receptor 1 (IGF-1R). MATERIALS AND METHODS Tumor tissue was obtained from two pediatric patients, tissue was dissociated, and primary cultures were established. Cultured cells were treated with picropodophyllin (PPP; 0, 1, and 2 μM for 48 h), a selective IGF-1R inhibitor. Histone acetylation and methylation patterns (H3K9ac, H3K18ac, H3K4me3, H3K27me3) and levels of histone deacetylases (HDACs; HDAC1, HDAC3, and SirT1) and histone acetyl transferases (GCN5 and p300) were examined. H3K9ac and H3K18ac decreased in response to treatment with PPP. HDAC levels showed a biphasic response, increasing with 1 μM PPP, but then decreasing with 2 μM PPP. CONCLUSION Inhibition of IGF-1R modified epigenetic status in AT/RT. Determining the mechanisms behind these modifications will guide the development of novel therapeutic targets for this malignant embryonal cancer.
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Affiliation(s)
- Kyu-Won Shim
- Pediatric Neurosurgery Research Lab, Developmental Biology Program, Division of Pediatric Neurosurgery, Children's Hospital of Chicago Research Center and Department of Neurosurgery, Northwestern University Feinberg School of Medicine, Chicago, IL 60614, USA
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mTOR: a link from the extracellular milieu to transcriptional regulation of oligodendrocyte development. ASN Neuro 2013; 5:e00108. [PMID: 23421405 PMCID: PMC3601842 DOI: 10.1042/an20120092] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Oligodendrocyte development is controlled by numerous extracellular signals that regulate a series of transcription factors that promote the differentiation of oligodendrocyte progenitor cells to myelinating cells in the central nervous system. A major element of this regulatory system that has only recently been studied is the intracellular signalling from surface receptors to transcription factors to down-regulate inhibitors and up-regulate inducers of oligodendrocyte differentiation and myelination. The current review focuses on one such pathway: the mTOR (mammalian target of rapamycin) pathway, which integrates signals in many cell systems and induces cell responses including cell proliferation and cell differentiation. This review describes the known functions of mTOR as they relate to oligodendrocyte development, and its recently discovered impact on oligodendrocyte differentiation and myelination. A potential model for its role in oligodendrocyte development is proposed.
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